1 /* Reload pseudo regs into hard regs for insns that require hard regs.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
25 #include "coretypes.h"
29 #include "hard-reg-set.h"
33 #include "insn-config.h"
39 #include "addresses.h"
40 #include "basic-block.h"
50 /* This file contains the reload pass of the compiler, which is
51 run after register allocation has been done. It checks that
52 each insn is valid (operands required to be in registers really
53 are in registers of the proper class) and fixes up invalid ones
54 by copying values temporarily into registers for the insns
57 The results of register allocation are described by the vector
58 reg_renumber; the insns still contain pseudo regs, but reg_renumber
59 can be used to find which hard reg, if any, a pseudo reg is in.
61 The technique we always use is to free up a few hard regs that are
62 called ``reload regs'', and for each place where a pseudo reg
63 must be in a hard reg, copy it temporarily into one of the reload regs.
65 Reload regs are allocated locally for every instruction that needs
66 reloads. When there are pseudos which are allocated to a register that
67 has been chosen as a reload reg, such pseudos must be ``spilled''.
68 This means that they go to other hard regs, or to stack slots if no other
69 available hard regs can be found. Spilling can invalidate more
70 insns, requiring additional need for reloads, so we must keep checking
71 until the process stabilizes.
73 For machines with different classes of registers, we must keep track
74 of the register class needed for each reload, and make sure that
75 we allocate enough reload registers of each class.
77 The file reload.c contains the code that checks one insn for
78 validity and reports the reloads that it needs. This file
79 is in charge of scanning the entire rtl code, accumulating the
80 reload needs, spilling, assigning reload registers to use for
81 fixing up each insn, and generating the new insns to copy values
82 into the reload registers. */
84 /* During reload_as_needed, element N contains a REG rtx for the hard reg
85 into which reg N has been reloaded (perhaps for a previous insn). */
86 static rtx *reg_last_reload_reg;
88 /* Elt N nonzero if reg_last_reload_reg[N] has been set in this insn
89 for an output reload that stores into reg N. */
90 static regset_head reg_has_output_reload;
92 /* Indicates which hard regs are reload-registers for an output reload
93 in the current insn. */
94 static HARD_REG_SET reg_is_output_reload;
96 /* Element N is the constant value to which pseudo reg N is equivalent,
97 or zero if pseudo reg N is not equivalent to a constant.
98 find_reloads looks at this in order to replace pseudo reg N
99 with the constant it stands for. */
100 rtx *reg_equiv_constant;
102 /* Element N is an invariant value to which pseudo reg N is equivalent.
103 eliminate_regs_in_insn uses this to replace pseudos in particular
105 rtx *reg_equiv_invariant;
107 /* Element N is a memory location to which pseudo reg N is equivalent,
108 prior to any register elimination (such as frame pointer to stack
109 pointer). Depending on whether or not it is a valid address, this value
110 is transferred to either reg_equiv_address or reg_equiv_mem. */
111 rtx *reg_equiv_memory_loc;
113 /* We allocate reg_equiv_memory_loc inside a varray so that the garbage
114 collector can keep track of what is inside. */
115 VEC(rtx,gc) *reg_equiv_memory_loc_vec;
117 /* Element N is the address of stack slot to which pseudo reg N is equivalent.
118 This is used when the address is not valid as a memory address
119 (because its displacement is too big for the machine.) */
120 rtx *reg_equiv_address;
122 /* Element N is the memory slot to which pseudo reg N is equivalent,
123 or zero if pseudo reg N is not equivalent to a memory slot. */
126 /* Element N is an EXPR_LIST of REG_EQUIVs containing MEMs with
127 alternate representations of the location of pseudo reg N. */
128 rtx *reg_equiv_alt_mem_list;
130 /* Widest width in which each pseudo reg is referred to (via subreg). */
131 static unsigned int *reg_max_ref_width;
133 /* Element N is the list of insns that initialized reg N from its equivalent
134 constant or memory slot. */
136 int reg_equiv_init_size;
138 /* Vector to remember old contents of reg_renumber before spilling. */
139 static short *reg_old_renumber;
141 /* During reload_as_needed, element N contains the last pseudo regno reloaded
142 into hard register N. If that pseudo reg occupied more than one register,
143 reg_reloaded_contents points to that pseudo for each spill register in
144 use; all of these must remain set for an inheritance to occur. */
145 static int reg_reloaded_contents[FIRST_PSEUDO_REGISTER];
147 /* During reload_as_needed, element N contains the insn for which
148 hard register N was last used. Its contents are significant only
149 when reg_reloaded_valid is set for this register. */
150 static rtx reg_reloaded_insn[FIRST_PSEUDO_REGISTER];
152 /* Indicate if reg_reloaded_insn / reg_reloaded_contents is valid. */
153 static HARD_REG_SET reg_reloaded_valid;
154 /* Indicate if the register was dead at the end of the reload.
155 This is only valid if reg_reloaded_contents is set and valid. */
156 static HARD_REG_SET reg_reloaded_dead;
158 /* Indicate whether the register's current value is one that is not
159 safe to retain across a call, even for registers that are normally
161 static HARD_REG_SET reg_reloaded_call_part_clobbered;
163 /* Number of spill-regs so far; number of valid elements of spill_regs. */
166 /* In parallel with spill_regs, contains REG rtx's for those regs.
167 Holds the last rtx used for any given reg, or 0 if it has never
168 been used for spilling yet. This rtx is reused, provided it has
170 static rtx spill_reg_rtx[FIRST_PSEUDO_REGISTER];
172 /* In parallel with spill_regs, contains nonzero for a spill reg
173 that was stored after the last time it was used.
174 The precise value is the insn generated to do the store. */
175 static rtx spill_reg_store[FIRST_PSEUDO_REGISTER];
177 /* This is the register that was stored with spill_reg_store. This is a
178 copy of reload_out / reload_out_reg when the value was stored; if
179 reload_out is a MEM, spill_reg_stored_to will be set to reload_out_reg. */
180 static rtx spill_reg_stored_to[FIRST_PSEUDO_REGISTER];
182 /* This table is the inverse mapping of spill_regs:
183 indexed by hard reg number,
184 it contains the position of that reg in spill_regs,
185 or -1 for something that is not in spill_regs.
187 ?!? This is no longer accurate. */
188 static short spill_reg_order[FIRST_PSEUDO_REGISTER];
190 /* This reg set indicates registers that can't be used as spill registers for
191 the currently processed insn. These are the hard registers which are live
192 during the insn, but not allocated to pseudos, as well as fixed
194 static HARD_REG_SET bad_spill_regs;
196 /* These are the hard registers that can't be used as spill register for any
197 insn. This includes registers used for user variables and registers that
198 we can't eliminate. A register that appears in this set also can't be used
199 to retry register allocation. */
200 static HARD_REG_SET bad_spill_regs_global;
202 /* Describes order of use of registers for reloading
203 of spilled pseudo-registers. `n_spills' is the number of
204 elements that are actually valid; new ones are added at the end.
206 Both spill_regs and spill_reg_order are used on two occasions:
207 once during find_reload_regs, where they keep track of the spill registers
208 for a single insn, but also during reload_as_needed where they show all
209 the registers ever used by reload. For the latter case, the information
210 is calculated during finish_spills. */
211 static short spill_regs[FIRST_PSEUDO_REGISTER];
213 /* This vector of reg sets indicates, for each pseudo, which hard registers
214 may not be used for retrying global allocation because the register was
215 formerly spilled from one of them. If we allowed reallocating a pseudo to
216 a register that it was already allocated to, reload might not
218 static HARD_REG_SET *pseudo_previous_regs;
220 /* This vector of reg sets indicates, for each pseudo, which hard
221 registers may not be used for retrying global allocation because they
222 are used as spill registers during one of the insns in which the
224 static HARD_REG_SET *pseudo_forbidden_regs;
226 /* All hard regs that have been used as spill registers for any insn are
227 marked in this set. */
228 static HARD_REG_SET used_spill_regs;
230 /* Index of last register assigned as a spill register. We allocate in
231 a round-robin fashion. */
232 static int last_spill_reg;
234 /* Nonzero if indirect addressing is supported on the machine; this means
235 that spilling (REG n) does not require reloading it into a register in
236 order to do (MEM (REG n)) or (MEM (PLUS (REG n) (CONST_INT c))). The
237 value indicates the level of indirect addressing supported, e.g., two
238 means that (MEM (MEM (REG n))) is also valid if (REG n) does not get
240 static char spill_indirect_levels;
242 /* Nonzero if indirect addressing is supported when the innermost MEM is
243 of the form (MEM (SYMBOL_REF sym)). It is assumed that the level to
244 which these are valid is the same as spill_indirect_levels, above. */
245 char indirect_symref_ok;
247 /* Nonzero if an address (plus (reg frame_pointer) (reg ...)) is valid. */
248 char double_reg_address_ok;
250 /* Record the stack slot for each spilled hard register. */
251 static rtx spill_stack_slot[FIRST_PSEUDO_REGISTER];
253 /* Width allocated so far for that stack slot. */
254 static unsigned int spill_stack_slot_width[FIRST_PSEUDO_REGISTER];
256 /* Record which pseudos needed to be spilled. */
257 static regset_head spilled_pseudos;
259 /* Used for communication between order_regs_for_reload and count_pseudo.
260 Used to avoid counting one pseudo twice. */
261 static regset_head pseudos_counted;
263 /* First uid used by insns created by reload in this function.
264 Used in find_equiv_reg. */
265 int reload_first_uid;
267 /* Flag set by local-alloc or global-alloc if anything is live in
268 a call-clobbered reg across calls. */
269 int caller_save_needed;
271 /* Set to 1 while reload_as_needed is operating.
272 Required by some machines to handle any generated moves differently. */
273 int reload_in_progress = 0;
275 /* These arrays record the insn_code of insns that may be needed to
276 perform input and output reloads of special objects. They provide a
277 place to pass a scratch register. */
278 enum insn_code reload_in_optab[NUM_MACHINE_MODES];
279 enum insn_code reload_out_optab[NUM_MACHINE_MODES];
281 /* This obstack is used for allocation of rtl during register elimination.
282 The allocated storage can be freed once find_reloads has processed the
284 static struct obstack reload_obstack;
286 /* Points to the beginning of the reload_obstack. All insn_chain structures
287 are allocated first. */
288 static char *reload_startobj;
290 /* The point after all insn_chain structures. Used to quickly deallocate
291 memory allocated in copy_reloads during calculate_needs_all_insns. */
292 static char *reload_firstobj;
294 /* This points before all local rtl generated by register elimination.
295 Used to quickly free all memory after processing one insn. */
296 static char *reload_insn_firstobj;
298 /* List of insn_chain instructions, one for every insn that reload needs to
300 struct insn_chain *reload_insn_chain;
302 /* List of all insns needing reloads. */
303 static struct insn_chain *insns_need_reload;
305 /* This structure is used to record information about register eliminations.
306 Each array entry describes one possible way of eliminating a register
307 in favor of another. If there is more than one way of eliminating a
308 particular register, the most preferred should be specified first. */
312 int from; /* Register number to be eliminated. */
313 int to; /* Register number used as replacement. */
314 HOST_WIDE_INT initial_offset; /* Initial difference between values. */
315 int can_eliminate; /* Nonzero if this elimination can be done. */
316 int can_eliminate_previous; /* Value of CAN_ELIMINATE in previous scan over
317 insns made by reload. */
318 HOST_WIDE_INT offset; /* Current offset between the two regs. */
319 HOST_WIDE_INT previous_offset;/* Offset at end of previous insn. */
320 int ref_outside_mem; /* "to" has been referenced outside a MEM. */
321 rtx from_rtx; /* REG rtx for the register to be eliminated.
322 We cannot simply compare the number since
323 we might then spuriously replace a hard
324 register corresponding to a pseudo
325 assigned to the reg to be eliminated. */
326 rtx to_rtx; /* REG rtx for the replacement. */
329 static struct elim_table *reg_eliminate = 0;
331 /* This is an intermediate structure to initialize the table. It has
332 exactly the members provided by ELIMINABLE_REGS. */
333 static const struct elim_table_1
337 } reg_eliminate_1[] =
339 /* If a set of eliminable registers was specified, define the table from it.
340 Otherwise, default to the normal case of the frame pointer being
341 replaced by the stack pointer. */
343 #ifdef ELIMINABLE_REGS
346 {{ FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}};
349 #define NUM_ELIMINABLE_REGS ARRAY_SIZE (reg_eliminate_1)
351 /* Record the number of pending eliminations that have an offset not equal
352 to their initial offset. If nonzero, we use a new copy of each
353 replacement result in any insns encountered. */
354 int num_not_at_initial_offset;
356 /* Count the number of registers that we may be able to eliminate. */
357 static int num_eliminable;
358 /* And the number of registers that are equivalent to a constant that
359 can be eliminated to frame_pointer / arg_pointer + constant. */
360 static int num_eliminable_invariants;
362 /* For each label, we record the offset of each elimination. If we reach
363 a label by more than one path and an offset differs, we cannot do the
364 elimination. This information is indexed by the difference of the
365 number of the label and the first label number. We can't offset the
366 pointer itself as this can cause problems on machines with segmented
367 memory. The first table is an array of flags that records whether we
368 have yet encountered a label and the second table is an array of arrays,
369 one entry in the latter array for each elimination. */
371 static int first_label_num;
372 static char *offsets_known_at;
373 static HOST_WIDE_INT (*offsets_at)[NUM_ELIMINABLE_REGS];
375 /* Number of labels in the current function. */
377 static int num_labels;
379 static void replace_pseudos_in (rtx *, enum machine_mode, rtx);
380 static void maybe_fix_stack_asms (void);
381 static void copy_reloads (struct insn_chain *);
382 static void calculate_needs_all_insns (int);
383 static int find_reg (struct insn_chain *, int);
384 static void find_reload_regs (struct insn_chain *);
385 static void select_reload_regs (void);
386 static void delete_caller_save_insns (void);
388 static void spill_failure (rtx, enum reg_class);
389 static void count_spilled_pseudo (int, int, int);
390 static void delete_dead_insn (rtx);
391 static void alter_reg (int, int);
392 static void set_label_offsets (rtx, rtx, int);
393 static void check_eliminable_occurrences (rtx);
394 static void elimination_effects (rtx, enum machine_mode);
395 static int eliminate_regs_in_insn (rtx, int);
396 static void update_eliminable_offsets (void);
397 static void mark_not_eliminable (rtx, rtx, void *);
398 static void set_initial_elim_offsets (void);
399 static bool verify_initial_elim_offsets (void);
400 static void set_initial_label_offsets (void);
401 static void set_offsets_for_label (rtx);
402 static void init_elim_table (void);
403 static void update_eliminables (HARD_REG_SET *);
404 static void spill_hard_reg (unsigned int, int);
405 static int finish_spills (int);
406 static void scan_paradoxical_subregs (rtx);
407 static void count_pseudo (int);
408 static void order_regs_for_reload (struct insn_chain *);
409 static void reload_as_needed (int);
410 static void forget_old_reloads_1 (rtx, rtx, void *);
411 static void forget_marked_reloads (regset);
412 static int reload_reg_class_lower (const void *, const void *);
413 static void mark_reload_reg_in_use (unsigned int, int, enum reload_type,
415 static void clear_reload_reg_in_use (unsigned int, int, enum reload_type,
417 static int reload_reg_free_p (unsigned int, int, enum reload_type);
418 static int reload_reg_free_for_value_p (int, int, int, enum reload_type,
420 static int free_for_value_p (int, enum machine_mode, int, enum reload_type,
422 static int reload_reg_reaches_end_p (unsigned int, int, enum reload_type);
423 static int allocate_reload_reg (struct insn_chain *, int, int);
424 static int conflicts_with_override (rtx);
425 static void failed_reload (rtx, int);
426 static int set_reload_reg (int, int);
427 static void choose_reload_regs_init (struct insn_chain *, rtx *);
428 static void choose_reload_regs (struct insn_chain *);
429 static void merge_assigned_reloads (rtx);
430 static void emit_input_reload_insns (struct insn_chain *, struct reload *,
432 static void emit_output_reload_insns (struct insn_chain *, struct reload *,
434 static void do_input_reload (struct insn_chain *, struct reload *, int);
435 static void do_output_reload (struct insn_chain *, struct reload *, int);
436 static bool inherit_piecemeal_p (int, int);
437 static void emit_reload_insns (struct insn_chain *);
438 static void delete_output_reload (rtx, int, int);
439 static void delete_address_reloads (rtx, rtx);
440 static void delete_address_reloads_1 (rtx, rtx, rtx);
441 static rtx inc_for_reload (rtx, rtx, rtx, int);
443 static void add_auto_inc_notes (rtx, rtx);
445 static void copy_eh_notes (rtx, rtx);
446 static int reloads_conflict (int, int);
447 static rtx gen_reload (rtx, rtx, int, enum reload_type);
448 static rtx emit_insn_if_valid_for_reload (rtx);
450 /* Initialize the reload pass once per compilation. */
457 /* Often (MEM (REG n)) is still valid even if (REG n) is put on the stack.
458 Set spill_indirect_levels to the number of levels such addressing is
459 permitted, zero if it is not permitted at all. */
462 = gen_rtx_MEM (Pmode,
465 LAST_VIRTUAL_REGISTER + 1),
467 spill_indirect_levels = 0;
469 while (memory_address_p (QImode, tem))
471 spill_indirect_levels++;
472 tem = gen_rtx_MEM (Pmode, tem);
475 /* See if indirect addressing is valid for (MEM (SYMBOL_REF ...)). */
477 tem = gen_rtx_MEM (Pmode, gen_rtx_SYMBOL_REF (Pmode, "foo"));
478 indirect_symref_ok = memory_address_p (QImode, tem);
480 /* See if reg+reg is a valid (and offsettable) address. */
482 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
484 tem = gen_rtx_PLUS (Pmode,
485 gen_rtx_REG (Pmode, HARD_FRAME_POINTER_REGNUM),
486 gen_rtx_REG (Pmode, i));
488 /* This way, we make sure that reg+reg is an offsettable address. */
489 tem = plus_constant (tem, 4);
491 if (memory_address_p (QImode, tem))
493 double_reg_address_ok = 1;
498 /* Initialize obstack for our rtl allocation. */
499 gcc_obstack_init (&reload_obstack);
500 reload_startobj = obstack_alloc (&reload_obstack, 0);
502 INIT_REG_SET (&spilled_pseudos);
503 INIT_REG_SET (&pseudos_counted);
506 /* List of insn chains that are currently unused. */
507 static struct insn_chain *unused_insn_chains = 0;
509 /* Allocate an empty insn_chain structure. */
511 new_insn_chain (void)
513 struct insn_chain *c;
515 if (unused_insn_chains == 0)
517 c = obstack_alloc (&reload_obstack, sizeof (struct insn_chain));
518 INIT_REG_SET (&c->live_throughout);
519 INIT_REG_SET (&c->dead_or_set);
523 c = unused_insn_chains;
524 unused_insn_chains = c->next;
526 c->is_caller_save_insn = 0;
527 c->need_operand_change = 0;
533 /* Small utility function to set all regs in hard reg set TO which are
534 allocated to pseudos in regset FROM. */
537 compute_use_by_pseudos (HARD_REG_SET *to, regset from)
540 reg_set_iterator rsi;
542 EXECUTE_IF_SET_IN_REG_SET (from, FIRST_PSEUDO_REGISTER, regno, rsi)
544 int r = reg_renumber[regno];
549 /* reload_combine uses the information from
550 BASIC_BLOCK->global_live_at_start, which might still
551 contain registers that have not actually been allocated
552 since they have an equivalence. */
553 gcc_assert (reload_completed);
557 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (regno)];
559 SET_HARD_REG_BIT (*to, r + nregs);
564 /* Replace all pseudos found in LOC with their corresponding
568 replace_pseudos_in (rtx *loc, enum machine_mode mem_mode, rtx usage)
581 unsigned int regno = REGNO (x);
583 if (regno < FIRST_PSEUDO_REGISTER)
586 x = eliminate_regs (x, mem_mode, usage);
590 replace_pseudos_in (loc, mem_mode, usage);
594 if (reg_equiv_constant[regno])
595 *loc = reg_equiv_constant[regno];
596 else if (reg_equiv_mem[regno])
597 *loc = reg_equiv_mem[regno];
598 else if (reg_equiv_address[regno])
599 *loc = gen_rtx_MEM (GET_MODE (x), reg_equiv_address[regno]);
602 gcc_assert (!REG_P (regno_reg_rtx[regno])
603 || REGNO (regno_reg_rtx[regno]) != regno);
604 *loc = regno_reg_rtx[regno];
609 else if (code == MEM)
611 replace_pseudos_in (& XEXP (x, 0), GET_MODE (x), usage);
615 /* Process each of our operands recursively. */
616 fmt = GET_RTX_FORMAT (code);
617 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
619 replace_pseudos_in (&XEXP (x, i), mem_mode, usage);
620 else if (*fmt == 'E')
621 for (j = 0; j < XVECLEN (x, i); j++)
622 replace_pseudos_in (& XVECEXP (x, i, j), mem_mode, usage);
626 /* Global variables used by reload and its subroutines. */
628 /* Set during calculate_needs if an insn needs register elimination. */
629 static int something_needs_elimination;
630 /* Set during calculate_needs if an insn needs an operand changed. */
631 static int something_needs_operands_changed;
633 /* Nonzero means we couldn't get enough spill regs. */
636 /* Main entry point for the reload pass.
638 FIRST is the first insn of the function being compiled.
640 GLOBAL nonzero means we were called from global_alloc
641 and should attempt to reallocate any pseudoregs that we
642 displace from hard regs we will use for reloads.
643 If GLOBAL is zero, we do not have enough information to do that,
644 so any pseudo reg that is spilled must go to the stack.
646 Return value is nonzero if reload failed
647 and we must not do any more for this function. */
650 reload (rtx first, int global)
654 struct elim_table *ep;
657 /* Make sure even insns with volatile mem refs are recognizable. */
662 reload_firstobj = obstack_alloc (&reload_obstack, 0);
664 /* Make sure that the last insn in the chain
665 is not something that needs reloading. */
666 emit_note (NOTE_INSN_DELETED);
668 /* Enable find_equiv_reg to distinguish insns made by reload. */
669 reload_first_uid = get_max_uid ();
671 #ifdef SECONDARY_MEMORY_NEEDED
672 /* Initialize the secondary memory table. */
673 clear_secondary_mem ();
676 /* We don't have a stack slot for any spill reg yet. */
677 memset (spill_stack_slot, 0, sizeof spill_stack_slot);
678 memset (spill_stack_slot_width, 0, sizeof spill_stack_slot_width);
680 /* Initialize the save area information for caller-save, in case some
684 /* Compute which hard registers are now in use
685 as homes for pseudo registers.
686 This is done here rather than (eg) in global_alloc
687 because this point is reached even if not optimizing. */
688 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
691 /* A function that receives a nonlocal goto must save all call-saved
693 if (current_function_has_nonlocal_label)
694 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
695 if (! call_used_regs[i] && ! fixed_regs[i] && ! LOCAL_REGNO (i))
696 regs_ever_live[i] = 1;
698 /* Find all the pseudo registers that didn't get hard regs
699 but do have known equivalent constants or memory slots.
700 These include parameters (known equivalent to parameter slots)
701 and cse'd or loop-moved constant memory addresses.
703 Record constant equivalents in reg_equiv_constant
704 so they will be substituted by find_reloads.
705 Record memory equivalents in reg_mem_equiv so they can
706 be substituted eventually by altering the REG-rtx's. */
708 reg_equiv_constant = XCNEWVEC (rtx, max_regno);
709 reg_equiv_invariant = XCNEWVEC (rtx, max_regno);
710 reg_equiv_mem = XCNEWVEC (rtx, max_regno);
711 reg_equiv_alt_mem_list = XCNEWVEC (rtx, max_regno);
712 reg_equiv_address = XCNEWVEC (rtx, max_regno);
713 reg_max_ref_width = XCNEWVEC (unsigned int, max_regno);
714 reg_old_renumber = XCNEWVEC (short, max_regno);
715 memcpy (reg_old_renumber, reg_renumber, max_regno * sizeof (short));
716 pseudo_forbidden_regs = XNEWVEC (HARD_REG_SET, max_regno);
717 pseudo_previous_regs = XCNEWVEC (HARD_REG_SET, max_regno);
719 CLEAR_HARD_REG_SET (bad_spill_regs_global);
721 /* Look for REG_EQUIV notes; record what each pseudo is equivalent
722 to. Also find all paradoxical subregs and find largest such for
725 num_eliminable_invariants = 0;
726 for (insn = first; insn; insn = NEXT_INSN (insn))
728 rtx set = single_set (insn);
730 /* We may introduce USEs that we want to remove at the end, so
731 we'll mark them with QImode. Make sure there are no
732 previously-marked insns left by say regmove. */
733 if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == USE
734 && GET_MODE (insn) != VOIDmode)
735 PUT_MODE (insn, VOIDmode);
738 scan_paradoxical_subregs (PATTERN (insn));
740 if (set != 0 && REG_P (SET_DEST (set)))
742 rtx note = find_reg_note (insn, REG_EQUIV, NULL_RTX);
748 i = REGNO (SET_DEST (set));
751 if (i <= LAST_VIRTUAL_REGISTER)
754 if (! function_invariant_p (x)
756 /* A function invariant is often CONSTANT_P but may
757 include a register. We promise to only pass
758 CONSTANT_P objects to LEGITIMATE_PIC_OPERAND_P. */
760 && LEGITIMATE_PIC_OPERAND_P (x)))
762 /* It can happen that a REG_EQUIV note contains a MEM
763 that is not a legitimate memory operand. As later
764 stages of reload assume that all addresses found
765 in the reg_equiv_* arrays were originally legitimate,
766 we ignore such REG_EQUIV notes. */
767 if (memory_operand (x, VOIDmode))
769 /* Always unshare the equivalence, so we can
770 substitute into this insn without touching the
772 reg_equiv_memory_loc[i] = copy_rtx (x);
774 else if (function_invariant_p (x))
776 if (GET_CODE (x) == PLUS)
778 /* This is PLUS of frame pointer and a constant,
779 and might be shared. Unshare it. */
780 reg_equiv_invariant[i] = copy_rtx (x);
781 num_eliminable_invariants++;
783 else if (x == frame_pointer_rtx || x == arg_pointer_rtx)
785 reg_equiv_invariant[i] = x;
786 num_eliminable_invariants++;
788 else if (LEGITIMATE_CONSTANT_P (x))
789 reg_equiv_constant[i] = x;
792 reg_equiv_memory_loc[i]
793 = force_const_mem (GET_MODE (SET_DEST (set)), x);
794 if (! reg_equiv_memory_loc[i])
795 reg_equiv_init[i] = NULL_RTX;
800 reg_equiv_init[i] = NULL_RTX;
805 reg_equiv_init[i] = NULL_RTX;
810 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
811 if (reg_equiv_init[i])
813 fprintf (dump_file, "init_insns for %u: ", i);
814 print_inline_rtx (dump_file, reg_equiv_init[i], 20);
815 fprintf (dump_file, "\n");
820 first_label_num = get_first_label_num ();
821 num_labels = max_label_num () - first_label_num;
823 /* Allocate the tables used to store offset information at labels. */
824 /* We used to use alloca here, but the size of what it would try to
825 allocate would occasionally cause it to exceed the stack limit and
826 cause a core dump. */
827 offsets_known_at = XNEWVEC (char, num_labels);
828 offsets_at = (HOST_WIDE_INT (*)[NUM_ELIMINABLE_REGS]) xmalloc (num_labels * NUM_ELIMINABLE_REGS * sizeof (HOST_WIDE_INT));
830 /* Alter each pseudo-reg rtx to contain its hard reg number.
831 Assign stack slots to the pseudos that lack hard regs or equivalents.
832 Do not touch virtual registers. */
834 for (i = LAST_VIRTUAL_REGISTER + 1; i < max_regno; i++)
837 /* If we have some registers we think can be eliminated, scan all insns to
838 see if there is an insn that sets one of these registers to something
839 other than itself plus a constant. If so, the register cannot be
840 eliminated. Doing this scan here eliminates an extra pass through the
841 main reload loop in the most common case where register elimination
843 for (insn = first; insn && num_eliminable; insn = NEXT_INSN (insn))
845 note_stores (PATTERN (insn), mark_not_eliminable, NULL);
847 maybe_fix_stack_asms ();
849 insns_need_reload = 0;
850 something_needs_elimination = 0;
852 /* Initialize to -1, which means take the first spill register. */
855 /* Spill any hard regs that we know we can't eliminate. */
856 CLEAR_HARD_REG_SET (used_spill_regs);
857 /* There can be multiple ways to eliminate a register;
858 they should be listed adjacently.
859 Elimination for any register fails only if all possible ways fail. */
860 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; )
863 int can_eliminate = 0;
866 can_eliminate |= ep->can_eliminate;
869 while (ep < ®_eliminate[NUM_ELIMINABLE_REGS] && ep->from == from);
871 spill_hard_reg (from, 1);
874 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
875 if (frame_pointer_needed)
876 spill_hard_reg (HARD_FRAME_POINTER_REGNUM, 1);
878 finish_spills (global);
880 /* From now on, we may need to generate moves differently. We may also
881 allow modifications of insns which cause them to not be recognized.
882 Any such modifications will be cleaned up during reload itself. */
883 reload_in_progress = 1;
885 /* This loop scans the entire function each go-round
886 and repeats until one repetition spills no additional hard regs. */
889 int something_changed;
892 HOST_WIDE_INT starting_frame_size;
894 /* Round size of stack frame to stack_alignment_needed. This must be done
895 here because the stack size may be a part of the offset computation
896 for register elimination, and there might have been new stack slots
897 created in the last iteration of this loop. */
898 if (cfun->stack_alignment_needed)
899 assign_stack_local (BLKmode, 0, cfun->stack_alignment_needed);
901 starting_frame_size = get_frame_size ();
903 set_initial_elim_offsets ();
904 set_initial_label_offsets ();
906 /* For each pseudo register that has an equivalent location defined,
907 try to eliminate any eliminable registers (such as the frame pointer)
908 assuming initial offsets for the replacement register, which
911 If the resulting location is directly addressable, substitute
912 the MEM we just got directly for the old REG.
914 If it is not addressable but is a constant or the sum of a hard reg
915 and constant, it is probably not addressable because the constant is
916 out of range, in that case record the address; we will generate
917 hairy code to compute the address in a register each time it is
918 needed. Similarly if it is a hard register, but one that is not
919 valid as an address register.
921 If the location is not addressable, but does not have one of the
922 above forms, assign a stack slot. We have to do this to avoid the
923 potential of producing lots of reloads if, e.g., a location involves
924 a pseudo that didn't get a hard register and has an equivalent memory
925 location that also involves a pseudo that didn't get a hard register.
927 Perhaps at some point we will improve reload_when_needed handling
928 so this problem goes away. But that's very hairy. */
930 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
931 if (reg_renumber[i] < 0 && reg_equiv_memory_loc[i])
933 rtx x = eliminate_regs (reg_equiv_memory_loc[i], 0, NULL_RTX);
935 if (strict_memory_address_p (GET_MODE (regno_reg_rtx[i]),
937 reg_equiv_mem[i] = x, reg_equiv_address[i] = 0;
938 else if (CONSTANT_P (XEXP (x, 0))
939 || (REG_P (XEXP (x, 0))
940 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER)
941 || (GET_CODE (XEXP (x, 0)) == PLUS
942 && REG_P (XEXP (XEXP (x, 0), 0))
943 && (REGNO (XEXP (XEXP (x, 0), 0))
944 < FIRST_PSEUDO_REGISTER)
945 && CONSTANT_P (XEXP (XEXP (x, 0), 1))))
946 reg_equiv_address[i] = XEXP (x, 0), reg_equiv_mem[i] = 0;
949 /* Make a new stack slot. Then indicate that something
950 changed so we go back and recompute offsets for
951 eliminable registers because the allocation of memory
952 below might change some offset. reg_equiv_{mem,address}
953 will be set up for this pseudo on the next pass around
955 reg_equiv_memory_loc[i] = 0;
956 reg_equiv_init[i] = 0;
961 if (caller_save_needed)
964 /* If we allocated another stack slot, redo elimination bookkeeping. */
965 if (starting_frame_size != get_frame_size ())
968 if (caller_save_needed)
970 save_call_clobbered_regs ();
971 /* That might have allocated new insn_chain structures. */
972 reload_firstobj = obstack_alloc (&reload_obstack, 0);
975 calculate_needs_all_insns (global);
977 CLEAR_REG_SET (&spilled_pseudos);
980 something_changed = 0;
982 /* If we allocated any new memory locations, make another pass
983 since it might have changed elimination offsets. */
984 if (starting_frame_size != get_frame_size ())
985 something_changed = 1;
987 /* Even if the frame size remained the same, we might still have
988 changed elimination offsets, e.g. if find_reloads called
989 force_const_mem requiring the back end to allocate a constant
990 pool base register that needs to be saved on the stack. */
991 else if (!verify_initial_elim_offsets ())
992 something_changed = 1;
995 HARD_REG_SET to_spill;
996 CLEAR_HARD_REG_SET (to_spill);
997 update_eliminables (&to_spill);
998 AND_COMPL_HARD_REG_SET(used_spill_regs, to_spill);
1000 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1001 if (TEST_HARD_REG_BIT (to_spill, i))
1003 spill_hard_reg (i, 1);
1006 /* Regardless of the state of spills, if we previously had
1007 a register that we thought we could eliminate, but now can
1008 not eliminate, we must run another pass.
1010 Consider pseudos which have an entry in reg_equiv_* which
1011 reference an eliminable register. We must make another pass
1012 to update reg_equiv_* so that we do not substitute in the
1013 old value from when we thought the elimination could be
1015 something_changed = 1;
1019 select_reload_regs ();
1023 if (insns_need_reload != 0 || did_spill)
1024 something_changed |= finish_spills (global);
1026 if (! something_changed)
1029 if (caller_save_needed)
1030 delete_caller_save_insns ();
1032 obstack_free (&reload_obstack, reload_firstobj);
1035 /* If global-alloc was run, notify it of any register eliminations we have
1038 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
1039 if (ep->can_eliminate)
1040 mark_elimination (ep->from, ep->to);
1042 /* If a pseudo has no hard reg, delete the insns that made the equivalence.
