1 //===-- PPCRegisterInfo.cpp - PowerPC Register Information ----------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file contains the PowerPC implementation of the TargetRegisterInfo
12 //===----------------------------------------------------------------------===//
14 #include "PPCRegisterInfo.h"
15 #include "PPCFrameLowering.h"
16 #include "PPCInstrBuilder.h"
17 #include "PPCMachineFunctionInfo.h"
18 #include "PPCSubtarget.h"
19 #include "PPCTargetMachine.h"
20 #include "llvm/ADT/BitVector.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineInstrBuilder.h"
26 #include "llvm/CodeGen/MachineModuleInfo.h"
27 #include "llvm/CodeGen/MachineRegisterInfo.h"
28 #include "llvm/CodeGen/RegisterScavenging.h"
29 #include "llvm/CodeGen/TargetFrameLowering.h"
30 #include "llvm/CodeGen/TargetInstrInfo.h"
31 #include "llvm/IR/CallingConv.h"
32 #include "llvm/IR/Constants.h"
33 #include "llvm/IR/Function.h"
34 #include "llvm/IR/Type.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Debug.h"
37 #include "llvm/Support/ErrorHandling.h"
38 #include "llvm/Support/MathExtras.h"
39 #include "llvm/Support/raw_ostream.h"
40 #include "llvm/Target/TargetMachine.h"
41 #include "llvm/Target/TargetOptions.h"
46 #define DEBUG_TYPE "reginfo"
48 #define GET_REGINFO_TARGET_DESC
49 #include "PPCGenRegisterInfo.inc"
51 STATISTIC(InflateGPRC, "Number of gprc inputs for getLargestLegalClass");
52 STATISTIC(InflateGP8RC, "Number of g8rc inputs for getLargestLegalClass");
55 EnableBasePointer("ppc-use-base-pointer", cl::Hidden, cl::init(true),
56 cl::desc("Enable use of a base pointer for complex stack frames"));
59 AlwaysBasePointer("ppc-always-use-base-pointer", cl::Hidden, cl::init(false),
60 cl::desc("Force the use of a base pointer in every function"));
63 EnableGPRToVecSpills("ppc-enable-gpr-to-vsr-spills", cl::Hidden, cl::init(false),
64 cl::desc("Enable spills from gpr to vsr rather than stack"));
67 StackPtrConst("ppc-stack-ptr-caller-preserved",
68 cl::desc("Consider R1 caller preserved so stack saves of "
69 "caller preserved registers can be LICM candidates"),
70 cl::init(true), cl::Hidden);
72 static cl::opt<unsigned>
73 MaxCRBitSpillDist("ppc-max-crbit-spill-dist",
74 cl::desc("Maximum search distance for definition of CR bit "
76 cl::Hidden, cl::init(100));
78 static unsigned offsetMinAlignForOpcode(unsigned OpC);
80 PPCRegisterInfo::PPCRegisterInfo(const PPCTargetMachine &TM)
81 : PPCGenRegisterInfo(TM.isPPC64() ? PPC::LR8 : PPC::LR,
83 TM.isPPC64() ? 0 : 1),
85 ImmToIdxMap[PPC::LD] = PPC::LDX; ImmToIdxMap[PPC::STD] = PPC::STDX;
86 ImmToIdxMap[PPC::LBZ] = PPC::LBZX; ImmToIdxMap[PPC::STB] = PPC::STBX;
87 ImmToIdxMap[PPC::LHZ] = PPC::LHZX; ImmToIdxMap[PPC::LHA] = PPC::LHAX;
88 ImmToIdxMap[PPC::LWZ] = PPC::LWZX; ImmToIdxMap[PPC::LWA] = PPC::LWAX;
89 ImmToIdxMap[PPC::LFS] = PPC::LFSX; ImmToIdxMap[PPC::LFD] = PPC::LFDX;
90 ImmToIdxMap[PPC::STH] = PPC::STHX; ImmToIdxMap[PPC::STW] = PPC::STWX;
91 ImmToIdxMap[PPC::STFS] = PPC::STFSX; ImmToIdxMap[PPC::STFD] = PPC::STFDX;
92 ImmToIdxMap[PPC::ADDI] = PPC::ADD4;
93 ImmToIdxMap[PPC::LWA_32] = PPC::LWAX_32;
96 ImmToIdxMap[PPC::LHA8] = PPC::LHAX8; ImmToIdxMap[PPC::LBZ8] = PPC::LBZX8;
97 ImmToIdxMap[PPC::LHZ8] = PPC::LHZX8; ImmToIdxMap[PPC::LWZ8] = PPC::LWZX8;
98 ImmToIdxMap[PPC::STB8] = PPC::STBX8; ImmToIdxMap[PPC::STH8] = PPC::STHX8;
99 ImmToIdxMap[PPC::STW8] = PPC::STWX8; ImmToIdxMap[PPC::STDU] = PPC::STDUX;
100 ImmToIdxMap[PPC::ADDI8] = PPC::ADD8;
103 ImmToIdxMap[PPC::DFLOADf32] = PPC::LXSSPX;
104 ImmToIdxMap[PPC::DFLOADf64] = PPC::LXSDX;
105 ImmToIdxMap[PPC::SPILLTOVSR_LD] = PPC::SPILLTOVSR_LDX;
106 ImmToIdxMap[PPC::SPILLTOVSR_ST] = PPC::SPILLTOVSR_STX;
107 ImmToIdxMap[PPC::DFSTOREf32] = PPC::STXSSPX;
108 ImmToIdxMap[PPC::DFSTOREf64] = PPC::STXSDX;
109 ImmToIdxMap[PPC::LXV] = PPC::LXVX;
110 ImmToIdxMap[PPC::LXSD] = PPC::LXSDX;
111 ImmToIdxMap[PPC::LXSSP] = PPC::LXSSPX;
112 ImmToIdxMap[PPC::STXV] = PPC::STXVX;
113 ImmToIdxMap[PPC::STXSD] = PPC::STXSDX;
114 ImmToIdxMap[PPC::STXSSP] = PPC::STXSSPX;
117 ImmToIdxMap[PPC::EVLDD] = PPC::EVLDDX;
118 ImmToIdxMap[PPC::EVSTDD] = PPC::EVSTDDX;
119 ImmToIdxMap[PPC::SPESTW] = PPC::SPESTWX;
120 ImmToIdxMap[PPC::SPELWZ] = PPC::SPELWZX;
123 /// getPointerRegClass - Return the register class to use to hold pointers.
124 /// This is used for addressing modes.
125 const TargetRegisterClass *
126 PPCRegisterInfo::getPointerRegClass(const MachineFunction &MF, unsigned Kind)
128 // Note that PPCInstrInfo::FoldImmediate also directly uses this Kind value
129 // when it checks for ZERO folding.
