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 Here is a synopsis of the contents of this library:
26 typedef unsigned su_int;
28 typedef long long di_int;
29 typedef unsigned long long du_int;
31 // Integral bit manipulation
33 di_int __ashldi3(di_int a, si_int b); // a << b
34 ti_int __ashlti3(ti_int a, si_int b); // a << b
36 di_int __ashrdi3(di_int a, si_int b); // a >> b arithmetic (sign fill)
37 ti_int __ashrti3(ti_int a, si_int b); // a >> b arithmetic (sign fill)
38 di_int __lshrdi3(di_int a, si_int b); // a >> b logical (zero fill)
39 ti_int __lshrti3(ti_int a, si_int b); // a >> b logical (zero fill)
41 si_int __clzsi2(si_int a); // count leading zeros
42 si_int __clzdi2(di_int a); // count leading zeros
43 si_int __clzti2(ti_int a); // count leading zeros
44 si_int __ctzsi2(si_int a); // count trailing zeros
45 si_int __ctzdi2(di_int a); // count trailing zeros
46 si_int __ctzti2(ti_int a); // count trailing zeros
48 si_int __ffssi2(si_int a); // find least significant 1 bit
49 si_int __ffsdi2(di_int a); // find least significant 1 bit
50 si_int __ffsti2(ti_int a); // find least significant 1 bit
52 si_int __paritysi2(si_int a); // bit parity
53 si_int __paritydi2(di_int a); // bit parity
54 si_int __parityti2(ti_int a); // bit parity
56 si_int __popcountsi2(si_int a); // bit population
57 si_int __popcountdi2(di_int a); // bit population
58 si_int __popcountti2(ti_int a); // bit population
60 uint32_t __bswapsi2(uint32_t a); // a byteswapped
61 uint64_t __bswapdi2(uint64_t a); // a byteswapped
63 // Integral arithmetic
65 di_int __negdi2 (di_int a); // -a
66 ti_int __negti2 (ti_int a); // -a
67 di_int __muldi3 (di_int a, di_int b); // a * b
68 ti_int __multi3 (ti_int a, ti_int b); // a * b
69 si_int __divsi3 (si_int a, si_int b); // a / b signed
70 di_int __divdi3 (di_int a, di_int b); // a / b signed
71 ti_int __divti3 (ti_int a, ti_int b); // a / b signed
72 su_int __udivsi3 (su_int n, su_int d); // a / b unsigned
73 du_int __udivdi3 (du_int a, du_int b); // a / b unsigned
74 tu_int __udivti3 (tu_int a, tu_int b); // a / b unsigned
75 si_int __modsi3 (si_int a, si_int b); // a % b signed
76 di_int __moddi3 (di_int a, di_int b); // a % b signed
77 ti_int __modti3 (ti_int a, ti_int b); // a % b signed
78 su_int __umodsi3 (su_int a, su_int b); // a % b unsigned
79 du_int __umoddi3 (du_int a, du_int b); // a % b unsigned
80 tu_int __umodti3 (tu_int a, tu_int b); // a % b unsigned
81 du_int __udivmoddi4(du_int a, du_int b, du_int* rem); // a / b, *rem = a % b unsigned
82 tu_int __udivmodti4(tu_int a, tu_int b, tu_int* rem); // a / b, *rem = a % b unsigned
83 su_int __udivmodsi4(su_int a, su_int b, su_int* rem); // a / b, *rem = a % b unsigned
84 si_int __divmodsi4(si_int a, si_int b, si_int* rem); // a / b, *rem = a % b signed
88 // Integral arithmetic with trapping overflow
90 si_int __absvsi2(si_int a); // abs(a)
91 di_int __absvdi2(di_int a); // abs(a)
92 ti_int __absvti2(ti_int a); // abs(a)
94 si_int __negvsi2(si_int a); // -a
95 di_int __negvdi2(di_int a); // -a
96 ti_int __negvti2(ti_int a); // -a
98 si_int __addvsi3(si_int a, si_int b); // a + b
99 di_int __addvdi3(di_int a, di_int b); // a + b
100 ti_int __addvti3(ti_int a, ti_int b); // a + b
102 si_int __subvsi3(si_int a, si_int b); // a - b
103 di_int __subvdi3(di_int a, di_int b); // a - b
104 ti_int __subvti3(ti_int a, ti_int b); // a - b
106 si_int __mulvsi3(si_int a, si_int b); // a * b
107 di_int __mulvdi3(di_int a, di_int b); // a * b
108 ti_int __mulvti3(ti_int a, ti_int b); // a * b
111 // Integral arithmetic which returns if overflow
113 si_int __mulosi4(si_int a, si_int b, int* overflow); // a * b, overflow set to one if result not in signed range
114 di_int __mulodi4(di_int a, di_int b, int* overflow); // a * b, overflow set to one if result not in signed range
115 ti_int __muloti4(ti_int a, ti_int b, int* overflow); // a * b, overflow set to
116 one if result not in signed range
119 // Integral comparison: a < b -> 0
123 si_int __cmpdi2 (di_int a, di_int b);
124 si_int __cmpti2 (ti_int a, ti_int b);