1043 If that insn didn't set the register (i.e., it copied the register to
1044 memory), just delete that insn instead of the equivalencing insn plus
1045 anything now dead. If we call delete_dead_insn on that insn, we may
1046 delete the insn that actually sets the register if the register dies
1047 there and that is incorrect. */
1049 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1051 if (reg_renumber[i] < 0 && reg_equiv_init[i] != 0)
1054 for (list = reg_equiv_init[i]; list; list = XEXP (list, 1))
1056 rtx equiv_insn = XEXP (list, 0);
1058 /* If we already deleted the insn or if it may trap, we can't
1059 delete it. The latter case shouldn't happen, but can
1060 if an insn has a variable address, gets a REG_EH_REGION
1061 note added to it, and then gets converted into a load
1062 from a constant address. */
1063 if (NOTE_P (equiv_insn)
1064 || can_throw_internal (equiv_insn))
1066 else if (reg_set_p (regno_reg_rtx[i], PATTERN (equiv_insn)))
1067 delete_dead_insn (equiv_insn);
1069 SET_INSN_DELETED (equiv_insn);
1074 /* Use the reload registers where necessary
1075 by generating move instructions to move the must-be-register
1076 values into or out of the reload registers. */
1078 if (insns_need_reload != 0 || something_needs_elimination
1079 || something_needs_operands_changed)
1081 HOST_WIDE_INT old_frame_size = get_frame_size ();
1083 reload_as_needed (global);
1085 gcc_assert (old_frame_size == get_frame_size ());
1087 gcc_assert (verify_initial_elim_offsets ());
1090 /* If we were able to eliminate the frame pointer, show that it is no
1091 longer live at the start of any basic block. If it ls live by
1092 virtue of being in a pseudo, that pseudo will be marked live
1093 and hence the frame pointer will be known to be live via that
1096 if (! frame_pointer_needed)
1098 CLEAR_REGNO_REG_SET (bb->il.rtl->global_live_at_start,
1099 HARD_FRAME_POINTER_REGNUM);
1101 /* Come here (with failure set nonzero) if we can't get enough spill
1105 CLEAR_REG_SET (&spilled_pseudos);
1106 reload_in_progress = 0;
1108 /* Now eliminate all pseudo regs by modifying them into
1109 their equivalent memory references.
1110 The REG-rtx's for the pseudos are modified in place,
1111 so all insns that used to refer to them now refer to memory.
1113 For a reg that has a reg_equiv_address, all those insns
1114 were changed by reloading so that no insns refer to it any longer;
1115 but the DECL_RTL of a variable decl may refer to it,
1116 and if so this causes the debugging info to mention the variable. */
1118 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
1122 if (reg_equiv_mem[i])
1123 addr = XEXP (reg_equiv_mem[i], 0);
1125 if (reg_equiv_address[i])
1126 addr = reg_equiv_address[i];
1130 if (reg_renumber[i] < 0)
1132 rtx reg = regno_reg_rtx[i];
1134 REG_USERVAR_P (reg) = 0;
1135 PUT_CODE (reg, MEM);
1136 XEXP (reg, 0) = addr;
1137 if (reg_equiv_memory_loc[i])
1138 MEM_COPY_ATTRIBUTES (reg, reg_equiv_memory_loc[i]);
1141 MEM_IN_STRUCT_P (reg) = MEM_SCALAR_P (reg) = 0;
1142 MEM_ATTRS (reg) = 0;
1144 MEM_NOTRAP_P (reg) = 1;
1146 else if (reg_equiv_mem[i])
1147 XEXP (reg_equiv_mem[i], 0) = addr;
1151 /* We must set reload_completed now since the cleanup_subreg_operands call
1152 below will re-recognize each insn and reload may have generated insns
1153 which are only valid during and after reload. */
1154 reload_completed = 1;
1156 /* Make a pass over all the insns and delete all USEs which we inserted
1157 only to tag a REG_EQUAL note on them. Remove all REG_DEAD and REG_UNUSED
1158 notes. Delete all CLOBBER insns, except those that refer to the return
1159 value and the special mem:BLK CLOBBERs added to prevent the scheduler
1160 from misarranging variable-array code, and simplify (subreg (reg))
1161 operands. Also remove all REG_RETVAL and REG_LIBCALL notes since they
1162 are no longer useful or accurate. Strip and regenerate REG_INC notes
1163 that may have been moved around. */
1165 for (insn = first; insn; insn = NEXT_INSN (insn))
1171 replace_pseudos_in (& CALL_INSN_FUNCTION_USAGE (insn),
1172 VOIDmode, CALL_INSN_FUNCTION_USAGE (insn));
1174 if ((GET_CODE (PATTERN (insn)) == USE
1175 /* We mark with QImode USEs introduced by reload itself. */
1176 && (GET_MODE (insn) == QImode
1177 || find_reg_note (insn, REG_EQUAL, NULL_RTX)))
1178 || (GET_CODE (PATTERN (insn)) == CLOBBER
1179 && (!MEM_P (XEXP (PATTERN (insn), 0))
1180 || GET_MODE (XEXP (PATTERN (insn), 0)) != BLKmode
1181 || (GET_CODE (XEXP (XEXP (PATTERN (insn), 0), 0)) != SCRATCH
1182 && XEXP (XEXP (PATTERN (insn), 0), 0)
1183 != stack_pointer_rtx))
1184 && (!REG_P (XEXP (PATTERN (insn), 0))
1185 || ! REG_FUNCTION_VALUE_P (XEXP (PATTERN (insn), 0)))))
1191 /* Some CLOBBERs may survive until here and still reference unassigned
1192 pseudos with const equivalent, which may in turn cause ICE in later
1193 passes if the reference remains in place. */
1194 if (GET_CODE (PATTERN (insn)) == CLOBBER)
1195 replace_pseudos_in (& XEXP (PATTERN (insn), 0),
1196 VOIDmode, PATTERN (insn));
1198 /* Discard obvious no-ops, even without -O. This optimization
1199 is fast and doesn't interfere with debugging. */
1200 if (NONJUMP_INSN_P (insn)
1201 && GET_CODE (PATTERN (insn)) == SET
1202 && REG_P (SET_SRC (PATTERN (insn)))
1203 && REG_P (SET_DEST (PATTERN (insn)))
1204 && (REGNO (SET_SRC (PATTERN (insn)))
1205 == REGNO (SET_DEST (PATTERN (insn)))))
1211 pnote = ®_NOTES (insn);
1214 if (REG_NOTE_KIND (*pnote) == REG_DEAD
1215 || REG_NOTE_KIND (*pnote) == REG_UNUSED
1216 || REG_NOTE_KIND (*pnote) == REG_INC
1217 || REG_NOTE_KIND (*pnote) == REG_RETVAL
1218 || REG_NOTE_KIND (*pnote) == REG_LIBCALL)
1219 *pnote = XEXP (*pnote, 1);
1221 pnote = &XEXP (*pnote, 1);
1225 add_auto_inc_notes (insn, PATTERN (insn));
1228 /* Simplify (subreg (reg)) if it appears as an operand. */
1229 cleanup_subreg_operands (insn);
1231 /* Clean up invalid ASMs so that they don't confuse later passes.
1233 if (asm_noperands (PATTERN (insn)) >= 0)
1235 extract_insn (insn);
1236 if (!constrain_operands (1))
1238 error_for_asm (insn,
1239 "%<asm%> operand has impossible constraints");
1246 /* If we are doing stack checking, give a warning if this function's
1247 frame size is larger than we expect. */
1248 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
1250 HOST_WIDE_INT size = get_frame_size () + STACK_CHECK_FIXED_FRAME_SIZE;
1251 static int verbose_warned = 0;
1253 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1254 if (regs_ever_live[i] && ! fixed_regs[i] && call_used_regs[i])
1255 size += UNITS_PER_WORD;
1257 if (size > STACK_CHECK_MAX_FRAME_SIZE)
1259 warning (0, "frame size too large for reliable stack checking");
1260 if (! verbose_warned)
1262 warning (0, "try reducing the number of local variables");
1268 /* Indicate that we no longer have known memory locations or constants. */
1269 if (reg_equiv_constant)
1270 free (reg_equiv_constant);
1271 if (reg_equiv_invariant)
1272 free (reg_equiv_invariant);
1273 reg_equiv_constant = 0;
1274 reg_equiv_invariant = 0;
1275 VEC_free (rtx, gc, reg_equiv_memory_loc_vec);
1276 reg_equiv_memory_loc = 0;
1278 if (offsets_known_at)
1279 free (offsets_known_at);
1283 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1284 if (reg_equiv_alt_mem_list[i])
1285 free_EXPR_LIST_list (®_equiv_alt_mem_list[i]);
1286 free (reg_equiv_alt_mem_list);
1288 free (reg_equiv_mem);
1290 free (reg_equiv_address);
1291 free (reg_max_ref_width);
1292 free (reg_old_renumber);
1293 free (pseudo_previous_regs);
1294 free (pseudo_forbidden_regs);
1296 CLEAR_HARD_REG_SET (used_spill_regs);
1297 for (i = 0; i < n_spills; i++)
1298 SET_HARD_REG_BIT (used_spill_regs, spill_regs[i]);
1300 /* Free all the insn_chain structures at once. */
1301 obstack_free (&reload_obstack, reload_startobj);
1302 unused_insn_chains = 0;
1303 fixup_abnormal_edges ();
1305 /* Replacing pseudos with their memory equivalents might have
1306 created shared rtx. Subsequent passes would get confused
1307 by this, so unshare everything here. */
1308 unshare_all_rtl_again (first);
1310 #ifdef STACK_BOUNDARY
1311 /* init_emit has set the alignment of the hard frame pointer
1312 to STACK_BOUNDARY. It is very likely no longer valid if
1313 the hard frame pointer was used for register allocation. */
1314 if (!frame_pointer_needed)
1315 REGNO_POINTER_ALIGN (HARD_FRAME_POINTER_REGNUM) = BITS_PER_UNIT;
1321 /* Yet another special case. Unfortunately, reg-stack forces people to
1322 write incorrect clobbers in asm statements. These clobbers must not
1323 cause the register to appear in bad_spill_regs, otherwise we'll call
1324 fatal_insn later. We clear the corresponding regnos in the live
1325 register sets to avoid this.
1326 The whole thing is rather sick, I'm afraid. */
1329 maybe_fix_stack_asms (void)
1332 const char *constraints[MAX_RECOG_OPERANDS];
1333 enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
1334 struct insn_chain *chain;
1336 for (chain = reload_insn_chain; chain != 0; chain = chain->next)
1339 HARD_REG_SET clobbered, allowed;
1342 if (! INSN_P (chain->insn)
1343 || (noperands = asm_noperands (PATTERN (chain->insn))) < 0)
1345 pat = PATTERN (chain->insn);
1346 if (GET_CODE (pat) != PARALLEL)
1349 CLEAR_HARD_REG_SET (clobbered);
1350 CLEAR_HARD_REG_SET (allowed);
1352 /* First, make a mask of all stack regs that are clobbered. */
1353 for (i = 0; i < XVECLEN (pat, 0); i++)
1355 rtx t = XVECEXP (pat, 0, i);
1356 if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0)))
1357 SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0)));
1360 /* Get the operand values and constraints out of the insn. */
1361 decode_asm_operands (pat, recog_data.operand, recog_data.operand_loc,
1362 constraints, operand_mode);
1364 /* For every operand, see what registers are allowed. */
1365 for (i = 0; i < noperands; i++)
1367 const char *p = constraints[i];
1368 /* For every alternative, we compute the class of registers allowed
1369 for reloading in CLS, and merge its contents into the reg set
1371 int cls = (int) NO_REGS;
1377 if (c == '\0' || c == ',' || c == '#')
1379 /* End of one alternative - mark the regs in the current
1380 class, and reset the class. */
1381 IOR_HARD_REG_SET (allowed, reg_class_contents[cls]);
1387 } while (c != '\0' && c != ',');
1395 case '=': case '+': case '*': case '%': case '?': case '!':
1396 case '0': case '1': case '2': case '3': case '4': case 'm':
1397 case '<': case '>': case 'V': case 'o': case '&': case 'E':
1398 case 'F': case 's': case 'i': case 'n': case 'X': case 'I':
1399 case 'J': case 'K': case 'L': case 'M': case 'N': case 'O':
1404 cls = (int) reg_class_subunion[cls]
1405 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)];
1410 cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS];
1414 if (EXTRA_ADDRESS_CONSTRAINT (c, p))
1415 cls = (int) reg_class_subunion[cls]
1416 [(int) base_reg_class (VOIDmode, ADDRESS, SCRATCH)];
1418 cls = (int) reg_class_subunion[cls]
1419 [(int) REG_CLASS_FROM_CONSTRAINT (c, p)];
1421 p += CONSTRAINT_LEN (c, p);
1424 /* Those of the registers which are clobbered, but allowed by the
1425 constraints, must be usable as reload registers. So clear them
1426 out of the life information. */
1427 AND_HARD_REG_SET (allowed, clobbered);
1428 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1429 if (TEST_HARD_REG_BIT (allowed, i))
1431 CLEAR_REGNO_REG_SET (&chain->live_throughout, i);
1432 CLEAR_REGNO_REG_SET (&chain->dead_or_set, i);
1439 /* Copy the global variables n_reloads and rld into the corresponding elts
1442 copy_reloads (struct insn_chain *chain)
1444 chain->n_reloads = n_reloads;
1445 chain->rld = obstack_alloc (&reload_obstack,
1446 n_reloads * sizeof (struct reload));
1447 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1448 reload_insn_firstobj = obstack_alloc (&reload_obstack, 0);
1451 /* Walk the chain of insns, and determine for each whether it needs reloads
1452 and/or eliminations. Build the corresponding insns_need_reload list, and
1453 set something_needs_elimination as appropriate. */
1455 calculate_needs_all_insns (int global)
1457 struct insn_chain **pprev_reload = &insns_need_reload;
1458 struct insn_chain *chain, *next = 0;
1460 something_needs_elimination = 0;
1462 reload_insn_firstobj = obstack_alloc (&reload_obstack, 0);
1463 for (chain = reload_insn_chain; chain != 0; chain = next)
1465 rtx insn = chain->insn;
1469 /* Clear out the shortcuts. */
1470 chain->n_reloads = 0;
1471 chain->need_elim = 0;
1472 chain->need_reload = 0;
1473 chain->need_operand_change = 0;
1475 /* If this is a label, a JUMP_INSN, or has REG_NOTES (which might
1476 include REG_LABEL), we need to see what effects this has on the
1477 known offsets at labels. */
1479 if (LABEL_P (insn) || JUMP_P (insn)
1480 || (INSN_P (insn) && REG_NOTES (insn) != 0))
1481 set_label_offsets (insn, insn, 0);
1485 rtx old_body = PATTERN (insn);
1486 int old_code = INSN_CODE (insn);
1487 rtx old_notes = REG_NOTES (insn);
1488 int did_elimination = 0;
1489 int operands_changed = 0;
1490 rtx set = single_set (insn);
1492 /* Skip insns that only set an equivalence. */
1493 if (set && REG_P (SET_DEST (set))
1494 && reg_renumber[REGNO (SET_DEST (set))] < 0
1495 && (reg_equiv_constant[REGNO (SET_DEST (set))]
1496 || (reg_equiv_invariant[REGNO (SET_DEST (set))]))
1497 && reg_equiv_init[REGNO (SET_DEST (set))])
1500 /* If needed, eliminate any eliminable registers. */
1501 if (num_eliminable || num_eliminable_invariants)
1502 did_elimination = eliminate_regs_in_insn (insn, 0);
1504 /* Analyze the instruction. */
1505 operands_changed = find_reloads (insn, 0, spill_indirect_levels,
1506 global, spill_reg_order);
1508 /* If a no-op set needs more than one reload, this is likely
1509 to be something that needs input address reloads. We
1510 can't get rid of this cleanly later, and it is of no use
1511 anyway, so discard it now.
1512 We only do this when expensive_optimizations is enabled,
1513 since this complements reload inheritance / output
1514 reload deletion, and it can make debugging harder. */
1515 if (flag_expensive_optimizations && n_reloads > 1)
1517 rtx set = single_set (insn);
1519 && SET_SRC (set) == SET_DEST (set)
1520 && REG_P (SET_SRC (set))
1521 && REGNO (SET_SRC (set)) >= FIRST_PSEUDO_REGISTER)
1524 /* Delete it from the reload chain. */
1526 chain->prev->next = next;
1528 reload_insn_chain = next;
1530 next->prev = chain->prev;
1531 chain->next = unused_insn_chains;
1532 unused_insn_chains = chain;
1537 update_eliminable_offsets ();
1539 /* Remember for later shortcuts which insns had any reloads or
1540 register eliminations. */
1541 chain->need_elim = did_elimination;
1542 chain->need_reload = n_reloads > 0;
1543 chain->need_operand_change = operands_changed;
1545 /* Discard any register replacements done. */
1546 if (did_elimination)
1548 obstack_free (&reload_obstack, reload_insn_firstobj);
1549 PATTERN (insn) = old_body;
1550 INSN_CODE (insn) = old_code;
1551 REG_NOTES (insn) = old_notes;
1552 something_needs_elimination = 1;
1555 something_needs_operands_changed |= operands_changed;
1559 copy_reloads (chain);
1560 *pprev_reload = chain;
1561 pprev_reload = &chain->next_need_reload;
1568 /* Comparison function for qsort to decide which of two reloads
1569 should be handled first. *P1 and *P2 are the reload numbers. */
1572 reload_reg_class_lower (const void *r1p, const void *r2p)
1574 int r1 = *(const short *) r1p, r2 = *(const short *) r2p;
1577 /* Consider required reloads before optional ones. */
1578 t = rld[r1].optional - rld[r2].optional;
1582 /* Count all solitary classes before non-solitary ones. */
1583 t = ((reg_class_size[(int) rld[r2].class] == 1)
1584 - (reg_class_size[(int) rld[r1].class] == 1));
1588 /* Aside from solitaires, consider all multi-reg groups first. */
1589 t = rld[r2].nregs - rld[r1].nregs;
1593 /* Consider reloads in order of increasing reg-class number. */
1594 t = (int) rld[r1].class - (int) rld[r2].class;
1598 /* If reloads are equally urgent, sort by reload number,
1599 so that the results of qsort leave nothing to chance. */
1603 /* The cost of spilling each hard reg. */
1604 static int spill_cost[FIRST_PSEUDO_REGISTER];
1606 /* When spilling multiple hard registers, we use SPILL_COST for the first
1607 spilled hard reg and SPILL_ADD_COST for subsequent regs. SPILL_ADD_COST
1608 only the first hard reg for a multi-reg pseudo. */
1609 static int spill_add_cost[FIRST_PSEUDO_REGISTER];
1611 /* Update the spill cost arrays, considering that pseudo REG is live. */
1614 count_pseudo (int reg)
1616 int freq = REG_FREQ (reg);
1617 int r = reg_renumber[reg];
1620 if (REGNO_REG_SET_P (&pseudos_counted, reg)
1621 || REGNO_REG_SET_P (&spilled_pseudos, reg))
1624 SET_REGNO_REG_SET (&pseudos_counted, reg);
1626 gcc_assert (r >= 0);
1628 spill_add_cost[r] += freq;
1630 nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1632 spill_cost[r + nregs] += freq;
1635 /* Calculate the SPILL_COST and SPILL_ADD_COST arrays and determine the
1636 contents of BAD_SPILL_REGS for the insn described by CHAIN. */
1639 order_regs_for_reload (struct insn_chain *chain)
1642 HARD_REG_SET used_by_pseudos;
1643 HARD_REG_SET used_by_pseudos2;
1644 reg_set_iterator rsi;
1646 COPY_HARD_REG_SET (bad_spill_regs, fixed_reg_set);
1648 memset (spill_cost, 0, sizeof spill_cost);
1649 memset (spill_add_cost, 0, sizeof spill_add_cost);
1651 /* Count number of uses of each hard reg by pseudo regs allocated to it
1652 and then order them by decreasing use. First exclude hard registers
1653 that are live in or across this insn. */
1655 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
1656 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
1657 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos);
1658 IOR_HARD_REG_SET (bad_spill_regs, used_by_pseudos2);
1660 /* Now find out which pseudos are allocated to it, and update
1662 CLEAR_REG_SET (&pseudos_counted);
1664 EXECUTE_IF_SET_IN_REG_SET
1665 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
1669 EXECUTE_IF_SET_IN_REG_SET
1670 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
1674 CLEAR_REG_SET (&pseudos_counted);
1677 /* Vector of reload-numbers showing the order in which the reloads should
1679 static short reload_order[MAX_RELOADS];
1681 /* This is used to keep track of the spill regs used in one insn. */
1682 static HARD_REG_SET used_spill_regs_local;
1684 /* We decided to spill hard register SPILLED, which has a size of
1685 SPILLED_NREGS. Determine how pseudo REG, which is live during the insn,
1686 is affected. We will add it to SPILLED_PSEUDOS if necessary, and we will
1687 update SPILL_COST/SPILL_ADD_COST. */
1690 count_spilled_pseudo (int spilled, int spilled_nregs, int reg)
1692 int r = reg_renumber[reg];
1693 int nregs = hard_regno_nregs[r][PSEUDO_REGNO_MODE (reg)];
1695 if (REGNO_REG_SET_P (&spilled_pseudos, reg)
1696 || spilled + spilled_nregs <= r || r + nregs <= spilled)
1699 SET_REGNO_REG_SET (&spilled_pseudos, reg);
1701 spill_add_cost[r] -= REG_FREQ (reg);
1703 spill_cost[r + nregs] -= REG_FREQ (reg);
1706 /* Find reload register to use for reload number ORDER. */
1709 find_reg (struct insn_chain *chain, int order)
1711 int rnum = reload_order[order];
1712 struct reload *rl = rld + rnum;
1713 int best_cost = INT_MAX;
1717 HARD_REG_SET not_usable;
1718 HARD_REG_SET used_by_other_reload;
1719 reg_set_iterator rsi;
1721 COPY_HARD_REG_SET (not_usable, bad_spill_regs);
1722 IOR_HARD_REG_SET (not_usable, bad_spill_regs_global);
1723 IOR_COMPL_HARD_REG_SET (not_usable, reg_class_contents[rl->class]);
1725 CLEAR_HARD_REG_SET (used_by_other_reload);
1726 for (k = 0; k < order; k++)
1728 int other = reload_order[k];
1730 if (rld[other].regno >= 0 && reloads_conflict (other, rnum))
1731 for (j = 0; j < rld[other].nregs; j++)
1732 SET_HARD_REG_BIT (used_by_other_reload, rld[other].regno + j);
1735 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
1737 unsigned int regno = i;
1739 if (! TEST_HARD_REG_BIT (not_usable, regno)
1740 && ! TEST_HARD_REG_BIT (used_by_other_reload, regno)
1741 && HARD_REGNO_MODE_OK (regno, rl->mode))
1743 int this_cost = spill_cost[regno];
1745 unsigned int this_nregs = hard_regno_nregs[regno][rl->mode];
1747 for (j = 1; j < this_nregs; j++)
1749 this_cost += spill_add_cost[regno + j];
1750 if ((TEST_HARD_REG_BIT (not_usable, regno + j))
1751 || TEST_HARD_REG_BIT (used_by_other_reload, regno + j))
1756 if (rl->in && REG_P (rl->in) && REGNO (rl->in) == regno)
1758 if (rl->out && REG_P (rl->out) && REGNO (rl->out) == regno)
1760 if (this_cost < best_cost
1761 /* Among registers with equal cost, prefer caller-saved ones, or
1762 use REG_ALLOC_ORDER if it is defined. */
1763 || (this_cost == best_cost
1764 #ifdef REG_ALLOC_ORDER
1765 && (inv_reg_alloc_order[regno]
1766 < inv_reg_alloc_order[best_reg])
1768 && call_used_regs[regno]
1769 && ! call_used_regs[best_reg]
1774 best_cost = this_cost;
1782 fprintf (dump_file, "Using reg %d for reload %d\n", best_reg, rnum);
1784 rl->nregs = hard_regno_nregs[best_reg][rl->mode];
1785 rl->regno = best_reg;
1787 EXECUTE_IF_SET_IN_REG_SET
1788 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, j, rsi)
1790 count_spilled_pseudo (best_reg, rl->nregs, j);
1793 EXECUTE_IF_SET_IN_REG_SET
1794 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, j, rsi)
1796 count_spilled_pseudo (best_reg, rl->nregs, j);
1799 for (i = 0; i < rl->nregs; i++)
1801 gcc_assert (spill_cost[best_reg + i] == 0);
1802 gcc_assert (spill_add_cost[best_reg + i] == 0);
1803 SET_HARD_REG_BIT (used_spill_regs_local, best_reg + i);
1808 /* Find more reload regs to satisfy the remaining need of an insn, which
1810 Do it by ascending class number, since otherwise a reg
1811 might be spilled for a big class and might fail to count
1812 for a smaller class even though it belongs to that class. */
1815 find_reload_regs (struct insn_chain *chain)
1819 /* In order to be certain of getting the registers we need,
1820 we must sort the reloads into order of increasing register class.
1821 Then our grabbing of reload registers will parallel the process
1822 that provided the reload registers. */
1823 for (i = 0; i < chain->n_reloads; i++)
1825 /* Show whether this reload already has a hard reg. */
1826 if (chain->rld[i].reg_rtx)
1828 int regno = REGNO (chain->rld[i].reg_rtx);
1829 chain->rld[i].regno = regno;
1831 = hard_regno_nregs[regno][GET_MODE (chain->rld[i].reg_rtx)];
1834 chain->rld[i].regno = -1;
1835 reload_order[i] = i;
1838 n_reloads = chain->n_reloads;
1839 memcpy (rld, chain->rld, n_reloads * sizeof (struct reload));
1841 CLEAR_HARD_REG_SET (used_spill_regs_local);
1844 fprintf (dump_file, "Spilling for insn %d.\n", INSN_UID (chain->insn));
1846 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
1848 /* Compute the order of preference for hard registers to spill. */
1850 order_regs_for_reload (chain);
1852 for (i = 0; i < n_reloads; i++)
1854 int r = reload_order[i];
1856 /* Ignore reloads that got marked inoperative. */
1857 if ((rld[r].out != 0 || rld[r].in != 0 || rld[r].secondary_p)
1858 && ! rld[r].optional
1859 && rld[r].regno == -1)
1860 if (! find_reg (chain, i))
1863 fprintf(dump_file, "reload failure for reload %d\n", r);
1864 spill_failure (chain->insn, rld[r].class);
1870 COPY_HARD_REG_SET (chain->used_spill_regs, used_spill_regs_local);
1871 IOR_HARD_REG_SET (used_spill_regs, used_spill_regs_local);
1873 memcpy (chain->rld, rld, n_reloads * sizeof (struct reload));
1877 select_reload_regs (void)
1879 struct insn_chain *chain;
1881 /* Try to satisfy the needs for each insn. */
1882 for (chain = insns_need_reload; chain != 0;
1883 chain = chain->next_need_reload)
1884 find_reload_regs (chain);
1887 /* Delete all insns that were inserted by emit_caller_save_insns during
1890 delete_caller_save_insns (void)
1892 struct insn_chain *c = reload_insn_chain;
1896 while (c != 0 && c->is_caller_save_insn)
1898 struct insn_chain *next = c->next;
1901 if (c == reload_insn_chain)
1902 reload_insn_chain = next;
1906 next->prev = c->prev;
1908 c->prev->next = next;
1909 c->next = unused_insn_chains;
1910 unused_insn_chains = c;
1918 /* Handle the failure to find a register to spill.
1919 INSN should be one of the insns which needed this particular spill reg. */
1922 spill_failure (rtx insn, enum reg_class class)
1924 if (asm_noperands (PATTERN (insn)) >= 0)
1925 error_for_asm (insn, "can't find a register in class %qs while "
1926 "reloading %<asm%>",
1927 reg_class_names[class]);
1930 error ("unable to find a register to spill in class %qs",
1931 reg_class_names[class]);
1935 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
1936 debug_reload_to_stream (dump_file);
1938 fatal_insn ("this is the insn:", insn);
1942 /* Delete an unneeded INSN and any previous insns who sole purpose is loading
1943 data that is dead in INSN. */
1946 delete_dead_insn (rtx insn)
1948 rtx prev = prev_real_insn (insn);
1951 /* If the previous insn sets a register that dies in our insn, delete it
1953 if (prev && GET_CODE (PATTERN (prev)) == SET
1954 && (prev_dest = SET_DEST (PATTERN (prev)), REG_P (prev_dest))
1955 && reg_mentioned_p (prev_dest, PATTERN (insn))
1956 && find_regno_note (insn, REG_DEAD, REGNO (prev_dest))
1957 && ! side_effects_p (SET_SRC (PATTERN (prev))))
1958 delete_dead_insn (prev);
1960 SET_INSN_DELETED (insn);
1963 /* Modify the home of pseudo-reg I.
1964 The new home is present in reg_renumber[I].
1966 FROM_REG may be the hard reg that the pseudo-reg is being spilled from;
1967 or it may be -1, meaning there is none or it is not relevant.
1968 This is used so that all pseudos spilled from a given hard reg
1969 can share one stack slot. */
1972 alter_reg (int i, int from_reg)
1974 /* When outputting an inline function, this can happen
1975 for a reg that isn't actually used. */
1976 if (regno_reg_rtx[i] == 0)
1979 /* If the reg got changed to a MEM at rtl-generation time,
1981 if (!REG_P (regno_reg_rtx[i]))
1984 /* Modify the reg-rtx to contain the new hard reg
1985 number or else to contain its pseudo reg number. */
1986 REGNO (regno_reg_rtx[i])
1987 = reg_renumber[i] >= 0 ? reg_renumber[i] : i;
1989 /* If we have a pseudo that is needed but has no hard reg or equivalent,
1990 allocate a stack slot for it. */
1992 if (reg_renumber[i] < 0
1993 && REG_N_REFS (i) > 0
1994 && reg_equiv_constant[i] == 0
1995 && (reg_equiv_invariant[i] == 0 || reg_equiv_init[i] == 0)
1996 && reg_equiv_memory_loc[i] == 0)
1999 enum machine_mode mode = GET_MODE (regno_reg_rtx[i]);
2000 unsigned int inherent_size = PSEUDO_REGNO_BYTES (i);
2001 unsigned int inherent_align = GET_MODE_ALIGNMENT (mode);
2002 unsigned int total_size = MAX (inherent_size, reg_max_ref_width[i]);
2003 unsigned int min_align = reg_max_ref_width[i] * BITS_PER_UNIT;
2006 /* Each pseudo reg has an inherent size which comes from its own mode,
2007 and a total size which provides room for paradoxical subregs
2008 which refer to the pseudo reg in wider modes.
2010 We can use a slot already allocated if it provides both
2011 enough inherent space and enough total space.
2012 Otherwise, we allocate a new slot, making sure that it has no less
2013 inherent space, and no less total space, then the previous slot. */
2016 /* No known place to spill from => no slot to reuse. */
2017 x = assign_stack_local (mode, total_size,
2018 min_align > inherent_align
2019 || total_size > inherent_size ? -1 : 0);
2020 if (BYTES_BIG_ENDIAN)
2021 /* Cancel the big-endian correction done in assign_stack_local.
2022 Get the address of the beginning of the slot.
2023 This is so we can do a big-endian correction unconditionally
2025 adjust = inherent_size - total_size;
2027 /* Nothing can alias this slot except this pseudo. */
2028 set_mem_alias_set (x, new_alias_set ());
2031 /* Reuse a stack slot if possible. */
2032 else if (spill_stack_slot[from_reg] != 0
2033 && spill_stack_slot_width[from_reg] >= total_size
2034 && (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
2036 && MEM_ALIGN (spill_stack_slot[from_reg]) >= min_align)
2037 x = spill_stack_slot[from_reg];
2039 /* Allocate a bigger slot. */
2042 /* Compute maximum size needed, both for inherent size
2043 and for total size. */
2046 if (spill_stack_slot[from_reg])
2048 if (GET_MODE_SIZE (GET_MODE (spill_stack_slot[from_reg]))
2050 mode = GET_MODE (spill_stack_slot[from_reg]);
2051 if (spill_stack_slot_width[from_reg] > total_size)
2052 total_size = spill_stack_slot_width[from_reg];
2053 if (MEM_ALIGN (spill_stack_slot[from_reg]) > min_align)
2054 min_align = MEM_ALIGN (spill_stack_slot[from_reg]);
2057 /* Make a slot with that size. */
2058 x = assign_stack_local (mode, total_size,
2059 min_align > inherent_align
2060 || total_size > inherent_size ? -1 : 0);
2063 /* All pseudos mapped to this slot can alias each other. */
2064 if (spill_stack_slot[from_reg])
2065 set_mem_alias_set (x, MEM_ALIAS_SET (spill_stack_slot[from_reg]));
2067 set_mem_alias_set (x, new_alias_set ());
2069 if (BYTES_BIG_ENDIAN)
2071 /* Cancel the big-endian correction done in assign_stack_local.
2072 Get the address of the beginning of the slot.
2073 This is so we can do a big-endian correction unconditionally
2075 adjust = GET_MODE_SIZE (mode) - total_size;
2078 = adjust_address_nv (x, mode_for_size (total_size
2084 spill_stack_slot[from_reg] = stack_slot;
2085 spill_stack_slot_width[from_reg] = total_size;
2088 /* On a big endian machine, the "address" of the slot
2089 is the address of the low part that fits its inherent mode. */
2090 if (BYTES_BIG_ENDIAN && inherent_size < total_size)
2091 adjust += (total_size - inherent_size);
2093 /* If we have any adjustment to make, or if the stack slot is the
2094 wrong mode, make a new stack slot. */
2095 x = adjust_address_nv (x, GET_MODE (regno_reg_rtx[i]), adjust);
2097 /* If we have a decl for the original register, set it for the
2098 memory. If this is a shared MEM, make a copy. */
2099 if (REG_EXPR (regno_reg_rtx[i])
2100 && DECL_P (REG_EXPR (regno_reg_rtx[i])))
2102 rtx decl = DECL_RTL_IF_SET (REG_EXPR (regno_reg_rtx[i]));
2104 /* We can do this only for the DECLs home pseudo, not for
2105 any copies of it, since otherwise when the stack slot
2106 is reused, nonoverlapping_memrefs_p might think they
2108 if (decl && REG_P (decl) && REGNO (decl) == (unsigned) i)
2110 if (from_reg != -1 && spill_stack_slot[from_reg] == x)
2113 set_mem_attrs_from_reg (x, regno_reg_rtx[i]);
2117 /* Save the stack slot for later. */
2118 reg_equiv_memory_loc[i] = x;
2122 /* Mark the slots in regs_ever_live for the hard regs
2123 used by pseudo-reg number REGNO. */
2126 mark_home_live (int regno)
2130 i = reg_renumber[regno];
2133 lim = i + hard_regno_nregs[i][PSEUDO_REGNO_MODE (regno)];
2135 regs_ever_live[i++] = 1;
2138 /* This function handles the tracking of elimination offsets around branches.