132 return &PPC::G8RC_NOX0RegClass;
133 return &PPC::GPRC_NOR0RegClass;
137 return &PPC::G8RCRegClass;
138 return &PPC::GPRCRegClass;
142 PPCRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
143 const PPCSubtarget &Subtarget = MF->getSubtarget<PPCSubtarget>();
144 if (MF->getFunction().getCallingConv() == CallingConv::AnyReg) {
145 if (!TM.isPPC64() && Subtarget.isAIXABI())
146 report_fatal_error("AnyReg unimplemented on 32-bit AIX.");
147 if (Subtarget.hasVSX())
148 return CSR_64_AllRegs_VSX_SaveList;
149 if (Subtarget.hasAltivec())
150 return CSR_64_AllRegs_Altivec_SaveList;
151 return CSR_64_AllRegs_SaveList;
154 // On PPC64, we might need to save r2 (but only if it is not reserved).
155 // We do not need to treat R2 as callee-saved when using PC-Relative calls
156 // because any direct uses of R2 will cause it to be reserved. If the function
157 // is a leaf or the only uses of R2 are implicit uses for calls, the calls
158 // will use the @notoc relocation which will cause this function to set the
159 // st_other bit to 1, thereby communicating to its caller that it arbitrarily
161 bool SaveR2 = MF->getRegInfo().isAllocatable(PPC::X2) &&
162 !Subtarget.isUsingPCRelativeCalls();
164 // Cold calling convention CSRs.
165 if (MF->getFunction().getCallingConv() == CallingConv::Cold) {
166 if (Subtarget.isAIXABI())
167 report_fatal_error("Cold calling unimplemented on AIX.");
169 if (Subtarget.hasAltivec())
170 return SaveR2 ? CSR_SVR64_ColdCC_R2_Altivec_SaveList
171 : CSR_SVR64_ColdCC_Altivec_SaveList;
172 return SaveR2 ? CSR_SVR64_ColdCC_R2_SaveList
173 : CSR_SVR64_ColdCC_SaveList;
176 if (Subtarget.hasAltivec())
177 return CSR_SVR32_ColdCC_Altivec_SaveList;
178 else if (Subtarget.hasSPE())
179 return CSR_SVR32_ColdCC_SPE_SaveList;
180 return CSR_SVR32_ColdCC_SaveList;
182 // Standard calling convention CSRs.
184 if (Subtarget.hasAltivec())
185 return SaveR2 ? CSR_PPC64_R2_Altivec_SaveList
186 : CSR_PPC64_Altivec_SaveList;
187 return SaveR2 ? CSR_PPC64_R2_SaveList : CSR_PPC64_SaveList;
190 if (Subtarget.isAIXABI())
191 return CSR_AIX32_SaveList;
192 if (Subtarget.hasAltivec())
193 return CSR_SVR432_Altivec_SaveList;
194 else if (Subtarget.hasSPE())
195 return CSR_SVR432_SPE_SaveList;
196 return CSR_SVR432_SaveList;
200 PPCRegisterInfo::getCallPreservedMask(const MachineFunction &MF,
201 CallingConv::ID CC) const {
202 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
203 if (CC == CallingConv::AnyReg) {
204 if (Subtarget.hasVSX())
205 return CSR_64_AllRegs_VSX_RegMask;
206 if (Subtarget.hasAltivec())
207 return CSR_64_AllRegs_Altivec_RegMask;
208 return CSR_64_AllRegs_RegMask;
211 if (Subtarget.isAIXABI()) {
212 assert(!Subtarget.hasAltivec() && "Altivec is not implemented on AIX yet.");
213 return TM.isPPC64() ? CSR_PPC64_RegMask : CSR_AIX32_RegMask;
216 if (CC == CallingConv::Cold) {
217 return TM.isPPC64() ? (Subtarget.hasAltivec() ? CSR_SVR64_ColdCC_Altivec_RegMask
218 : CSR_SVR64_ColdCC_RegMask)
219 : (Subtarget.hasAltivec() ? CSR_SVR32_ColdCC_Altivec_RegMask
220 : (Subtarget.hasSPE()
221 ? CSR_SVR32_ColdCC_SPE_RegMask
222 : CSR_SVR32_ColdCC_RegMask));
225 return TM.isPPC64() ? (Subtarget.hasAltivec() ? CSR_PPC64_Altivec_RegMask
227 : (Subtarget.hasAltivec()
228 ? CSR_SVR432_Altivec_RegMask
229 : (Subtarget.hasSPE() ? CSR_SVR432_SPE_RegMask
230 : CSR_SVR432_RegMask));
234 PPCRegisterInfo::getNoPreservedMask() const {
235 return CSR_NoRegs_RegMask;
238 void PPCRegisterInfo::adjustStackMapLiveOutMask(uint32_t *Mask) const {
239 for (unsigned PseudoReg : {PPC::ZERO, PPC::ZERO8, PPC::RM})
240 Mask[PseudoReg / 32] &= ~(1u << (PseudoReg % 32));
243 BitVector PPCRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
244 BitVector Reserved(getNumRegs());
245 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
246 const PPCFrameLowering *TFI = getFrameLowering(MF);
248 // The ZERO register is not really a register, but the representation of r0
249 // when used in instructions that treat r0 as the constant 0.
250 markSuperRegs(Reserved, PPC::ZERO);
252 // The FP register is also not really a register, but is the representation
253 // of the frame pointer register used by ISD::FRAMEADDR.
254 markSuperRegs(Reserved, PPC::FP);
256 // The BP register is also not really a register, but is the representation
257 // of the base pointer register used by setjmp.
258 markSuperRegs(Reserved, PPC::BP);
260 // The counter registers must be reserved so that counter-based loops can
261 // be correctly formed (and the mtctr instructions are not DCE'd).
262 markSuperRegs(Reserved, PPC::CTR);
263 markSuperRegs(Reserved, PPC::CTR8);
265 markSuperRegs(Reserved, PPC::R1);
266 markSuperRegs(Reserved, PPC::LR);
267 markSuperRegs(Reserved, PPC::LR8);
268 markSuperRegs(Reserved, PPC::RM);
270 markSuperRegs(Reserved, PPC::VRSAVE);
272 // The SVR4 ABI reserves r2 and r13
273 if (Subtarget.isSVR4ABI()) {
274 // We only reserve r2 if we need to use the TOC pointer. If we have no
275 // explicit uses of the TOC pointer (meaning we're a leaf function with
276 // no constant-pool loads, etc.) and we have no potential uses inside an
277 // inline asm block, then we can treat r2 has an ordinary callee-saved
279 const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
280 if (!TM.isPPC64() || FuncInfo->usesTOCBasePtr() || MF.hasInlineAsm())
281 markSuperRegs(Reserved, PPC::R2); // System-reserved register
282 markSuperRegs(Reserved, PPC::R13); // Small Data Area pointer register
285 // Always reserve r2 on AIX for now.
286 // TODO: Make r2 allocatable on AIX/XCOFF for some leaf functions.
287 if (Subtarget.isAIXABI())
288 markSuperRegs(Reserved, PPC::R2); // System-reserved register
290 // On PPC64, r13 is the thread pointer. Never allocate this register.
