2 ================================
4 This directory and its subdirectories contain source code for the compiler
7 Compiler-RT is open source software. You may freely distribute it under the
8 terms of the license agreement found in LICENSE.txt.
10 ================================
12 This is a replacement library for libgcc. Each function is contained
13 in its own file. Each function has a corresponding unit test under
16 A rudimentary script to test each file is in the file called
19 Here is the specification for this library:
21 http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc
23 Please note that the libgcc specification explicitly mentions actual types of
24 arguments and returned values being expressed with machine modes.
25 In some cases particular types such as "int", "unsigned", "long long", etc.
26 may be specified just as examples there.
28 Here is a synopsis of the contents of this library:
30 typedef int32_t si_int;
31 typedef uint32_t su_int;
33 typedef int64_t di_int;
34 typedef uint64_t du_int;
36 // Integral bit manipulation
38 di_int __ashldi3(di_int a, si_int b); // a << b
39 ti_int __ashlti3(ti_int a, si_int b); // a << b
41 di_int __ashrdi3(di_int a, si_int b); // a >> b arithmetic (sign fill)
42 ti_int __ashrti3(ti_int a, si_int b); // a >> b arithmetic (sign fill)
43 di_int __lshrdi3(di_int a, si_int b); // a >> b logical (zero fill)
44 ti_int __lshrti3(ti_int a, si_int b); // a >> b logical (zero fill)
46 int __clzsi2(si_int a); // count leading zeros
47 int __clzdi2(di_int a); // count leading zeros
48 int __clzti2(ti_int a); // count leading zeros
49 int __ctzsi2(si_int a); // count trailing zeros
50 int __ctzdi2(di_int a); // count trailing zeros
51 int __ctzti2(ti_int a); // count trailing zeros
53 int __ffssi2(si_int a); // find least significant 1 bit
54 int __ffsdi2(di_int a); // find least significant 1 bit
55 int __ffsti2(ti_int a); // find least significant 1 bit
57 int __paritysi2(si_int a); // bit parity
58 int __paritydi2(di_int a); // bit parity
59 int __parityti2(ti_int a); // bit parity
61 int __popcountsi2(si_int a); // bit population
62 int __popcountdi2(di_int a); // bit population
63 int __popcountti2(ti_int a); // bit population
65 uint32_t __bswapsi2(uint32_t a); // a byteswapped
66 uint64_t __bswapdi2(uint64_t a); // a byteswapped
68 // Integral arithmetic
70 di_int __negdi2 (di_int a); // -a
71 ti_int __negti2 (ti_int a); // -a
72 di_int __muldi3 (di_int a, di_int b); // a * b
73 ti_int __multi3 (ti_int a, ti_int b); // a * b
74 si_int __divsi3 (si_int a, si_int b); // a / b signed
75 di_int __divdi3 (di_int a, di_int b); // a / b signed
76 ti_int __divti3 (ti_int a, ti_int b); // a / b signed
77 su_int __udivsi3 (su_int n, su_int d); // a / b unsigned
78 du_int __udivdi3 (du_int a, du_int b); // a / b unsigned
79 tu_int __udivti3 (tu_int a, tu_int b); // a / b unsigned
80 si_int __modsi3 (si_int a, si_int b); // a % b signed
81 di_int __moddi3 (di_int a, di_int b); // a % b signed
82 ti_int __modti3 (ti_int a, ti_int b); // a % b signed
83 su_int __umodsi3 (su_int a, su_int b); // a % b unsigned
84 du_int __umoddi3 (du_int a, du_int b); // a % b unsigned
85 tu_int __umodti3 (tu_int a, tu_int b); // a % b unsigned
86 du_int __udivmoddi4(du_int a, du_int b, du_int* rem); // a / b, *rem = a % b unsigned
87 tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); // a / b, *rem = a % b unsigned
88 su_int __udivmodsi4(su_int a, su_int b, su_int* rem); // a / b, *rem = a % b unsigned
89 si_int __divmodsi4(si_int a, si_int b, si_int* rem); // a / b, *rem = a % b signed
93 // Integral arithmetic with trapping overflow
95 si_int __absvsi2(si_int a); // abs(a)
96 di_int __absvdi2(di_int a); // abs(a)
97 ti_int __absvti2(ti_int a); // abs(a)
99 si_int __negvsi2(si_int a); // -a
100 di_int __negvdi2(di_int a); // -a
101 ti_int __negvti2(ti_int a); // -a
103 si_int __addvsi3(si_int a, si_int b); // a + b
104 di_int __addvdi3(di_int a, di_int b); // a + b
105 ti_int __addvti3(ti_int a, ti_int b); // a + b
107 si_int __subvsi3(si_int a, si_int b); // a - b
108 di_int __subvdi3(di_int a, di_int b); // a - b
109 ti_int __subvti3(ti_int a, ti_int b); // a - b
111 si_int __mulvsi3(si_int a, si_int b); // a * b
112 di_int __mulvdi3(di_int a, di_int b); // a * b
113 ti_int __mulvti3(ti_int a, ti_int b); // a * b
116 // Integral arithmetic which returns if overflow
118 si_int __mulosi4(si_int a, si_int b, int* overflow); // a * b, overflow set to one if result not in signed range