125 si_int __ucmpdi2(du_int a, du_int b);
126 si_int __ucmpti2(tu_int a, tu_int b);
128 // Integral / floating point conversion
130 di_int __fixsfdi( float a);
131 di_int __fixdfdi( double a);
132 di_int __fixxfdi(long double a);
134 ti_int __fixsfti( float a);
135 ti_int __fixdfti( double a);
136 ti_int __fixxfti(long double a);
137 uint64_t __fixtfdi(long double input); // ppc only, doesn't match documentation
139 su_int __fixunssfsi( float a);
140 su_int __fixunsdfsi( double a);
141 su_int __fixunsxfsi(long double a);
143 du_int __fixunssfdi( float a);
144 du_int __fixunsdfdi( double a);
145 du_int __fixunsxfdi(long double a);
147 tu_int __fixunssfti( float a);
148 tu_int __fixunsdfti( double a);
149 tu_int __fixunsxfti(long double a);
150 uint64_t __fixunstfdi(long double input); // ppc only
152 float __floatdisf(di_int a);
153 double __floatdidf(di_int a);
154 long double __floatdixf(di_int a);
155 long double __floatditf(int64_t a); // ppc only
157 float __floattisf(ti_int a);
158 double __floattidf(ti_int a);
159 long double __floattixf(ti_int a);
161 float __floatundisf(du_int a);
162 double __floatundidf(du_int a);
163 long double __floatundixf(du_int a);
164 long double __floatunditf(uint64_t a); // ppc only
166 float __floatuntisf(tu_int a);
167 double __floatuntidf(tu_int a);
168 long double __floatuntixf(tu_int a);
170 // Floating point raised to integer power
172 float __powisf2( float a, si_int b); // a ^ b
173 double __powidf2( double a, si_int b); // a ^ b
174 long double __powixf2(long double a, si_int b); // a ^ b
175 long double __powitf2(long double a, si_int b); // ppc only, a ^ b
177 // Complex arithmetic
179 // (a + ib) * (c + id)
181 float _Complex __mulsc3( float a, float b, float c, float d);
182 double _Complex __muldc3(double a, double b, double c, double d);
183 long double _Complex __mulxc3(long double a, long double b,
184 long double c, long double d);
185 long double _Complex __multc3(long double a, long double b,
186 long double c, long double d); // ppc only
188 // (a + ib) / (c + id)
190 float _Complex __divsc3( float a, float b, float c, float d);
191 double _Complex __divdc3(double a, double b, double c, double d);
192 long double _Complex __divxc3(long double a, long double b,
193 long double c, long double d);
194 long double _Complex __divtc3(long double a, long double b,
195 long double c, long double d); // ppc only
200 // __clear_cache() is used to tell process that new instructions have been
201 // written to an address range. Necessary on processors that do not have
202 // a unified instruction and data cache.
203 void __clear_cache(void* start, void* end);
205 // __enable_execute_stack() is used with nested functions when a trampoline
206 // function is written onto the stack and that page range needs to be made
208 void __enable_execute_stack(void* addr);
210 // __gcc_personality_v0() is normally only called by the system unwinder.
211 // C code (as opposed to C++) normally does not need a personality function
212 // because there are no catch clauses or destructors to be run. But there
213 // is a C language extension __attribute__((cleanup(func))) which marks local
214 // variables as needing the cleanup function "func" to be run when the
215 // variable goes out of scope. That includes when an exception is thrown,
216 // so a personality handler is needed.
217 _Unwind_Reason_Code __gcc_personality_v0(int version, _Unwind_Action actions,
218 uint64_t exceptionClass, struct _Unwind_Exception* exceptionObject,
219 _Unwind_Context_t context);
221 // for use with some implementations of assert() in <assert.h>
222 void __eprintf(const char* format, const char* assertion_expression,
223 const char* line, const char* file);
225 // for systems with emulated thread local storage
226 void* __emutls_get_address(struct __emutls_control*);
229 // Power PC specific functions
231 // There is no C interface to the saveFP/restFP functions. They are helper
232 // functions called by the prolog and epilog of functions that need to save
233 // a number of non-volatile float point registers.