2140 X is a piece of RTL being scanned.
2142 INSN is the insn that it came from, if any.
2144 INITIAL_P is nonzero if we are to set the offset to be the initial
2145 offset and zero if we are setting the offset of the label to be the
2149 set_label_offsets (rtx x, rtx insn, int initial_p)
2151 enum rtx_code code = GET_CODE (x);
2154 struct elim_table *p;
2159 if (LABEL_REF_NONLOCAL_P (x))
2164 /* ... fall through ... */
2167 /* If we know nothing about this label, set the desired offsets. Note
2168 that this sets the offset at a label to be the offset before a label
2169 if we don't know anything about the label. This is not correct for
2170 the label after a BARRIER, but is the best guess we can make. If
2171 we guessed wrong, we will suppress an elimination that might have
2172 been possible had we been able to guess correctly. */
2174 if (! offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num])
2176 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2177 offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2178 = (initial_p ? reg_eliminate[i].initial_offset
2179 : reg_eliminate[i].offset);
2180 offsets_known_at[CODE_LABEL_NUMBER (x) - first_label_num] = 1;
2183 /* Otherwise, if this is the definition of a label and it is
2184 preceded by a BARRIER, set our offsets to the known offset of
2188 && (tem = prev_nonnote_insn (insn)) != 0
2190 set_offsets_for_label (insn);
2192 /* If neither of the above cases is true, compare each offset
2193 with those previously recorded and suppress any eliminations
2194 where the offsets disagree. */
2196 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
2197 if (offsets_at[CODE_LABEL_NUMBER (x) - first_label_num][i]
2198 != (initial_p ? reg_eliminate[i].initial_offset
2199 : reg_eliminate[i].offset))
2200 reg_eliminate[i].can_eliminate = 0;
2205 set_label_offsets (PATTERN (insn), insn, initial_p);
2207 /* ... fall through ... */
2211 /* Any labels mentioned in REG_LABEL notes can be branched to indirectly
2212 and hence must have all eliminations at their initial offsets. */
2213 for (tem = REG_NOTES (x); tem; tem = XEXP (tem, 1))
2214 if (REG_NOTE_KIND (tem) == REG_LABEL)
2215 set_label_offsets (XEXP (tem, 0), insn, 1);
2221 /* Each of the labels in the parallel or address vector must be
2222 at their initial offsets. We want the first field for PARALLEL
2223 and ADDR_VEC and the second field for ADDR_DIFF_VEC. */
2225 for (i = 0; i < (unsigned) XVECLEN (x, code == ADDR_DIFF_VEC); i++)
2226 set_label_offsets (XVECEXP (x, code == ADDR_DIFF_VEC, i),
2231 /* We only care about setting PC. If the source is not RETURN,
2232 IF_THEN_ELSE, or a label, disable any eliminations not at
2233 their initial offsets. Similarly if any arm of the IF_THEN_ELSE
2234 isn't one of those possibilities. For branches to a label,
2235 call ourselves recursively.
2237 Note that this can disable elimination unnecessarily when we have
2238 a non-local goto since it will look like a non-constant jump to
2239 someplace in the current function. This isn't a significant
2240 problem since such jumps will normally be when all elimination
2241 pairs are back to their initial offsets. */
2243 if (SET_DEST (x) != pc_rtx)
2246 switch (GET_CODE (SET_SRC (x)))
2253 set_label_offsets (SET_SRC (x), insn, initial_p);
2257 tem = XEXP (SET_SRC (x), 1);
2258 if (GET_CODE (tem) == LABEL_REF)
2259 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2260 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2263 tem = XEXP (SET_SRC (x), 2);
2264 if (GET_CODE (tem) == LABEL_REF)
2265 set_label_offsets (XEXP (tem, 0), insn, initial_p);
2266 else if (GET_CODE (tem) != PC && GET_CODE (tem) != RETURN)
2274 /* If we reach here, all eliminations must be at their initial
2275 offset because we are doing a jump to a variable address. */
2276 for (p = reg_eliminate; p < ®_eliminate[NUM_ELIMINABLE_REGS]; p++)
2277 if (p->offset != p->initial_offset)
2278 p->can_eliminate = 0;
2286 /* Scan X and replace any eliminable registers (such as fp) with a
2287 replacement (such as sp), plus an offset.
2289 MEM_MODE is the mode of an enclosing MEM. We need this to know how
2290 much to adjust a register for, e.g., PRE_DEC. Also, if we are inside a
2291 MEM, we are allowed to replace a sum of a register and the constant zero
2292 with the register, which we cannot do outside a MEM. In addition, we need
2293 to record the fact that a register is referenced outside a MEM.
2295 If INSN is an insn, it is the insn containing X. If we replace a REG
2296 in a SET_DEST with an equivalent MEM and INSN is nonzero, write a
2297 CLOBBER of the pseudo after INSN so find_equiv_regs will know that
2298 the REG is being modified.
2300 Alternatively, INSN may be a note (an EXPR_LIST or INSN_LIST).
2301 That's used when we eliminate in expressions stored in notes.
2302 This means, do not set ref_outside_mem even if the reference
2305 REG_EQUIV_MEM and REG_EQUIV_ADDRESS contain address that have had
2306 replacements done assuming all offsets are at their initial values. If
2307 they are not, or if REG_EQUIV_ADDRESS is nonzero for a pseudo we
2308 encounter, return the actual location so that find_reloads will do
2309 the proper thing. */
2312 eliminate_regs_1 (rtx x, enum machine_mode mem_mode, rtx insn,
2313 bool may_use_invariant)
2315 enum rtx_code code = GET_CODE (x);
2316 struct elim_table *ep;
2323 if (! current_function_decl)
2345 /* First handle the case where we encounter a bare register that
2346 is eliminable. Replace it with a PLUS. */
2347 if (regno < FIRST_PSEUDO_REGISTER)
2349 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2351 if (ep->from_rtx == x && ep->can_eliminate)
2352 return plus_constant (ep->to_rtx, ep->previous_offset);
2355 else if (reg_renumber && reg_renumber[regno] < 0
2356 && reg_equiv_invariant && reg_equiv_invariant[regno])
2358 if (may_use_invariant)
2359 return eliminate_regs_1 (copy_rtx (reg_equiv_invariant[regno]),
2360 mem_mode, insn, true);
2361 /* There exists at least one use of REGNO that cannot be
2362 eliminated. Prevent the defining insn from being deleted. */
2363 reg_equiv_init[regno] = NULL_RTX;
2364 alter_reg (regno, -1);
2368 /* You might think handling MINUS in a manner similar to PLUS is a
2369 good idea. It is not. It has been tried multiple times and every
2370 time the change has had to have been reverted.
2372 Other parts of reload know a PLUS is special (gen_reload for example)
2373 and require special code to handle code a reloaded PLUS operand.
2375 Also consider backends where the flags register is clobbered by a
2376 MINUS, but we can emit a PLUS that does not clobber flags (IA-32,
2377 lea instruction comes to mind). If we try to reload a MINUS, we
2378 may kill the flags register that was holding a useful value.
2380 So, please before trying to handle MINUS, consider reload as a
2381 whole instead of this little section as well as the backend issues. */
2383 /* If this is the sum of an eliminable register and a constant, rework
2385 if (REG_P (XEXP (x, 0))
2386 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2387 && CONSTANT_P (XEXP (x, 1)))
2389 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2391 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2393 /* The only time we want to replace a PLUS with a REG (this
2394 occurs when the constant operand of the PLUS is the negative
2395 of the offset) is when we are inside a MEM. We won't want
2396 to do so at other times because that would change the
2397 structure of the insn in a way that reload can't handle.
2398 We special-case the commonest situation in
2399 eliminate_regs_in_insn, so just replace a PLUS with a
2400 PLUS here, unless inside a MEM. */
2401 if (mem_mode != 0 && GET_CODE (XEXP (x, 1)) == CONST_INT
2402 && INTVAL (XEXP (x, 1)) == - ep->previous_offset)
2405 return gen_rtx_PLUS (Pmode, ep->to_rtx,
2406 plus_constant (XEXP (x, 1),
2407 ep->previous_offset));
2410 /* If the register is not eliminable, we are done since the other
2411 operand is a constant. */
2415 /* If this is part of an address, we want to bring any constant to the
2416 outermost PLUS. We will do this by doing register replacement in
2417 our operands and seeing if a constant shows up in one of them.
2419 Note that there is no risk of modifying the structure of the insn,
2420 since we only get called for its operands, thus we are either
2421 modifying the address inside a MEM, or something like an address
2422 operand of a load-address insn. */
2425 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true);
2426 rtx new1 = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true);
2428 if (reg_renumber && (new0 != XEXP (x, 0) || new1 != XEXP (x, 1)))
2430 /* If one side is a PLUS and the other side is a pseudo that
2431 didn't get a hard register but has a reg_equiv_constant,
2432 we must replace the constant here since it may no longer
2433 be in the position of any operand. */
2434 if (GET_CODE (new0) == PLUS && REG_P (new1)
2435 && REGNO (new1) >= FIRST_PSEUDO_REGISTER
2436 && reg_renumber[REGNO (new1)] < 0
2437 && reg_equiv_constant != 0
2438 && reg_equiv_constant[REGNO (new1)] != 0)
2439 new1 = reg_equiv_constant[REGNO (new1)];
2440 else if (GET_CODE (new1) == PLUS && REG_P (new0)
2441 && REGNO (new0) >= FIRST_PSEUDO_REGISTER
2442 && reg_renumber[REGNO (new0)] < 0
2443 && reg_equiv_constant[REGNO (new0)] != 0)
2444 new0 = reg_equiv_constant[REGNO (new0)];
2446 new = form_sum (new0, new1);
2448 /* As above, if we are not inside a MEM we do not want to
2449 turn a PLUS into something else. We might try to do so here
2450 for an addition of 0 if we aren't optimizing. */
2451 if (! mem_mode && GET_CODE (new) != PLUS)
2452 return gen_rtx_PLUS (GET_MODE (x), new, const0_rtx);
2460 /* If this is the product of an eliminable register and a
2461 constant, apply the distribute law and move the constant out
2462 so that we have (plus (mult ..) ..). This is needed in order
2463 to keep load-address insns valid. This case is pathological.
2464 We ignore the possibility of overflow here. */
2465 if (REG_P (XEXP (x, 0))
2466 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER
2467 && GET_CODE (XEXP (x, 1)) == CONST_INT)
2468 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2470 if (ep->from_rtx == XEXP (x, 0) && ep->can_eliminate)
2473 /* Refs inside notes don't count for this purpose. */
2474 && ! (insn != 0 && (GET_CODE (insn) == EXPR_LIST
2475 || GET_CODE (insn) == INSN_LIST)))
2476 ep->ref_outside_mem = 1;
2479 plus_constant (gen_rtx_MULT (Pmode, ep->to_rtx, XEXP (x, 1)),
2480 ep->previous_offset * INTVAL (XEXP (x, 1)));
2483 /* ... fall through ... */
2487 /* See comments before PLUS about handling MINUS. */
2489 case DIV: case UDIV:
2490 case MOD: case UMOD:
2491 case AND: case IOR: case XOR:
2492 case ROTATERT: case ROTATE:
2493 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
2495 case GE: case GT: case GEU: case GTU:
2496 case LE: case LT: case LEU: case LTU:
2498 rtx new0 = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2499 rtx new1 = XEXP (x, 1)
2500 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, false) : 0;
2502 if (new0 != XEXP (x, 0) || new1 != XEXP (x, 1))
2503 return gen_rtx_fmt_ee (code, GET_MODE (x), new0, new1);
2508 /* If we have something in XEXP (x, 0), the usual case, eliminate it. */
2511 new = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, true);
2512 if (new != XEXP (x, 0))
2514 /* If this is a REG_DEAD note, it is not valid anymore.
2515 Using the eliminated version could result in creating a
2516 REG_DEAD note for the stack or frame pointer. */
2517 if (GET_MODE (x) == REG_DEAD)
2519 ? eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true)
2522 x = gen_rtx_EXPR_LIST (REG_NOTE_KIND (x), new, XEXP (x, 1));
2526 /* ... fall through ... */
2529 /* Now do eliminations in the rest of the chain. If this was
2530 an EXPR_LIST, this might result in allocating more memory than is
2531 strictly needed, but it simplifies the code. */
2534 new = eliminate_regs_1 (XEXP (x, 1), mem_mode, insn, true);
2535 if (new != XEXP (x, 1))
2537 gen_rtx_fmt_ee (GET_CODE (x), GET_MODE (x), XEXP (x, 0), new);
2545 case STRICT_LOW_PART:
2547 case SIGN_EXTEND: case ZERO_EXTEND:
2548 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2549 case FLOAT: case FIX:
2550 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2558 new = eliminate_regs_1 (XEXP (x, 0), mem_mode, insn, false);
2559 if (new != XEXP (x, 0))
2560 return gen_rtx_fmt_e (code, GET_MODE (x), new);
2564 /* Similar to above processing, but preserve SUBREG_BYTE.
2565 Convert (subreg (mem)) to (mem) if not paradoxical.
2566 Also, if we have a non-paradoxical (subreg (pseudo)) and the
2567 pseudo didn't get a hard reg, we must replace this with the
2568 eliminated version of the memory location because push_reload
2569 may do the replacement in certain circumstances. */
2570 if (REG_P (SUBREG_REG (x))
2571 && (GET_MODE_SIZE (GET_MODE (x))
2572 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2573 && reg_equiv_memory_loc != 0
2574 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2576 new = SUBREG_REG (x);
2579 new = eliminate_regs_1 (SUBREG_REG (x), mem_mode, insn, false);
2581 if (new != SUBREG_REG (x))
2583 int x_size = GET_MODE_SIZE (GET_MODE (x));
2584 int new_size = GET_MODE_SIZE (GET_MODE (new));
2587 && ((x_size < new_size
2588 #ifdef WORD_REGISTER_OPERATIONS
2589 /* On these machines, combine can create rtl of the form
2590 (set (subreg:m1 (reg:m2 R) 0) ...)
2591 where m1 < m2, and expects something interesting to
2592 happen to the entire word. Moreover, it will use the
2593 (reg:m2 R) later, expecting all bits to be preserved.
2594 So if the number of words is the same, preserve the
2595 subreg so that push_reload can see it. */
2596 && ! ((x_size - 1) / UNITS_PER_WORD
2597 == (new_size -1 ) / UNITS_PER_WORD)
2600 || x_size == new_size)
2602 return adjust_address_nv (new, GET_MODE (x), SUBREG_BYTE (x));
2604 return gen_rtx_SUBREG (GET_MODE (x), new, SUBREG_BYTE (x));
2610 /* Our only special processing is to pass the mode of the MEM to our
2611 recursive call and copy the flags. While we are here, handle this
2612 case more efficiently. */
2614 replace_equiv_address_nv (x,
2615 eliminate_regs_1 (XEXP (x, 0), GET_MODE (x),
2619 /* Handle insn_list USE that a call to a pure function may generate. */
2620 new = eliminate_regs_1 (XEXP (x, 0), 0, insn, false);
2621 if (new != XEXP (x, 0))
2622 return gen_rtx_USE (GET_MODE (x), new);
2634 /* Process each of our operands recursively. If any have changed, make a
2636 fmt = GET_RTX_FORMAT (code);
2637 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2641 new = eliminate_regs_1 (XEXP (x, i), mem_mode, insn, false);
2642 if (new != XEXP (x, i) && ! copied)
2644 x = shallow_copy_rtx (x);
2649 else if (*fmt == 'E')
2652 for (j = 0; j < XVECLEN (x, i); j++)
2654 new = eliminate_regs_1 (XVECEXP (x, i, j), mem_mode, insn, false);
2655 if (new != XVECEXP (x, i, j) && ! copied_vec)
2657 rtvec new_v = gen_rtvec_v (XVECLEN (x, i),
2661 x = shallow_copy_rtx (x);
2664 XVEC (x, i) = new_v;
2667 XVECEXP (x, i, j) = new;
2676 eliminate_regs (rtx x, enum machine_mode mem_mode, rtx insn)
2678 return eliminate_regs_1 (x, mem_mode, insn, false);
2681 /* Scan rtx X for modifications of elimination target registers. Update
2682 the table of eliminables to reflect the changed state. MEM_MODE is
2683 the mode of an enclosing MEM rtx, or VOIDmode if not within a MEM. */
2686 elimination_effects (rtx x, enum machine_mode mem_mode)
2688 enum rtx_code code = GET_CODE (x);
2689 struct elim_table *ep;
2713 /* First handle the case where we encounter a bare register that
2714 is eliminable. Replace it with a PLUS. */
2715 if (regno < FIRST_PSEUDO_REGISTER)
2717 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2719 if (ep->from_rtx == x && ep->can_eliminate)
2722 ep->ref_outside_mem = 1;
2727 else if (reg_renumber[regno] < 0 && reg_equiv_constant
2728 && reg_equiv_constant[regno]
2729 && ! function_invariant_p (reg_equiv_constant[regno]))
2730 elimination_effects (reg_equiv_constant[regno], mem_mode);
2739 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2740 if (ep->to_rtx == XEXP (x, 0))
2742 int size = GET_MODE_SIZE (mem_mode);
2744 /* If more bytes than MEM_MODE are pushed, account for them. */
2745 #ifdef PUSH_ROUNDING
2746 if (ep->to_rtx == stack_pointer_rtx)
2747 size = PUSH_ROUNDING (size);
2749 if (code == PRE_DEC || code == POST_DEC)
2751 else if (code == PRE_INC || code == POST_INC)
2753 else if ((code == PRE_MODIFY || code == POST_MODIFY)
2754 && GET_CODE (XEXP (x, 1)) == PLUS
2755 && XEXP (x, 0) == XEXP (XEXP (x, 1), 0)
2756 && CONSTANT_P (XEXP (XEXP (x, 1), 1)))
2757 ep->offset -= INTVAL (XEXP (XEXP (x, 1), 1));
2760 /* These two aren't unary operators. */
2761 if (code == POST_MODIFY || code == PRE_MODIFY)
2764 /* Fall through to generic unary operation case. */
2765 case STRICT_LOW_PART:
2767 case SIGN_EXTEND: case ZERO_EXTEND:
2768 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
2769 case FLOAT: case FIX:
2770 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
2778 elimination_effects (XEXP (x, 0), mem_mode);
2782 if (REG_P (SUBREG_REG (x))
2783 && (GET_MODE_SIZE (GET_MODE (x))
2784 <= GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2785 && reg_equiv_memory_loc != 0
2786 && reg_equiv_memory_loc[REGNO (SUBREG_REG (x))] != 0)
2789 elimination_effects (SUBREG_REG (x), mem_mode);
2793 /* If using a register that is the source of an eliminate we still
2794 think can be performed, note it cannot be performed since we don't
2795 know how this register is used. */
2796 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2797 if (ep->from_rtx == XEXP (x, 0))
2798 ep->can_eliminate = 0;
2800 elimination_effects (XEXP (x, 0), mem_mode);
2804 /* If clobbering a register that is the replacement register for an
2805 elimination we still think can be performed, note that it cannot
2806 be performed. Otherwise, we need not be concerned about it. */
2807 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2808 if (ep->to_rtx == XEXP (x, 0))
2809 ep->can_eliminate = 0;
2811 elimination_effects (XEXP (x, 0), mem_mode);
2815 /* Check for setting a register that we know about. */
2816 if (REG_P (SET_DEST (x)))
2818 /* See if this is setting the replacement register for an
2821 If DEST is the hard frame pointer, we do nothing because we
2822 assume that all assignments to the frame pointer are for
2823 non-local gotos and are being done at a time when they are valid
2824 and do not disturb anything else. Some machines want to
2825 eliminate a fake argument pointer (or even a fake frame pointer)
2826 with either the real frame or the stack pointer. Assignments to
2827 the hard frame pointer must not prevent this elimination. */
2829 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
2831 if (ep->to_rtx == SET_DEST (x)
2832 && SET_DEST (x) != hard_frame_pointer_rtx)
2834 /* If it is being incremented, adjust the offset. Otherwise,
2835 this elimination can't be done. */
2836 rtx src = SET_SRC (x);
2838 if (GET_CODE (src) == PLUS
2839 && XEXP (src, 0) == SET_DEST (x)
2840 && GET_CODE (XEXP (src, 1)) == CONST_INT)
2841 ep->offset -= INTVAL (XEXP (src, 1));
2843 ep->can_eliminate = 0;
2847 elimination_effects (SET_DEST (x), 0);
2848 elimination_effects (SET_SRC (x), 0);
2852 /* Our only special processing is to pass the mode of the MEM to our
2854 elimination_effects (XEXP (x, 0), GET_MODE (x));
2861 fmt = GET_RTX_FORMAT (code);
2862 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2865 elimination_effects (XEXP (x, i), mem_mode);
2866 else if (*fmt == 'E')
2867 for (j = 0; j < XVECLEN (x, i); j++)
2868 elimination_effects (XVECEXP (x, i, j), mem_mode);
2872 /* Descend through rtx X and verify that no references to eliminable registers
2873 remain. If any do remain, mark the involved register as not
2877 check_eliminable_occurrences (rtx x)
2886 code = GET_CODE (x);
2888 if (code == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
2890 struct elim_table *ep;
2892 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2893 if (ep->from_rtx == x)
2894 ep->can_eliminate = 0;
2898 fmt = GET_RTX_FORMAT (code);
2899 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2902 check_eliminable_occurrences (XEXP (x, i));
2903 else if (*fmt == 'E')
2906 for (j = 0; j < XVECLEN (x, i); j++)
2907 check_eliminable_occurrences (XVECEXP (x, i, j));
2912 /* Scan INSN and eliminate all eliminable registers in it.
2914 If REPLACE is nonzero, do the replacement destructively. Also
2915 delete the insn as dead it if it is setting an eliminable register.
2917 If REPLACE is zero, do all our allocations in reload_obstack.
2919 If no eliminations were done and this insn doesn't require any elimination
2920 processing (these are not identical conditions: it might be updating sp,
2921 but not referencing fp; this needs to be seen during reload_as_needed so
2922 that the offset between fp and sp can be taken into consideration), zero
2923 is returned. Otherwise, 1 is returned. */
2926 eliminate_regs_in_insn (rtx insn, int replace)
2928 int icode = recog_memoized (insn);
2929 rtx old_body = PATTERN (insn);
2930 int insn_is_asm = asm_noperands (old_body) >= 0;
2931 rtx old_set = single_set (insn);
2935 rtx substed_operand[MAX_RECOG_OPERANDS];
2936 rtx orig_operand[MAX_RECOG_OPERANDS];
2937 struct elim_table *ep;
2938 rtx plus_src, plus_cst_src;
2940 if (! insn_is_asm && icode < 0)
2942 gcc_assert (GET_CODE (PATTERN (insn)) == USE
2943 || GET_CODE (PATTERN (insn)) == CLOBBER
2944 || GET_CODE (PATTERN (insn)) == ADDR_VEC
2945 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
2946 || GET_CODE (PATTERN (insn)) == ASM_INPUT);
2950 if (old_set != 0 && REG_P (SET_DEST (old_set))
2951 && REGNO (SET_DEST (old_set)) < FIRST_PSEUDO_REGISTER)
2953 /* Check for setting an eliminable register. */
2954 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
2955 if (ep->from_rtx == SET_DEST (old_set) && ep->can_eliminate)
2957 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2958 /* If this is setting the frame pointer register to the
2959 hardware frame pointer register and this is an elimination
2960 that will be done (tested above), this insn is really
2961 adjusting the frame pointer downward to compensate for
2962 the adjustment done before a nonlocal goto. */
2963 if (ep->from == FRAME_POINTER_REGNUM
2964 && ep->to == HARD_FRAME_POINTER_REGNUM)
2966 rtx base = SET_SRC (old_set);
2967 rtx base_insn = insn;
2968 HOST_WIDE_INT offset = 0;
2970 while (base != ep->to_rtx)
2972 rtx prev_insn, prev_set;
2974 if (GET_CODE (base) == PLUS
2975 && GET_CODE (XEXP (base, 1)) == CONST_INT)
2977 offset += INTVAL (XEXP (base, 1));
2978 base = XEXP (base, 0);
2980 else if ((prev_insn = prev_nonnote_insn (base_insn)) != 0
2981 && (prev_set = single_set (prev_insn)) != 0
2982 && rtx_equal_p (SET_DEST (prev_set), base))
2984 base = SET_SRC (prev_set);
2985 base_insn = prev_insn;
2991 if (base == ep->to_rtx)
2994 = plus_constant (ep->to_rtx, offset - ep->offset);
2996 new_body = old_body;
2999 new_body = copy_insn (old_body);
3000 if (REG_NOTES (insn))
3001 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3003 PATTERN (insn) = new_body;
3004 old_set = single_set (insn);
3006 /* First see if this insn remains valid when we
3007 make the change. If not, keep the INSN_CODE
3008 the same and let reload fit it up. */
3009 validate_change (insn, &SET_SRC (old_set), src, 1);
3010 validate_change (insn, &SET_DEST (old_set),
3012 if (! apply_change_group ())
3014 SET_SRC (old_set) = src;
3015 SET_DEST (old_set) = ep->to_rtx;
3024 /* In this case this insn isn't serving a useful purpose. We
3025 will delete it in reload_as_needed once we know that this
3026 elimination is, in fact, being done.
3028 If REPLACE isn't set, we can't delete this insn, but needn't
3029 process it since it won't be used unless something changes. */
3032 delete_dead_insn (insn);
3040 /* We allow one special case which happens to work on all machines we
3041 currently support: a single set with the source or a REG_EQUAL
3042 note being a PLUS of an eliminable register and a constant. */
3043 plus_src = plus_cst_src = 0;
3044 if (old_set && REG_P (SET_DEST (old_set)))
3046 if (GET_CODE (SET_SRC (old_set)) == PLUS)
3047 plus_src = SET_SRC (old_set);
3048 /* First see if the source is of the form (plus (...) CST). */
3050 && GET_CODE (XEXP (plus_src, 1)) == CONST_INT)
3051 plus_cst_src = plus_src;
3052 else if (REG_P (SET_SRC (old_set))
3055 /* Otherwise, see if we have a REG_EQUAL note of the form
3056 (plus (...) CST). */
3058 for (links = REG_NOTES (insn); links; links = XEXP (links, 1))
3060 if (REG_NOTE_KIND (links) == REG_EQUAL
3061 && GET_CODE (XEXP (links, 0)) == PLUS
3062 && GET_CODE (XEXP (XEXP (links, 0), 1)) == CONST_INT)
3064 plus_cst_src = XEXP (links, 0);
3070 /* Check that the first operand of the PLUS is a hard reg or
3071 the lowpart subreg of one. */
3074 rtx reg = XEXP (plus_cst_src, 0);
3075 if (GET_CODE (reg) == SUBREG && subreg_lowpart_p (reg))
3076 reg = SUBREG_REG (reg);
3078 if (!REG_P (reg) || REGNO (reg) >= FIRST_PSEUDO_REGISTER)
3084 rtx reg = XEXP (plus_cst_src, 0);
3085 HOST_WIDE_INT offset = INTVAL (XEXP (plus_cst_src, 1));
3087 if (GET_CODE (reg) == SUBREG)
3088 reg = SUBREG_REG (reg);
3090 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3091 if (ep->from_rtx == reg && ep->can_eliminate)
3093 rtx to_rtx = ep->to_rtx;
3094 offset += ep->offset;
3095 offset = trunc_int_for_mode (offset, GET_MODE (reg));
3097 if (GET_CODE (XEXP (plus_cst_src, 0)) == SUBREG)
3098 to_rtx = gen_lowpart (GET_MODE (XEXP (plus_cst_src, 0)),
3100 /* If we have a nonzero offset, and the source is already
3101 a simple REG, the following transformation would
3102 increase the cost of the insn by replacing a simple REG
3103 with (plus (reg sp) CST). So try only when we already
3104 had a PLUS before. */
3105 if (offset == 0 || plus_src)
3107 rtx new_src = plus_constant (to_rtx, offset);
3109 new_body = old_body;
3112 new_body = copy_insn (old_body);
3113 if (REG_NOTES (insn))
3114 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3116 PATTERN (insn) = new_body;
3117 old_set = single_set (insn);
3119 /* First see if this insn remains valid when we make the
3120 change. If not, try to replace the whole pattern with
3121 a simple set (this may help if the original insn was a
3122 PARALLEL that was only recognized as single_set due to
3123 REG_UNUSED notes). If this isn't valid either, keep
3124 the INSN_CODE the same and let reload fix it up. */
3125 if (!validate_change (insn, &SET_SRC (old_set), new_src, 0))
3127 rtx new_pat = gen_rtx_SET (VOIDmode,
3128 SET_DEST (old_set), new_src);
3130 if (!validate_change (insn, &PATTERN (insn), new_pat, 0))
3131 SET_SRC (old_set) = new_src;
3138 /* This can't have an effect on elimination offsets, so skip right
3144 /* Determine the effects of this insn on elimination offsets. */
3145 elimination_effects (old_body, 0);
3147 /* Eliminate all eliminable registers occurring in operands that
3148 can be handled by reload. */
3149 extract_insn (insn);
3150 for (i = 0; i < recog_data.n_operands; i++)
3152 orig_operand[i] = recog_data.operand[i];
3153 substed_operand[i] = recog_data.operand[i];
3155 /* For an asm statement, every operand is eliminable. */
3156 if (insn_is_asm || insn_data[icode].operand[i].eliminable)
3158 bool is_set_src, in_plus;
3160 /* Check for setting a register that we know about. */
3161 if (recog_data.operand_type[i] != OP_IN
3162 && REG_P (orig_operand[i]))
3164 /* If we are assigning to a register that can be eliminated, it
3165 must be as part of a PARALLEL, since the code above handles
3166 single SETs. We must indicate that we can no longer
3167 eliminate this reg. */
3168 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS];
3170 if (ep->from_rtx == orig_operand[i])
3171 ep->can_eliminate = 0;
3174 /* Companion to the above plus substitution, we can allow
3175 invariants as the source of a plain move. */
3177 if (old_set && recog_data.operand_loc[i] == &SET_SRC (old_set))
3181 && (recog_data.operand_loc[i] == &XEXP (plus_src, 0)
3182 || recog_data.operand_loc[i] == &XEXP (plus_src, 1)))
3186 = eliminate_regs_1 (recog_data.operand[i], 0,
3187 replace ? insn : NULL_RTX,
3188 is_set_src || in_plus);
3189 if (substed_operand[i] != orig_operand[i])
3191 /* Terminate the search in check_eliminable_occurrences at
3193 *recog_data.operand_loc[i] = 0;
3195 /* If an output operand changed from a REG to a MEM and INSN is an
3196 insn, write a CLOBBER insn. */
3197 if (recog_data.operand_type[i] != OP_IN
3198 && REG_P (orig_operand[i])
3199 && MEM_P (substed_operand[i])
3201 emit_insn_after (gen_rtx_CLOBBER (VOIDmode, orig_operand[i]),
3206 for (i = 0; i < recog_data.n_dups; i++)
3207 *recog_data.dup_loc[i]
3208 = *recog_data.operand_loc[(int) recog_data.dup_num[i]];
3210 /* If any eliminable remain, they aren't eliminable anymore. */
3211 check_eliminable_occurrences (old_body);
3213 /* Substitute the operands; the new values are in the substed_operand
3215 for (i = 0; i < recog_data.n_operands; i++)
3216 *recog_data.operand_loc[i] = substed_operand[i];
3217 for (i = 0; i < recog_data.n_dups; i++)
3218 *recog_data.dup_loc[i] = substed_operand[(int) recog_data.dup_num[i]];
3220 /* If we are replacing a body that was a (set X (plus Y Z)), try to
3221 re-recognize the insn. We do this in case we had a simple addition
3222 but now can do this as a load-address. This saves an insn in this
3224 If re-recognition fails, the old insn code number will still be used,
3225 and some register operands may have changed into PLUS expressions.
3226 These will be handled by find_reloads by loading them into a register
3231 /* If we aren't replacing things permanently and we changed something,
3232 make another copy to ensure that all the RTL is new. Otherwise
3233 things can go wrong if find_reload swaps commutative operands
3234 and one is inside RTL that has been copied while the other is not. */
3235 new_body = old_body;
3238 new_body = copy_insn (old_body);
3239 if (REG_NOTES (insn))
3240 REG_NOTES (insn) = copy_insn_1 (REG_NOTES (insn));
3242 PATTERN (insn) = new_body;
3244 /* If we had a move insn but now we don't, rerecognize it. This will
3245 cause spurious re-recognition if the old move had a PARALLEL since
3246 the new one still will, but we can't call single_set without
3247 having put NEW_BODY into the insn and the re-recognition won't
3248 hurt in this rare case. */
3249 /* ??? Why this huge if statement - why don't we just rerecognize the
3253 && ((REG_P (SET_SRC (old_set))
3254 && (GET_CODE (new_body) != SET
3255 || !REG_P (SET_SRC (new_body))))
3256 /* If this was a load from or store to memory, compare
3257 the MEM in recog_data.operand to the one in the insn.
3258 If they are not equal, then rerecognize the insn. */
3260 && ((MEM_P (SET_SRC (old_set))
3261 && SET_SRC (old_set) != recog_data.operand[1])
3262 || (MEM_P (SET_DEST (old_set))
3263 && SET_DEST (old_set) != recog_data.operand[0])))
3264 /* If this was an add insn before, rerecognize. */
3265 || GET_CODE (SET_SRC (old_set)) == PLUS))
3267 int new_icode = recog (PATTERN (insn), insn, 0);
3269 INSN_CODE (insn) = new_icode;
3273 /* Restore the old body. If there were any changes to it, we made a copy
3274 of it while the changes were still in place, so we'll correctly return
3275 a modified insn below. */
3278 /* Restore the old body. */
3279 for (i = 0; i < recog_data.n_operands; i++)
3280 *recog_data.operand_loc[i] = orig_operand[i];
3281 for (i = 0; i < recog_data.n_dups; i++)
3282 *recog_data.dup_loc[i] = orig_operand[(int) recog_data.dup_num[i]];
3285 /* Update all elimination pairs to reflect the status after the current
3286 insn. The changes we make were determined by the earlier call to
3287 elimination_effects.