119 di_int __mulodi4(di_int a, di_int b, int* overflow); // a * b, overflow set to one if result not in signed range
120 ti_int __muloti4(ti_int a, ti_int b, int* overflow); // a * b, overflow set to
121 one if result not in signed range
124 // Integral comparison: a < b -> 0
128 si_int __cmpdi2 (di_int a, di_int b);
129 si_int __cmpti2 (ti_int a, ti_int b);
130 si_int __ucmpdi2(du_int a, du_int b);
131 si_int __ucmpti2(tu_int a, tu_int b);
133 // Integral / floating point conversion
135 di_int __fixsfdi( float a);
136 di_int __fixdfdi( double a);
137 di_int __fixxfdi(long double a);
139 ti_int __fixsfti( float a);
140 ti_int __fixdfti( double a);
141 ti_int __fixxfti(long double a);
142 uint64_t __fixtfdi(long double input); // ppc only, doesn't match documentation
144 su_int __fixunssfsi( float a);
145 su_int __fixunsdfsi( double a);
146 su_int __fixunsxfsi(long double a);
148 du_int __fixunssfdi( float a);
149 du_int __fixunsdfdi( double a);
150 du_int __fixunsxfdi(long double a);
152 tu_int __fixunssfti( float a);
153 tu_int __fixunsdfti( double a);
154 tu_int __fixunsxfti(long double a);
155 uint64_t __fixunstfdi(long double input); // ppc only
157 float __floatdisf(di_int a);
158 double __floatdidf(di_int a);
159 long double __floatdixf(di_int a);
160 long double __floatditf(int64_t a); // ppc only
162 float __floattisf(ti_int a);
163 double __floattidf(ti_int a);
164 long double __floattixf(ti_int a);
166 float __floatundisf(du_int a);
167 double __floatundidf(du_int a);
168 long double __floatundixf(du_int a);
169 long double __floatunditf(uint64_t a); // ppc only
171 float __floatuntisf(tu_int a);
172 double __floatuntidf(tu_int a);
173 long double __floatuntixf(tu_int a);
175 // Floating point raised to integer power
177 float __powisf2( float a, int b); // a ^ b
178 double __powidf2( double a, int b); // a ^ b
179 long double __powixf2(long double a, int b); // a ^ b
180 long double __powitf2(long double a, int b); // ppc only, a ^ b
182 // Complex arithmetic
184 // (a + ib) * (c + id)
186 float _Complex __mulsc3( float a, float b, float c, float d);
187 double _Complex __muldc3(double a, double b, double c, double d);
188 long double _Complex __mulxc3(long double a, long double b,
189 long double c, long double d);
190 long double _Complex __multc3(long double a, long double b,
191 long double c, long double d); // ppc only
193 // (a + ib) / (c + id)
195 float _Complex __divsc3( float a, float b, float c, float d);
196 double _Complex __divdc3(double a, double b, double c, double d);
197 long double _Complex __divxc3(long double a, long double b,
198 long double c, long double d);
199 long double _Complex __divtc3(long double a, long double b,
200 long double c, long double d); // ppc only
205 // __clear_cache() is used to tell process that new instructions have been
206 // written to an address range. Necessary on processors that do not have
207 // a unified instruction and data cache.
208 void __clear_cache(void* start, void* end);
210 // __enable_execute_stack() is used with nested functions when a trampoline
211 // function is written onto the stack and that page range needs to be made
213 void __enable_execute_stack(void* addr);
215 // __gcc_personality_v0() is normally only called by the system unwinder.
216 // C code (as opposed to C++) normally does not need a personality function
217 // because there are no catch clauses or destructors to be run. But there
218 // is a C language extension __attribute__((cleanup(func))) which marks local
219 // variables as needing the cleanup function "func" to be run when the
220 // variable goes out of scope. That includes when an exception is thrown,
221 // so a personality handler is needed.
222 _Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions,
223 uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
224 _Unwind_Context_t context);
226 // for use with some implementations of assert() in <assert.h>
227 void __eprintf(const char* format, const char* assertion_expression,
228 const char* line, const char* file);
230 // for systems with emulated thread local storage
231 void* __emutls_get_address(struct __emutls_control*);
234 // Power PC specific functions
236 // There is no C interface to the saveFP/restFP functions. They are helper
237 // functions called by the prolog and epilog of functions that need to save
238 // a number of non-volatile float point registers.