292 markSuperRegs(Reserved, PPC::R13);
294 if (TFI->needsFP(MF))
295 markSuperRegs(Reserved, PPC::R31);
297 bool IsPositionIndependent = TM.isPositionIndependent();
298 if (hasBasePointer(MF)) {
299 if (Subtarget.is32BitELFABI() && IsPositionIndependent)
300 markSuperRegs(Reserved, PPC::R29);
302 markSuperRegs(Reserved, PPC::R30);
305 if (Subtarget.is32BitELFABI() && IsPositionIndependent)
306 markSuperRegs(Reserved, PPC::R30);
308 // Reserve Altivec registers when Altivec is unavailable.
309 if (!Subtarget.hasAltivec())
310 for (TargetRegisterClass::iterator I = PPC::VRRCRegClass.begin(),
311 IE = PPC::VRRCRegClass.end(); I != IE; ++I)
312 markSuperRegs(Reserved, *I);
314 assert(checkAllSuperRegsMarked(Reserved));
318 bool PPCRegisterInfo::requiresFrameIndexScavenging(const MachineFunction &MF) const {
319 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
320 const PPCInstrInfo *InstrInfo = Subtarget.getInstrInfo();
321 const MachineFrameInfo &MFI = MF.getFrameInfo();
322 const std::vector<CalleeSavedInfo> &Info = MFI.getCalleeSavedInfo();
324 // If the callee saved info is invalid we have to default to true for safety.
325 if (!MFI.isCalleeSavedInfoValid())
328 // We will require the use of X-Forms because the frame is larger than what
329 // can be represented in signed 16 bits that fit in the immediate of a D-Form.
330 // If we need an X-Form then we need a register to store the address offset.
331 unsigned FrameSize = MFI.getStackSize();
332 // Signed 16 bits means that the FrameSize cannot be more than 15 bits.
333 if (FrameSize & ~0x7FFF)
336 // The callee saved info is valid so it can be traversed.
337 // Checking for registers that need saving that do not have load or store
338 // forms where the address offset is an immediate.
339 for (unsigned i = 0; i < Info.size(); i++) {
340 int FrIdx = Info[i].getFrameIdx();
341 unsigned Reg = Info[i].getReg();
343 const TargetRegisterClass *RC = getMinimalPhysRegClass(Reg);
344 unsigned Opcode = InstrInfo->getStoreOpcodeForSpill(RC);
345 if (!MFI.isFixedObjectIndex(FrIdx)) {
346 // This is not a fixed object. If it requires alignment then we may still
347 // need to use the XForm.
348 if (offsetMinAlignForOpcode(Opcode) > 1)
353 // 1) A fixed frame index object which we know are aligned so
354 // as long as we have a valid DForm/DSForm/DQForm (non XForm) we don't
355 // need to consider the alignment here.
356 // 2) A not fixed object but in that case we now know that the min required
357 // alignment is no more than 1 based on the previous check.
358 if (InstrInfo->isXFormMemOp(Opcode))
364 bool PPCRegisterInfo::isCallerPreservedPhysReg(MCRegister PhysReg,
365 const MachineFunction &MF) const {
366 assert(Register::isPhysicalRegister(PhysReg));
367 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
368 const MachineFrameInfo &MFI = MF.getFrameInfo();
372 if (!Subtarget.isSVR4ABI())
374 if (PhysReg == PPC::X2)
375 // X2 is guaranteed to be preserved within a function if it is reserved.
376 // The reason it's reserved is that it's the TOC pointer (and the function
377 // uses the TOC). In functions where it isn't reserved (i.e. leaf functions
378 // with no TOC access), we can't claim that it is preserved.
379 return (getReservedRegs(MF).test(PPC::X2));
380 if (StackPtrConst && (PhysReg == PPC::X1) && !MFI.hasVarSizedObjects()
381 && !MFI.hasOpaqueSPAdjustment())
382 // The value of the stack pointer does not change within a function after
383 // the prologue and before the epilogue if there are no dynamic allocations
384 // and no inline asm which clobbers X1.
389 unsigned PPCRegisterInfo::getRegPressureLimit(const TargetRegisterClass *RC,
390 MachineFunction &MF) const {
391 const PPCFrameLowering *TFI = getFrameLowering(MF);
392 const unsigned DefaultSafety = 1;
394 switch (RC->getID()) {
397 case PPC::G8RC_NOX0RegClassID:
398 case PPC::GPRC_NOR0RegClassID:
399 case PPC::SPERCRegClassID:
400 case PPC::G8RCRegClassID:
401 case PPC::GPRCRegClassID: {
402 unsigned FP = TFI->hasFP(MF) ? 1 : 0;
403 return 32 - FP - DefaultSafety;
405 case PPC::F8RCRegClassID:
406 case PPC::F4RCRegClassID:
407 case PPC::QFRCRegClassID:
408 case PPC::QSRCRegClassID:
409 case PPC::QBRCRegClassID:
410 case PPC::VRRCRegClassID:
411 case PPC::VFRCRegClassID:
412 case PPC::VSLRCRegClassID:
413 return 32 - DefaultSafety;
414 case PPC::VSRCRegClassID:
415 case PPC::VSFRCRegClassID:
416 case PPC::VSSRCRegClassID:
417 return 64 - DefaultSafety;
418 case PPC::CRRCRegClassID:
419 return 8 - DefaultSafety;
423 const TargetRegisterClass *
424 PPCRegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC,
425 const MachineFunction &MF) const {
426 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
427 if (Subtarget.hasVSX()) {
428 // With VSX, we can inflate various sub-register classes to the full VSX
431 // For Power9 we allow the user to enable GPR to vector spills.
432 // FIXME: Currently limited to spilling GP8RC. A follow on patch will add
433 // support to spill GPRC.
434 if (TM.isELFv2ABI()) {
435 if (Subtarget.hasP9Vector() && EnableGPRToVecSpills &&
436 RC == &PPC::G8RCRegClass) {
438 return &PPC::SPILLTOVSRRCRegClass;
440 if (RC == &PPC::GPRCRegClass && EnableGPRToVecSpills)
443 if (RC == &PPC::F8RCRegClass)
444 return &PPC::VSFRCRegClass;
445 else if (RC == &PPC::VRRCRegClass)
446 return &PPC::VSRCRegClass;
447 else if (RC == &PPC::F4RCRegClass && Subtarget.hasP8Vector())
448 return &PPC::VSSRCRegClass;
451 return TargetRegisterInfo::getLargestLegalSuperClass(RC, MF);
454 //===----------------------------------------------------------------------===//
455 // Stack Frame Processing methods
456 //===----------------------------------------------------------------------===//
458 /// lowerDynamicAlloc - Generate the code for allocating an object in the
459 /// current frame. The sequence of code will be in the general form
461 /// addi R0, SP, \#frameSize ; get the address of the previous frame
462 /// stwxu R0, SP, Rnegsize ; add and update the SP with the negated size
463 /// addi Rnew, SP, \#maxCalFrameSize ; get the top of the allocation
465 void PPCRegisterInfo::lowerDynamicAlloc(MachineBasicBlock::iterator II) const {
466 // Get the instruction.