3289 We also detect cases where register elimination cannot be done,
3290 namely, if a register would be both changed and referenced outside a MEM
3291 in the resulting insn since such an insn is often undefined and, even if
3292 not, we cannot know what meaning will be given to it. Note that it is
3293 valid to have a register used in an address in an insn that changes it
3294 (presumably with a pre- or post-increment or decrement).
3296 If anything changes, return nonzero. */
3298 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3300 if (ep->previous_offset != ep->offset && ep->ref_outside_mem)
3301 ep->can_eliminate = 0;
3303 ep->ref_outside_mem = 0;
3305 if (ep->previous_offset != ep->offset)
3310 /* If we changed something, perform elimination in REG_NOTES. This is
3311 needed even when REPLACE is zero because a REG_DEAD note might refer
3312 to a register that we eliminate and could cause a different number
3313 of spill registers to be needed in the final reload pass than in
3315 if (val && REG_NOTES (insn) != 0)
3317 = eliminate_regs_1 (REG_NOTES (insn), 0, REG_NOTES (insn), true);
3322 /* Loop through all elimination pairs.
3323 Recalculate the number not at initial offset.
3325 Compute the maximum offset (minimum offset if the stack does not
3326 grow downward) for each elimination pair. */
3329 update_eliminable_offsets (void)
3331 struct elim_table *ep;
3333 num_not_at_initial_offset = 0;
3334 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3336 ep->previous_offset = ep->offset;
3337 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3338 num_not_at_initial_offset++;
3342 /* Given X, a SET or CLOBBER of DEST, if DEST is the target of a register
3343 replacement we currently believe is valid, mark it as not eliminable if X
3344 modifies DEST in any way other than by adding a constant integer to it.
3346 If DEST is the frame pointer, we do nothing because we assume that
3347 all assignments to the hard frame pointer are nonlocal gotos and are being
3348 done at a time when they are valid and do not disturb anything else.
3349 Some machines want to eliminate a fake argument pointer with either the
3350 frame or stack pointer. Assignments to the hard frame pointer must not
3351 prevent this elimination.
3353 Called via note_stores from reload before starting its passes to scan
3354 the insns of the function. */
3357 mark_not_eliminable (rtx dest, rtx x, void *data ATTRIBUTE_UNUSED)
3361 /* A SUBREG of a hard register here is just changing its mode. We should
3362 not see a SUBREG of an eliminable hard register, but check just in
3364 if (GET_CODE (dest) == SUBREG)
3365 dest = SUBREG_REG (dest);
3367 if (dest == hard_frame_pointer_rtx)
3370 for (i = 0; i < NUM_ELIMINABLE_REGS; i++)
3371 if (reg_eliminate[i].can_eliminate && dest == reg_eliminate[i].to_rtx
3372 && (GET_CODE (x) != SET
3373 || GET_CODE (SET_SRC (x)) != PLUS
3374 || XEXP (SET_SRC (x), 0) != dest
3375 || GET_CODE (XEXP (SET_SRC (x), 1)) != CONST_INT))
3377 reg_eliminate[i].can_eliminate_previous
3378 = reg_eliminate[i].can_eliminate = 0;
3383 /* Verify that the initial elimination offsets did not change since the
3384 last call to set_initial_elim_offsets. This is used to catch cases
3385 where something illegal happened during reload_as_needed that could
3386 cause incorrect code to be generated if we did not check for it. */
3389 verify_initial_elim_offsets (void)
3393 if (!num_eliminable)
3396 #ifdef ELIMINABLE_REGS
3398 struct elim_table *ep;
3400 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3402 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, t);
3403 if (t != ep->initial_offset)
3408 INITIAL_FRAME_POINTER_OFFSET (t);
3409 if (t != reg_eliminate[0].initial_offset)
3416 /* Reset all offsets on eliminable registers to their initial values. */
3419 set_initial_elim_offsets (void)
3421 struct elim_table *ep = reg_eliminate;
3423 #ifdef ELIMINABLE_REGS
3424 for (; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3426 INITIAL_ELIMINATION_OFFSET (ep->from, ep->to, ep->initial_offset);
3427 ep->previous_offset = ep->offset = ep->initial_offset;
3430 INITIAL_FRAME_POINTER_OFFSET (ep->initial_offset);
3431 ep->previous_offset = ep->offset = ep->initial_offset;
3434 num_not_at_initial_offset = 0;
3437 /* Subroutine of set_initial_label_offsets called via for_each_eh_label. */
3440 set_initial_eh_label_offset (rtx label)
3442 set_label_offsets (label, NULL_RTX, 1);
3445 /* Initialize the known label offsets.
3446 Set a known offset for each forced label to be at the initial offset
3447 of each elimination. We do this because we assume that all
3448 computed jumps occur from a location where each elimination is
3449 at its initial offset.
3450 For all other labels, show that we don't know the offsets. */
3453 set_initial_label_offsets (void)
3456 memset (offsets_known_at, 0, num_labels);
3458 for (x = forced_labels; x; x = XEXP (x, 1))
3460 set_label_offsets (XEXP (x, 0), NULL_RTX, 1);
3462 for_each_eh_label (set_initial_eh_label_offset);
3465 /* Set all elimination offsets to the known values for the code label given
3469 set_offsets_for_label (rtx insn)
3472 int label_nr = CODE_LABEL_NUMBER (insn);
3473 struct elim_table *ep;
3475 num_not_at_initial_offset = 0;
3476 for (i = 0, ep = reg_eliminate; i < NUM_ELIMINABLE_REGS; ep++, i++)
3478 ep->offset = ep->previous_offset
3479 = offsets_at[label_nr - first_label_num][i];
3480 if (ep->can_eliminate && ep->offset != ep->initial_offset)
3481 num_not_at_initial_offset++;
3485 /* See if anything that happened changes which eliminations are valid.
3486 For example, on the SPARC, whether or not the frame pointer can
3487 be eliminated can depend on what registers have been used. We need
3488 not check some conditions again (such as flag_omit_frame_pointer)
3489 since they can't have changed. */
3492 update_eliminables (HARD_REG_SET *pset)
3494 int previous_frame_pointer_needed = frame_pointer_needed;
3495 struct elim_table *ep;
3497 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3498 if ((ep->from == HARD_FRAME_POINTER_REGNUM && FRAME_POINTER_REQUIRED)
3499 #ifdef ELIMINABLE_REGS
3500 || ! CAN_ELIMINATE (ep->from, ep->to)
3503 ep->can_eliminate = 0;
3505 /* Look for the case where we have discovered that we can't replace
3506 register A with register B and that means that we will now be
3507 trying to replace register A with register C. This means we can
3508 no longer replace register C with register B and we need to disable
3509 such an elimination, if it exists. This occurs often with A == ap,
3510 B == sp, and C == fp. */
3512 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3514 struct elim_table *op;
3517 if (! ep->can_eliminate && ep->can_eliminate_previous)
3519 /* Find the current elimination for ep->from, if there is a
3521 for (op = reg_eliminate;
3522 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3523 if (op->from == ep->from && op->can_eliminate)
3529 /* See if there is an elimination of NEW_TO -> EP->TO. If so,
3531 for (op = reg_eliminate;
3532 op < ®_eliminate[NUM_ELIMINABLE_REGS]; op++)
3533 if (op->from == new_to && op->to == ep->to)
3534 op->can_eliminate = 0;
3538 /* See if any registers that we thought we could eliminate the previous
3539 time are no longer eliminable. If so, something has changed and we
3540 must spill the register. Also, recompute the number of eliminable
3541 registers and see if the frame pointer is needed; it is if there is
3542 no elimination of the frame pointer that we can perform. */
3544 frame_pointer_needed = 1;
3545 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3547 if (ep->can_eliminate && ep->from == FRAME_POINTER_REGNUM
3548 && ep->to != HARD_FRAME_POINTER_REGNUM)
3549 frame_pointer_needed = 0;
3551 if (! ep->can_eliminate && ep->can_eliminate_previous)
3553 ep->can_eliminate_previous = 0;
3554 SET_HARD_REG_BIT (*pset, ep->from);
3559 /* If we didn't need a frame pointer last time, but we do now, spill
3560 the hard frame pointer. */
3561 if (frame_pointer_needed && ! previous_frame_pointer_needed)
3562 SET_HARD_REG_BIT (*pset, HARD_FRAME_POINTER_REGNUM);
3565 /* Initialize the table of registers to eliminate. */
3568 init_elim_table (void)
3570 struct elim_table *ep;
3571 #ifdef ELIMINABLE_REGS
3572 const struct elim_table_1 *ep1;
3576 reg_eliminate = xcalloc (sizeof (struct elim_table), NUM_ELIMINABLE_REGS);
3578 /* Does this function require a frame pointer? */
3580 frame_pointer_needed = (! flag_omit_frame_pointer
3581 /* ?? If EXIT_IGNORE_STACK is set, we will not save
3582 and restore sp for alloca. So we can't eliminate
3583 the frame pointer in that case. At some point,
3584 we should improve this by emitting the
3585 sp-adjusting insns for this case. */
3586 || (current_function_calls_alloca
3587 && EXIT_IGNORE_STACK)
3588 || current_function_accesses_prior_frames
3589 || FRAME_POINTER_REQUIRED);
3593 #ifdef ELIMINABLE_REGS
3594 for (ep = reg_eliminate, ep1 = reg_eliminate_1;
3595 ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++, ep1++)
3597 ep->from = ep1->from;
3599 ep->can_eliminate = ep->can_eliminate_previous
3600 = (CAN_ELIMINATE (ep->from, ep->to)
3601 && ! (ep->to == STACK_POINTER_REGNUM && frame_pointer_needed));
3604 reg_eliminate[0].from = reg_eliminate_1[0].from;
3605 reg_eliminate[0].to = reg_eliminate_1[0].to;
3606 reg_eliminate[0].can_eliminate = reg_eliminate[0].can_eliminate_previous
3607 = ! frame_pointer_needed;
3610 /* Count the number of eliminable registers and build the FROM and TO
3611 REG rtx's. Note that code in gen_rtx_REG will cause, e.g.,
3612 gen_rtx_REG (Pmode, STACK_POINTER_REGNUM) to equal stack_pointer_rtx.
3613 We depend on this. */
3614 for (ep = reg_eliminate; ep < ®_eliminate[NUM_ELIMINABLE_REGS]; ep++)
3616 num_eliminable += ep->can_eliminate;
3617 ep->from_rtx = gen_rtx_REG (Pmode, ep->from);
3618 ep->to_rtx = gen_rtx_REG (Pmode, ep->to);
3622 /* Kick all pseudos out of hard register REGNO.
3624 If CANT_ELIMINATE is nonzero, it means that we are doing this spill
3625 because we found we can't eliminate some register. In the case, no pseudos
3626 are allowed to be in the register, even if they are only in a block that
3627 doesn't require spill registers, unlike the case when we are spilling this
3628 hard reg to produce another spill register.
3630 Return nonzero if any pseudos needed to be kicked out. */
3633 spill_hard_reg (unsigned int regno, int cant_eliminate)
3639 SET_HARD_REG_BIT (bad_spill_regs_global, regno);
3640 regs_ever_live[regno] = 1;
3643 /* Spill every pseudo reg that was allocated to this reg
3644 or to something that overlaps this reg. */
3646 for (i = FIRST_PSEUDO_REGISTER; i < max_regno; i++)
3647 if (reg_renumber[i] >= 0
3648 && (unsigned int) reg_renumber[i] <= regno
3649 && ((unsigned int) reg_renumber[i]
3650 + hard_regno_nregs[(unsigned int) reg_renumber[i]]
3651 [PSEUDO_REGNO_MODE (i)]
3653 SET_REGNO_REG_SET (&spilled_pseudos, i);
3656 /* After find_reload_regs has been run for all insn that need reloads,
3657 and/or spill_hard_regs was called, this function is used to actually
3658 spill pseudo registers and try to reallocate them. It also sets up the
3659 spill_regs array for use by choose_reload_regs. */
3662 finish_spills (int global)
3664 struct insn_chain *chain;
3665 int something_changed = 0;
3667 reg_set_iterator rsi;
3669 /* Build the spill_regs array for the function. */
3670 /* If there are some registers still to eliminate and one of the spill regs
3671 wasn't ever used before, additional stack space may have to be
3672 allocated to store this register. Thus, we may have changed the offset
3673 between the stack and frame pointers, so mark that something has changed.
3675 One might think that we need only set VAL to 1 if this is a call-used
3676 register. However, the set of registers that must be saved by the
3677 prologue is not identical to the call-used set. For example, the
3678 register used by the call insn for the return PC is a call-used register,
3679 but must be saved by the prologue. */
3682 for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3683 if (TEST_HARD_REG_BIT (used_spill_regs, i))
3685 spill_reg_order[i] = n_spills;
3686 spill_regs[n_spills++] = i;
3687 if (num_eliminable && ! regs_ever_live[i])
3688 something_changed = 1;
3689 regs_ever_live[i] = 1;
3692 spill_reg_order[i] = -1;
3694 EXECUTE_IF_SET_IN_REG_SET (&spilled_pseudos, FIRST_PSEUDO_REGISTER, i, rsi)
3696 /* Record the current hard register the pseudo is allocated to in
3697 pseudo_previous_regs so we avoid reallocating it to the same
3698 hard reg in a later pass. */
3699 gcc_assert (reg_renumber[i] >= 0);
3701 SET_HARD_REG_BIT (pseudo_previous_regs[i], reg_renumber[i]);
3702 /* Mark it as no longer having a hard register home. */
3703 reg_renumber[i] = -1;
3704 /* We will need to scan everything again. */
3705 something_changed = 1;
3708 /* Retry global register allocation if possible. */
3711 memset (pseudo_forbidden_regs, 0, max_regno * sizeof (HARD_REG_SET));
3712 /* For every insn that needs reloads, set the registers used as spill
3713 regs in pseudo_forbidden_regs for every pseudo live across the
3715 for (chain = insns_need_reload; chain; chain = chain->next_need_reload)
3717 EXECUTE_IF_SET_IN_REG_SET
3718 (&chain->live_throughout, FIRST_PSEUDO_REGISTER, i, rsi)
3720 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3721 chain->used_spill_regs);
3723 EXECUTE_IF_SET_IN_REG_SET
3724 (&chain->dead_or_set, FIRST_PSEUDO_REGISTER, i, rsi)
3726 IOR_HARD_REG_SET (pseudo_forbidden_regs[i],
3727 chain->used_spill_regs);
3731 /* Retry allocating the spilled pseudos. For each reg, merge the
3732 various reg sets that indicate which hard regs can't be used,
3733 and call retry_global_alloc.
3734 We change spill_pseudos here to only contain pseudos that did not
3735 get a new hard register. */
3736 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3737 if (reg_old_renumber[i] != reg_renumber[i])
3739 HARD_REG_SET forbidden;
3740 COPY_HARD_REG_SET (forbidden, bad_spill_regs_global);
3741 IOR_HARD_REG_SET (forbidden, pseudo_forbidden_regs[i]);
3742 IOR_HARD_REG_SET (forbidden, pseudo_previous_regs[i]);
3743 retry_global_alloc (i, forbidden);
3744 if (reg_renumber[i] >= 0)
3745 CLEAR_REGNO_REG_SET (&spilled_pseudos, i);
3749 /* Fix up the register information in the insn chain.
3750 This involves deleting those of the spilled pseudos which did not get
3751 a new hard register home from the live_{before,after} sets. */
3752 for (chain = reload_insn_chain; chain; chain = chain->next)
3754 HARD_REG_SET used_by_pseudos;
3755 HARD_REG_SET used_by_pseudos2;
3757 AND_COMPL_REG_SET (&chain->live_throughout, &spilled_pseudos);
3758 AND_COMPL_REG_SET (&chain->dead_or_set, &spilled_pseudos);
3760 /* Mark any unallocated hard regs as available for spills. That
3761 makes inheritance work somewhat better. */
3762 if (chain->need_reload)
3764 REG_SET_TO_HARD_REG_SET (used_by_pseudos, &chain->live_throughout);
3765 REG_SET_TO_HARD_REG_SET (used_by_pseudos2, &chain->dead_or_set);
3766 IOR_HARD_REG_SET (used_by_pseudos, used_by_pseudos2);
3768 /* Save the old value for the sanity test below. */
3769 COPY_HARD_REG_SET (used_by_pseudos2, chain->used_spill_regs);
3771 compute_use_by_pseudos (&used_by_pseudos, &chain->live_throughout);
3772 compute_use_by_pseudos (&used_by_pseudos, &chain->dead_or_set);
3773 COMPL_HARD_REG_SET (chain->used_spill_regs, used_by_pseudos);
3774 AND_HARD_REG_SET (chain->used_spill_regs, used_spill_regs);
3776 /* Make sure we only enlarge the set. */
3777 GO_IF_HARD_REG_SUBSET (used_by_pseudos2, chain->used_spill_regs, ok);
3783 /* Let alter_reg modify the reg rtx's for the modified pseudos. */
3784 for (i = FIRST_PSEUDO_REGISTER; i < (unsigned)max_regno; i++)
3786 int regno = reg_renumber[i];
3787 if (reg_old_renumber[i] == regno)
3790 alter_reg (i, reg_old_renumber[i]);
3791 reg_old_renumber[i] = regno;
3795 fprintf (dump_file, " Register %d now on stack.\n\n", i);
3797 fprintf (dump_file, " Register %d now in %d.\n\n",
3798 i, reg_renumber[i]);
3802 return something_changed;
3805 /* Find all paradoxical subregs within X and update reg_max_ref_width. */
3808 scan_paradoxical_subregs (rtx x)
3812 enum rtx_code code = GET_CODE (x);
3822 case CONST_VECTOR: /* shouldn't happen, but just in case. */
3830 if (REG_P (SUBREG_REG (x))
3831 && (GET_MODE_SIZE (GET_MODE (x))
3832 > reg_max_ref_width[REGNO (SUBREG_REG (x))]))
3833 reg_max_ref_width[REGNO (SUBREG_REG (x))]
3834 = GET_MODE_SIZE (GET_MODE (x));
3841 fmt = GET_RTX_FORMAT (code);
3842 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3845 scan_paradoxical_subregs (XEXP (x, i));
3846 else if (fmt[i] == 'E')
3849 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
3850 scan_paradoxical_subregs (XVECEXP (x, i, j));
3855 /* A subroutine of reload_as_needed. If INSN has a REG_EH_REGION note,
3856 examine all of the reload insns between PREV and NEXT exclusive, and
3857 annotate all that may trap. */
3860 fixup_eh_region_note (rtx insn, rtx prev, rtx next)
3862 rtx note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
3863 unsigned int trap_count;
3869 if (may_trap_p (PATTERN (insn)))
3873 remove_note (insn, note);
3877 for (i = NEXT_INSN (prev); i != next; i = NEXT_INSN (i))
3878 if (INSN_P (i) && i != insn && may_trap_p (PATTERN (i)))
3882 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (note, 0), REG_NOTES (i));
3886 /* Reload pseudo-registers into hard regs around each insn as needed.
3887 Additional register load insns are output before the insn that needs it
3888 and perhaps store insns after insns that modify the reloaded pseudo reg.
3890 reg_last_reload_reg and reg_reloaded_contents keep track of
3891 which registers are already available in reload registers.
3892 We update these for the reloads that we perform,
3893 as the insns are scanned. */
3896 reload_as_needed (int live_known)
3898 struct insn_chain *chain;
3899 #if defined (AUTO_INC_DEC)
3904 memset (spill_reg_rtx, 0, sizeof spill_reg_rtx);
3905 memset (spill_reg_store, 0, sizeof spill_reg_store);
3906 reg_last_reload_reg = XCNEWVEC (rtx, max_regno);
3907 INIT_REG_SET (®_has_output_reload);
3908 CLEAR_HARD_REG_SET (reg_reloaded_valid);
3909 CLEAR_HARD_REG_SET (reg_reloaded_call_part_clobbered);
3911 set_initial_elim_offsets ();
3913 for (chain = reload_insn_chain; chain; chain = chain->next)
3916 rtx insn = chain->insn;
3917 rtx old_next = NEXT_INSN (insn);
3919 /* If we pass a label, copy the offsets from the label information
3920 into the current offsets of each elimination. */
3922 set_offsets_for_label (insn);
3924 else if (INSN_P (insn))
3926 regset_head regs_to_forget;
3927 INIT_REG_SET (®s_to_forget);
3928 note_stores (PATTERN (insn), forget_old_reloads_1, ®s_to_forget);
3930 /* If this is a USE and CLOBBER of a MEM, ensure that any
3931 references to eliminable registers have been removed. */
3933 if ((GET_CODE (PATTERN (insn)) == USE
3934 || GET_CODE (PATTERN (insn)) == CLOBBER)
3935 && MEM_P (XEXP (PATTERN (insn), 0)))
3936 XEXP (XEXP (PATTERN (insn), 0), 0)
3937 = eliminate_regs (XEXP (XEXP (PATTERN (insn), 0), 0),
3938 GET_MODE (XEXP (PATTERN (insn), 0)),
3941 /* If we need to do register elimination processing, do so.
3942 This might delete the insn, in which case we are done. */
3943 if ((num_eliminable || num_eliminable_invariants) && chain->need_elim)
3945 eliminate_regs_in_insn (insn, 1);
3948 update_eliminable_offsets ();
3949 CLEAR_REG_SET (®s_to_forget);
3954 /* If need_elim is nonzero but need_reload is zero, one might think
3955 that we could simply set n_reloads to 0. However, find_reloads
3956 could have done some manipulation of the insn (such as swapping
3957 commutative operands), and these manipulations are lost during
3958 the first pass for every insn that needs register elimination.
3959 So the actions of find_reloads must be redone here. */
3961 if (! chain->need_elim && ! chain->need_reload
3962 && ! chain->need_operand_change)
3964 /* First find the pseudo regs that must be reloaded for this insn.
3965 This info is returned in the tables reload_... (see reload.h).
3966 Also modify the body of INSN by substituting RELOAD
3967 rtx's for those pseudo regs. */
3970 CLEAR_REG_SET (®_has_output_reload);
3971 CLEAR_HARD_REG_SET (reg_is_output_reload);
3973 find_reloads (insn, 1, spill_indirect_levels, live_known,
3979 rtx next = NEXT_INSN (insn);
3982 prev = PREV_INSN (insn);
3984 /* Now compute which reload regs to reload them into. Perhaps
3985 reusing reload regs from previous insns, or else output
3986 load insns to reload them. Maybe output store insns too.
3987 Record the choices of reload reg in reload_reg_rtx. */
3988 choose_reload_regs (chain);
3990 /* Merge any reloads that we didn't combine for fear of
3991 increasing the number of spill registers needed but now
3992 discover can be safely merged. */
3993 if (SMALL_REGISTER_CLASSES)
3994 merge_assigned_reloads (insn);
3996 /* Generate the insns to reload operands into or out of
3997 their reload regs. */
3998 emit_reload_insns (chain);
4000 /* Substitute the chosen reload regs from reload_reg_rtx
4001 into the insn's body (or perhaps into the bodies of other
4002 load and store insn that we just made for reloading
4003 and that we moved the structure into). */
4004 subst_reloads (insn);
4006 /* Adjust the exception region notes for loads and stores. */
4007 if (flag_non_call_exceptions && !CALL_P (insn))
4008 fixup_eh_region_note (insn, prev, next);
4010 /* If this was an ASM, make sure that all the reload insns
4011 we have generated are valid. If not, give an error
4013 if (asm_noperands (PATTERN (insn)) >= 0)
4014 for (p = NEXT_INSN (prev); p != next; p = NEXT_INSN (p))
4015 if (p != insn && INSN_P (p)
4016 && GET_CODE (PATTERN (p)) != USE
4017 && (recog_memoized (p) < 0
4018 || (extract_insn (p), ! constrain_operands (1))))
4020 error_for_asm (insn,
4021 "%<asm%> operand requires "
4022 "impossible reload");
4027 if (num_eliminable && chain->need_elim)
4028 update_eliminable_offsets ();
4030 /* Any previously reloaded spilled pseudo reg, stored in this insn,
4031 is no longer validly lying around to save a future reload.
4032 Note that this does not detect pseudos that were reloaded
4033 for this insn in order to be stored in
4034 (obeying register constraints). That is correct; such reload
4035 registers ARE still valid. */
4036 forget_marked_reloads (®s_to_forget);
4037 CLEAR_REG_SET (®s_to_forget);
4039 /* There may have been CLOBBER insns placed after INSN. So scan
4040 between INSN and NEXT and use them to forget old reloads. */
4041 for (x = NEXT_INSN (insn); x != old_next; x = NEXT_INSN (x))
4042 if (NONJUMP_INSN_P (x) && GET_CODE (PATTERN (x)) == CLOBBER)
4043 note_stores (PATTERN (x), forget_old_reloads_1, NULL);
4046 /* Likewise for regs altered by auto-increment in this insn.
4047 REG_INC notes have been changed by reloading:
4048 find_reloads_address_1 records substitutions for them,
4049 which have been performed by subst_reloads above. */
4050 for (i = n_reloads - 1; i >= 0; i--)
4052 rtx in_reg = rld[i].in_reg;
4055 enum rtx_code code = GET_CODE (in_reg);
4056 /* PRE_INC / PRE_DEC will have the reload register ending up
4057 with the same value as the stack slot, but that doesn't
4058 hold true for POST_INC / POST_DEC. Either we have to
4059 convert the memory access to a true POST_INC / POST_DEC,
4060 or we can't use the reload register for inheritance. */
4061 if ((code == POST_INC || code == POST_DEC)
4062 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4063 REGNO (rld[i].reg_rtx))
4064 /* Make sure it is the inc/dec pseudo, and not
4065 some other (e.g. output operand) pseudo. */
4066 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4067 == REGNO (XEXP (in_reg, 0))))
4070 rtx reload_reg = rld[i].reg_rtx;
4071 enum machine_mode mode = GET_MODE (reload_reg);
4075 for (p = PREV_INSN (old_next); p != prev; p = PREV_INSN (p))
4077 /* We really want to ignore REG_INC notes here, so
4078 use PATTERN (p) as argument to reg_set_p . */
4079 if (reg_set_p (reload_reg, PATTERN (p)))
4081 n = count_occurrences (PATTERN (p), reload_reg, 0);
4086 n = validate_replace_rtx (reload_reg,
4087 gen_rtx_fmt_e (code,
4092 /* We must also verify that the constraints
4093 are met after the replacement. */
4096 n = constrain_operands (1);
4100 /* If the constraints were not met, then
4101 undo the replacement. */
4104 validate_replace_rtx (gen_rtx_fmt_e (code,
4117 = gen_rtx_EXPR_LIST (REG_INC, reload_reg,
4119 /* Mark this as having an output reload so that the
4120 REG_INC processing code below won't invalidate
4121 the reload for inheritance. */
4122 SET_HARD_REG_BIT (reg_is_output_reload,
4123 REGNO (reload_reg));
4124 SET_REGNO_REG_SET (®_has_output_reload,
4125 REGNO (XEXP (in_reg, 0)));
4128 forget_old_reloads_1 (XEXP (in_reg, 0), NULL_RTX,
4131 else if ((code == PRE_INC || code == PRE_DEC)
4132 && TEST_HARD_REG_BIT (reg_reloaded_valid,
4133 REGNO (rld[i].reg_rtx))
4134 /* Make sure it is the inc/dec pseudo, and not
4135 some other (e.g. output operand) pseudo. */
4136 && ((unsigned) reg_reloaded_contents[REGNO (rld[i].reg_rtx)]
4137 == REGNO (XEXP (in_reg, 0))))
4139 SET_HARD_REG_BIT (reg_is_output_reload,
4140 REGNO (rld[i].reg_rtx));
4141 SET_REGNO_REG_SET (®_has_output_reload,
4142 REGNO (XEXP (in_reg, 0)));
4146 /* If a pseudo that got a hard register is auto-incremented,
4147 we must purge records of copying it into pseudos without
4149 for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
4150 if (REG_NOTE_KIND (x) == REG_INC)
4152 /* See if this pseudo reg was reloaded in this insn.
4153 If so, its last-reload info is still valid
4154 because it is based on this insn's reload. */
4155 for (i = 0; i < n_reloads; i++)
4156 if (rld[i].out == XEXP (x, 0))
4160 forget_old_reloads_1 (XEXP (x, 0), NULL_RTX, NULL);
4164 /* A reload reg's contents are unknown after a label. */
4166 CLEAR_HARD_REG_SET (reg_reloaded_valid);
4168 /* Don't assume a reload reg is still good after a call insn
4169 if it is a call-used reg, or if it contains a value that will
4170 be partially clobbered by the call. */
4171 else if (CALL_P (insn))
4173 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, call_used_reg_set);
4174 AND_COMPL_HARD_REG_SET (reg_reloaded_valid, reg_reloaded_call_part_clobbered);
4179 free (reg_last_reload_reg);
4180 CLEAR_REG_SET (®_has_output_reload);
4183 /* Discard all record of any value reloaded from X,
4184 or reloaded in X from someplace else;
4185 unless X is an output reload reg of the current insn.
4187 X may be a hard reg (the reload reg)
4188 or it may be a pseudo reg that was reloaded from.
4190 When DATA is non-NULL just mark the registers in regset
4191 to be forgotten later. */
4194 forget_old_reloads_1 (rtx x, rtx ignored ATTRIBUTE_UNUSED,
4199 regset regs = (regset) data;
4201 /* note_stores does give us subregs of hard regs,
4202 subreg_regno_offset requires a hard reg. */
4203 while (GET_CODE (x) == SUBREG)
4205 /* We ignore the subreg offset when calculating the regno,
4206 because we are using the entire underlying hard register
4216 if (regno >= FIRST_PSEUDO_REGISTER)
4222 nr = hard_regno_nregs[regno][GET_MODE (x)];
4223 /* Storing into a spilled-reg invalidates its contents.
4224 This can happen if a block-local pseudo is allocated to that reg
4225 and it wasn't spilled because this block's total need is 0.
4226 Then some insn might have an optional reload and use this reg. */
4228 for (i = 0; i < nr; i++)
4229 /* But don't do this if the reg actually serves as an output
4230 reload reg in the current instruction. */
4232 || ! TEST_HARD_REG_BIT (reg_is_output_reload, regno + i))
4234 CLEAR_HARD_REG_BIT (reg_reloaded_valid, regno + i);
4235 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, regno + i);
4236 spill_reg_store[regno + i] = 0;
4242 SET_REGNO_REG_SET (regs, regno + nr);
4245 /* Since value of X has changed,
4246 forget any value previously copied from it. */
4249 /* But don't forget a copy if this is the output reload
4250 that establishes the copy's validity. */
4252 || !REGNO_REG_SET_P (®_has_output_reload, regno + nr))
4253 reg_last_reload_reg[regno + nr] = 0;
4257 /* Forget the reloads marked in regset by previous function. */
4259 forget_marked_reloads (regset regs)
4262 reg_set_iterator rsi;
4263 EXECUTE_IF_SET_IN_REG_SET (regs, 0, reg, rsi)
4265 if (reg < FIRST_PSEUDO_REGISTER
4266 /* But don't do this if the reg actually serves as an output
4267 reload reg in the current instruction. */
4269 || ! TEST_HARD_REG_BIT (reg_is_output_reload, reg)))
4271 CLEAR_HARD_REG_BIT (reg_reloaded_valid, reg);
4272 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, reg);
4273 spill_reg_store[reg] = 0;
4276 || !REGNO_REG_SET_P (®_has_output_reload, reg))
4277 reg_last_reload_reg[reg] = 0;
4281 /* The following HARD_REG_SETs indicate when each hard register is
4282 used for a reload of various parts of the current insn. */
4284 /* If reg is unavailable for all reloads. */
4285 static HARD_REG_SET reload_reg_unavailable;
4286 /* If reg is in use as a reload reg for a RELOAD_OTHER reload. */
4287 static HARD_REG_SET reload_reg_used;
4288 /* If reg is in use for a RELOAD_FOR_INPUT_ADDRESS reload for operand I. */
4289 static HARD_REG_SET reload_reg_used_in_input_addr[MAX_RECOG_OPERANDS];
4290 /* If reg is in use for a RELOAD_FOR_INPADDR_ADDRESS reload for operand I. */
4291 static HARD_REG_SET reload_reg_used_in_inpaddr_addr[MAX_RECOG_OPERANDS];
4292 /* If reg is in use for a RELOAD_FOR_OUTPUT_ADDRESS reload for operand I. */
4293 static HARD_REG_SET reload_reg_used_in_output_addr[MAX_RECOG_OPERANDS];
4294 /* If reg is in use for a RELOAD_FOR_OUTADDR_ADDRESS reload for operand I. */
4295 static HARD_REG_SET reload_reg_used_in_outaddr_addr[MAX_RECOG_OPERANDS];
4296 /* If reg is in use for a RELOAD_FOR_INPUT reload for operand I. */
4297 static HARD_REG_SET reload_reg_used_in_input[MAX_RECOG_OPERANDS];
4298 /* If reg is in use for a RELOAD_FOR_OUTPUT reload for operand I. */
4299 static HARD_REG_SET reload_reg_used_in_output[MAX_RECOG_OPERANDS];
4300 /* If reg is in use for a RELOAD_FOR_OPERAND_ADDRESS reload. */
4301 static HARD_REG_SET reload_reg_used_in_op_addr;
4302 /* If reg is in use for a RELOAD_FOR_OPADDR_ADDR reload. */
4303 static HARD_REG_SET reload_reg_used_in_op_addr_reload;
4304 /* If reg is in use for a RELOAD_FOR_INSN reload. */
4305 static HARD_REG_SET reload_reg_used_in_insn;
4306 /* If reg is in use for a RELOAD_FOR_OTHER_ADDRESS reload. */
4307 static HARD_REG_SET reload_reg_used_in_other_addr;
4309 /* If reg is in use as a reload reg for any sort of reload. */
4310 static HARD_REG_SET reload_reg_used_at_all;
4312 /* If reg is use as an inherited reload. We just mark the first register
4314 static HARD_REG_SET reload_reg_used_for_inherit;
4316 /* Records which hard regs are used in any way, either as explicit use or
4317 by being allocated to a pseudo during any point of the current insn. */
4318 static HARD_REG_SET reg_used_in_insn;
4320 /* Mark reg REGNO as in use for a reload of the sort spec'd by OPNUM and
4321 TYPE. MODE is used to indicate how many consecutive regs are
4325 mark_reload_reg_in_use (unsigned int regno, int opnum, enum reload_type type,
4326 enum machine_mode mode)
4328 unsigned int nregs = hard_regno_nregs[regno][mode];
4331 for (i = regno; i < nregs + regno; i++)
4336 SET_HARD_REG_BIT (reload_reg_used, i);
4339 case RELOAD_FOR_INPUT_ADDRESS:
4340 SET_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], i);
4343 case RELOAD_FOR_INPADDR_ADDRESS:
4344 SET_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], i);
4347 case RELOAD_FOR_OUTPUT_ADDRESS:
4348 SET_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], i);
4351 case RELOAD_FOR_OUTADDR_ADDRESS:
4352 SET_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], i);
4355 case RELOAD_FOR_OPERAND_ADDRESS:
4356 SET_HARD_REG_BIT (reload_reg_used_in_op_addr, i);
4359 case RELOAD_FOR_OPADDR_ADDR:
4360 SET_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, i);
4363 case RELOAD_FOR_OTHER_ADDRESS:
4364 SET_HARD_REG_BIT (reload_reg_used_in_other_addr, i);
4367 case RELOAD_FOR_INPUT:
4368 SET_HARD_REG_BIT (reload_reg_used_in_input[opnum], i);
4371 case RELOAD_FOR_OUTPUT:
4372 SET_HARD_REG_BIT (reload_reg_used_in_output[opnum], i);
4375 case RELOAD_FOR_INSN:
4376 SET_HARD_REG_BIT (reload_reg_used_in_insn, i);
4380 SET_HARD_REG_BIT (reload_reg_used_at_all, i);
4384 /* Similarly, but show REGNO is no longer in use for a reload. */
4387 clear_reload_reg_in_use (unsigned int regno, int opnum,
4388 enum reload_type type, enum machine_mode mode)
4390 unsigned int nregs = hard_regno_nregs[regno][mode];
4391 unsigned int start_regno, end_regno, r;
4393 /* A complication is that for some reload types, inheritance might
4394 allow multiple reloads of the same types to share a reload register.