242 // PowerPC has a standard template for trampoline functions. This function
243 // generates a custom trampoline function with the specific realFunc
244 // and localsPtr values.
245 void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated,
246 const void* realFunc, void* localsPtr);
248 // adds two 128-bit double-double precision values ( x + y )
249 long double __gcc_qadd(long double x, long double y);
251 // subtracts two 128-bit double-double precision values ( x - y )
252 long double __gcc_qsub(long double x, long double y);
254 // multiples two 128-bit double-double precision values ( x * y )
255 long double __gcc_qmul(long double x, long double y);
257 // divides two 128-bit double-double precision values ( x / y )
258 long double __gcc_qdiv(long double a, long double b);
261 // ARM specific functions
263 // There is no C interface to the switch* functions. These helper functions
264 // are only needed by Thumb1 code for efficient switch table generation.
270 // There is no C interface to the *_vfp_d8_d15_regs functions. There are
271 // called in the prolog and epilog of Thumb1 functions. When the C++ ABI use
272 // SJLJ for exceptions, each function with a catch clause or destuctors needs
273 // to save and restore all registers in it prolog and epliog. But there is
274 // no way to access vector and high float registers from thumb1 code, so the
275 // compiler must add call outs to these helper functions in the prolog and
277 restore_vfp_d8_d15_regs
281 // Note: long ago ARM processors did not have floating point hardware support.
282 // Floating point was done in software and floating point parameters were
283 // passed in integer registers. When hardware support was added for floating
284 // point, new *vfp functions were added to do the same operations but with
285 // floating point parameters in floating point registers.
287 // Undocumented functions
289 float __addsf3vfp(float a, float b); // Appears to return a + b
290 double __adddf3vfp(double a, double b); // Appears to return a + b
291 float __divsf3vfp(float a, float b); // Appears to return a / b
292 double __divdf3vfp(double a, double b); // Appears to return a / b
293 int __eqsf2vfp(float a, float b); // Appears to return one
294 // iff a == b and neither is NaN.
295 int __eqdf2vfp(double a, double b); // Appears to return one
296 // iff a == b and neither is NaN.
297 double __extendsfdf2vfp(float a); // Appears to convert from
299 int __fixdfsivfp(double a); // Appears to convert from
301 int __fixsfsivfp(float a); // Appears to convert from
303 unsigned int __fixunssfsivfp(float a); // Appears to convert from
304 // float to unsigned int.
305 unsigned int __fixunsdfsivfp(double a); // Appears to convert from
306 // double to unsigned int.
307 double __floatsidfvfp(int a); // Appears to convert from
309 float __floatsisfvfp(int a); // Appears to convert from
311 double __floatunssidfvfp(unsigned int a); // Appears to convert from
312 // unisgned int to double.
313 float __floatunssisfvfp(unsigned int a); // Appears to convert from
314 // unisgned int to float.
315 int __gedf2vfp(double a, double b); // Appears to return __gedf2
317 int __gesf2vfp(float a, float b); // Appears to return __gesf2
319 int __gtdf2vfp(double a, double b); // Appears to return __gtdf2
321 int __gtsf2vfp(float a, float b); // Appears to return __gtsf2
323 int __ledf2vfp(double a, double b); // Appears to return __ledf2
325 int __lesf2vfp(float a, float b); // Appears to return __lesf2
327 int __ltdf2vfp(double a, double b); // Appears to return __ltdf2
329 int __ltsf2vfp(float a, float b); // Appears to return __ltsf2
331 double __muldf3vfp(double a, double b); // Appears to return a * b
332 float __mulsf3vfp(float a, float b); // Appears to return a * b
333 int __nedf2vfp(double a, double b); // Appears to return __nedf2
335 double __negdf2vfp(double a); // Appears to return -a
336 float __negsf2vfp(float a); // Appears to return -a
337 float __negsf2vfp(float a); // Appears to return -a
338 double __subdf3vfp(double a, double b); // Appears to return a - b
339 float __subsf3vfp(float a, float b); // Appears to return a - b
340 float __truncdfsf2vfp(double a); // Appears to convert from
342 int __unorddf2vfp(double a, double b); // Appears to return __unorddf2
343 int __unordsf2vfp(float a, float b); // Appears to return __unordsf2
346 Preconditions are listed for each function at the definition when there are any.
347 Any preconditions reflect the specification at
348 http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc.
350 Assumptions are listed in "int_lib.h", and in individual files. Where possible
351 assumptions are checked at compile time.