467 MachineInstr &MI = *II;
468 // Get the instruction's basic block.
469 MachineBasicBlock &MBB = *MI.getParent();
470 // Get the basic block's function.
471 MachineFunction &MF = *MBB.getParent();
472 // Get the frame info.
473 MachineFrameInfo &MFI = MF.getFrameInfo();
474 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
475 // Get the instruction info.
476 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
477 // Determine whether 64-bit pointers are used.
478 bool LP64 = TM.isPPC64();
479 DebugLoc dl = MI.getDebugLoc();
481 // Get the maximum call stack size.
482 unsigned maxCallFrameSize = MFI.getMaxCallFrameSize();
483 Align MaxAlign = MFI.getMaxAlign();
484 assert(isAligned(MaxAlign, maxCallFrameSize) &&
485 "Maximum call-frame size not sufficiently aligned");
488 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
489 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
490 Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
491 bool KillNegSizeReg = MI.getOperand(1).isKill();
492 Register NegSizeReg = MI.getOperand(1).getReg();
494 prepareDynamicAlloca(II, NegSizeReg, KillNegSizeReg, Reg);
495 // Grow the stack and update the stack pointer link, then determine the
496 // address of new allocated space.
498 BuildMI(MBB, II, dl, TII.get(PPC::STDUX), PPC::X1)
499 .addReg(Reg, RegState::Kill)
501 .addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
502 BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), MI.getOperand(0).getReg())
504 .addImm(maxCallFrameSize);
506 BuildMI(MBB, II, dl, TII.get(PPC::STWUX), PPC::R1)
507 .addReg(Reg, RegState::Kill)
509 .addReg(NegSizeReg, getKillRegState(KillNegSizeReg));
510 BuildMI(MBB, II, dl, TII.get(PPC::ADDI), MI.getOperand(0).getReg())
512 .addImm(maxCallFrameSize);
515 // Discard the DYNALLOC instruction.
519 /// To accomplish dynamic stack allocation, we have to calculate exact size
520 /// subtracted from the stack pointer according alignment information and get
521 /// previous frame pointer.
522 void PPCRegisterInfo::prepareDynamicAlloca(MachineBasicBlock::iterator II,
523 Register &NegSizeReg,
524 bool &KillNegSizeReg,
525 Register &FramePointer) const {
526 // Get the instruction.
527 MachineInstr &MI = *II;
528 // Get the instruction's basic block.
529 MachineBasicBlock &MBB = *MI.getParent();
530 // Get the basic block's function.
531 MachineFunction &MF = *MBB.getParent();
532 // Get the frame info.
533 MachineFrameInfo &MFI = MF.getFrameInfo();
534 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
535 // Get the instruction info.
536 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
537 // Determine whether 64-bit pointers are used.
538 bool LP64 = TM.isPPC64();
539 DebugLoc dl = MI.getDebugLoc();
540 // Get the total frame size.
541 unsigned FrameSize = MFI.getStackSize();
543 // Get stack alignments.
544 const PPCFrameLowering *TFI = getFrameLowering(MF);
545 Align TargetAlign = TFI->getStackAlign();
546 Align MaxAlign = MFI.getMaxAlign();
548 // Determine the previous frame's address. If FrameSize can't be
549 // represented as 16 bits or we need special alignment, then we load the
550 // previous frame's address from 0(SP). Why not do an addis of the hi?
551 // Because R0 is our only safe tmp register and addi/addis treat R0 as zero.
552 // Constructing the constant and adding would take 3 instructions.
553 // Fortunately, a frame greater than 32K is rare.
554 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
555 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
557 if (MaxAlign < TargetAlign && isInt<16>(FrameSize)) {
559 BuildMI(MBB, II, dl, TII.get(PPC::ADDI8), FramePointer)
563 BuildMI(MBB, II, dl, TII.get(PPC::ADDI), FramePointer)
567 BuildMI(MBB, II, dl, TII.get(PPC::LD), FramePointer)
571 BuildMI(MBB, II, dl, TII.get(PPC::LWZ), FramePointer)
575 // Determine the actual NegSizeReg according to alignment info.
577 if (MaxAlign > TargetAlign) {
578 unsigned UnalNegSizeReg = NegSizeReg;
579 NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
581 // Unfortunately, there is no andi, only andi., and we can't insert that
582 // here because we might clobber cr0 while it is live.
583 BuildMI(MBB, II, dl, TII.get(PPC::LI8), NegSizeReg)
584 .addImm(~(MaxAlign.value() - 1));
586 unsigned NegSizeReg1 = NegSizeReg;
587 NegSizeReg = MF.getRegInfo().createVirtualRegister(G8RC);
588 BuildMI(MBB, II, dl, TII.get(PPC::AND8), NegSizeReg)
589 .addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
590 .addReg(NegSizeReg1, RegState::Kill);
591 KillNegSizeReg = true;
594 if (MaxAlign > TargetAlign) {
595 unsigned UnalNegSizeReg = NegSizeReg;
596 NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
598 // Unfortunately, there is no andi, only andi., and we can't insert that
599 // here because we might clobber cr0 while it is live.
600 BuildMI(MBB, II, dl, TII.get(PPC::LI), NegSizeReg)
601 .addImm(~(MaxAlign.value() - 1));
603 unsigned NegSizeReg1 = NegSizeReg;
604 NegSizeReg = MF.getRegInfo().createVirtualRegister(GPRC);
605 BuildMI(MBB, II, dl, TII.get(PPC::AND), NegSizeReg)
606 .addReg(UnalNegSizeReg, getKillRegState(KillNegSizeReg))
607 .addReg(NegSizeReg1, RegState::Kill);
608 KillNegSizeReg = true;
613 void PPCRegisterInfo::lowerPrepareProbedAlloca(
614 MachineBasicBlock::iterator II) const {
615 MachineInstr &MI = *II;
616 // Get the instruction's basic block.
617 MachineBasicBlock &MBB = *MI.getParent();
618 // Get the basic block's function.
619 MachineFunction &MF = *MBB.getParent();
620 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
621 // Get the instruction info.
622 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
623 // Determine whether 64-bit pointers are used.
624 bool LP64 = TM.isPPC64();
625 DebugLoc dl = MI.getDebugLoc();
626 Register FramePointer = MI.getOperand(0).getReg();
627 const Register ActualNegSizeReg = MI.getOperand(1).getReg();
628 bool KillNegSizeReg = MI.getOperand(2).isKill();
629 Register NegSizeReg = MI.getOperand(2).getReg();
630 const MCInstrDesc &CopyInst = TII.get(LP64 ? PPC::OR8 : PPC::OR);
631 // RegAllocator might allocate FramePointer and NegSizeReg in the same phyreg.