237 // PowerPC has a standard template for trampoline functions. This function
238 // generates a custom trampoline function with the specific realFunc
239 // and localsPtr values.
240 void __trampoline_setup(uint32_t* trampOnStack, int trampSizeAllocated,
241 const void* realFunc, void* localsPtr);
243 // adds two 128-bit double-double precision values ( x + y )
244 long double __gcc_qadd(long double x, long double y);
246 // subtracts two 128-bit double-double precision values ( x - y )
247 long double __gcc_qsub(long double x, long double y);
249 // multiples two 128-bit double-double precision values ( x * y )
250 long double __gcc_qmul(long double x, long double y);
252 // divides two 128-bit double-double precision values ( x / y )
253 long double __gcc_qdiv(long double a, long double b);
256 // ARM specific functions
258 // There is no C interface to the switch* functions. These helper functions
259 // are only needed by Thumb1 code for efficient switch table generation.
265 // There is no C interface to the *_vfp_d8_d15_regs functions. There are
266 // called in the prolog and epilog of Thumb1 functions. When the C++ ABI use
267 // SJLJ for exceptions, each function with a catch clause or destuctors needs
268 // to save and restore all registers in it prolog and epliog. But there is
269 // no way to access vector and high float registers from thumb1 code, so the
270 // compiler must add call outs to these helper functions in the prolog and
272 restore_vfp_d8_d15_regs
276 // Note: long ago ARM processors did not have floating point hardware support.
277 // Floating point was done in software and floating point parameters were
278 // passed in integer registers. When hardware support was added for floating
279 // point, new *vfp functions were added to do the same operations but with
280 // floating point parameters in floating point registers.
282 // Undocumented functions
284 float __addsf3vfp(float a, float b); // Appears to return a + b
285 double __adddf3vfp(double a, double b); // Appears to return a + b
286 float __divsf3vfp(float a, float b); // Appears to return a / b
287 double __divdf3vfp(double a, double b); // Appears to return a / b
288 int __eqsf2vfp(float a, float b); // Appears to return one
289 // iff a == b and neither is NaN.
290 int __eqdf2vfp(double a, double b); // Appears to return one
291 // iff a == b and neither is NaN.
292 double __extendsfdf2vfp(float a); // Appears to convert from
294 int __fixdfsivfp(double a); // Appears to convert from
296 int __fixsfsivfp(float a); // Appears to convert from
298 unsigned int __fixunssfsivfp(float a); // Appears to convert from
299 // float to unsigned int.
300 unsigned int __fixunsdfsivfp(double a); // Appears to convert from
301 // double to unsigned int.
302 double __floatsidfvfp(int a); // Appears to convert from
304 float __floatsisfvfp(int a); // Appears to convert from
306 double __floatunssidfvfp(unsigned int a); // Appears to convert from
307 // unisgned int to double.
308 float __floatunssisfvfp(unsigned int a); // Appears to convert from
309 // unisgned int to float.
310 int __gedf2vfp(double a, double b); // Appears to return __gedf2
312 int __gesf2vfp(float a, float b); // Appears to return __gesf2
314 int __gtdf2vfp(double a, double b); // Appears to return __gtdf2
316 int __gtsf2vfp(float a, float b); // Appears to return __gtsf2
318 int __ledf2vfp(double a, double b); // Appears to return __ledf2
320 int __lesf2vfp(float a, float b); // Appears to return __lesf2
322 int __ltdf2vfp(double a, double b); // Appears to return __ltdf2
324 int __ltsf2vfp(float a, float b); // Appears to return __ltsf2
326 double __muldf3vfp(double a, double b); // Appears to return a * b
327 float __mulsf3vfp(float a, float b); // Appears to return a * b
328 int __nedf2vfp(double a, double b); // Appears to return __nedf2
330 double __negdf2vfp(double a); // Appears to return -a
331 float __negsf2vfp(float a); // Appears to return -a
332 float __negsf2vfp(float a); // Appears to return -a
333 double __subdf3vfp(double a, double b); // Appears to return a - b
334 float __subsf3vfp(float a, float b); // Appears to return a - b
335 float __truncdfsf2vfp(double a); // Appears to convert from
337 int __unorddf2vfp(double a, double b); // Appears to return __unorddf2
338 int __unordsf2vfp(float a, float b); // Appears to return __unordsf2
341 Preconditions are listed for each function at the definition when there are any.
342 Any preconditions reflect the specification at
343 http://gcc.gnu.org/onlinedocs/gccint/Libgcc.html#Libgcc.
345 Assumptions are listed in "int_lib.h", and in individual files. Where possible
346 assumptions are checked at compile time.