4395 We set check_opnum if we have to check only reloads with the same
4396 operand number, and check_any if we have to check all reloads. */
4397 int check_opnum = 0;
4399 HARD_REG_SET *used_in_set;
4404 used_in_set = &reload_reg_used;
4407 case RELOAD_FOR_INPUT_ADDRESS:
4408 used_in_set = &reload_reg_used_in_input_addr[opnum];
4411 case RELOAD_FOR_INPADDR_ADDRESS:
4413 used_in_set = &reload_reg_used_in_inpaddr_addr[opnum];
4416 case RELOAD_FOR_OUTPUT_ADDRESS:
4417 used_in_set = &reload_reg_used_in_output_addr[opnum];
4420 case RELOAD_FOR_OUTADDR_ADDRESS:
4422 used_in_set = &reload_reg_used_in_outaddr_addr[opnum];
4425 case RELOAD_FOR_OPERAND_ADDRESS:
4426 used_in_set = &reload_reg_used_in_op_addr;
4429 case RELOAD_FOR_OPADDR_ADDR:
4431 used_in_set = &reload_reg_used_in_op_addr_reload;
4434 case RELOAD_FOR_OTHER_ADDRESS:
4435 used_in_set = &reload_reg_used_in_other_addr;
4439 case RELOAD_FOR_INPUT:
4440 used_in_set = &reload_reg_used_in_input[opnum];
4443 case RELOAD_FOR_OUTPUT:
4444 used_in_set = &reload_reg_used_in_output[opnum];
4447 case RELOAD_FOR_INSN:
4448 used_in_set = &reload_reg_used_in_insn;
4453 /* We resolve conflicts with remaining reloads of the same type by
4454 excluding the intervals of reload registers by them from the
4455 interval of freed reload registers. Since we only keep track of
4456 one set of interval bounds, we might have to exclude somewhat
4457 more than what would be necessary if we used a HARD_REG_SET here.
4458 But this should only happen very infrequently, so there should
4459 be no reason to worry about it. */
4461 start_regno = regno;
4462 end_regno = regno + nregs;
4463 if (check_opnum || check_any)
4465 for (i = n_reloads - 1; i >= 0; i--)
4467 if (rld[i].when_needed == type
4468 && (check_any || rld[i].opnum == opnum)
4471 unsigned int conflict_start = true_regnum (rld[i].reg_rtx);
4472 unsigned int conflict_end
4474 + hard_regno_nregs[conflict_start][rld[i].mode]);
4476 /* If there is an overlap with the first to-be-freed register,
4477 adjust the interval start. */
4478 if (conflict_start <= start_regno && conflict_end > start_regno)
4479 start_regno = conflict_end;
4480 /* Otherwise, if there is a conflict with one of the other
4481 to-be-freed registers, adjust the interval end. */
4482 if (conflict_start > start_regno && conflict_start < end_regno)
4483 end_regno = conflict_start;
4488 for (r = start_regno; r < end_regno; r++)
4489 CLEAR_HARD_REG_BIT (*used_in_set, r);
4492 /* 1 if reg REGNO is free as a reload reg for a reload of the sort
4493 specified by OPNUM and TYPE. */
4496 reload_reg_free_p (unsigned int regno, int opnum, enum reload_type type)
4500 /* In use for a RELOAD_OTHER means it's not available for anything. */
4501 if (TEST_HARD_REG_BIT (reload_reg_used, regno)
4502 || TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4508 /* In use for anything means we can't use it for RELOAD_OTHER. */
4509 if (TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno)
4510 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4511 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4512 || TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4515 for (i = 0; i < reload_n_operands; i++)
4516 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4517 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4518 || TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4519 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4520 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4521 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4526 case RELOAD_FOR_INPUT:
4527 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4528 || TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno))
4531 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4534 /* If it is used for some other input, can't use it. */
4535 for (i = 0; i < reload_n_operands; i++)
4536 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4539 /* If it is used in a later operand's address, can't use it. */
4540 for (i = opnum + 1; i < reload_n_operands; i++)
4541 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4542 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4547 case RELOAD_FOR_INPUT_ADDRESS:
4548 /* Can't use a register if it is used for an input address for this
4549 operand or used as an input in an earlier one. */
4550 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[opnum], regno)
4551 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4554 for (i = 0; i < opnum; i++)
4555 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4560 case RELOAD_FOR_INPADDR_ADDRESS:
4561 /* Can't use a register if it is used for an input address
4562 for this operand or used as an input in an earlier
4564 if (TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[opnum], regno))
4567 for (i = 0; i < opnum; i++)
4568 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4573 case RELOAD_FOR_OUTPUT_ADDRESS:
4574 /* Can't use a register if it is used for an output address for this
4575 operand or used as an output in this or a later operand. Note
4576 that multiple output operands are emitted in reverse order, so
4577 the conflicting ones are those with lower indices. */
4578 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[opnum], regno))
4581 for (i = 0; i <= opnum; i++)
4582 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4587 case RELOAD_FOR_OUTADDR_ADDRESS:
4588 /* Can't use a register if it is used for an output address
4589 for this operand or used as an output in this or a
4590 later operand. Note that multiple output operands are
4591 emitted in reverse order, so the conflicting ones are
4592 those with lower indices. */
4593 if (TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[opnum], regno))
4596 for (i = 0; i <= opnum; i++)
4597 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4602 case RELOAD_FOR_OPERAND_ADDRESS:
4603 for (i = 0; i < reload_n_operands; i++)
4604 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4607 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4608 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4610 case RELOAD_FOR_OPADDR_ADDR:
4611 for (i = 0; i < reload_n_operands; i++)
4612 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4615 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno));
4617 case RELOAD_FOR_OUTPUT:
4618 /* This cannot share a register with RELOAD_FOR_INSN reloads, other
4619 outputs, or an operand address for this or an earlier output.
4620 Note that multiple output operands are emitted in reverse order,
4621 so the conflicting ones are those with higher indices. */
4622 if (TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno))
4625 for (i = 0; i < reload_n_operands; i++)
4626 if (TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4629 for (i = opnum; i < reload_n_operands; i++)
4630 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4631 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4636 case RELOAD_FOR_INSN:
4637 for (i = 0; i < reload_n_operands; i++)
4638 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno)
4639 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4642 return (! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4643 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno));
4645 case RELOAD_FOR_OTHER_ADDRESS:
4646 return ! TEST_HARD_REG_BIT (reload_reg_used_in_other_addr, regno);
4653 /* Return 1 if the value in reload reg REGNO, as used by a reload
4654 needed for the part of the insn specified by OPNUM and TYPE,
4655 is still available in REGNO at the end of the insn.
4657 We can assume that the reload reg was already tested for availability
4658 at the time it is needed, and we should not check this again,
4659 in case the reg has already been marked in use. */
4662 reload_reg_reaches_end_p (unsigned int regno, int opnum, enum reload_type type)
4669 /* Since a RELOAD_OTHER reload claims the reg for the entire insn,
4670 its value must reach the end. */
4673 /* If this use is for part of the insn,
4674 its value reaches if no subsequent part uses the same register.
4675 Just like the above function, don't try to do this with lots
4678 case RELOAD_FOR_OTHER_ADDRESS:
4679 /* Here we check for everything else, since these don't conflict
4680 with anything else and everything comes later. */
4682 for (i = 0; i < reload_n_operands; i++)
4683 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4684 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4685 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno)
4686 || TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4687 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4688 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4691 return (! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4692 && ! TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno)
4693 && ! TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4694 && ! TEST_HARD_REG_BIT (reload_reg_used, regno));
4696 case RELOAD_FOR_INPUT_ADDRESS:
4697 case RELOAD_FOR_INPADDR_ADDRESS:
4698 /* Similar, except that we check only for this and subsequent inputs
4699 and the address of only subsequent inputs and we do not need
4700 to check for RELOAD_OTHER objects since they are known not to
4703 for (i = opnum; i < reload_n_operands; i++)
4704 if (TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4707 for (i = opnum + 1; i < reload_n_operands; i++)
4708 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4709 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno))
4712 for (i = 0; i < reload_n_operands; i++)
4713 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4714 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4715 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4718 if (TEST_HARD_REG_BIT (reload_reg_used_in_op_addr_reload, regno))
4721 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4722 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4723 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4725 case RELOAD_FOR_INPUT:
4726 /* Similar to input address, except we start at the next operand for
4727 both input and input address and we do not check for
4728 RELOAD_FOR_OPERAND_ADDRESS and RELOAD_FOR_INSN since these
4731 for (i = opnum + 1; i < reload_n_operands; i++)
4732 if (TEST_HARD_REG_BIT (reload_reg_used_in_input_addr[i], regno)
4733 || TEST_HARD_REG_BIT (reload_reg_used_in_inpaddr_addr[i], regno)
4734 || TEST_HARD_REG_BIT (reload_reg_used_in_input[i], regno))
4737 /* ... fall through ... */
4739 case RELOAD_FOR_OPERAND_ADDRESS:
4740 /* Check outputs and their addresses. */
4742 for (i = 0; i < reload_n_operands; i++)
4743 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4744 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4745 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4748 return (!TEST_HARD_REG_BIT (reload_reg_used, regno));
4750 case RELOAD_FOR_OPADDR_ADDR:
4751 for (i = 0; i < reload_n_operands; i++)
4752 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4753 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno)
4754 || TEST_HARD_REG_BIT (reload_reg_used_in_output[i], regno))
4757 return (!TEST_HARD_REG_BIT (reload_reg_used_in_op_addr, regno)
4758 && !TEST_HARD_REG_BIT (reload_reg_used_in_insn, regno)
4759 && !TEST_HARD_REG_BIT (reload_reg_used, regno));
4761 case RELOAD_FOR_INSN:
4762 /* These conflict with other outputs with RELOAD_OTHER. So
4763 we need only check for output addresses. */
4765 opnum = reload_n_operands;
4767 /* ... fall through ... */
4769 case RELOAD_FOR_OUTPUT:
4770 case RELOAD_FOR_OUTPUT_ADDRESS:
4771 case RELOAD_FOR_OUTADDR_ADDRESS:
4772 /* We already know these can't conflict with a later output. So the
4773 only thing to check are later output addresses.
4774 Note that multiple output operands are emitted in reverse order,
4775 so the conflicting ones are those with lower indices. */
4776 for (i = 0; i < opnum; i++)
4777 if (TEST_HARD_REG_BIT (reload_reg_used_in_output_addr[i], regno)
4778 || TEST_HARD_REG_BIT (reload_reg_used_in_outaddr_addr[i], regno))
4788 /* Return 1 if the reloads denoted by R1 and R2 cannot share a register.
4791 This function uses the same algorithm as reload_reg_free_p above. */
4794 reloads_conflict (int r1, int r2)
4796 enum reload_type r1_type = rld[r1].when_needed;
4797 enum reload_type r2_type = rld[r2].when_needed;
4798 int r1_opnum = rld[r1].opnum;
4799 int r2_opnum = rld[r2].opnum;
4801 /* RELOAD_OTHER conflicts with everything. */
4802 if (r2_type == RELOAD_OTHER)
4805 /* Otherwise, check conflicts differently for each type. */
4809 case RELOAD_FOR_INPUT:
4810 return (r2_type == RELOAD_FOR_INSN
4811 || r2_type == RELOAD_FOR_OPERAND_ADDRESS
4812 || r2_type == RELOAD_FOR_OPADDR_ADDR
4813 || r2_type == RELOAD_FOR_INPUT
4814 || ((r2_type == RELOAD_FOR_INPUT_ADDRESS
4815 || r2_type == RELOAD_FOR_INPADDR_ADDRESS)
4816 && r2_opnum > r1_opnum));
4818 case RELOAD_FOR_INPUT_ADDRESS:
4819 return ((r2_type == RELOAD_FOR_INPUT_ADDRESS && r1_opnum == r2_opnum)
4820 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4822 case RELOAD_FOR_INPADDR_ADDRESS:
4823 return ((r2_type == RELOAD_FOR_INPADDR_ADDRESS && r1_opnum == r2_opnum)
4824 || (r2_type == RELOAD_FOR_INPUT && r2_opnum < r1_opnum));
4826 case RELOAD_FOR_OUTPUT_ADDRESS:
4827 return ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS && r2_opnum == r1_opnum)
4828 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4830 case RELOAD_FOR_OUTADDR_ADDRESS:
4831 return ((r2_type == RELOAD_FOR_OUTADDR_ADDRESS && r2_opnum == r1_opnum)
4832 || (r2_type == RELOAD_FOR_OUTPUT && r2_opnum <= r1_opnum));
4834 case RELOAD_FOR_OPERAND_ADDRESS:
4835 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_INSN
4836 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
4838 case RELOAD_FOR_OPADDR_ADDR:
4839 return (r2_type == RELOAD_FOR_INPUT
4840 || r2_type == RELOAD_FOR_OPADDR_ADDR);
4842 case RELOAD_FOR_OUTPUT:
4843 return (r2_type == RELOAD_FOR_INSN || r2_type == RELOAD_FOR_OUTPUT
4844 || ((r2_type == RELOAD_FOR_OUTPUT_ADDRESS
4845 || r2_type == RELOAD_FOR_OUTADDR_ADDRESS)
4846 && r2_opnum >= r1_opnum));
4848 case RELOAD_FOR_INSN:
4849 return (r2_type == RELOAD_FOR_INPUT || r2_type == RELOAD_FOR_OUTPUT
4850 || r2_type == RELOAD_FOR_INSN
4851 || r2_type == RELOAD_FOR_OPERAND_ADDRESS);
4853 case RELOAD_FOR_OTHER_ADDRESS:
4854 return r2_type == RELOAD_FOR_OTHER_ADDRESS;
4864 /* Indexed by reload number, 1 if incoming value
4865 inherited from previous insns. */
4866 static char reload_inherited[MAX_RELOADS];
4868 /* For an inherited reload, this is the insn the reload was inherited from,
4869 if we know it. Otherwise, this is 0. */
4870 static rtx reload_inheritance_insn[MAX_RELOADS];
4872 /* If nonzero, this is a place to get the value of the reload,
4873 rather than using reload_in. */
4874 static rtx reload_override_in[MAX_RELOADS];
4876 /* For each reload, the hard register number of the register used,
4877 or -1 if we did not need a register for this reload. */
4878 static int reload_spill_index[MAX_RELOADS];
4880 /* Subroutine of free_for_value_p, used to check a single register.
4881 START_REGNO is the starting regno of the full reload register
4882 (possibly comprising multiple hard registers) that we are considering. */
4885 reload_reg_free_for_value_p (int start_regno, int regno, int opnum,
4886 enum reload_type type, rtx value, rtx out,
4887 int reloadnum, int ignore_address_reloads)
4890 /* Set if we see an input reload that must not share its reload register
4891 with any new earlyclobber, but might otherwise share the reload
4892 register with an output or input-output reload. */
4893 int check_earlyclobber = 0;
4897 if (TEST_HARD_REG_BIT (reload_reg_unavailable, regno))
4900 if (out == const0_rtx)
4906 /* We use some pseudo 'time' value to check if the lifetimes of the
4907 new register use would overlap with the one of a previous reload
4908 that is not read-only or uses a different value.
4909 The 'time' used doesn't have to be linear in any shape or form, just
4911 Some reload types use different 'buckets' for each operand.
4912 So there are MAX_RECOG_OPERANDS different time values for each
4914 We compute TIME1 as the time when the register for the prospective
4915 new reload ceases to be live, and TIME2 for each existing
4916 reload as the time when that the reload register of that reload
4918 Where there is little to be gained by exact lifetime calculations,
4919 we just make conservative assumptions, i.e. a longer lifetime;
4920 this is done in the 'default:' cases. */
4923 case RELOAD_FOR_OTHER_ADDRESS:
4924 /* RELOAD_FOR_OTHER_ADDRESS conflicts with RELOAD_OTHER reloads. */
4925 time1 = copy ? 0 : 1;
4928 time1 = copy ? 1 : MAX_RECOG_OPERANDS * 5 + 5;
4930 /* For each input, we may have a sequence of RELOAD_FOR_INPADDR_ADDRESS,
4931 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_INPUT. By adding 0 / 1 / 2 ,
4932 respectively, to the time values for these, we get distinct time
4933 values. To get distinct time values for each operand, we have to
4934 multiply opnum by at least three. We round that up to four because
4935 multiply by four is often cheaper. */
4936 case RELOAD_FOR_INPADDR_ADDRESS:
4937 time1 = opnum * 4 + 2;
4939 case RELOAD_FOR_INPUT_ADDRESS:
4940 time1 = opnum * 4 + 3;
4942 case RELOAD_FOR_INPUT:
4943 /* All RELOAD_FOR_INPUT reloads remain live till the instruction
4944 executes (inclusive). */
4945 time1 = copy ? opnum * 4 + 4 : MAX_RECOG_OPERANDS * 4 + 3;
4947 case RELOAD_FOR_OPADDR_ADDR:
4949 <= (MAX_RECOG_OPERANDS - 1) * 4 + 4 == MAX_RECOG_OPERANDS * 4 */
4950 time1 = MAX_RECOG_OPERANDS * 4 + 1;
4952 case RELOAD_FOR_OPERAND_ADDRESS:
4953 /* RELOAD_FOR_OPERAND_ADDRESS reloads are live even while the insn
4955 time1 = copy ? MAX_RECOG_OPERANDS * 4 + 2 : MAX_RECOG_OPERANDS * 4 + 3;
4957 case RELOAD_FOR_OUTADDR_ADDRESS:
4958 time1 = MAX_RECOG_OPERANDS * 4 + 4 + opnum;
4960 case RELOAD_FOR_OUTPUT_ADDRESS:
4961 time1 = MAX_RECOG_OPERANDS * 4 + 5 + opnum;
4964 time1 = MAX_RECOG_OPERANDS * 5 + 5;
4967 for (i = 0; i < n_reloads; i++)
4969 rtx reg = rld[i].reg_rtx;
4970 if (reg && REG_P (reg)
4971 && ((unsigned) regno - true_regnum (reg)
4972 <= hard_regno_nregs[REGNO (reg)][GET_MODE (reg)] - (unsigned) 1)
4975 rtx other_input = rld[i].in;
4977 /* If the other reload loads the same input value, that
4978 will not cause a conflict only if it's loading it into
4979 the same register. */
4980 if (true_regnum (reg) != start_regno)
4981 other_input = NULL_RTX;
4982 if (! other_input || ! rtx_equal_p (other_input, value)
4983 || rld[i].out || out)
4986 switch (rld[i].when_needed)
4988 case RELOAD_FOR_OTHER_ADDRESS:
4991 case RELOAD_FOR_INPADDR_ADDRESS:
4992 /* find_reloads makes sure that a
4993 RELOAD_FOR_{INP,OP,OUT}ADDR_ADDRESS reload is only used
4994 by at most one - the first -
4995 RELOAD_FOR_{INPUT,OPERAND,OUTPUT}_ADDRESS . If the
4996 address reload is inherited, the address address reload
4997 goes away, so we can ignore this conflict. */
4998 if (type == RELOAD_FOR_INPUT_ADDRESS && reloadnum == i + 1
4999 && ignore_address_reloads
5000 /* Unless the RELOAD_FOR_INPUT is an auto_inc expression.
5001 Then the address address is still needed to store
5002 back the new address. */
5003 && ! rld[reloadnum].out)
5005 /* Likewise, if a RELOAD_FOR_INPUT can inherit a value, its
5006 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS
5008 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5009 && ignore_address_reloads
5010 /* Unless we are reloading an auto_inc expression. */
5011 && ! rld[reloadnum].out)
5013 time2 = rld[i].opnum * 4 + 2;
5015 case RELOAD_FOR_INPUT_ADDRESS:
5016 if (type == RELOAD_FOR_INPUT && opnum == rld[i].opnum
5017 && ignore_address_reloads
5018 && ! rld[reloadnum].out)
5020 time2 = rld[i].opnum * 4 + 3;
5022 case RELOAD_FOR_INPUT:
5023 time2 = rld[i].opnum * 4 + 4;
5024 check_earlyclobber = 1;
5026 /* rld[i].opnum * 4 + 4 <= (MAX_RECOG_OPERAND - 1) * 4 + 4
5027 == MAX_RECOG_OPERAND * 4 */
5028 case RELOAD_FOR_OPADDR_ADDR:
5029 if (type == RELOAD_FOR_OPERAND_ADDRESS && reloadnum == i + 1
5030 && ignore_address_reloads
5031 && ! rld[reloadnum].out)
5033 time2 = MAX_RECOG_OPERANDS * 4 + 1;
5035 case RELOAD_FOR_OPERAND_ADDRESS:
5036 time2 = MAX_RECOG_OPERANDS * 4 + 2;
5037 check_earlyclobber = 1;
5039 case RELOAD_FOR_INSN:
5040 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5042 case RELOAD_FOR_OUTPUT:
5043 /* All RELOAD_FOR_OUTPUT reloads become live just after the
5044 instruction is executed. */
5045 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5047 /* The first RELOAD_FOR_OUTADDR_ADDRESS reload conflicts with
5048 the RELOAD_FOR_OUTPUT reloads, so assign it the same time
5050 case RELOAD_FOR_OUTADDR_ADDRESS:
5051 if (type == RELOAD_FOR_OUTPUT_ADDRESS && reloadnum == i + 1
5052 && ignore_address_reloads
5053 && ! rld[reloadnum].out)
5055 time2 = MAX_RECOG_OPERANDS * 4 + 4 + rld[i].opnum;
5057 case RELOAD_FOR_OUTPUT_ADDRESS:
5058 time2 = MAX_RECOG_OPERANDS * 4 + 5 + rld[i].opnum;
5061 /* If there is no conflict in the input part, handle this
5062 like an output reload. */
5063 if (! rld[i].in || rtx_equal_p (other_input, value))
5065 time2 = MAX_RECOG_OPERANDS * 4 + 4;
5066 /* Earlyclobbered outputs must conflict with inputs. */
5067 if (earlyclobber_operand_p (rld[i].out))
5068 time2 = MAX_RECOG_OPERANDS * 4 + 3;
5073 /* RELOAD_OTHER might be live beyond instruction execution,
5074 but this is not obvious when we set time2 = 1. So check
5075 here if there might be a problem with the new reload
5076 clobbering the register used by the RELOAD_OTHER. */
5084 && (! rld[i].in || rld[i].out
5085 || ! rtx_equal_p (other_input, value)))
5086 || (out && rld[reloadnum].out_reg
5087 && time2 >= MAX_RECOG_OPERANDS * 4 + 3))
5093 /* Earlyclobbered outputs must conflict with inputs. */
5094 if (check_earlyclobber && out && earlyclobber_operand_p (out))
5100 /* Return 1 if the value in reload reg REGNO, as used by a reload
5101 needed for the part of the insn specified by OPNUM and TYPE,
5102 may be used to load VALUE into it.
5104 MODE is the mode in which the register is used, this is needed to
5105 determine how many hard regs to test.
5107 Other read-only reloads with the same value do not conflict
5108 unless OUT is nonzero and these other reloads have to live while
5109 output reloads live.
5110 If OUT is CONST0_RTX, this is a special case: it means that the
5111 test should not be for using register REGNO as reload register, but
5112 for copying from register REGNO into the reload register.
5114 RELOADNUM is the number of the reload we want to load this value for;
5115 a reload does not conflict with itself.
5117 When IGNORE_ADDRESS_RELOADS is set, we can not have conflicts with
5118 reloads that load an address for the very reload we are considering.
5120 The caller has to make sure that there is no conflict with the return
5124 free_for_value_p (int regno, enum machine_mode mode, int opnum,
5125 enum reload_type type, rtx value, rtx out, int reloadnum,
5126 int ignore_address_reloads)
5128 int nregs = hard_regno_nregs[regno][mode];
5130 if (! reload_reg_free_for_value_p (regno, regno + nregs, opnum, type,
5131 value, out, reloadnum,
5132 ignore_address_reloads))
5137 /* Return nonzero if the rtx X is invariant over the current function. */
5138 /* ??? Actually, the places where we use this expect exactly what is
5139 tested here, and not everything that is function invariant. In
5140 particular, the frame pointer and arg pointer are special cased;
5141 pic_offset_table_rtx is not, and we must not spill these things to
5145 function_invariant_p (rtx x)
5149 if (x == frame_pointer_rtx || x == arg_pointer_rtx)
5151 if (GET_CODE (x) == PLUS
5152 && (XEXP (x, 0) == frame_pointer_rtx || XEXP (x, 0) == arg_pointer_rtx)
5153 && CONSTANT_P (XEXP (x, 1)))
5158 /* Determine whether the reload reg X overlaps any rtx'es used for
5159 overriding inheritance. Return nonzero if so. */
5162 conflicts_with_override (rtx x)
5165 for (i = 0; i < n_reloads; i++)
5166 if (reload_override_in[i]
5167 && reg_overlap_mentioned_p (x, reload_override_in[i]))
5172 /* Give an error message saying we failed to find a reload for INSN,
5173 and clear out reload R. */
5175 failed_reload (rtx insn, int r)
5177 if (asm_noperands (PATTERN (insn)) < 0)
5178 /* It's the compiler's fault. */
5179 fatal_insn ("could not find a spill register", insn);
5181 /* It's the user's fault; the operand's mode and constraint
5182 don't match. Disable this reload so we don't crash in final. */
5183 error_for_asm (insn,
5184 "%<asm%> operand constraint incompatible with operand size");
5188 rld[r].optional = 1;
5189 rld[r].secondary_p = 1;
5192 /* I is the index in SPILL_REG_RTX of the reload register we are to allocate
5193 for reload R. If it's valid, get an rtx for it. Return nonzero if
5196 set_reload_reg (int i, int r)
5199 rtx reg = spill_reg_rtx[i];
5201 if (reg == 0 || GET_MODE (reg) != rld[r].mode)
5202 spill_reg_rtx[i] = reg
5203 = gen_rtx_REG (rld[r].mode, spill_regs[i]);
5205 regno = true_regnum (reg);
5207 /* Detect when the reload reg can't hold the reload mode.
5208 This used to be one `if', but Sequent compiler can't handle that. */
5209 if (HARD_REGNO_MODE_OK (regno, rld[r].mode))
5211 enum machine_mode test_mode = VOIDmode;
5213 test_mode = GET_MODE (rld[r].in);
5214 /* If rld[r].in has VOIDmode, it means we will load it
5215 in whatever mode the reload reg has: to wit, rld[r].mode.
5216 We have already tested that for validity. */
5217 /* Aside from that, we need to test that the expressions
5218 to reload from or into have modes which are valid for this
5219 reload register. Otherwise the reload insns would be invalid. */
5220 if (! (rld[r].in != 0 && test_mode != VOIDmode
5221 && ! HARD_REGNO_MODE_OK (regno, test_mode)))
5222 if (! (rld[r].out != 0
5223 && ! HARD_REGNO_MODE_OK (regno, GET_MODE (rld[r].out))))
5225 /* The reg is OK. */
5228 /* Mark as in use for this insn the reload regs we use
5230 mark_reload_reg_in_use (spill_regs[i], rld[r].opnum,
5231 rld[r].when_needed, rld[r].mode);
5233 rld[r].reg_rtx = reg;
5234 reload_spill_index[r] = spill_regs[i];
5241 /* Find a spill register to use as a reload register for reload R.
5242 LAST_RELOAD is nonzero if this is the last reload for the insn being
5245 Set rld[R].reg_rtx to the register allocated.
5247 We return 1 if successful, or 0 if we couldn't find a spill reg and
5248 we didn't change anything. */
5251 allocate_reload_reg (struct insn_chain *chain ATTRIBUTE_UNUSED, int r,
5256 /* If we put this reload ahead, thinking it is a group,
5257 then insist on finding a group. Otherwise we can grab a
5258 reg that some other reload needs.
5259 (That can happen when we have a 68000 DATA_OR_FP_REG
5260 which is a group of data regs or one fp reg.)
5261 We need not be so restrictive if there are no more reloads
5264 ??? Really it would be nicer to have smarter handling
5265 for that kind of reg class, where a problem like this is normal.
5266 Perhaps those classes should be avoided for reloading
5267 by use of more alternatives. */
5269 int force_group = rld[r].nregs > 1 && ! last_reload;
5271 /* If we want a single register and haven't yet found one,
5272 take any reg in the right class and not in use.
5273 If we want a consecutive group, here is where we look for it.
5275 We use two passes so we can first look for reload regs to
5276 reuse, which are already in use for other reloads in this insn,
5277 and only then use additional registers.
5278 I think that maximizing reuse is needed to make sure we don't
5279 run out of reload regs. Suppose we have three reloads, and
5280 reloads A and B can share regs. These need two regs.
5281 Suppose A and B are given different regs.
5282 That leaves none for C. */
5283 for (pass = 0; pass < 2; pass++)
5285 /* I is the index in spill_regs.
5286 We advance it round-robin between insns to use all spill regs
5287 equally, so that inherited reloads have a chance
5288 of leapfrogging each other. */
5292 for (count = 0; count < n_spills; count++)
5294 int class = (int) rld[r].class;
5300 regnum = spill_regs[i];
5302 if ((reload_reg_free_p (regnum, rld[r].opnum,
5305 /* We check reload_reg_used to make sure we
5306 don't clobber the return register. */
5307 && ! TEST_HARD_REG_BIT (reload_reg_used, regnum)
5308 && free_for_value_p (regnum, rld[r].mode, rld[r].opnum,
5309 rld[r].when_needed, rld[r].in,
5311 && TEST_HARD_REG_BIT (reg_class_contents[class], regnum)
5312 && HARD_REGNO_MODE_OK (regnum, rld[r].mode)
5313 /* Look first for regs to share, then for unshared. But
5314 don't share regs used for inherited reloads; they are
5315 the ones we want to preserve. */
5317 || (TEST_HARD_REG_BIT (reload_reg_used_at_all,
5319 && ! TEST_HARD_REG_BIT (reload_reg_used_for_inherit,
5322 int nr = hard_regno_nregs[regnum][rld[r].mode];
5323 /* Avoid the problem where spilling a GENERAL_OR_FP_REG
5324 (on 68000) got us two FP regs. If NR is 1,
5325 we would reject both of them. */
5328 /* If we need only one reg, we have already won. */
5331 /* But reject a single reg if we demand a group. */
5336 /* Otherwise check that as many consecutive regs as we need
5337 are available here. */
5340 int regno = regnum + nr - 1;
5341 if (!(TEST_HARD_REG_BIT (reg_class_contents[class], regno)
5342 && spill_reg_order[regno] >= 0
5343 && reload_reg_free_p (regno, rld[r].opnum,
5344 rld[r].when_needed)))
5353 /* If we found something on pass 1, omit pass 2. */
5354 if (count < n_spills)
5358 /* We should have found a spill register by now. */
5359 if (count >= n_spills)
5362 /* I is the index in SPILL_REG_RTX of the reload register we are to
5363 allocate. Get an rtx for it and find its register number. */
5365 return set_reload_reg (i, r);
5368 /* Initialize all the tables needed to allocate reload registers.
5369 CHAIN is the insn currently being processed; SAVE_RELOAD_REG_RTX
5370 is the array we use to restore the reg_rtx field for every reload. */
5373 choose_reload_regs_init (struct insn_chain *chain, rtx *save_reload_reg_rtx)
5377 for (i = 0; i < n_reloads; i++)
5378 rld[i].reg_rtx = save_reload_reg_rtx[i];
5380 memset (reload_inherited, 0, MAX_RELOADS);
5381 memset (reload_inheritance_insn, 0, MAX_RELOADS * sizeof (rtx));
5382 memset (reload_override_in, 0, MAX_RELOADS * sizeof (rtx));
5384 CLEAR_HARD_REG_SET (reload_reg_used);
5385 CLEAR_HARD_REG_SET (reload_reg_used_at_all);
5386 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr);
5387 CLEAR_HARD_REG_SET (reload_reg_used_in_op_addr_reload);
5388 CLEAR_HARD_REG_SET (reload_reg_used_in_insn);
5389 CLEAR_HARD_REG_SET (reload_reg_used_in_other_addr);
5391 CLEAR_HARD_REG_SET (reg_used_in_insn);
5394 REG_SET_TO_HARD_REG_SET (tmp, &chain->live_throughout);
5395 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5396 REG_SET_TO_HARD_REG_SET (tmp, &chain->dead_or_set);
5397 IOR_HARD_REG_SET (reg_used_in_insn, tmp);
5398 compute_use_by_pseudos (®_used_in_insn, &chain->live_throughout);
5399 compute_use_by_pseudos (®_used_in_insn, &chain->dead_or_set);
5402 for (i = 0; i < reload_n_operands; i++)
5404 CLEAR_HARD_REG_SET (reload_reg_used_in_output[i]);
5405 CLEAR_HARD_REG_SET (reload_reg_used_in_input[i]);
5406 CLEAR_HARD_REG_SET (reload_reg_used_in_input_addr[i]);
5407 CLEAR_HARD_REG_SET (reload_reg_used_in_inpaddr_addr[i]);
5408 CLEAR_HARD_REG_SET (reload_reg_used_in_output_addr[i]);
5409 CLEAR_HARD_REG_SET (reload_reg_used_in_outaddr_addr[i]);
5412 COMPL_HARD_REG_SET (reload_reg_unavailable, chain->used_spill_regs);
5414 CLEAR_HARD_REG_SET (reload_reg_used_for_inherit);
5416 for (i = 0; i < n_reloads; i++)
5417 /* If we have already decided to use a certain register,
5418 don't use it in another way. */
5420 mark_reload_reg_in_use (REGNO (rld[i].reg_rtx), rld[i].opnum,
5421 rld[i].when_needed, rld[i].mode);
5424 /* Assign hard reg targets for the pseudo-registers we must reload
5425 into hard regs for this insn.