632 if (FramePointer == NegSizeReg) {
633 assert(KillNegSizeReg && "FramePointer is a def and NegSizeReg is an use, "
634 "NegSizeReg should be killed");
635 // FramePointer is clobbered earlier than the use of NegSizeReg in
636 // prepareDynamicAlloca, save NegSizeReg in ActualNegSizeReg to avoid
638 BuildMI(MBB, II, dl, CopyInst, ActualNegSizeReg)
641 NegSizeReg = ActualNegSizeReg;
642 KillNegSizeReg = false;
644 prepareDynamicAlloca(II, NegSizeReg, KillNegSizeReg, FramePointer);
645 // NegSizeReg might be updated in prepareDynamicAlloca if MaxAlign >
647 if (NegSizeReg != ActualNegSizeReg)
648 BuildMI(MBB, II, dl, CopyInst, ActualNegSizeReg)
654 void PPCRegisterInfo::lowerDynamicAreaOffset(
655 MachineBasicBlock::iterator II) const {
656 // Get the instruction.
657 MachineInstr &MI = *II;
658 // Get the instruction's basic block.
659 MachineBasicBlock &MBB = *MI.getParent();
660 // Get the basic block's function.
661 MachineFunction &MF = *MBB.getParent();
662 // Get the frame info.
663 MachineFrameInfo &MFI = MF.getFrameInfo();
664 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
665 // Get the instruction info.
666 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
668 unsigned maxCallFrameSize = MFI.getMaxCallFrameSize();
669 bool is64Bit = TM.isPPC64();
670 DebugLoc dl = MI.getDebugLoc();
671 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LI8 : PPC::LI),
672 MI.getOperand(0).getReg())
673 .addImm(maxCallFrameSize);
677 /// lowerCRSpilling - Generate the code for spilling a CR register. Instead of
678 /// reserving a whole register (R0), we scrounge for one here. This generates
681 /// mfcr rA ; Move the conditional register into GPR rA.
682 /// rlwinm rA, rA, SB, 0, 31 ; Shift the bits left so they are in CR0's slot.
683 /// stw rA, FI ; Store rA to the frame.
685 void PPCRegisterInfo::lowerCRSpilling(MachineBasicBlock::iterator II,
686 unsigned FrameIndex) const {
687 // Get the instruction.
688 MachineInstr &MI = *II; // ; SPILL_CR <SrcReg>, <offset>
689 // Get the instruction's basic block.
690 MachineBasicBlock &MBB = *MI.getParent();
691 MachineFunction &MF = *MBB.getParent();
692 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
693 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
694 DebugLoc dl = MI.getDebugLoc();
696 bool LP64 = TM.isPPC64();
697 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
698 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
700 Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
701 Register SrcReg = MI.getOperand(0).getReg();
703 // We need to store the CR in the low 4-bits of the saved value. First, issue
704 // an MFOCRF to save all of the CRBits and, if needed, kill the SrcReg.
705 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
706 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
708 // If the saved register wasn't CR0, shift the bits left so that they are in
710 if (SrcReg != PPC::CR0) {
712 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
714 // rlwinm rA, rA, ShiftBits, 0, 31.
715 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
716 .addReg(Reg1, RegState::Kill)
717 .addImm(getEncodingValue(SrcReg) * 4)
722 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
723 .addReg(Reg, RegState::Kill),
726 // Discard the pseudo instruction.
730 void PPCRegisterInfo::lowerCRRestore(MachineBasicBlock::iterator II,
731 unsigned FrameIndex) const {
732 // Get the instruction.
733 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CR <offset>
734 // Get the instruction's basic block.
735 MachineBasicBlock &MBB = *MI.getParent();
736 MachineFunction &MF = *MBB.getParent();
737 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
738 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
739 DebugLoc dl = MI.getDebugLoc();
741 bool LP64 = TM.isPPC64();
742 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
743 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
745 Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
746 Register DestReg = MI.getOperand(0).getReg();
747 assert(MI.definesRegister(DestReg) &&
748 "RESTORE_CR does not define its destination");
750 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
753 // If the reloaded register isn't CR0, shift the bits right so that they are
754 // in the right CR's slot.
755 if (DestReg != PPC::CR0) {
757 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
759 unsigned ShiftBits = getEncodingValue(DestReg)*4;
760 // rlwinm r11, r11, 32-ShiftBits, 0, 31.
761 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
762 .addReg(Reg1, RegState::Kill).addImm(32-ShiftBits).addImm(0)
766 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF), DestReg)
767 .addReg(Reg, RegState::Kill);
769 // Discard the pseudo instruction.
773 void PPCRegisterInfo::lowerCRBitSpilling(MachineBasicBlock::iterator II,
774 unsigned FrameIndex) const {
775 // Get the instruction.
776 MachineInstr &MI = *II; // ; SPILL_CRBIT <SrcReg>, <offset>
777 // Get the instruction's basic block.
778 MachineBasicBlock &MBB = *MI.getParent();
779 MachineFunction &MF = *MBB.getParent();
780 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
781 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
782 const TargetRegisterInfo* TRI = Subtarget.getRegisterInfo();
783 DebugLoc dl = MI.getDebugLoc();
785 bool LP64 = TM.isPPC64();
786 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
787 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
789 Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
790 Register SrcReg = MI.getOperand(0).getReg();
792 // Search up the BB to find the definition of the CR bit.
793 MachineBasicBlock::reverse_iterator Ins = MI;
794 MachineBasicBlock::reverse_iterator Rend = MBB.rend();
796 unsigned CRBitSpillDistance = 0;
797 bool SeenUse = false;
798 for (; Ins != Rend; ++Ins) {
800 if (Ins->modifiesRegister(SrcReg, TRI))
803 if (Ins->readsRegister(SrcReg, TRI))
805 // Unable to find CR bit definition within maximum search distance.
806 if (CRBitSpillDistance == MaxCRBitSpillDist) {
810 // Skip debug instructions when counting CR bit spill distance.
811 if (!Ins->isDebugInstr())
812 CRBitSpillDistance++;
815 // Unable to find the definition of the CR bit in the MBB.
816 if (Ins == MBB.rend())
819 bool SpillsKnownBit = false;
820 // There is no need to extract the CR bit if its value is already known.
821 switch (Ins->getOpcode()) {
823 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LI8 : PPC::LI), Reg)
825 SpillsKnownBit = true;
828 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LIS8 : PPC::LIS), Reg)
830 SpillsKnownBit = true;
833 // On Power9, we can use SETB to extract the LT bit. This only works for
834 // the LT bit since SETB produces -1/1/0 for LT/GT/<neither>. So the value
835 // of the bit we care about (32-bit sign bit) will be set to the value of
836 // the LT bit (regardless of the other bits in the CR field).
837 if (Subtarget.isISA3_0()) {
838 if (SrcReg == PPC::CR0LT || SrcReg == PPC::CR1LT ||
839 SrcReg == PPC::CR2LT || SrcReg == PPC::CR3LT ||
840 SrcReg == PPC::CR4LT || SrcReg == PPC::CR5LT ||
841 SrcReg == PPC::CR6LT || SrcReg == PPC::CR7LT) {
842 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::SETB8 : PPC::SETB), Reg)
843 .addReg(getCRFromCRBit(SrcReg), RegState::Undef);
848 // We need to move the CR field that contains the CR bit we are spilling.
849 // The super register may not be explicitly defined (i.e. it can be defined
850 // by a CR-logical that only defines the subreg) so we state that the CR
851 // field is undef. Also, in order to preserve the kill flag on the CR bit,
852 // we add it as an implicit use.
853 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), Reg)
854 .addReg(getCRFromCRBit(SrcReg), RegState::Undef)
856 RegState::Implicit | getKillRegState(MI.getOperand(0).isKill()));
858 // If the saved register wasn't CR0LT, shift the bits left so that the bit
859 // to store is the first one. Mask all but that bit.
861 Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
863 // rlwinm rA, rA, ShiftBits, 0, 0.
864 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWINM8 : PPC::RLWINM), Reg)
865 .addReg(Reg1, RegState::Kill)
866 .addImm(getEncodingValue(SrcReg))
867 .addImm(0).addImm(0);
869 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::STW8 : PPC::STW))
870 .addReg(Reg, RegState::Kill),
873 bool KillsCRBit = MI.killsRegister(SrcReg, TRI);
874 // Discard the pseudo instruction.
876 if (SpillsKnownBit && KillsCRBit && !SeenUse) {
877 Ins->setDesc(TII.get(PPC::UNENCODED_NOP));
878 Ins->RemoveOperand(0);
882 void PPCRegisterInfo::lowerCRBitRestore(MachineBasicBlock::iterator II,
883 unsigned FrameIndex) const {
884 // Get the instruction.
885 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_CRBIT <offset>
886 // Get the instruction's basic block.
887 MachineBasicBlock &MBB = *MI.getParent();
888 MachineFunction &MF = *MBB.getParent();
889 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
890 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
891 DebugLoc dl = MI.getDebugLoc();
893 bool LP64 = TM.isPPC64();
894 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
895 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
897 Register Reg = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
898 Register DestReg = MI.getOperand(0).getReg();
899 assert(MI.definesRegister(DestReg) &&
900 "RESTORE_CRBIT does not define its destination");
902 addFrameReference(BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::LWZ8 : PPC::LWZ),
905 BuildMI(MBB, II, dl, TII.get(TargetOpcode::IMPLICIT_DEF), DestReg);
907 Register RegO = MF.getRegInfo().createVirtualRegister(LP64 ? G8RC : GPRC);
908 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MFOCRF8 : PPC::MFOCRF), RegO)
909 .addReg(getCRFromCRBit(DestReg));
911 unsigned ShiftBits = getEncodingValue(DestReg);
912 // rlwimi r11, r10, 32-ShiftBits, ..., ...
913 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::RLWIMI8 : PPC::RLWIMI), RegO)
914 .addReg(RegO, RegState::Kill)
915 .addReg(Reg, RegState::Kill)
916 .addImm(ShiftBits ? 32 - ShiftBits : 0)
920 BuildMI(MBB, II, dl, TII.get(LP64 ? PPC::MTOCRF8 : PPC::MTOCRF),
921 getCRFromCRBit(DestReg))
922 .addReg(RegO, RegState::Kill)
923 // Make sure we have a use dependency all the way through this
924 // sequence of instructions. We can't have the other bits in the CR
925 // modified in between the mfocrf and the mtocrf.
926 .addReg(getCRFromCRBit(DestReg), RegState::Implicit);
928 // Discard the pseudo instruction.
932 void PPCRegisterInfo::lowerVRSAVESpilling(MachineBasicBlock::iterator II,
933 unsigned FrameIndex) const {
934 // Get the instruction.
935 MachineInstr &MI = *II; // ; SPILL_VRSAVE <SrcReg>, <offset>
936 // Get the instruction's basic block.
937 MachineBasicBlock &MBB = *MI.getParent();
938 MachineFunction &MF = *MBB.getParent();
939 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
940 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
941 DebugLoc dl = MI.getDebugLoc();
943 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
944 Register Reg = MF.getRegInfo().createVirtualRegister(GPRC);
945 Register SrcReg = MI.getOperand(0).getReg();
947 BuildMI(MBB, II, dl, TII.get(PPC::MFVRSAVEv), Reg)
948 .addReg(SrcReg, getKillRegState(MI.getOperand(0).isKill()));
951 BuildMI(MBB, II, dl, TII.get(PPC::STW)).addReg(Reg, RegState::Kill),
954 // Discard the pseudo instruction.
958 void PPCRegisterInfo::lowerVRSAVERestore(MachineBasicBlock::iterator II,
959 unsigned FrameIndex) const {
960 // Get the instruction.
961 MachineInstr &MI = *II; // ; <DestReg> = RESTORE_VRSAVE <offset>
962 // Get the instruction's basic block.
963 MachineBasicBlock &MBB = *MI.getParent();
964 MachineFunction &MF = *MBB.getParent();
965 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
966 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
967 DebugLoc dl = MI.getDebugLoc();
969 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
970 Register Reg = MF.getRegInfo().createVirtualRegister(GPRC);
971 Register DestReg = MI.getOperand(0).getReg();
972 assert(MI.definesRegister(DestReg) &&
973 "RESTORE_VRSAVE does not define its destination");
975 addFrameReference(BuildMI(MBB, II, dl, TII.get(PPC::LWZ),
978 BuildMI(MBB, II, dl, TII.get(PPC::MTVRSAVEv), DestReg)
979 .addReg(Reg, RegState::Kill);
981 // Discard the pseudo instruction.
985 bool PPCRegisterInfo::hasReservedSpillSlot(const MachineFunction &MF,
986 Register Reg, int &FrameIdx) const {
987 // For the nonvolatile condition registers (CR2, CR3, CR4) return true to
988 // prevent allocating an additional frame slot.
989 // For 64-bit ELF and AIX, the CR save area is in the linkage area at SP+8,
990 // for 32-bit AIX the CR save area is in the linkage area at SP+4.
991 // We have created a FrameIndex to that spill slot to keep the CalleSaveInfos
993 // For 32-bit ELF, we have previously created the stack slot if needed, so
994 // return its FrameIdx.
995 if (PPC::CR2 <= Reg && Reg <= PPC::CR4) {
996 FrameIdx = MF.getInfo<PPCFunctionInfo>()->getCRSpillFrameIndex();
1002 // If the offset must be a multiple of some value, return what that value is.
1003 static unsigned offsetMinAlignForOpcode(unsigned OpC) {
1013 case PPC::DFLOADf32:
1014 case PPC::DFLOADf64:
1015 case PPC::DFSTOREf32:
1016 case PPC::DFSTOREf64:
1031 // If the offset must be a multiple of some value, return what that value is.