5426 Also output the instructions to copy them in and out of the hard regs.
5428 For machines with register classes, we are responsible for
5429 finding a reload reg in the proper class. */
5432 choose_reload_regs (struct insn_chain *chain)
5434 rtx insn = chain->insn;
5436 unsigned int max_group_size = 1;
5437 enum reg_class group_class = NO_REGS;
5438 int pass, win, inheritance;
5440 rtx save_reload_reg_rtx[MAX_RELOADS];
5442 /* In order to be certain of getting the registers we need,
5443 we must sort the reloads into order of increasing register class.
5444 Then our grabbing of reload registers will parallel the process
5445 that provided the reload registers.
5447 Also note whether any of the reloads wants a consecutive group of regs.
5448 If so, record the maximum size of the group desired and what
5449 register class contains all the groups needed by this insn. */
5451 for (j = 0; j < n_reloads; j++)
5453 reload_order[j] = j;
5454 if (rld[j].reg_rtx != NULL_RTX)
5456 gcc_assert (REG_P (rld[j].reg_rtx)
5457 && HARD_REGISTER_P (rld[j].reg_rtx));
5458 reload_spill_index[j] = REGNO (rld[j].reg_rtx);
5461 reload_spill_index[j] = -1;
5463 if (rld[j].nregs > 1)
5465 max_group_size = MAX (rld[j].nregs, max_group_size);
5467 = reg_class_superunion[(int) rld[j].class][(int) group_class];
5470 save_reload_reg_rtx[j] = rld[j].reg_rtx;
5474 qsort (reload_order, n_reloads, sizeof (short), reload_reg_class_lower);
5476 /* If -O, try first with inheritance, then turning it off.
5477 If not -O, don't do inheritance.
5478 Using inheritance when not optimizing leads to paradoxes
5479 with fp on the 68k: fp numbers (not NaNs) fail to be equal to themselves
5480 because one side of the comparison might be inherited. */
5482 for (inheritance = optimize > 0; inheritance >= 0; inheritance--)
5484 choose_reload_regs_init (chain, save_reload_reg_rtx);
5486 /* Process the reloads in order of preference just found.
5487 Beyond this point, subregs can be found in reload_reg_rtx.
5489 This used to look for an existing reloaded home for all of the
5490 reloads, and only then perform any new reloads. But that could lose
5491 if the reloads were done out of reg-class order because a later
5492 reload with a looser constraint might have an old home in a register
5493 needed by an earlier reload with a tighter constraint.
5495 To solve this, we make two passes over the reloads, in the order
5496 described above. In the first pass we try to inherit a reload
5497 from a previous insn. If there is a later reload that needs a
5498 class that is a proper subset of the class being processed, we must
5499 also allocate a spill register during the first pass.
5501 Then make a second pass over the reloads to allocate any reloads
5502 that haven't been given registers yet. */
5504 for (j = 0; j < n_reloads; j++)
5506 int r = reload_order[j];
5507 rtx search_equiv = NULL_RTX;
5509 /* Ignore reloads that got marked inoperative. */
5510 if (rld[r].out == 0 && rld[r].in == 0
5511 && ! rld[r].secondary_p)
5514 /* If find_reloads chose to use reload_in or reload_out as a reload
5515 register, we don't need to chose one. Otherwise, try even if it
5516 found one since we might save an insn if we find the value lying
5518 Try also when reload_in is a pseudo without a hard reg. */
5519 if (rld[r].in != 0 && rld[r].reg_rtx != 0
5520 && (rtx_equal_p (rld[r].in, rld[r].reg_rtx)
5521 || (rtx_equal_p (rld[r].out, rld[r].reg_rtx)
5522 && !MEM_P (rld[r].in)
5523 && true_regnum (rld[r].in) < FIRST_PSEUDO_REGISTER)))
5526 #if 0 /* No longer needed for correct operation.
5527 It might give better code, or might not; worth an experiment? */
5528 /* If this is an optional reload, we can't inherit from earlier insns
5529 until we are sure that any non-optional reloads have been allocated.
5530 The following code takes advantage of the fact that optional reloads
5531 are at the end of reload_order. */
5532 if (rld[r].optional != 0)
5533 for (i = 0; i < j; i++)
5534 if ((rld[reload_order[i]].out != 0
5535 || rld[reload_order[i]].in != 0
5536 || rld[reload_order[i]].secondary_p)
5537 && ! rld[reload_order[i]].optional
5538 && rld[reload_order[i]].reg_rtx == 0)
5539 allocate_reload_reg (chain, reload_order[i], 0);
5542 /* First see if this pseudo is already available as reloaded
5543 for a previous insn. We cannot try to inherit for reloads
5544 that are smaller than the maximum number of registers needed
5545 for groups unless the register we would allocate cannot be used
5548 We could check here to see if this is a secondary reload for
5549 an object that is already in a register of the desired class.
5550 This would avoid the need for the secondary reload register.
5551 But this is complex because we can't easily determine what
5552 objects might want to be loaded via this reload. So let a
5553 register be allocated here. In `emit_reload_insns' we suppress
5554 one of the loads in the case described above. */
5560 enum machine_mode mode = VOIDmode;
5564 else if (REG_P (rld[r].in))
5566 regno = REGNO (rld[r].in);
5567 mode = GET_MODE (rld[r].in);
5569 else if (REG_P (rld[r].in_reg))
5571 regno = REGNO (rld[r].in_reg);
5572 mode = GET_MODE (rld[r].in_reg);
5574 else if (GET_CODE (rld[r].in_reg) == SUBREG
5575 && REG_P (SUBREG_REG (rld[r].in_reg)))
5577 byte = SUBREG_BYTE (rld[r].in_reg);
5578 regno = REGNO (SUBREG_REG (rld[r].in_reg));
5579 if (regno < FIRST_PSEUDO_REGISTER)
5580 regno = subreg_regno (rld[r].in_reg);
5581 mode = GET_MODE (rld[r].in_reg);
5584 else if (GET_RTX_CLASS (GET_CODE (rld[r].in_reg)) == RTX_AUTOINC
5585 && REG_P (XEXP (rld[r].in_reg, 0)))
5587 regno = REGNO (XEXP (rld[r].in_reg, 0));
5588 mode = GET_MODE (XEXP (rld[r].in_reg, 0));
5589 rld[r].out = rld[r].in;
5593 /* This won't work, since REGNO can be a pseudo reg number.
5594 Also, it takes much more hair to keep track of all the things
5595 that can invalidate an inherited reload of part of a pseudoreg. */
5596 else if (GET_CODE (rld[r].in) == SUBREG
5597 && REG_P (SUBREG_REG (rld[r].in)))
5598 regno = subreg_regno (rld[r].in);
5601 if (regno >= 0 && reg_last_reload_reg[regno] != 0)
5603 enum reg_class class = rld[r].class, last_class;
5604 rtx last_reg = reg_last_reload_reg[regno];
5605 enum machine_mode need_mode;
5607 i = REGNO (last_reg);
5608 i += subreg_regno_offset (i, GET_MODE (last_reg), byte, mode);
5609 last_class = REGNO_REG_CLASS (i);
5615 = smallest_mode_for_size (GET_MODE_BITSIZE (mode)
5616 + byte * BITS_PER_UNIT,
5617 GET_MODE_CLASS (mode));
5619 if ((GET_MODE_SIZE (GET_MODE (last_reg))
5620 >= GET_MODE_SIZE (need_mode))
5621 #ifdef CANNOT_CHANGE_MODE_CLASS
5622 /* Verify that the register in "i" can be obtained
5624 && !REG_CANNOT_CHANGE_MODE_P (REGNO (last_reg),
5625 GET_MODE (last_reg),
5628 && reg_reloaded_contents[i] == regno
5629 && TEST_HARD_REG_BIT (reg_reloaded_valid, i)
5630 && HARD_REGNO_MODE_OK (i, rld[r].mode)
5631 && (TEST_HARD_REG_BIT (reg_class_contents[(int) class], i)
5632 /* Even if we can't use this register as a reload
5633 register, we might use it for reload_override_in,
5634 if copying it to the desired class is cheap
5636 || ((REGISTER_MOVE_COST (mode, last_class, class)
5637 < MEMORY_MOVE_COST (mode, class, 1))
5638 && (secondary_reload_class (1, class, mode,
5641 #ifdef SECONDARY_MEMORY_NEEDED
5642 && ! SECONDARY_MEMORY_NEEDED (last_class, class,
5647 && (rld[r].nregs == max_group_size
5648 || ! TEST_HARD_REG_BIT (reg_class_contents[(int) group_class],
5650 && free_for_value_p (i, rld[r].mode, rld[r].opnum,
5651 rld[r].when_needed, rld[r].in,
5654 /* If a group is needed, verify that all the subsequent
5655 registers still have their values intact. */
5656 int nr = hard_regno_nregs[i][rld[r].mode];
5659 for (k = 1; k < nr; k++)
5660 if (reg_reloaded_contents[i + k] != regno
5661 || ! TEST_HARD_REG_BIT (reg_reloaded_valid, i + k))
5669 last_reg = (GET_MODE (last_reg) == mode
5670 ? last_reg : gen_rtx_REG (mode, i));
5673 for (k = 0; k < nr; k++)
5674 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5677 /* We found a register that contains the
5678 value we need. If this register is the
5679 same as an `earlyclobber' operand of the
5680 current insn, just mark it as a place to
5681 reload from since we can't use it as the
5682 reload register itself. */
5684 for (i1 = 0; i1 < n_earlyclobbers; i1++)
5685 if (reg_overlap_mentioned_for_reload_p
5686 (reg_last_reload_reg[regno],
5687 reload_earlyclobbers[i1]))
5690 if (i1 != n_earlyclobbers
5691 || ! (free_for_value_p (i, rld[r].mode,
5693 rld[r].when_needed, rld[r].in,
5695 /* Don't use it if we'd clobber a pseudo reg. */
5696 || (TEST_HARD_REG_BIT (reg_used_in_insn, i)
5698 && ! TEST_HARD_REG_BIT (reg_reloaded_dead, i))
5699 /* Don't clobber the frame pointer. */
5700 || (i == HARD_FRAME_POINTER_REGNUM
5701 && frame_pointer_needed
5703 /* Don't really use the inherited spill reg
5704 if we need it wider than we've got it. */
5705 || (GET_MODE_SIZE (rld[r].mode)
5706 > GET_MODE_SIZE (mode))
5709 /* If find_reloads chose reload_out as reload
5710 register, stay with it - that leaves the
5711 inherited register for subsequent reloads. */
5712 || (rld[r].out && rld[r].reg_rtx
5713 && rtx_equal_p (rld[r].out, rld[r].reg_rtx)))
5715 if (! rld[r].optional)
5717 reload_override_in[r] = last_reg;
5718 reload_inheritance_insn[r]
5719 = reg_reloaded_insn[i];
5725 /* We can use this as a reload reg. */
5726 /* Mark the register as in use for this part of
5728 mark_reload_reg_in_use (i,
5732 rld[r].reg_rtx = last_reg;
5733 reload_inherited[r] = 1;
5734 reload_inheritance_insn[r]
5735 = reg_reloaded_insn[i];
5736 reload_spill_index[r] = i;
5737 for (k = 0; k < nr; k++)
5738 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5746 /* Here's another way to see if the value is already lying around. */
5749 && ! reload_inherited[r]
5751 && (CONSTANT_P (rld[r].in)
5752 || GET_CODE (rld[r].in) == PLUS
5753 || REG_P (rld[r].in)
5754 || MEM_P (rld[r].in))
5755 && (rld[r].nregs == max_group_size
5756 || ! reg_classes_intersect_p (rld[r].class, group_class)))
5757 search_equiv = rld[r].in;
5758 /* If this is an output reload from a simple move insn, look
5759 if an equivalence for the input is available. */
5760 else if (inheritance && rld[r].in == 0 && rld[r].out != 0)
5762 rtx set = single_set (insn);
5765 && rtx_equal_p (rld[r].out, SET_DEST (set))
5766 && CONSTANT_P (SET_SRC (set)))
5767 search_equiv = SET_SRC (set);
5773 = find_equiv_reg (search_equiv, insn, rld[r].class,
5774 -1, NULL, 0, rld[r].mode);
5780 regno = REGNO (equiv);
5783 /* This must be a SUBREG of a hard register.
5784 Make a new REG since this might be used in an
5785 address and not all machines support SUBREGs
5787 gcc_assert (GET_CODE (equiv) == SUBREG);
5788 regno = subreg_regno (equiv);
5789 equiv = gen_rtx_REG (rld[r].mode, regno);
5790 /* If we choose EQUIV as the reload register, but the
5791 loop below decides to cancel the inheritance, we'll
5792 end up reloading EQUIV in rld[r].mode, not the mode
5793 it had originally. That isn't safe when EQUIV isn't
5794 available as a spill register since its value might
5795 still be live at this point. */
5796 for (i = regno; i < regno + (int) rld[r].nregs; i++)
5797 if (TEST_HARD_REG_BIT (reload_reg_unavailable, i))
5802 /* If we found a spill reg, reject it unless it is free
5803 and of the desired class. */
5807 int bad_for_class = 0;
5808 int max_regno = regno + rld[r].nregs;
5810 for (i = regno; i < max_regno; i++)
5812 regs_used |= TEST_HARD_REG_BIT (reload_reg_used_at_all,
5814 bad_for_class |= ! TEST_HARD_REG_BIT (reg_class_contents[(int) rld[r].class],
5819 && ! free_for_value_p (regno, rld[r].mode,
5820 rld[r].opnum, rld[r].when_needed,
5821 rld[r].in, rld[r].out, r, 1))
5826 if (equiv != 0 && ! HARD_REGNO_MODE_OK (regno, rld[r].mode))
5829 /* We found a register that contains the value we need.
5830 If this register is the same as an `earlyclobber' operand
5831 of the current insn, just mark it as a place to reload from
5832 since we can't use it as the reload register itself. */
5835 for (i = 0; i < n_earlyclobbers; i++)
5836 if (reg_overlap_mentioned_for_reload_p (equiv,
5837 reload_earlyclobbers[i]))
5839 if (! rld[r].optional)
5840 reload_override_in[r] = equiv;
5845 /* If the equiv register we have found is explicitly clobbered
5846 in the current insn, it depends on the reload type if we
5847 can use it, use it for reload_override_in, or not at all.
5848 In particular, we then can't use EQUIV for a
5849 RELOAD_FOR_OUTPUT_ADDRESS reload. */
5853 if (regno_clobbered_p (regno, insn, rld[r].mode, 2))
5854 switch (rld[r].when_needed)
5856 case RELOAD_FOR_OTHER_ADDRESS:
5857 case RELOAD_FOR_INPADDR_ADDRESS:
5858 case RELOAD_FOR_INPUT_ADDRESS:
5859 case RELOAD_FOR_OPADDR_ADDR:
5862 case RELOAD_FOR_INPUT:
5863 case RELOAD_FOR_OPERAND_ADDRESS:
5864 if (! rld[r].optional)
5865 reload_override_in[r] = equiv;
5871 else if (regno_clobbered_p (regno, insn, rld[r].mode, 1))
5872 switch (rld[r].when_needed)
5874 case RELOAD_FOR_OTHER_ADDRESS:
5875 case RELOAD_FOR_INPADDR_ADDRESS:
5876 case RELOAD_FOR_INPUT_ADDRESS:
5877 case RELOAD_FOR_OPADDR_ADDR:
5878 case RELOAD_FOR_OPERAND_ADDRESS:
5879 case RELOAD_FOR_INPUT:
5882 if (! rld[r].optional)
5883 reload_override_in[r] = equiv;
5891 /* If we found an equivalent reg, say no code need be generated
5892 to load it, and use it as our reload reg. */
5894 && (regno != HARD_FRAME_POINTER_REGNUM
5895 || !frame_pointer_needed))
5897 int nr = hard_regno_nregs[regno][rld[r].mode];
5899 rld[r].reg_rtx = equiv;
5900 reload_inherited[r] = 1;
5902 /* If reg_reloaded_valid is not set for this register,
5903 there might be a stale spill_reg_store lying around.
5904 We must clear it, since otherwise emit_reload_insns
5905 might delete the store. */
5906 if (! TEST_HARD_REG_BIT (reg_reloaded_valid, regno))
5907 spill_reg_store[regno] = NULL_RTX;
5908 /* If any of the hard registers in EQUIV are spill
5909 registers, mark them as in use for this insn. */
5910 for (k = 0; k < nr; k++)
5912 i = spill_reg_order[regno + k];
5915 mark_reload_reg_in_use (regno, rld[r].opnum,
5918 SET_HARD_REG_BIT (reload_reg_used_for_inherit,
5925 /* If we found a register to use already, or if this is an optional
5926 reload, we are done. */
5927 if (rld[r].reg_rtx != 0 || rld[r].optional != 0)
5931 /* No longer needed for correct operation. Might or might
5932 not give better code on the average. Want to experiment? */
5934 /* See if there is a later reload that has a class different from our
5935 class that intersects our class or that requires less register
5936 than our reload. If so, we must allocate a register to this
5937 reload now, since that reload might inherit a previous reload
5938 and take the only available register in our class. Don't do this
5939 for optional reloads since they will force all previous reloads
5940 to be allocated. Also don't do this for reloads that have been
5943 for (i = j + 1; i < n_reloads; i++)
5945 int s = reload_order[i];
5947 if ((rld[s].in == 0 && rld[s].out == 0
5948 && ! rld[s].secondary_p)
5952 if ((rld[s].class != rld[r].class
5953 && reg_classes_intersect_p (rld[r].class,
5955 || rld[s].nregs < rld[r].nregs)
5962 allocate_reload_reg (chain, r, j == n_reloads - 1);
5966 /* Now allocate reload registers for anything non-optional that
5967 didn't get one yet. */
5968 for (j = 0; j < n_reloads; j++)
5970 int r = reload_order[j];
5972 /* Ignore reloads that got marked inoperative. */
5973 if (rld[r].out == 0 && rld[r].in == 0 && ! rld[r].secondary_p)
5976 /* Skip reloads that already have a register allocated or are
5978 if (rld[r].reg_rtx != 0 || rld[r].optional)
5981 if (! allocate_reload_reg (chain, r, j == n_reloads - 1))
5985 /* If that loop got all the way, we have won. */
5992 /* Loop around and try without any inheritance. */
5997 /* First undo everything done by the failed attempt
5998 to allocate with inheritance. */
5999 choose_reload_regs_init (chain, save_reload_reg_rtx);
6001 /* Some sanity tests to verify that the reloads found in the first
6002 pass are identical to the ones we have now. */
6003 gcc_assert (chain->n_reloads == n_reloads);
6005 for (i = 0; i < n_reloads; i++)
6007 if (chain->rld[i].regno < 0 || chain->rld[i].reg_rtx != 0)
6009 gcc_assert (chain->rld[i].when_needed == rld[i].when_needed);
6010 for (j = 0; j < n_spills; j++)
6011 if (spill_regs[j] == chain->rld[i].regno)
6012 if (! set_reload_reg (j, i))
6013 failed_reload (chain->insn, i);
6017 /* If we thought we could inherit a reload, because it seemed that
6018 nothing else wanted the same reload register earlier in the insn,
6019 verify that assumption, now that all reloads have been assigned.
6020 Likewise for reloads where reload_override_in has been set. */
6022 /* If doing expensive optimizations, do one preliminary pass that doesn't
6023 cancel any inheritance, but removes reloads that have been needed only
6024 for reloads that we know can be inherited. */
6025 for (pass = flag_expensive_optimizations; pass >= 0; pass--)
6027 for (j = 0; j < n_reloads; j++)
6029 int r = reload_order[j];
6031 if (reload_inherited[r] && rld[r].reg_rtx)
6032 check_reg = rld[r].reg_rtx;
6033 else if (reload_override_in[r]
6034 && (REG_P (reload_override_in[r])
6035 || GET_CODE (reload_override_in[r]) == SUBREG))
6036 check_reg = reload_override_in[r];
6039 if (! free_for_value_p (true_regnum (check_reg), rld[r].mode,
6040 rld[r].opnum, rld[r].when_needed, rld[r].in,
6041 (reload_inherited[r]
6042 ? rld[r].out : const0_rtx),
6047 reload_inherited[r] = 0;
6048 reload_override_in[r] = 0;
6050 /* If we can inherit a RELOAD_FOR_INPUT, or can use a
6051 reload_override_in, then we do not need its related
6052 RELOAD_FOR_INPUT_ADDRESS / RELOAD_FOR_INPADDR_ADDRESS reloads;
6053 likewise for other reload types.
6054 We handle this by removing a reload when its only replacement
6055 is mentioned in reload_in of the reload we are going to inherit.
6056 A special case are auto_inc expressions; even if the input is
6057 inherited, we still need the address for the output. We can
6058 recognize them because they have RELOAD_OUT set to RELOAD_IN.
6059 If we succeeded removing some reload and we are doing a preliminary
6060 pass just to remove such reloads, make another pass, since the
6061 removal of one reload might allow us to inherit another one. */
6063 && rld[r].out != rld[r].in
6064 && remove_address_replacements (rld[r].in) && pass)
6069 /* Now that reload_override_in is known valid,
6070 actually override reload_in. */
6071 for (j = 0; j < n_reloads; j++)
6072 if (reload_override_in[j])
6073 rld[j].in = reload_override_in[j];
6075 /* If this reload won't be done because it has been canceled or is
6076 optional and not inherited, clear reload_reg_rtx so other
6077 routines (such as subst_reloads) don't get confused. */
6078 for (j = 0; j < n_reloads; j++)
6079 if (rld[j].reg_rtx != 0
6080 && ((rld[j].optional && ! reload_inherited[j])
6081 || (rld[j].in == 0 && rld[j].out == 0
6082 && ! rld[j].secondary_p)))
6084 int regno = true_regnum (rld[j].reg_rtx);
6086 if (spill_reg_order[regno] >= 0)
6087 clear_reload_reg_in_use (regno, rld[j].opnum,
6088 rld[j].when_needed, rld[j].mode);
6090 reload_spill_index[j] = -1;
6093 /* Record which pseudos and which spill regs have output reloads. */
6094 for (j = 0; j < n_reloads; j++)
6096 int r = reload_order[j];
6098 i = reload_spill_index[r];
6100 /* I is nonneg if this reload uses a register.
6101 If rld[r].reg_rtx is 0, this is an optional reload
6102 that we opted to ignore. */
6103 if (rld[r].out_reg != 0 && REG_P (rld[r].out_reg)
6104 && rld[r].reg_rtx != 0)
6106 int nregno = REGNO (rld[r].out_reg);
6109 if (nregno < FIRST_PSEUDO_REGISTER)
6110 nr = hard_regno_nregs[nregno][rld[r].mode];
6113 SET_REGNO_REG_SET (®_has_output_reload,
6118 nr = hard_regno_nregs[i][rld[r].mode];
6120 SET_HARD_REG_BIT (reg_is_output_reload, i + nr);
6123 gcc_assert (rld[r].when_needed == RELOAD_OTHER
6124 || rld[r].when_needed == RELOAD_FOR_OUTPUT
6125 || rld[r].when_needed == RELOAD_FOR_INSN);
6130 /* Deallocate the reload register for reload R. This is called from
6131 remove_address_replacements. */
6134 deallocate_reload_reg (int r)
6138 if (! rld[r].reg_rtx)
6140 regno = true_regnum (rld[r].reg_rtx);
6142 if (spill_reg_order[regno] >= 0)
6143 clear_reload_reg_in_use (regno, rld[r].opnum, rld[r].when_needed,
6145 reload_spill_index[r] = -1;
6148 /* If SMALL_REGISTER_CLASSES is nonzero, we may not have merged two
6149 reloads of the same item for fear that we might not have enough reload
6150 registers. However, normally they will get the same reload register
6151 and hence actually need not be loaded twice.
6153 Here we check for the most common case of this phenomenon: when we have
6154 a number of reloads for the same object, each of which were allocated
6155 the same reload_reg_rtx, that reload_reg_rtx is not used for any other
6156 reload, and is not modified in the insn itself. If we find such,
6157 merge all the reloads and set the resulting reload to RELOAD_OTHER.
6158 This will not increase the number of spill registers needed and will
6159 prevent redundant code. */
6162 merge_assigned_reloads (rtx insn)
6166 /* Scan all the reloads looking for ones that only load values and
6167 are not already RELOAD_OTHER and ones whose reload_reg_rtx are
6168 assigned and not modified by INSN. */
6170 for (i = 0; i < n_reloads; i++)
6172 int conflicting_input = 0;
6173 int max_input_address_opnum = -1;
6174 int min_conflicting_input_opnum = MAX_RECOG_OPERANDS;
6176 if (rld[i].in == 0 || rld[i].when_needed == RELOAD_OTHER
6177 || rld[i].out != 0 || rld[i].reg_rtx == 0
6178 || reg_set_p (rld[i].reg_rtx, insn))
6181 /* Look at all other reloads. Ensure that the only use of this
6182 reload_reg_rtx is in a reload that just loads the same value
6183 as we do. Note that any secondary reloads must be of the identical
6184 class since the values, modes, and result registers are the
6185 same, so we need not do anything with any secondary reloads. */
6187 for (j = 0; j < n_reloads; j++)
6189 if (i == j || rld[j].reg_rtx == 0
6190 || ! reg_overlap_mentioned_p (rld[j].reg_rtx,
6194 if (rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6195 && rld[j].opnum > max_input_address_opnum)
6196 max_input_address_opnum = rld[j].opnum;
6198 /* If the reload regs aren't exactly the same (e.g, different modes)
6199 or if the values are different, we can't merge this reload.
6200 But if it is an input reload, we might still merge
6201 RELOAD_FOR_INPUT_ADDRESS and RELOAD_FOR_OTHER_ADDRESS reloads. */
6203 if (! rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6204 || rld[j].out != 0 || rld[j].in == 0
6205 || ! rtx_equal_p (rld[i].in, rld[j].in))
6207 if (rld[j].when_needed != RELOAD_FOR_INPUT
6208 || ((rld[i].when_needed != RELOAD_FOR_INPUT_ADDRESS
6209 || rld[i].opnum > rld[j].opnum)
6210 && rld[i].when_needed != RELOAD_FOR_OTHER_ADDRESS))
6212 conflicting_input = 1;
6213 if (min_conflicting_input_opnum > rld[j].opnum)
6214 min_conflicting_input_opnum = rld[j].opnum;
6218 /* If all is OK, merge the reloads. Only set this to RELOAD_OTHER if
6219 we, in fact, found any matching reloads. */
6222 && max_input_address_opnum <= min_conflicting_input_opnum)
6224 gcc_assert (rld[i].when_needed != RELOAD_FOR_OUTPUT);
6226 for (j = 0; j < n_reloads; j++)
6227 if (i != j && rld[j].reg_rtx != 0
6228 && rtx_equal_p (rld[i].reg_rtx, rld[j].reg_rtx)
6229 && (! conflicting_input
6230 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6231 || rld[j].when_needed == RELOAD_FOR_OTHER_ADDRESS))
6233 rld[i].when_needed = RELOAD_OTHER;
6235 reload_spill_index[j] = -1;
6236 transfer_replacements (i, j);
6239 /* If this is now RELOAD_OTHER, look for any reloads that load
6240 parts of this operand and set them to RELOAD_FOR_OTHER_ADDRESS
6241 if they were for inputs, RELOAD_OTHER for outputs. Note that
6242 this test is equivalent to looking for reloads for this operand
6244 /* We must take special care with RELOAD_FOR_OUTPUT_ADDRESS; it may
6245 share registers with a RELOAD_FOR_INPUT, so we can not change it
6246 to RELOAD_FOR_OTHER_ADDRESS. We should never need to, since we
6247 do not modify RELOAD_FOR_OUTPUT. */
6249 if (rld[i].when_needed == RELOAD_OTHER)
6250 for (j = 0; j < n_reloads; j++)
6252 && rld[j].when_needed != RELOAD_OTHER
6253 && rld[j].when_needed != RELOAD_FOR_OTHER_ADDRESS
6254 && rld[j].when_needed != RELOAD_FOR_OUTPUT_ADDRESS
6255 && (! conflicting_input
6256 || rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6257 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6258 && reg_overlap_mentioned_for_reload_p (rld[j].in,
6264 = ((rld[j].when_needed == RELOAD_FOR_INPUT_ADDRESS
6265 || rld[j].when_needed == RELOAD_FOR_INPADDR_ADDRESS)
6266 ? RELOAD_FOR_OTHER_ADDRESS : RELOAD_OTHER);
6268 /* Check to see if we accidentally converted two
6269 reloads that use the same reload register with
6270 different inputs to the same type. If so, the
6271 resulting code won't work. */
6273 for (k = 0; k < j; k++)
6274 gcc_assert (rld[k].in == 0 || rld[k].reg_rtx == 0
6275 || rld[k].when_needed != rld[j].when_needed
6276 || !rtx_equal_p (rld[k].reg_rtx,
6278 || rtx_equal_p (rld[k].in,
6285 /* These arrays are filled by emit_reload_insns and its subroutines. */
6286 static rtx input_reload_insns[MAX_RECOG_OPERANDS];
6287 static rtx other_input_address_reload_insns = 0;
6288 static rtx other_input_reload_insns = 0;
6289 static rtx input_address_reload_insns[MAX_RECOG_OPERANDS];
6290 static rtx inpaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6291 static rtx output_reload_insns[MAX_RECOG_OPERANDS];
6292 static rtx output_address_reload_insns[MAX_RECOG_OPERANDS];
6293 static rtx outaddr_address_reload_insns[MAX_RECOG_OPERANDS];
6294 static rtx operand_reload_insns = 0;
6295 static rtx other_operand_reload_insns = 0;
6296 static rtx other_output_reload_insns[MAX_RECOG_OPERANDS];
6298 /* Values to be put in spill_reg_store are put here first. */
6299 static rtx new_spill_reg_store[FIRST_PSEUDO_REGISTER];
6300 static HARD_REG_SET reg_reloaded_died;
6302 /* Check if *RELOAD_REG is suitable as an intermediate or scratch register
6303 of class NEW_CLASS with mode NEW_MODE. Or alternatively, if alt_reload_reg
6304 is nonzero, if that is suitable. On success, change *RELOAD_REG to the
6305 adjusted register, and return true. Otherwise, return false. */
6307 reload_adjust_reg_for_temp (rtx *reload_reg, rtx alt_reload_reg,
6308 enum reg_class new_class,
6309 enum machine_mode new_mode)
6314 for (reg = *reload_reg; reg; reg = alt_reload_reg, alt_reload_reg = 0)
6316 unsigned regno = REGNO (reg);
6318 if (!TEST_HARD_REG_BIT (reg_class_contents[(int) new_class], regno))
6320 if (GET_MODE (reg) != new_mode)
6322 if (!HARD_REGNO_MODE_OK (regno, new_mode))
6324 if (hard_regno_nregs[regno][new_mode]
6325 > hard_regno_nregs[regno][GET_MODE (reg)])
6327 reg = reload_adjust_reg_for_mode (reg, new_mode);
6335 /* Check if *RELOAD_REG is suitable as a scratch register for the reload
6336 pattern with insn_code ICODE, or alternatively, if alt_reload_reg is
6337 nonzero, if that is suitable. On success, change *RELOAD_REG to the
6338 adjusted register, and return true. Otherwise, return false. */
6340 reload_adjust_reg_for_icode (rtx *reload_reg, rtx alt_reload_reg,
6341 enum insn_code icode)
6344 enum reg_class new_class = scratch_reload_class (icode);
6345 enum machine_mode new_mode = insn_data[(int) icode].operand[2].mode;
6347 return reload_adjust_reg_for_temp (reload_reg, alt_reload_reg,
6348 new_class, new_mode);
6351 /* Generate insns to perform reload RL, which is for the insn in CHAIN and
6352 has the number J. OLD contains the value to be used as input. */
6355 emit_input_reload_insns (struct insn_chain *chain, struct reload *rl,
6358 rtx insn = chain->insn;
6359 rtx reloadreg = rl->reg_rtx;
6360 rtx oldequiv_reg = 0;
6363 enum machine_mode mode;
6366 /* Determine the mode to reload in.
6367 This is very tricky because we have three to choose from.
6368 There is the mode the insn operand wants (rl->inmode).
6369 There is the mode of the reload register RELOADREG.
6370 There is the intrinsic mode of the operand, which we could find
6371 by stripping some SUBREGs.
6372 It turns out that RELOADREG's mode is irrelevant:
6373 we can change that arbitrarily.
6375 Consider (SUBREG:SI foo:QI) as an operand that must be SImode;
6376 then the reload reg may not support QImode moves, so use SImode.
6377 If foo is in memory due to spilling a pseudo reg, this is safe,
6378 because the QImode value is in the least significant part of a
6379 slot big enough for a SImode. If foo is some other sort of
6380 memory reference, then it is impossible to reload this case,
6381 so previous passes had better make sure this never happens.
6383 Then consider a one-word union which has SImode and one of its
6384 members is a float, being fetched as (SUBREG:SF union:SI).
6385 We must fetch that as SFmode because we could be loading into
6386 a float-only register. In this case OLD's mode is correct.
6388 Consider an immediate integer: it has VOIDmode. Here we need
6389 to get a mode from something else.
6391 In some cases, there is a fourth mode, the operand's
6392 containing mode. If the insn specifies a containing mode for
6393 this operand, it overrides all others.