1032 static unsigned offsetMinAlign(const MachineInstr &MI) {
1033 unsigned OpC = MI.getOpcode();
1034 return offsetMinAlignForOpcode(OpC);
1037 // Return the OffsetOperandNo given the FIOperandNum (and the instruction).
1038 static unsigned getOffsetONFromFION(const MachineInstr &MI,
1039 unsigned FIOperandNum) {
1040 // Take into account whether it's an add or mem instruction
1041 unsigned OffsetOperandNo = (FIOperandNum == 2) ? 1 : 2;
1042 if (MI.isInlineAsm())
1043 OffsetOperandNo = FIOperandNum - 1;
1044 else if (MI.getOpcode() == TargetOpcode::STACKMAP ||
1045 MI.getOpcode() == TargetOpcode::PATCHPOINT)
1046 OffsetOperandNo = FIOperandNum + 1;
1048 return OffsetOperandNo;
1052 PPCRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
1053 int SPAdj, unsigned FIOperandNum,
1054 RegScavenger *RS) const {
1055 assert(SPAdj == 0 && "Unexpected");
1057 // Get the instruction.
1058 MachineInstr &MI = *II;
1059 // Get the instruction's basic block.
1060 MachineBasicBlock &MBB = *MI.getParent();
1061 // Get the basic block's function.
1062 MachineFunction &MF = *MBB.getParent();
1063 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
1064 // Get the instruction info.
1065 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
1066 // Get the frame info.
1067 MachineFrameInfo &MFI = MF.getFrameInfo();
1068 DebugLoc dl = MI.getDebugLoc();
1070 unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
1072 // Get the frame index.
1073 int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
1075 // Get the frame pointer save index. Users of this index are primarily
1076 // DYNALLOC instructions.
1077 PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
1078 int FPSI = FI->getFramePointerSaveIndex();
1079 // Get the instruction opcode.
1080 unsigned OpC = MI.getOpcode();
1082 if ((OpC == PPC::DYNAREAOFFSET || OpC == PPC::DYNAREAOFFSET8)) {
1083 lowerDynamicAreaOffset(II);
1087 // Special case for dynamic alloca.
1088 if (FPSI && FrameIndex == FPSI &&
1089 (OpC == PPC::DYNALLOC || OpC == PPC::DYNALLOC8)) {
1090 lowerDynamicAlloc(II);
1094 if (FPSI && FrameIndex == FPSI &&
1095 (OpC == PPC::PREPARE_PROBED_ALLOCA_64 ||
1096 OpC == PPC::PREPARE_PROBED_ALLOCA_32 ||
1097 OpC == PPC::PREPARE_PROBED_ALLOCA_NEGSIZE_SAME_REG_64 ||
1098 OpC == PPC::PREPARE_PROBED_ALLOCA_NEGSIZE_SAME_REG_32)) {
1099 lowerPrepareProbedAlloca(II);
1103 // Special case for pseudo-ops SPILL_CR and RESTORE_CR, etc.
1104 if (OpC == PPC::SPILL_CR) {
1105 lowerCRSpilling(II, FrameIndex);
1107 } else if (OpC == PPC::RESTORE_CR) {
1108 lowerCRRestore(II, FrameIndex);
1110 } else if (OpC == PPC::SPILL_CRBIT) {
1111 lowerCRBitSpilling(II, FrameIndex);
1113 } else if (OpC == PPC::RESTORE_CRBIT) {
1114 lowerCRBitRestore(II, FrameIndex);
1116 } else if (OpC == PPC::SPILL_VRSAVE) {
1117 lowerVRSAVESpilling(II, FrameIndex);
1119 } else if (OpC == PPC::RESTORE_VRSAVE) {
1120 lowerVRSAVERestore(II, FrameIndex);
1124 // Replace the FrameIndex with base register with GPR1 (SP) or GPR31 (FP).
1125 MI.getOperand(FIOperandNum).ChangeToRegister(
1126 FrameIndex < 0 ? getBaseRegister(MF) : getFrameRegister(MF), false);
1128 // If the instruction is not present in ImmToIdxMap, then it has no immediate
1129 // form (and must be r+r).
1130 bool noImmForm = !MI.isInlineAsm() && OpC != TargetOpcode::STACKMAP &&
1131 OpC != TargetOpcode::PATCHPOINT && !ImmToIdxMap.count(OpC);
1133 // Now add the frame object offset to the offset from r1.
1134 int Offset = MFI.getObjectOffset(FrameIndex);
1135 Offset += MI.getOperand(OffsetOperandNo).getImm();
1137 // If we're not using a Frame Pointer that has been set to the value of the
1138 // SP before having the stack size subtracted from it, then add the stack size
1139 // to Offset to get the correct offset.
1140 // Naked functions have stack size 0, although getStackSize may not reflect
1141 // that because we didn't call all the pieces that compute it for naked
1143 if (!MF.getFunction().hasFnAttribute(Attribute::Naked)) {
1144 if (!(hasBasePointer(MF) && FrameIndex < 0))
1145 Offset += MFI.getStackSize();
1148 // If we can, encode the offset directly into the instruction. If this is a
1149 // normal PPC "ri" instruction, any 16-bit value can be safely encoded. If
1150 // this is a PPC64 "ix" instruction, only a 16-bit value with the low two bits
1151 // clear can be encoded. This is extremely uncommon, because normally you
1152 // only "std" to a stack slot that is at least 4-byte aligned, but it can
1153 // happen in invalid code.
1154 assert(OpC != PPC::DBG_VALUE &&
1155 "This should be handled in a target-independent way");
1156 bool OffsetFitsMnemonic = (OpC == PPC::EVSTDD || OpC == PPC::EVLDD) ?