6395 I am not sure whether the algorithm here is always right,
6396 but it does the right things in those cases. */
6398 mode = GET_MODE (old);
6399 if (mode == VOIDmode)
6402 /* delete_output_reload is only invoked properly if old contains
6403 the original pseudo register. Since this is replaced with a
6404 hard reg when RELOAD_OVERRIDE_IN is set, see if we can
6405 find the pseudo in RELOAD_IN_REG. */
6406 if (reload_override_in[j]
6407 && REG_P (rl->in_reg))
6414 else if (REG_P (oldequiv))
6415 oldequiv_reg = oldequiv;
6416 else if (GET_CODE (oldequiv) == SUBREG)
6417 oldequiv_reg = SUBREG_REG (oldequiv);
6419 /* If we are reloading from a register that was recently stored in
6420 with an output-reload, see if we can prove there was
6421 actually no need to store the old value in it. */
6423 if (optimize && REG_P (oldequiv)
6424 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6425 && spill_reg_store[REGNO (oldequiv)]
6427 && (dead_or_set_p (insn, spill_reg_stored_to[REGNO (oldequiv)])
6428 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6430 delete_output_reload (insn, j, REGNO (oldequiv));
6432 /* Encapsulate both RELOADREG and OLDEQUIV into that mode,
6433 then load RELOADREG from OLDEQUIV. Note that we cannot use
6434 gen_lowpart_common since it can do the wrong thing when
6435 RELOADREG has a multi-word mode. Note that RELOADREG
6436 must always be a REG here. */
6438 if (GET_MODE (reloadreg) != mode)
6439 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6440 while (GET_CODE (oldequiv) == SUBREG && GET_MODE (oldequiv) != mode)
6441 oldequiv = SUBREG_REG (oldequiv);
6442 if (GET_MODE (oldequiv) != VOIDmode
6443 && mode != GET_MODE (oldequiv))
6444 oldequiv = gen_lowpart_SUBREG (mode, oldequiv);
6446 /* Switch to the right place to emit the reload insns. */
6447 switch (rl->when_needed)
6450 where = &other_input_reload_insns;
6452 case RELOAD_FOR_INPUT:
6453 where = &input_reload_insns[rl->opnum];
6455 case RELOAD_FOR_INPUT_ADDRESS:
6456 where = &input_address_reload_insns[rl->opnum];
6458 case RELOAD_FOR_INPADDR_ADDRESS:
6459 where = &inpaddr_address_reload_insns[rl->opnum];
6461 case RELOAD_FOR_OUTPUT_ADDRESS:
6462 where = &output_address_reload_insns[rl->opnum];
6464 case RELOAD_FOR_OUTADDR_ADDRESS:
6465 where = &outaddr_address_reload_insns[rl->opnum];
6467 case RELOAD_FOR_OPERAND_ADDRESS:
6468 where = &operand_reload_insns;
6470 case RELOAD_FOR_OPADDR_ADDR:
6471 where = &other_operand_reload_insns;
6473 case RELOAD_FOR_OTHER_ADDRESS:
6474 where = &other_input_address_reload_insns;
6480 push_to_sequence (*where);
6482 /* Auto-increment addresses must be reloaded in a special way. */
6483 if (rl->out && ! rl->out_reg)
6485 /* We are not going to bother supporting the case where a
6486 incremented register can't be copied directly from
6487 OLDEQUIV since this seems highly unlikely. */
6488 gcc_assert (rl->secondary_in_reload < 0);
6490 if (reload_inherited[j])
6491 oldequiv = reloadreg;
6493 old = XEXP (rl->in_reg, 0);
6495 if (optimize && REG_P (oldequiv)
6496 && REGNO (oldequiv) < FIRST_PSEUDO_REGISTER
6497 && spill_reg_store[REGNO (oldequiv)]
6499 && (dead_or_set_p (insn,
6500 spill_reg_stored_to[REGNO (oldequiv)])
6501 || rtx_equal_p (spill_reg_stored_to[REGNO (oldequiv)],
6503 delete_output_reload (insn, j, REGNO (oldequiv));
6505 /* Prevent normal processing of this reload. */
6507 /* Output a special code sequence for this case. */
6508 new_spill_reg_store[REGNO (reloadreg)]
6509 = inc_for_reload (reloadreg, oldequiv, rl->out,
6513 /* If we are reloading a pseudo-register that was set by the previous
6514 insn, see if we can get rid of that pseudo-register entirely
6515 by redirecting the previous insn into our reload register. */
6517 else if (optimize && REG_P (old)
6518 && REGNO (old) >= FIRST_PSEUDO_REGISTER
6519 && dead_or_set_p (insn, old)
6520 /* This is unsafe if some other reload
6521 uses the same reg first. */
6522 && ! conflicts_with_override (reloadreg)
6523 && free_for_value_p (REGNO (reloadreg), rl->mode, rl->opnum,
6524 rl->when_needed, old, rl->out, j, 0))
6526 rtx temp = PREV_INSN (insn);
6527 while (temp && NOTE_P (temp))
6528 temp = PREV_INSN (temp);
6530 && NONJUMP_INSN_P (temp)
6531 && GET_CODE (PATTERN (temp)) == SET
6532 && SET_DEST (PATTERN (temp)) == old
6533 /* Make sure we can access insn_operand_constraint. */
6534 && asm_noperands (PATTERN (temp)) < 0
6535 /* This is unsafe if operand occurs more than once in current
6536 insn. Perhaps some occurrences aren't reloaded. */
6537 && count_occurrences (PATTERN (insn), old, 0) == 1)
6539 rtx old = SET_DEST (PATTERN (temp));
6540 /* Store into the reload register instead of the pseudo. */
6541 SET_DEST (PATTERN (temp)) = reloadreg;
6543 /* Verify that resulting insn is valid. */
6544 extract_insn (temp);
6545 if (constrain_operands (1))
6547 /* If the previous insn is an output reload, the source is
6548 a reload register, and its spill_reg_store entry will
6549 contain the previous destination. This is now
6551 if (REG_P (SET_SRC (PATTERN (temp)))
6552 && REGNO (SET_SRC (PATTERN (temp))) < FIRST_PSEUDO_REGISTER)
6554 spill_reg_store[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6555 spill_reg_stored_to[REGNO (SET_SRC (PATTERN (temp)))] = 0;
6558 /* If these are the only uses of the pseudo reg,
6559 pretend for GDB it lives in the reload reg we used. */
6560 if (REG_N_DEATHS (REGNO (old)) == 1
6561 && REG_N_SETS (REGNO (old)) == 1)
6563 reg_renumber[REGNO (old)] = REGNO (rl->reg_rtx);
6564 alter_reg (REGNO (old), -1);
6570 SET_DEST (PATTERN (temp)) = old;
6575 /* We can't do that, so output an insn to load RELOADREG. */
6577 /* If we have a secondary reload, pick up the secondary register
6578 and icode, if any. If OLDEQUIV and OLD are different or
6579 if this is an in-out reload, recompute whether or not we
6580 still need a secondary register and what the icode should
6581 be. If we still need a secondary register and the class or
6582 icode is different, go back to reloading from OLD if using
6583 OLDEQUIV means that we got the wrong type of register. We
6584 cannot have different class or icode due to an in-out reload
6585 because we don't make such reloads when both the input and
6586 output need secondary reload registers. */
6588 if (! special && rl->secondary_in_reload >= 0)
6590 rtx second_reload_reg = 0;
6591 rtx third_reload_reg = 0;
6592 int secondary_reload = rl->secondary_in_reload;
6593 rtx real_oldequiv = oldequiv;
6596 enum insn_code icode;
6597 enum insn_code tertiary_icode = CODE_FOR_nothing;
6599 /* If OLDEQUIV is a pseudo with a MEM, get the real MEM
6600 and similarly for OLD.
6601 See comments in get_secondary_reload in reload.c. */
6602 /* If it is a pseudo that cannot be replaced with its
6603 equivalent MEM, we must fall back to reload_in, which
6604 will have all the necessary substitutions registered.
6605 Likewise for a pseudo that can't be replaced with its
6606 equivalent constant.
6608 Take extra care for subregs of such pseudos. Note that
6609 we cannot use reg_equiv_mem in this case because it is
6610 not in the right mode. */
6613 if (GET_CODE (tmp) == SUBREG)
6614 tmp = SUBREG_REG (tmp);
6616 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6617 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6618 || reg_equiv_constant[REGNO (tmp)] != 0))
6620 if (! reg_equiv_mem[REGNO (tmp)]
6621 || num_not_at_initial_offset
6622 || GET_CODE (oldequiv) == SUBREG)
6623 real_oldequiv = rl->in;
6625 real_oldequiv = reg_equiv_mem[REGNO (tmp)];
6629 if (GET_CODE (tmp) == SUBREG)
6630 tmp = SUBREG_REG (tmp);
6632 && REGNO (tmp) >= FIRST_PSEUDO_REGISTER
6633 && (reg_equiv_memory_loc[REGNO (tmp)] != 0
6634 || reg_equiv_constant[REGNO (tmp)] != 0))
6636 if (! reg_equiv_mem[REGNO (tmp)]
6637 || num_not_at_initial_offset
6638 || GET_CODE (old) == SUBREG)
6641 real_old = reg_equiv_mem[REGNO (tmp)];
6644 second_reload_reg = rld[secondary_reload].reg_rtx;
6645 if (rld[secondary_reload].secondary_in_reload >= 0)
6647 int tertiary_reload = rld[secondary_reload].secondary_in_reload;
6649 third_reload_reg = rld[tertiary_reload].reg_rtx;
6650 tertiary_icode = rld[secondary_reload].secondary_in_icode;
6651 /* We'd have to add more code for quartary reloads. */
6652 gcc_assert (rld[tertiary_reload].secondary_in_reload < 0);
6654 icode = rl->secondary_in_icode;
6656 if ((old != oldequiv && ! rtx_equal_p (old, oldequiv))
6657 || (rl->in != 0 && rl->out != 0))
6659 secondary_reload_info sri, sri2;
6660 enum reg_class new_class, new_t_class;
6662 sri.icode = CODE_FOR_nothing;
6663 sri.prev_sri = NULL;
6664 new_class = targetm.secondary_reload (1, real_oldequiv, rl->class,
6667 if (new_class == NO_REGS && sri.icode == CODE_FOR_nothing)
6668 second_reload_reg = 0;
6669 else if (new_class == NO_REGS)
6671 if (reload_adjust_reg_for_icode (&second_reload_reg,
6672 third_reload_reg, sri.icode))
6673 icode = sri.icode, third_reload_reg = 0;
6675 oldequiv = old, real_oldequiv = real_old;
6677 else if (sri.icode != CODE_FOR_nothing)
6678 /* We currently lack a way to express this in reloads. */
6682 sri2.icode = CODE_FOR_nothing;
6683 sri2.prev_sri = &sri;
6684 new_t_class = targetm.secondary_reload (1, real_oldequiv,
6685 new_class, mode, &sri);
6686 if (new_t_class == NO_REGS && sri2.icode == CODE_FOR_nothing)
6688 if (reload_adjust_reg_for_temp (&second_reload_reg,
6691 third_reload_reg = 0, tertiary_icode = sri2.icode;
6693 oldequiv = old, real_oldequiv = real_old;
6695 else if (new_t_class == NO_REGS && sri2.icode != CODE_FOR_nothing)
6697 rtx intermediate = second_reload_reg;
6699 if (reload_adjust_reg_for_temp (&intermediate, NULL,
6701 && reload_adjust_reg_for_icode (&third_reload_reg, NULL,
6704 second_reload_reg = intermediate;
6705 tertiary_icode = sri2.icode;
6708 oldequiv = old, real_oldequiv = real_old;
6710 else if (new_t_class != NO_REGS && sri2.icode == CODE_FOR_nothing)
6712 rtx intermediate = second_reload_reg;
6714 if (reload_adjust_reg_for_temp (&intermediate, NULL,
6716 && reload_adjust_reg_for_temp (&third_reload_reg, NULL,
6719 second_reload_reg = intermediate;
6720 tertiary_icode = sri2.icode;
6723 oldequiv = old, real_oldequiv = real_old;
6726 /* This could be handled more intelligently too. */
6727 oldequiv = old, real_oldequiv = real_old;
6731 /* If we still need a secondary reload register, check
6732 to see if it is being used as a scratch or intermediate
6733 register and generate code appropriately. If we need
6734 a scratch register, use REAL_OLDEQUIV since the form of
6735 the insn may depend on the actual address if it is
6738 if (second_reload_reg)
6740 if (icode != CODE_FOR_nothing)
6742 /* We'd have to add extra code to handle this case. */
6743 gcc_assert (!third_reload_reg);
6745 emit_insn (GEN_FCN (icode) (reloadreg, real_oldequiv,
6746 second_reload_reg));
6751 /* See if we need a scratch register to load the
6752 intermediate register (a tertiary reload). */
6753 if (tertiary_icode != CODE_FOR_nothing)
6755 emit_insn ((GEN_FCN (tertiary_icode)
6756 (second_reload_reg, real_oldequiv,
6757 third_reload_reg)));
6759 else if (third_reload_reg)
6761 gen_reload (third_reload_reg, real_oldequiv,
6764 gen_reload (second_reload_reg, third_reload_reg,
6769 gen_reload (second_reload_reg, real_oldequiv,
6773 oldequiv = second_reload_reg;
6778 if (! special && ! rtx_equal_p (reloadreg, oldequiv))
6780 rtx real_oldequiv = oldequiv;
6782 if ((REG_P (oldequiv)
6783 && REGNO (oldequiv) >= FIRST_PSEUDO_REGISTER
6784 && (reg_equiv_memory_loc[REGNO (oldequiv)] != 0
6785 || reg_equiv_constant[REGNO (oldequiv)] != 0))
6786 || (GET_CODE (oldequiv) == SUBREG
6787 && REG_P (SUBREG_REG (oldequiv))
6788 && (REGNO (SUBREG_REG (oldequiv))
6789 >= FIRST_PSEUDO_REGISTER)
6790 && ((reg_equiv_memory_loc
6791 [REGNO (SUBREG_REG (oldequiv))] != 0)
6792 || (reg_equiv_constant
6793 [REGNO (SUBREG_REG (oldequiv))] != 0)))
6794 || (CONSTANT_P (oldequiv)
6795 && (PREFERRED_RELOAD_CLASS (oldequiv,
6796 REGNO_REG_CLASS (REGNO (reloadreg)))
6798 real_oldequiv = rl->in;
6799 gen_reload (reloadreg, real_oldequiv, rl->opnum,
6803 if (flag_non_call_exceptions)
6804 copy_eh_notes (insn, get_insns ());
6806 /* End this sequence. */
6807 *where = get_insns ();
6810 /* Update reload_override_in so that delete_address_reloads_1
6811 can see the actual register usage. */
6813 reload_override_in[j] = oldequiv;
6816 /* Generate insns to for the output reload RL, which is for the insn described
6817 by CHAIN and has the number J. */
6819 emit_output_reload_insns (struct insn_chain *chain, struct reload *rl,
6822 rtx reloadreg = rl->reg_rtx;
6823 rtx insn = chain->insn;
6826 enum machine_mode mode = GET_MODE (old);
6829 if (rl->when_needed == RELOAD_OTHER)
6832 push_to_sequence (output_reload_insns[rl->opnum]);
6834 /* Determine the mode to reload in.
6835 See comments above (for input reloading). */
6837 if (mode == VOIDmode)
6839 /* VOIDmode should never happen for an output. */
6840 if (asm_noperands (PATTERN (insn)) < 0)
6841 /* It's the compiler's fault. */
6842 fatal_insn ("VOIDmode on an output", insn);
6843 error_for_asm (insn, "output operand is constant in %<asm%>");
6844 /* Prevent crash--use something we know is valid. */
6846 old = gen_rtx_REG (mode, REGNO (reloadreg));
6849 if (GET_MODE (reloadreg) != mode)
6850 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6852 /* If we need two reload regs, set RELOADREG to the intermediate
6853 one, since it will be stored into OLD. We might need a secondary
6854 register only for an input reload, so check again here. */
6856 if (rl->secondary_out_reload >= 0)
6859 int secondary_reload = rl->secondary_out_reload;
6860 int tertiary_reload = rld[secondary_reload].secondary_out_reload;
6862 if (REG_P (old) && REGNO (old) >= FIRST_PSEUDO_REGISTER
6863 && reg_equiv_mem[REGNO (old)] != 0)
6864 real_old = reg_equiv_mem[REGNO (old)];
6866 if (secondary_reload_class (0, rl->class, mode, real_old) != NO_REGS)
6868 rtx second_reloadreg = reloadreg;
6869 reloadreg = rld[secondary_reload].reg_rtx;
6871 /* See if RELOADREG is to be used as a scratch register
6872 or as an intermediate register. */
6873 if (rl->secondary_out_icode != CODE_FOR_nothing)
6875 /* We'd have to add extra code to handle this case. */
6876 gcc_assert (tertiary_reload < 0);
6878 emit_insn ((GEN_FCN (rl->secondary_out_icode)
6879 (real_old, second_reloadreg, reloadreg)));
6884 /* See if we need both a scratch and intermediate reload
6887 enum insn_code tertiary_icode
6888 = rld[secondary_reload].secondary_out_icode;
6890 /* We'd have to add more code for quartary reloads. */
6891 gcc_assert (tertiary_reload < 0
6892 || rld[tertiary_reload].secondary_out_reload < 0);
6894 if (GET_MODE (reloadreg) != mode)
6895 reloadreg = reload_adjust_reg_for_mode (reloadreg, mode);
6897 if (tertiary_icode != CODE_FOR_nothing)
6899 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
6902 /* Copy primary reload reg to secondary reload reg.
6903 (Note that these have been swapped above, then
6904 secondary reload reg to OLD using our insn.) */
6906 /* If REAL_OLD is a paradoxical SUBREG, remove it
6907 and try to put the opposite SUBREG on
6909 if (GET_CODE (real_old) == SUBREG
6910 && (GET_MODE_SIZE (GET_MODE (real_old))
6911 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (real_old))))
6912 && 0 != (tem = gen_lowpart_common
6913 (GET_MODE (SUBREG_REG (real_old)),
6915 real_old = SUBREG_REG (real_old), reloadreg = tem;
6917 gen_reload (reloadreg, second_reloadreg,
6918 rl->opnum, rl->when_needed);
6919 emit_insn ((GEN_FCN (tertiary_icode)
6920 (real_old, reloadreg, third_reloadreg)));
6926 /* Copy between the reload regs here and then to
6929 gen_reload (reloadreg, second_reloadreg,
6930 rl->opnum, rl->when_needed);
6931 if (tertiary_reload >= 0)
6933 rtx third_reloadreg = rld[tertiary_reload].reg_rtx;
6935 gen_reload (third_reloadreg, reloadreg,
6936 rl->opnum, rl->when_needed);
6937 reloadreg = third_reloadreg;
6944 /* Output the last reload insn. */
6949 /* Don't output the last reload if OLD is not the dest of
6950 INSN and is in the src and is clobbered by INSN. */
6951 if (! flag_expensive_optimizations
6953 || !(set = single_set (insn))
6954 || rtx_equal_p (old, SET_DEST (set))
6955 || !reg_mentioned_p (old, SET_SRC (set))
6956 || !((REGNO (old) < FIRST_PSEUDO_REGISTER)
6957 && regno_clobbered_p (REGNO (old), insn, rl->mode, 0)))
6958 gen_reload (old, reloadreg, rl->opnum,
6962 /* Look at all insns we emitted, just to be safe. */
6963 for (p = get_insns (); p; p = NEXT_INSN (p))
6966 rtx pat = PATTERN (p);
6968 /* If this output reload doesn't come from a spill reg,
6969 clear any memory of reloaded copies of the pseudo reg.
6970 If this output reload comes from a spill reg,
6971 reg_has_output_reload will make this do nothing. */
6972 note_stores (pat, forget_old_reloads_1, NULL);
6974 if (reg_mentioned_p (rl->reg_rtx, pat))
6976 rtx set = single_set (insn);
6977 if (reload_spill_index[j] < 0
6979 && SET_SRC (set) == rl->reg_rtx)
6981 int src = REGNO (SET_SRC (set));
6983 reload_spill_index[j] = src;
6984 SET_HARD_REG_BIT (reg_is_output_reload, src);
6985 if (find_regno_note (insn, REG_DEAD, src))
6986 SET_HARD_REG_BIT (reg_reloaded_died, src);
6988 if (REGNO (rl->reg_rtx) < FIRST_PSEUDO_REGISTER)
6990 int s = rl->secondary_out_reload;
6991 set = single_set (p);
6992 /* If this reload copies only to the secondary reload
6993 register, the secondary reload does the actual
6995 if (s >= 0 && set == NULL_RTX)
6996 /* We can't tell what function the secondary reload
6997 has and where the actual store to the pseudo is
6998 made; leave new_spill_reg_store alone. */
7001 && SET_SRC (set) == rl->reg_rtx
7002 && SET_DEST (set) == rld[s].reg_rtx)
7004 /* Usually the next instruction will be the
7005 secondary reload insn; if we can confirm
7006 that it is, setting new_spill_reg_store to
7007 that insn will allow an extra optimization. */
7008 rtx s_reg = rld[s].reg_rtx;
7009 rtx next = NEXT_INSN (p);
7010 rld[s].out = rl->out;
7011 rld[s].out_reg = rl->out_reg;
7012 set = single_set (next);
7013 if (set && SET_SRC (set) == s_reg
7014 && ! new_spill_reg_store[REGNO (s_reg)])
7016 SET_HARD_REG_BIT (reg_is_output_reload,
7018 new_spill_reg_store[REGNO (s_reg)] = next;
7022 new_spill_reg_store[REGNO (rl->reg_rtx)] = p;
7027 if (rl->when_needed == RELOAD_OTHER)
7029 emit_insn (other_output_reload_insns[rl->opnum]);
7030 other_output_reload_insns[rl->opnum] = get_insns ();
7033 output_reload_insns[rl->opnum] = get_insns ();
7035 if (flag_non_call_exceptions)
7036 copy_eh_notes (insn, get_insns ());
7041 /* Do input reloading for reload RL, which is for the insn described by CHAIN
7042 and has the number J. */
7044 do_input_reload (struct insn_chain *chain, struct reload *rl, int j)
7046 rtx insn = chain->insn;
7047 rtx old = (rl->in && MEM_P (rl->in)
7048 ? rl->in_reg : rl->in);
7051 /* AUTO_INC reloads need to be handled even if inherited. We got an
7052 AUTO_INC reload if reload_out is set but reload_out_reg isn't. */
7053 && (! reload_inherited[j] || (rl->out && ! rl->out_reg))
7054 && ! rtx_equal_p (rl->reg_rtx, old)
7055 && rl->reg_rtx != 0)
7056 emit_input_reload_insns (chain, rld + j, old, j);
7058 /* When inheriting a wider reload, we have a MEM in rl->in,
7059 e.g. inheriting a SImode output reload for
7060 (mem:HI (plus:SI (reg:SI 14 fp) (const_int 10))) */
7061 if (optimize && reload_inherited[j] && rl->in
7063 && MEM_P (rl->in_reg)
7064 && reload_spill_index[j] >= 0
7065 && TEST_HARD_REG_BIT (reg_reloaded_valid, reload_spill_index[j]))
7066 rl->in = regno_reg_rtx[reg_reloaded_contents[reload_spill_index[j]]];
7068 /* If we are reloading a register that was recently stored in with an
7069 output-reload, see if we can prove there was
7070 actually no need to store the old value in it. */
7073 /* Only attempt this for input reloads; for RELOAD_OTHER we miss
7074 that there may be multiple uses of the previous output reload.
7075 Restricting to RELOAD_FOR_INPUT is mostly paranoia. */
7076 && rl->when_needed == RELOAD_FOR_INPUT
7077 && (reload_inherited[j] || reload_override_in[j])
7079 && REG_P (rl->reg_rtx)
7080 && spill_reg_store[REGNO (rl->reg_rtx)] != 0
7082 /* There doesn't seem to be any reason to restrict this to pseudos
7083 and doing so loses in the case where we are copying from a
7084 register of the wrong class. */
7085 && (REGNO (spill_reg_stored_to[REGNO (rl->reg_rtx)])
7086 >= FIRST_PSEUDO_REGISTER)
7088 /* The insn might have already some references to stackslots
7089 replaced by MEMs, while reload_out_reg still names the
7091 && (dead_or_set_p (insn,
7092 spill_reg_stored_to[REGNO (rl->reg_rtx)])
7093 || rtx_equal_p (spill_reg_stored_to[REGNO (rl->reg_rtx)],
7095 delete_output_reload (insn, j, REGNO (rl->reg_rtx));
7098 /* Do output reloading for reload RL, which is for the insn described by
7099 CHAIN and has the number J.
7100 ??? At some point we need to support handling output reloads of
7101 JUMP_INSNs or insns that set cc0. */
7103 do_output_reload (struct insn_chain *chain, struct reload *rl, int j)
7106 rtx insn = chain->insn;
7107 /* If this is an output reload that stores something that is
7108 not loaded in this same reload, see if we can eliminate a previous
7110 rtx pseudo = rl->out_reg;
7115 && ! rtx_equal_p (rl->in_reg, pseudo)
7116 && REGNO (pseudo) >= FIRST_PSEUDO_REGISTER
7117 && reg_last_reload_reg[REGNO (pseudo)])
7119 int pseudo_no = REGNO (pseudo);
7120 int last_regno = REGNO (reg_last_reload_reg[pseudo_no]);
7122 /* We don't need to test full validity of last_regno for
7123 inherit here; we only want to know if the store actually
7124 matches the pseudo. */
7125 if (TEST_HARD_REG_BIT (reg_reloaded_valid, last_regno)
7126 && reg_reloaded_contents[last_regno] == pseudo_no
7127 && spill_reg_store[last_regno]
7128 && rtx_equal_p (pseudo, spill_reg_stored_to[last_regno]))
7129 delete_output_reload (insn, j, last_regno);
7134 || rl->reg_rtx == old
7135 || rl->reg_rtx == 0)
7138 /* An output operand that dies right away does need a reload,
7139 but need not be copied from it. Show the new location in the
7141 if ((REG_P (old) || GET_CODE (old) == SCRATCH)
7142 && (note = find_reg_note (insn, REG_UNUSED, old)) != 0)
7144 XEXP (note, 0) = rl->reg_rtx;
7147 /* Likewise for a SUBREG of an operand that dies. */
7148 else if (GET_CODE (old) == SUBREG
7149 && REG_P (SUBREG_REG (old))
7150 && 0 != (note = find_reg_note (insn, REG_UNUSED,
7153 XEXP (note, 0) = gen_lowpart_common (GET_MODE (old),
7157 else if (GET_CODE (old) == SCRATCH)
7158 /* If we aren't optimizing, there won't be a REG_UNUSED note,
7159 but we don't want to make an output reload. */
7162 /* If is a JUMP_INSN, we can't support output reloads yet. */
7163 gcc_assert (NONJUMP_INSN_P (insn));
7165 emit_output_reload_insns (chain, rld + j, j);
7168 /* Reload number R reloads from or to a group of hard registers starting at
7169 register REGNO. Return true if it can be treated for inheritance purposes
7170 like a group of reloads, each one reloading a single hard register.
7171 The caller has already checked that the spill register and REGNO use
7172 the same number of registers to store the reload value. */
7175 inherit_piecemeal_p (int r ATTRIBUTE_UNUSED, int regno ATTRIBUTE_UNUSED)
7177 #ifdef CANNOT_CHANGE_MODE_CLASS
7178 return (!REG_CANNOT_CHANGE_MODE_P (reload_spill_index[r],
7179 GET_MODE (rld[r].reg_rtx),
7180 reg_raw_mode[reload_spill_index[r]])
7181 && !REG_CANNOT_CHANGE_MODE_P (regno,
7182 GET_MODE (rld[r].reg_rtx),
7183 reg_raw_mode[regno]));
7189 /* Output insns to reload values in and out of the chosen reload regs. */
7192 emit_reload_insns (struct insn_chain *chain)
7194 rtx insn = chain->insn;
7198 CLEAR_HARD_REG_SET (reg_reloaded_died);
7200 for (j = 0; j < reload_n_operands; j++)
7201 input_reload_insns[j] = input_address_reload_insns[j]
7202 = inpaddr_address_reload_insns[j]
7203 = output_reload_insns[j] = output_address_reload_insns[j]
7204 = outaddr_address_reload_insns[j]
7205 = other_output_reload_insns[j] = 0;
7206 other_input_address_reload_insns = 0;
7207 other_input_reload_insns = 0;
7208 operand_reload_insns = 0;
7209 other_operand_reload_insns = 0;
7211 /* Dump reloads into the dump file. */
7214 fprintf (dump_file, "\nReloads for insn # %d\n", INSN_UID (insn));
7215 debug_reload_to_stream (dump_file);
7218 /* Now output the instructions to copy the data into and out of the
7219 reload registers. Do these in the order that the reloads were reported,
7220 since reloads of base and index registers precede reloads of operands
7221 and the operands may need the base and index registers reloaded. */
7223 for (j = 0; j < n_reloads; j++)
7226 && REGNO (rld[j].reg_rtx) < FIRST_PSEUDO_REGISTER)
7227 new_spill_reg_store[REGNO (rld[j].reg_rtx)] = 0;
7229 do_input_reload (chain, rld + j, j);
7230 do_output_reload (chain, rld + j, j);
7233 /* Now write all the insns we made for reloads in the order expected by
7234 the allocation functions. Prior to the insn being reloaded, we write
7235 the following reloads:
7237 RELOAD_FOR_OTHER_ADDRESS reloads for input addresses.
7239 RELOAD_OTHER reloads.
7241 For each operand, any RELOAD_FOR_INPADDR_ADDRESS reloads followed
7242 by any RELOAD_FOR_INPUT_ADDRESS reloads followed by the
7243 RELOAD_FOR_INPUT reload for the operand.
7245 RELOAD_FOR_OPADDR_ADDRS reloads.
7247 RELOAD_FOR_OPERAND_ADDRESS reloads.
7249 After the insn being reloaded, we write the following:
7251 For each operand, any RELOAD_FOR_OUTADDR_ADDRESS reloads followed
7252 by any RELOAD_FOR_OUTPUT_ADDRESS reload followed by the
7253 RELOAD_FOR_OUTPUT reload, followed by any RELOAD_OTHER output
7254 reloads for the operand. The RELOAD_OTHER output reloads are
7255 output in descending order by reload number. */
7257 emit_insn_before (other_input_address_reload_insns, insn);
7258 emit_insn_before (other_input_reload_insns, insn);
7260 for (j = 0; j < reload_n_operands; j++)
7262 emit_insn_before (inpaddr_address_reload_insns[j], insn);
7263 emit_insn_before (input_address_reload_insns[j], insn);
7264 emit_insn_before (input_reload_insns[j], insn);
7267 emit_insn_before (other_operand_reload_insns, insn);
7268 emit_insn_before (operand_reload_insns, insn);
7270 for (j = 0; j < reload_n_operands; j++)
7272 rtx x = emit_insn_after (outaddr_address_reload_insns[j], insn);
7273 x = emit_insn_after (output_address_reload_insns[j], x);
7274 x = emit_insn_after (output_reload_insns[j], x);
7275 emit_insn_after (other_output_reload_insns[j], x);
7278 /* For all the spill regs newly reloaded in this instruction,
7279 record what they were reloaded from, so subsequent instructions
7280 can inherit the reloads.
7282 Update spill_reg_store for the reloads of this insn.
7283 Copy the elements that were updated in the loop above. */
7285 for (j = 0; j < n_reloads; j++)
7287 int r = reload_order[j];
7288 int i = reload_spill_index[r];
7290 /* If this is a non-inherited input reload from a pseudo, we must
7291 clear any memory of a previous store to the same pseudo. Only do
7292 something if there will not be an output reload for the pseudo
7294 if (rld[r].in_reg != 0
7295 && ! (reload_inherited[r] || reload_override_in[r]))
7297 rtx reg = rld[r].in_reg;
7299 if (GET_CODE (reg) == SUBREG)
7300 reg = SUBREG_REG (reg);
7303 && REGNO (reg) >= FIRST_PSEUDO_REGISTER
7304 && !REGNO_REG_SET_P (®_has_output_reload, REGNO (reg)))
7306 int nregno = REGNO (reg);
7308 if (reg_last_reload_reg[nregno])
7310 int last_regno = REGNO (reg_last_reload_reg[nregno]);
7312 if (reg_reloaded_contents[last_regno] == nregno)
7313 spill_reg_store[last_regno] = 0;
7318 /* I is nonneg if this reload used a register.
7319 If rld[r].reg_rtx is 0, this is an optional reload
7320 that we opted to ignore. */
7322 if (i >= 0 && rld[r].reg_rtx != 0)
7324 int nr = hard_regno_nregs[i][GET_MODE (rld[r].reg_rtx)];
7326 int part_reaches_end = 0;
7327 int all_reaches_end = 1;
7329 /* For a multi register reload, we need to check if all or part
7330 of the value lives to the end. */
7331 for (k = 0; k < nr; k++)
7333 if (reload_reg_reaches_end_p (i + k, rld[r].opnum,
7334 rld[r].when_needed))
7335 part_reaches_end = 1;
7337 all_reaches_end = 0;
7340 /* Ignore reloads that don't reach the end of the insn in
7342 if (all_reaches_end)
7344 /* First, clear out memory of what used to be in this spill reg.
7345 If consecutive registers are used, clear them all. */
7347 for (k = 0; k < nr; k++)
7349 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7350 CLEAR_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7353 /* Maybe the spill reg contains a copy of reload_out. */
7355 && (REG_P (rld[r].out)
7359 || REG_P (rld[r].out_reg)))
7361 rtx out = (REG_P (rld[r].out)
7365 /* AUTO_INC */ : XEXP (rld[r].in_reg, 0));
7366 int nregno = REGNO (out);
7367 int nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7368 : hard_regno_nregs[nregno]
7369 [GET_MODE (rld[r].reg_rtx)]);
7372 spill_reg_store[i] = new_spill_reg_store[i];
7373 spill_reg_stored_to[i] = out;
7374 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7376 piecemeal = (nregno < FIRST_PSEUDO_REGISTER
7378 && inherit_piecemeal_p (r, nregno));
7380 /* If NREGNO is a hard register, it may occupy more than
7381 one register. If it does, say what is in the
7382 rest of the registers assuming that both registers
7383 agree on how many words the object takes. If not,
7384 invalidate the subsequent registers. */
7386 if (nregno < FIRST_PSEUDO_REGISTER)
7387 for (k = 1; k < nnr; k++)
7388 reg_last_reload_reg[nregno + k]
7390 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7393 /* Now do the inverse operation. */
7394 for (k = 0; k < nr; k++)
7396 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7397 reg_reloaded_contents[i + k]
7398 = (nregno >= FIRST_PSEUDO_REGISTER || !piecemeal
7401 reg_reloaded_insn[i + k] = insn;
7402 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7403 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (out)))
7404 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7408 /* Maybe the spill reg contains a copy of reload_in. Only do
7409 something if there will not be an output reload for
7410 the register being reloaded. */
7411 else if (rld[r].out_reg == 0
7413 && ((REG_P (rld[r].in)
7414 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER
7415 && !REGNO_REG_SET_P (®_has_output_reload,
7417 || (REG_P (rld[r].in_reg)
7418 && !REGNO_REG_SET_P (®_has_output_reload,
7419 REGNO (rld[r].in_reg))))
7420 && ! reg_set_p (rld[r].reg_rtx, PATTERN (insn)))
7427 if (REG_P (rld[r].in)
7428 && REGNO (rld[r].in) >= FIRST_PSEUDO_REGISTER)
7430 else if (REG_P (rld[r].in_reg))
7433 in = XEXP (rld[r].in_reg, 0);
7434 nregno = REGNO (in);
7436 nnr = (nregno >= FIRST_PSEUDO_REGISTER ? 1
7437 : hard_regno_nregs[nregno]
7438 [GET_MODE (rld[r].reg_rtx)]);
7440 reg_last_reload_reg[nregno] = rld[r].reg_rtx;
7442 piecemeal = (nregno < FIRST_PSEUDO_REGISTER
7444 && inherit_piecemeal_p (r, nregno));
7446 if (nregno < FIRST_PSEUDO_REGISTER)
7447 for (k = 1; k < nnr; k++)
7448 reg_last_reload_reg[nregno + k]
7450 ? regno_reg_rtx[REGNO (rld[r].reg_rtx) + k]
7453 /* Unless we inherited this reload, show we haven't
7454 recently done a store.
7455 Previous stores of inherited auto_inc expressions
7456 also have to be discarded. */
7457 if (! reload_inherited[r]
7458 || (rld[r].out && ! rld[r].out_reg))
7459 spill_reg_store[i] = 0;
7461 for (k = 0; k < nr; k++)
7463 CLEAR_HARD_REG_BIT (reg_reloaded_dead, i + k);
7464 reg_reloaded_contents[i + k]
7465 = (nregno >= FIRST_PSEUDO_REGISTER || !piecemeal
7468 reg_reloaded_insn[i + k] = insn;
7469 SET_HARD_REG_BIT (reg_reloaded_valid, i + k);
7470 if (HARD_REGNO_CALL_PART_CLOBBERED (i + k, GET_MODE (in)))
7471 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered, i + k);
7476 /* However, if part of the reload reaches the end, then we must
7477 invalidate the old info for the part that survives to the end. */
7478 else if (part_reaches_end)
7480 for (k = 0; k < nr; k++)
7481 if (reload_reg_reaches_end_p (i + k,
7483 rld[r].when_needed))
7484 CLEAR_HARD_REG_BIT (reg_reloaded_valid, i + k);
7488 /* The following if-statement was #if 0'd in 1.34 (or before...).
7489 It's reenabled in 1.35 because supposedly nothing else
7490 deals with this problem. */
7492 /* If a register gets output-reloaded from a non-spill register,
7493 that invalidates any previous reloaded copy of it.
7494 But forget_old_reloads_1 won't get to see it, because
7495 it thinks only about the original insn. So invalidate it here.
7496 Also do the same thing for RELOAD_OTHER constraints where the
7497 output is discarded. */
7499 && ((rld[r].out != 0
7500 && (REG_P (rld[r].out)
7501 || (MEM_P (rld[r].out)
7502 && REG_P (rld[r].out_reg))))
7503 || (rld[r].out == 0 && rld[r].out_reg
7504 && REG_P (rld[r].out_reg))))
7506 rtx out = ((rld[r].out && REG_P (rld[r].out))
7507 ? rld[r].out : rld[r].out_reg);
7508 int nregno = REGNO (out);
7509 if (nregno >= FIRST_PSEUDO_REGISTER)
7511 rtx src_reg, store_insn = NULL_RTX;
7513 reg_last_reload_reg[nregno] = 0;
7515 /* If we can find a hard register that is stored, record
7516 the storing insn so that we may delete this insn with
7517 delete_output_reload. */
7518 src_reg = rld[r].reg_rtx;
7520 /* If this is an optional reload, try to find the source reg
7521 from an input reload. */
7524 rtx set = single_set (insn);
7525 if (set && SET_DEST (set) == rld[r].out)
7529 src_reg = SET_SRC (set);
7531 for (k = 0; k < n_reloads; k++)
7533 if (rld[k].in == src_reg)
7535 src_reg = rld[k].reg_rtx;
7542 store_insn = new_spill_reg_store[REGNO (src_reg)];
7543 if (src_reg && REG_P (src_reg)
7544 && REGNO (src_reg) < FIRST_PSEUDO_REGISTER)
7546 int src_regno = REGNO (src_reg);
7547 int nr = hard_regno_nregs[src_regno][rld[r].mode];
7548 /* The place where to find a death note varies with
7549 PRESERVE_DEATH_INFO_REGNO_P . The condition is not
7550 necessarily checked exactly in the code that moves
7551 notes, so just check both locations. */
7552 rtx note = find_regno_note (insn, REG_DEAD, src_regno);
7553 if (! note && store_insn)
7554 note = find_regno_note (store_insn, REG_DEAD, src_regno);
7557 spill_reg_store[src_regno + nr] = store_insn;
7558 spill_reg_stored_to[src_regno + nr] = out;
7559 reg_reloaded_contents[src_regno + nr] = nregno;
7560 reg_reloaded_insn[src_regno + nr] = store_insn;
7561 CLEAR_HARD_REG_BIT (reg_reloaded_dead, src_regno + nr);
7562 SET_HARD_REG_BIT (reg_reloaded_valid, src_regno + nr);
7563 if (HARD_REGNO_CALL_PART_CLOBBERED (src_regno + nr,
7564 GET_MODE (src_reg)))
7565 SET_HARD_REG_BIT (reg_reloaded_call_part_clobbered,
7567 SET_HARD_REG_BIT (reg_is_output_reload, src_regno + nr);
7569 SET_HARD_REG_BIT (reg_reloaded_died, src_regno);
7571 CLEAR_HARD_REG_BIT (reg_reloaded_died, src_regno);
7573 reg_last_reload_reg[nregno] = src_reg;
7574 /* We have to set reg_has_output_reload here, or else
7575 forget_old_reloads_1 will clear reg_last_reload_reg
7577 SET_REGNO_REG_SET (®_has_output_reload,
7583 int num_regs = hard_regno_nregs[nregno][GET_MODE (out)];
7585 while (num_regs-- > 0)
7586 reg_last_reload_reg[nregno + num_regs] = 0;
7590 IOR_HARD_REG_SET (reg_reloaded_dead, reg_reloaded_died);
7593 /* Go through the motions to emit INSN and test if it is strictly valid.
7594 Return the emitted insn if valid, else return NULL. */
7597 emit_insn_if_valid_for_reload (rtx insn)
7599 rtx last = get_last_insn ();
7602 insn = emit_insn (insn);
7603 code = recog_memoized (insn);
7607 extract_insn (insn);
7608 /* We want constrain operands to treat this insn strictly in its
7609 validity determination, i.e., the way it would after reload has
7611 if (constrain_operands (1))
7615 delete_insns_since (last);
7619 /* Emit code to perform a reload from IN (which may be a reload register) to
7620 OUT (which may also be a reload register). IN or OUT is from operand
7621 OPNUM with reload type TYPE.
7623 Returns first insn emitted. */
7626 gen_reload (rtx out, rtx in, int opnum, enum reload_type type)
7628 rtx last = get_last_insn ();
7631 /* If IN is a paradoxical SUBREG, remove it and try to put the
7632 opposite SUBREG on OUT. Likewise for a paradoxical SUBREG on OUT. */
7633 if (GET_CODE (in) == SUBREG
7634 && (GET_MODE_SIZE (GET_MODE (in))
7635 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (in))))
7636 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (in)), out)) != 0)
7637 in = SUBREG_REG (in), out = tem;
7638 else if (GET_CODE (out) == SUBREG
7639 && (GET_MODE_SIZE (GET_MODE (out))
7640 > GET_MODE_SIZE (GET_MODE (SUBREG_REG (out))))
7641 && (tem = gen_lowpart_common (GET_MODE (SUBREG_REG (out)), in)) != 0)
7642 out = SUBREG_REG (out), in = tem;
7644 /* How to do this reload can get quite tricky. Normally, we are being
7645 asked to reload a simple operand, such as a MEM, a constant, or a pseudo
7646 register that didn't get a hard register. In that case we can just
7647 call emit_move_insn.
7649 We can also be asked to reload a PLUS that adds a register or a MEM to
7650 another register, constant or MEM. This can occur during frame pointer
7651 elimination and while reloading addresses. This case is handled by
7652 trying to emit a single insn to perform the add. If it is not valid,
7653 we use a two insn sequence.
7655 Or we can be asked to reload an unary operand that was a fragment of
7656 an addressing mode, into a register. If it isn't recognized as-is,
7657 we try making the unop operand and the reload-register the same:
7658 (set reg:X (unop:X expr:Y))
7659 -> (set reg:Y expr:Y) (set reg:X (unop:X reg:Y)).
7661 Finally, we could be called to handle an 'o' constraint by putting
7662 an address into a register. In that case, we first try to do this
7663 with a named pattern of "reload_load_address". If no such pattern
7664 exists, we just emit a SET insn and hope for the best (it will normally
7665 be valid on machines that use 'o').
7667 This entire process is made complex because reload will never
7668 process the insns we generate here and so we must ensure that
7669 they will fit their constraints and also by the fact that parts of
7670 IN might be being reloaded separately and replaced with spill registers.
7671 Because of this, we are, in some sense, just guessing the right approach
7672 here. The one listed above seems to work.
7674 ??? At some point, this whole thing needs to be rethought. */
7676 if (GET_CODE (in) == PLUS
7677 && (REG_P (XEXP (in, 0))
7678 || GET_CODE (XEXP (in, 0)) == SUBREG
7679 || MEM_P (XEXP (in, 0)))
7680 && (REG_P (XEXP (in, 1))
7681 || GET_CODE (XEXP (in, 1)) == SUBREG
7682 || CONSTANT_P (XEXP (in, 1))
7683 || MEM_P (XEXP (in, 1))))
7685 /* We need to compute the sum of a register or a MEM and another
7686 register, constant, or MEM, and put it into the reload
7687 register. The best possible way of doing this is if the machine
7688 has a three-operand ADD insn that accepts the required operands.
7690 The simplest approach is to try to generate such an insn and see if it
7691 is recognized and matches its constraints. If so, it can be used.
7693 It might be better not to actually emit the insn unless it is valid,
7694 but we need to pass the insn as an operand to `recog' and
7695 `extract_insn' and it is simpler to emit and then delete the insn if
7696 not valid than to dummy things up. */
7698 rtx op0, op1, tem, insn;
7701 op0 = find_replacement (&XEXP (in, 0));
7702 op1 = find_replacement (&XEXP (in, 1));
7704 /* Since constraint checking is strict, commutativity won't be
7705 checked, so we need to do that here to avoid spurious failure
7706 if the add instruction is two-address and the second operand
7707 of the add is the same as the reload reg, which is frequently
7708 the case. If the insn would be A = B + A, rearrange it so
7709 it will be A = A + B as constrain_operands expects. */
7711 if (REG_P (XEXP (in, 1))
7712 && REGNO (out) == REGNO (XEXP (in, 1)))
7713 tem = op0, op0 = op1, op1 = tem;
7715 if (op0 != XEXP (in, 0) || op1 != XEXP (in, 1))
7716 in = gen_rtx_PLUS (GET_MODE (in), op0, op1);
7718 insn = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
7722 /* If that failed, we must use a conservative two-insn sequence.
7724 Use a move to copy one operand into the reload register. Prefer
7725 to reload a constant, MEM or pseudo since the move patterns can
7726 handle an arbitrary operand. If OP1 is not a constant, MEM or
7727 pseudo and OP1 is not a valid operand for an add instruction, then
7730 After reloading one of the operands into the reload register, add
7731 the reload register to the output register.
7733 If there is another way to do this for a specific machine, a
7734 DEFINE_PEEPHOLE should be specified that recognizes the sequence
7737 code = (int) add_optab->handlers[(int) GET_MODE (out)].insn_code;
7739 if (CONSTANT_P (op1) || MEM_P (op1) || GET_CODE (op1) == SUBREG
7741 && REGNO (op1) >= FIRST_PSEUDO_REGISTER)
7742 || (code != CODE_FOR_nothing
7743 && ! ((*insn_data[code].operand[2].predicate)
7744 (op1, insn_data[code].operand[2].mode))))
7745 tem = op0, op0 = op1, op1 = tem;
7747 gen_reload (out, op0, opnum, type);
7749 /* If OP0 and OP1 are the same, we can use OUT for OP1.
7750 This fixes a problem on the 32K where the stack pointer cannot
7751 be used as an operand of an add insn. */
7753 if (rtx_equal_p (op0, op1))
7756 insn = emit_insn_if_valid_for_reload (gen_add2_insn (out, op1));
7759 /* Add a REG_EQUIV note so that find_equiv_reg can find it. */
7761 = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7765 /* If that failed, copy the address register to the reload register.
7766 Then add the constant to the reload register. */
7768 gen_reload (out, op1, opnum, type);
7769 insn = emit_insn (gen_add2_insn (out, op0));
7770 REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7773 #ifdef SECONDARY_MEMORY_NEEDED
7774 /* If we need a memory location to do the move, do it that way. */
7775 else if ((REG_P (in) || GET_CODE (in) == SUBREG)
7776 && reg_or_subregno (in) < FIRST_PSEUDO_REGISTER
7777 && (REG_P (out) || GET_CODE (out) == SUBREG)
7778 && reg_or_subregno (out) < FIRST_PSEUDO_REGISTER
7779 && SECONDARY_MEMORY_NEEDED (REGNO_REG_CLASS (reg_or_subregno (in)),
7780 REGNO_REG_CLASS (reg_or_subregno (out)),
7783 /* Get the memory to use and rewrite both registers to its mode. */
7784 rtx loc = get_secondary_mem (in, GET_MODE (out), opnum, type);
7786 if (GET_MODE (loc) != GET_MODE (out))
7787 out = gen_rtx_REG (GET_MODE (loc), REGNO (out));
7789 if (GET_MODE (loc) != GET_MODE (in))
7790 in = gen_rtx_REG (GET_MODE (loc), REGNO (in));
7792 gen_reload (loc, in, opnum, type);
7793 gen_reload (out, loc, opnum, type);
7796 else if (REG_P (out) && UNARY_P (in))
7803 op1 = find_replacement (&XEXP (in, 0));
7804 if (op1 != XEXP (in, 0))
7805 in = gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in), op1);
7807 /* First, try a plain SET. */
7808 set = emit_insn_if_valid_for_reload (gen_rtx_SET (VOIDmode, out, in));
7812 /* If that failed, move the inner operand to the reload
7813 register, and try the same unop with the inner expression
7814 replaced with the reload register. */
7816 if (GET_MODE (op1) != GET_MODE (out))
7817 out_moded = gen_rtx_REG (GET_MODE (op1), REGNO (out));
7821 gen_reload (out_moded, op1, opnum, type);
7824 = gen_rtx_SET (VOIDmode, out,
7825 gen_rtx_fmt_e (GET_CODE (in), GET_MODE (in),
7827 insn = emit_insn_if_valid_for_reload (insn);
7831 = gen_rtx_EXPR_LIST (REG_EQUIV, in, REG_NOTES (insn));
7835 fatal_insn ("Failure trying to reload:", set);
7837 /* If IN is a simple operand, use gen_move_insn. */
7838 else if (OBJECT_P (in) || GET_CODE (in) == SUBREG)
7840 tem = emit_insn (gen_move_insn (out, in));
7841 /* IN may contain a LABEL_REF, if so add a REG_LABEL note. */
7842 mark_jump_label (in, tem, 0);
7845 #ifdef HAVE_reload_load_address
7846 else if (HAVE_reload_load_address)
7847 emit_insn (gen_reload_load_address (out, in));
7850 /* Otherwise, just write (set OUT IN) and hope for the best. */
7852 emit_insn (gen_rtx_SET (VOIDmode, out, in));
7854 /* Return the first insn emitted.
7855 We can not just return get_last_insn, because there may have
7856 been multiple instructions emitted. Also note that gen_move_insn may
7857 emit more than one insn itself, so we can not assume that there is one
7858 insn emitted per emit_insn_before call. */
7860 return last ? NEXT_INSN (last) : get_insns ();
7863 /* Delete a previously made output-reload whose result we now believe
7864 is not needed. First we double-check.
7866 INSN is the insn now being processed.
7867 LAST_RELOAD_REG is the hard register number for which we want to delete
7868 the last output reload.
7869 J is the reload-number that originally used REG. The caller has made
7870 certain that reload J doesn't use REG any longer for input. */
7873 delete_output_reload (rtx insn, int j, int last_reload_reg)
7875 rtx output_reload_insn = spill_reg_store[last_reload_reg];
7876 rtx reg = spill_reg_stored_to[last_reload_reg];
7879 int n_inherited = 0;
7883 /* It is possible that this reload has been only used to set another reload
7884 we eliminated earlier and thus deleted this instruction too. */
7885 if (INSN_DELETED_P (output_reload_insn))
7888 /* Get the raw pseudo-register referred to. */
7890 while (GET_CODE (reg) == SUBREG)
7891 reg = SUBREG_REG (reg);
7892 substed = reg_equiv_memory_loc[REGNO (reg)];
7894 /* This is unsafe if the operand occurs more often in the current
7895 insn than it is inherited. */
7896 for (k = n_reloads - 1; k >= 0; k--)
7898 rtx reg2 = rld[k].in;
7901 if (MEM_P (reg2) || reload_override_in[k])
7902 reg2 = rld[k].in_reg;
7904 if (rld[k].out && ! rld[k].out_reg)
7905 reg2 = XEXP (rld[k].in_reg, 0);
7907 while (GET_CODE (reg2) == SUBREG)
7908 reg2 = SUBREG_REG (reg2);
7909 if (rtx_equal_p (reg2, reg))
7911 if (reload_inherited[k] || reload_override_in[k] || k == j)
7914 reg2 = rld[k].out_reg;
7917 while (GET_CODE (reg2) == SUBREG)
7918 reg2 = XEXP (reg2, 0);
7919 if (rtx_equal_p (reg2, reg))
7926 n_occurrences = count_occurrences (PATTERN (insn), reg, 0);
7928 n_occurrences += count_occurrences (PATTERN (insn),
7929 eliminate_regs (substed, 0,
7931 for (i1 = reg_equiv_alt_mem_list [REGNO (reg)]; i1; i1 = XEXP (i1, 1))
7933 gcc_assert (!rtx_equal_p (XEXP (i1, 0), substed));
7934 n_occurrences += count_occurrences (PATTERN (insn), XEXP (i1, 0), 0);
7936 if (n_occurrences > n_inherited)
7939 /* If the pseudo-reg we are reloading is no longer referenced
7940 anywhere between the store into it and here,
7941 and we're within the same basic block, then the value can only
7942 pass through the reload reg and end up here.
7943 Otherwise, give up--return. */
7944 for (i1 = NEXT_INSN (output_reload_insn);
7945 i1 != insn; i1 = NEXT_INSN (i1))
7947 if (NOTE_INSN_BASIC_BLOCK_P (i1))
7949 if ((NONJUMP_INSN_P (i1) || CALL_P (i1))
7950 && reg_mentioned_p (reg, PATTERN (i1)))
7952 /* If this is USE in front of INSN, we only have to check that
7953 there are no more references than accounted for by inheritance. */
7954 while (NONJUMP_INSN_P (i1) && GET_CODE (PATTERN (i1)) == USE)
7956 n_occurrences += rtx_equal_p (reg, XEXP (PATTERN (i1), 0)) != 0;
7957 i1 = NEXT_INSN (i1);
7959 if (n_occurrences <= n_inherited && i1 == insn)
7965 /* We will be deleting the insn. Remove the spill reg information. */
7966 for (k = hard_regno_nregs[last_reload_reg][GET_MODE (reg)]; k-- > 0; )
7968 spill_reg_store[last_reload_reg + k] = 0;
7969 spill_reg_stored_to[last_reload_reg + k] = 0;
7972 /* The caller has already checked that REG dies or is set in INSN.
7973 It has also checked that we are optimizing, and thus some
7974 inaccuracies in the debugging information are acceptable.
7975 So we could just delete output_reload_insn. But in some cases
7976 we can improve the debugging information without sacrificing
7977 optimization - maybe even improving the code: See if the pseudo
7978 reg has been completely replaced with reload regs. If so, delete
7979 the store insn and forget we had a stack slot for the pseudo. */
7980 if (rld[j].out != rld[j].in
7981 && REG_N_DEATHS (REGNO (reg)) == 1
7982 && REG_N_SETS (REGNO (reg)) == 1
7983 && REG_BASIC_BLOCK (REGNO (reg)) >= 0
7984 && find_regno_note (insn, REG_DEAD, REGNO (reg)))
7988 /* We know that it was used only between here and the beginning of
7989 the current basic block. (We also know that the last use before
7990 INSN was the output reload we are thinking of deleting, but never
7991 mind that.) Search that range; see if any ref remains. */
7992 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
7994 rtx set = single_set (i2);
7996 /* Uses which just store in the pseudo don't count,
7997 since if they are the only uses, they are dead. */
7998 if (set != 0 && SET_DEST (set) == reg)
8003 if ((NONJUMP_INSN_P (i2) || CALL_P (i2))
8004 && reg_mentioned_p (reg, PATTERN (i2)))
8006 /* Some other ref remains; just delete the output reload we
8008 delete_address_reloads (output_reload_insn, insn);
8009 delete_insn (output_reload_insn);
8014 /* Delete the now-dead stores into this pseudo. Note that this
8015 loop also takes care of deleting output_reload_insn. */
8016 for (i2 = PREV_INSN (insn); i2; i2 = PREV_INSN (i2))
8018 rtx set = single_set (i2);
8020 if (set != 0 && SET_DEST (set) == reg)
8022 delete_address_reloads (i2, insn);
8030 /* For the debugging info, say the pseudo lives in this reload reg. */
8031 reg_renumber[REGNO (reg)] = REGNO (rld[j].reg_rtx);
8032 alter_reg (REGNO (reg), -1);
8036 delete_address_reloads (output_reload_insn, insn);
8037 delete_insn (output_reload_insn);
8041 /* We are going to delete DEAD_INSN. Recursively delete loads of
8042 reload registers used in DEAD_INSN that are not used till CURRENT_INSN.
8043 CURRENT_INSN is being reloaded, so we have to check its reloads too. */
8045 delete_address_reloads (rtx dead_insn, rtx current_insn)
8047 rtx set = single_set (dead_insn);
8048 rtx set2, dst, prev, next;
8051 rtx dst = SET_DEST (set);
8053 delete_address_reloads_1 (dead_insn, XEXP (dst, 0), current_insn);
8055 /* If we deleted the store from a reloaded post_{in,de}c expression,
8056 we can delete the matching adds. */
8057 prev = PREV_INSN (dead_insn);
8058 next = NEXT_INSN (dead_insn);
8059 if (! prev || ! next)
8061 set = single_set (next);
8062 set2 = single_set (prev);
8064 || GET_CODE (SET_SRC (set)) != PLUS || GET_CODE (SET_SRC (set2)) != PLUS
8065 || GET_CODE (XEXP (SET_SRC (set), 1)) != CONST_INT
8066 || GET_CODE (XEXP (SET_SRC (set2), 1)) != CONST_INT)
8068 dst = SET_DEST (set);
8069 if (! rtx_equal_p (dst, SET_DEST (set2))
8070 || ! rtx_equal_p (dst, XEXP (SET_SRC (set), 0))
8071 || ! rtx_equal_p (dst, XEXP (SET_SRC (set2), 0))
8072 || (INTVAL (XEXP (SET_SRC (set), 1))
8073 != -INTVAL (XEXP (SET_SRC (set2), 1))))
8075 delete_related_insns (prev);
8076 delete_related_insns (next);
8079 /* Subfunction of delete_address_reloads: process registers found in X. */
8081 delete_address_reloads_1 (rtx dead_insn, rtx x, rtx current_insn)
8083 rtx prev, set, dst, i2;
8085 enum rtx_code code = GET_CODE (x);
8089 const char *fmt = GET_RTX_FORMAT (code);
8090 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8093 delete_address_reloads_1 (dead_insn, XEXP (x, i), current_insn);
8094 else if (fmt[i] == 'E')
8096 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8097 delete_address_reloads_1 (dead_insn, XVECEXP (x, i, j),
8104 if (spill_reg_order[REGNO (x)] < 0)
8107 /* Scan backwards for the insn that sets x. This might be a way back due
8109 for (prev = PREV_INSN (dead_insn); prev; prev = PREV_INSN (prev))
8111 code = GET_CODE (prev);
8112 if (code == CODE_LABEL || code == JUMP_INSN)
8116 if (reg_set_p (x, PATTERN (prev)))
8118 if (reg_referenced_p (x, PATTERN (prev)))
8121 if (! prev || INSN_UID (prev) < reload_first_uid)
8123 /* Check that PREV only sets the reload register. */
8124 set = single_set (prev);
8127 dst = SET_DEST (set);
8129 || ! rtx_equal_p (dst, x))
8131 if (! reg_set_p (dst, PATTERN (dead_insn)))
8133 /* Check if DST was used in a later insn -
8134 it might have been inherited. */
8135 for (i2 = NEXT_INSN (dead_insn); i2; i2 = NEXT_INSN (i2))
8141 if (reg_referenced_p (dst, PATTERN (i2)))
8143 /* If there is a reference to the register in the current insn,
8144 it might be loaded in a non-inherited reload. If no other
8145 reload uses it, that means the register is set before
8147 if (i2 == current_insn)
8149 for (j = n_reloads - 1; j >= 0; j--)
8150 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8151 || reload_override_in[j] == dst)
8153 for (j = n_reloads - 1; j >= 0; j--)
8154 if (rld[j].in && rld[j].reg_rtx == dst)
8163 /* If DST is still live at CURRENT_INSN, check if it is used for
8164 any reload. Note that even if CURRENT_INSN sets DST, we still
8165 have to check the reloads. */
8166 if (i2 == current_insn)
8168 for (j = n_reloads - 1; j >= 0; j--)
8169 if ((rld[j].reg_rtx == dst && reload_inherited[j])
8170 || reload_override_in[j] == dst)
8172 /* ??? We can't finish the loop here, because dst might be
8173 allocated to a pseudo in this block if no reload in this
8174 block needs any of the classes containing DST - see
8175 spill_hard_reg. There is no easy way to tell this, so we
8176 have to scan till the end of the basic block. */
8178 if (reg_set_p (dst, PATTERN (i2)))
8182 delete_address_reloads_1 (prev, SET_SRC (set), current_insn);
8183 reg_reloaded_contents[REGNO (dst)] = -1;
8187 /* Output reload-insns to reload VALUE into RELOADREG.
8188 VALUE is an autoincrement or autodecrement RTX whose operand
8189 is a register or memory location;
8190 so reloading involves incrementing that location.
8191 IN is either identical to VALUE, or some cheaper place to reload from.
8193 INC_AMOUNT is the number to increment or decrement by (always positive).
8194 This cannot be deduced from VALUE.
8196 Return the instruction that stores into RELOADREG. */
8199 inc_for_reload (rtx reloadreg, rtx in, rtx value, int inc_amount)
8201 /* REG or MEM to be copied and incremented. */
8202 rtx incloc = find_replacement (&XEXP (value, 0));
8203 /* Nonzero if increment after copying. */
8204 int post = (GET_CODE (value) == POST_DEC || GET_CODE (value) == POST_INC
8205 || GET_CODE (value) == POST_MODIFY);
8211 rtx real_in = in == value ? incloc : in;
8213 /* No hard register is equivalent to this register after
8214 inc/dec operation. If REG_LAST_RELOAD_REG were nonzero,
8215 we could inc/dec that register as well (maybe even using it for
8216 the source), but I'm not sure it's worth worrying about. */
8218 reg_last_reload_reg[REGNO (incloc)] = 0;
8220 if (GET_CODE (value) == PRE_MODIFY || GET_CODE (value) == POST_MODIFY)
8222 gcc_assert (GET_CODE (XEXP (value, 1)) == PLUS);
8223 inc = find_replacement (&XEXP (XEXP (value, 1), 1));
8227 if (GET_CODE (value) == PRE_DEC || GET_CODE (value) == POST_DEC)
8228 inc_amount = -inc_amount;
8230 inc = GEN_INT (inc_amount);
8233 /* If this is post-increment, first copy the location to the reload reg. */
8234 if (post && real_in != reloadreg)
8235 emit_insn (gen_move_insn (reloadreg, real_in));
8239 /* See if we can directly increment INCLOC. Use a method similar to
8240 that in gen_reload. */
8242 last = get_last_insn ();
8243 add_insn = emit_insn (gen_rtx_SET (VOIDmode, incloc,
8244 gen_rtx_PLUS (GET_MODE (incloc),
8247 code = recog_memoized (add_insn);
8250 extract_insn (add_insn);
8251 if (constrain_operands (1))
8253 /* If this is a pre-increment and we have incremented the value
8254 where it lives, copy the incremented value to RELOADREG to
8255 be used as an address. */
8258 emit_insn (gen_move_insn (reloadreg, incloc));
8263 delete_insns_since (last);
8266 /* If couldn't do the increment directly, must increment in RELOADREG.
8267 The way we do this depends on whether this is pre- or post-increment.
8268 For pre-increment, copy INCLOC to the reload register, increment it
8269 there, then save back. */
8273 if (in != reloadreg)
8274 emit_insn (gen_move_insn (reloadreg, real_in));
8275 emit_insn (gen_add2_insn (reloadreg, inc));
8276 store = emit_insn (gen_move_insn (incloc, reloadreg));
8281 Because this might be a jump insn or a compare, and because RELOADREG
8282 may not be available after the insn in an input reload, we must do
8283 the incrementation before the insn being reloaded for.
8285 We have already copied IN to RELOADREG. Increment the copy in
8286 RELOADREG, save that back, then decrement RELOADREG so it has
8287 the original value. */
8289 emit_insn (gen_add2_insn (reloadreg, inc));
8290 store = emit_insn (gen_move_insn (incloc, reloadreg));
8291 if (GET_CODE (inc) == CONST_INT)
8292 emit_insn (gen_add2_insn (reloadreg, GEN_INT (-INTVAL(inc))));
8294 emit_insn (gen_sub2_insn (reloadreg, inc));
8302 add_auto_inc_notes (rtx insn, rtx x)
8304 enum rtx_code code = GET_CODE (x);
8308 if (code == MEM && auto_inc_p (XEXP (x, 0)))
8311 = gen_rtx_EXPR_LIST (REG_INC, XEXP (XEXP (x, 0), 0), REG_NOTES (insn));
8315 /* Scan all the operand sub-expressions. */
8316 fmt = GET_RTX_FORMAT (code);
8317 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
8320 add_auto_inc_notes (insn, XEXP (x, i));
8321 else if (fmt[i] == 'E')
8322 for (j = XVECLEN (x, i) - 1; j >= 0; j--)
8323 add_auto_inc_notes (insn, XVECEXP (x, i, j));
8328 /* Copy EH notes from an insn to its reloads. */
8330 copy_eh_notes (rtx insn, rtx x)
8332 rtx eh_note = find_reg_note (insn, REG_EH_REGION, NULL_RTX);
8335 for (; x != 0; x = NEXT_INSN (x))
8337 if (may_trap_p (PATTERN (x)))
8339 = gen_rtx_EXPR_LIST (REG_EH_REGION, XEXP (eh_note, 0),
8345 /* This is used by reload pass, that does emit some instructions after
8346 abnormal calls moving basic block end, but in fact it wants to emit
8347 them on the edge. Looks for abnormal call edges, find backward the
8348 proper call and fix the damage.
8350 Similar handle instructions throwing exceptions internally. */
8352 fixup_abnormal_edges (void)
8354 bool inserted = false;
8362 /* Look for cases we are interested in - calls or instructions causing
8364 FOR_EACH_EDGE (e, ei, bb->succs)
8366 if (e->flags & EDGE_ABNORMAL_CALL)
8368 if ((e->flags & (EDGE_ABNORMAL | EDGE_EH))
8369 == (EDGE_ABNORMAL | EDGE_EH))
8372 if (e && !CALL_P (BB_END (bb))
8373 && !can_throw_internal (BB_END (bb)))
8377 /* Get past the new insns generated. Allow notes, as the insns
8378 may be already deleted. */
8380 while ((NONJUMP_INSN_P (insn) || NOTE_P (insn))
8381 && !can_throw_internal (insn)
8382 && insn != BB_HEAD (bb))
8383 insn = PREV_INSN (insn);
8385 if (CALL_P (insn) || can_throw_internal (insn))
8389 stop = NEXT_INSN (BB_END (bb));
8391 insn = NEXT_INSN (insn);
8393 FOR_EACH_EDGE (e, ei, bb->succs)
8394 if (e->flags & EDGE_FALLTHRU)
8397 while (insn && insn != stop)
8399 next = NEXT_INSN (insn);
8404 /* Sometimes there's still the return value USE.
8405 If it's placed after a trapping call (i.e. that
8406 call is the last insn anyway), we have no fallthru
8407 edge. Simply delete this use and don't try to insert
8408 on the non-existent edge. */
8409 if (GET_CODE (PATTERN (insn)) != USE)
8411 /* We're not deleting it, we're moving it. */
8412 INSN_DELETED_P (insn) = 0;
8413 PREV_INSN (insn) = NULL_RTX;
8414 NEXT_INSN (insn) = NULL_RTX;
8416 insert_insn_on_edge (insn, e);
8424 /* It may be that we don't find any such trapping insn. In this
8425 case we discovered quite late that the insn that had been
8426 marked as can_throw_internal in fact couldn't trap at all.
8427 So we should in fact delete the EH edges out of the block. */
8429 purge_dead_edges (bb);
8433 /* We've possibly turned single trapping insn into multiple ones. */
8434 if (flag_non_call_exceptions)
8437 blocks = sbitmap_alloc (last_basic_block);
8438 sbitmap_ones (blocks);
8439 find_many_sub_basic_blocks (blocks);
8443 commit_edge_insertions ();
8445 #ifdef ENABLE_CHECKING
8446 /* Verify that we didn't turn one trapping insn into many, and that
8447 we found and corrected all of the problems wrt fixups on the
8449 verify_flow_info ();
projects / FreeBSD / releng / 10.0.git / blob