1159 if (!noImmForm && ((OffsetFitsMnemonic &&
1160 ((Offset % offsetMinAlign(MI)) == 0)) ||
1161 OpC == TargetOpcode::STACKMAP ||
1162 OpC == TargetOpcode::PATCHPOINT)) {
1163 MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
1167 // The offset doesn't fit into a single register, scavenge one to build the
1170 bool is64Bit = TM.isPPC64();
1171 const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
1172 const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
1173 const TargetRegisterClass *RC = is64Bit ? G8RC : GPRC;
1174 Register SRegHi = MF.getRegInfo().createVirtualRegister(RC),
1175 SReg = MF.getRegInfo().createVirtualRegister(RC);
1177 // Insert a set of rA with the full offset value before the ld, st, or add
1178 if (isInt<16>(Offset))
1179 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LI8 : PPC::LI), SReg)
1182 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::LIS8 : PPC::LIS), SRegHi)
1183 .addImm(Offset >> 16);
1184 BuildMI(MBB, II, dl, TII.get(is64Bit ? PPC::ORI8 : PPC::ORI), SReg)
1185 .addReg(SRegHi, RegState::Kill)
1189 // Convert into indexed form of the instruction:
1191 // sth 0:rA, 1:imm 2:(rB) ==> sthx 0:rA, 2:rB, 1:r0
1192 // addi 0:rA 1:rB, 2, imm ==> add 0:rA, 1:rB, 2:r0
1193 unsigned OperandBase;
1197 else if (OpC != TargetOpcode::INLINEASM &&
1198 OpC != TargetOpcode::INLINEASM_BR) {
1199 assert(ImmToIdxMap.count(OpC) &&
1200 "No indexed form of load or store available!");
1201 unsigned NewOpcode = ImmToIdxMap.find(OpC)->second;
1202 MI.setDesc(TII.get(NewOpcode));
1205 OperandBase = OffsetOperandNo;
1208 Register StackReg = MI.getOperand(FIOperandNum).getReg();
1209 MI.getOperand(OperandBase).ChangeToRegister(StackReg, false);
1210 MI.getOperand(OperandBase + 1).ChangeToRegister(SReg, false, false, true);
1213 Register PPCRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
1214 const PPCFrameLowering *TFI = getFrameLowering(MF);
1217 return TFI->hasFP(MF) ? PPC::R31 : PPC::R1;
1219 return TFI->hasFP(MF) ? PPC::X31 : PPC::X1;
1222 Register PPCRegisterInfo::getBaseRegister(const MachineFunction &MF) const {
1223 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
1224 if (!hasBasePointer(MF))
1225 return getFrameRegister(MF);
1230 if (Subtarget.isSVR4ABI() && TM.isPositionIndependent())
1236 bool PPCRegisterInfo::hasBasePointer(const MachineFunction &MF) const {
1237 if (!EnableBasePointer)
1239 if (AlwaysBasePointer)
1242 // If we need to realign the stack, then the stack pointer can no longer
1243 // serve as an offset into the caller's stack space. As a result, we need a
1245 return needsStackRealignment(MF);
1248 /// Returns true if the instruction's frame index
1249 /// reference would be better served by a base register other than FP
1250 /// or SP. Used by LocalStackFrameAllocation to determine which frame index
1251 /// references it should create new base registers for.
1252 bool PPCRegisterInfo::
1253 needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const {
1254 assert(Offset < 0 && "Local offset must be negative");
1256 // It's the load/store FI references that cause issues, as it can be difficult
1257 // to materialize the offset if it won't fit in the literal field. Estimate
1258 // based on the size of the local frame and some conservative assumptions
1259 // about the rest of the stack frame (note, this is pre-regalloc, so
1260 // we don't know everything for certain yet) whether this offset is likely
1261 // to be out of range of the immediate. Return true if so.
1263 // We only generate virtual base registers for loads and stores that have
1264 // an r+i form. Return false for everything else.
1265 unsigned OpC = MI->getOpcode();
1266 if (!ImmToIdxMap.count(OpC))
1269 // Don't generate a new virtual base register just to add zero to it.
1270 if ((OpC == PPC::ADDI || OpC == PPC::ADDI8) &&
1271 MI->getOperand(2).getImm() == 0)
1274 MachineBasicBlock &MBB = *MI->getParent();
1275 MachineFunction &MF = *MBB.getParent();
1276 const PPCFrameLowering *TFI = getFrameLowering(MF);
1277 unsigned StackEst = TFI->determineFrameLayout(MF, true);
1279 // If we likely don't need a stack frame, then we probably don't need a
1280 // virtual base register either.
1284 // Estimate an offset from the stack pointer.
1285 // The incoming offset is relating to the SP at the start of the function,
1286 // but when we access the local it'll be relative to the SP after local
1287 // allocation, so adjust our SP-relative offset by that allocation size.
1290 // The frame pointer will point to the end of the stack, so estimate the
1291 // offset as the difference between the object offset and the FP location.
1292 return !isFrameOffsetLegal(MI, getBaseRegister(MF), Offset);
1295 /// Insert defining instruction(s) for BaseReg to
1296 /// be a pointer to FrameIdx at the beginning of the basic block.
1297 void PPCRegisterInfo::materializeFrameBaseRegister(MachineBasicBlock *MBB,
1300 int64_t Offset) const {
1301 unsigned ADDriOpc = TM.isPPC64() ? PPC::ADDI8 : PPC::ADDI;
1303 MachineBasicBlock::iterator Ins = MBB->begin();
1304 DebugLoc DL; // Defaults to "unknown"
1305 if (Ins != MBB->end())
1306 DL = Ins->getDebugLoc();
1308 const MachineFunction &MF = *MBB->getParent();
1309 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
1310 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
1311 const MCInstrDesc &MCID = TII.get(ADDriOpc);
1312 MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
1313 MRI.constrainRegClass(BaseReg, TII.getRegClass(MCID, 0, this, MF));
1315 BuildMI(*MBB, Ins, DL, MCID, BaseReg)
1316 .addFrameIndex(FrameIdx).addImm(Offset);
1319 void PPCRegisterInfo::resolveFrameIndex(MachineInstr &MI, Register BaseReg,
1320 int64_t Offset) const {
1321 unsigned FIOperandNum = 0;
1322 while (!MI.getOperand(FIOperandNum).isFI()) {
1324 assert(FIOperandNum < MI.getNumOperands() &&
1325 "Instr doesn't have FrameIndex operand!");
1328 MI.getOperand(FIOperandNum).ChangeToRegister(BaseReg, false);
1329 unsigned OffsetOperandNo = getOffsetONFromFION(MI, FIOperandNum);
1330 Offset += MI.getOperand(OffsetOperandNo).getImm();
1331 MI.getOperand(OffsetOperandNo).ChangeToImmediate(Offset);
1333 MachineBasicBlock &MBB = *MI.getParent();
1334 MachineFunction &MF = *MBB.getParent();
1335 const PPCSubtarget &Subtarget = MF.getSubtarget<PPCSubtarget>();
1336 const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
1337 const MCInstrDesc &MCID = MI.getDesc();
1338 MachineRegisterInfo &MRI = MF.getRegInfo();
1339 MRI.constrainRegClass(BaseReg,
1340 TII.getRegClass(MCID, FIOperandNum, this, MF));
1343 bool PPCRegisterInfo::isFrameOffsetLegal(const MachineInstr *MI,
1345 int64_t Offset) const {
1346 unsigned FIOperandNum = 0;
1347 while (!MI->getOperand(FIOperandNum).isFI()) {
1349 assert(FIOperandNum < MI->getNumOperands() &&
1350 "Instr doesn't have FrameIndex operand!");
1353 unsigned OffsetOperandNo = getOffsetONFromFION(*MI, FIOperandNum);
1354 Offset += MI->getOperand(OffsetOperandNo).getImm();
1356 return MI->getOpcode() == PPC::DBG_VALUE || // DBG_VALUE is always Reg+Imm
1357 MI->getOpcode() == TargetOpcode::STACKMAP ||
1358 MI->getOpcode() == TargetOpcode::PATCHPOINT ||
1359 (isInt<16>(Offset) && (Offset % offsetMinAlign(*MI)) == 0);