libgcc.texi revision 132718
1@c Copyright (C) 2003, 2004 Free Software Foundation, Inc. 2@c This is part of the GCC manual. 3@c For copying conditions, see the file gcc.texi. 4@c Contributed by Aldy Hernandez <aldy@quesejoda.com> 5 6@node Libgcc 7@chapter The GCC low-level runtime library 8 9GCC provides a low-level runtime library, @file{libgcc.a} or 10@file{libgcc_s.so.1} on some platforms. GCC generates calls to 11routines in this library automatically, whenever it needs to perform 12some operation that is too complicated to emit inline code for. 13 14Most of the routines in @code{libgcc} handle arithmetic operations 15that the target processor cannot perform directly. This includes 16integer multiply and divide on some machines, and all floating-point 17operations on other machines. @code{libgcc} also includes routines 18for exception handling, and a handful of miscellaneous operations. 19 20Some of these routines can be defined in mostly machine-independent C. 21Others must be hand-written in assembly language for each processor 22that needs them. 23 24GCC will also generate calls to C library routines, such as 25@code{memcpy} and @code{memset}, in some cases. The set of routines 26that GCC may possibly use is documented in @ref{Other 27Builtins,,,gcc, Using the GNU Compiler Collection (GCC)}. 28 29These routines take arguments and return values of a specific machine 30mode, not a specific C type. @xref{Machine Modes}, for an explanation 31of this concept. For illustrative purposes, in this chapter the 32floating point type @code{float} is assumed to correspond to @code{SFmode}; 33@code{double} to @code{DFmode}; and @code{@w{long double}} to both 34@code{TFmode} and @code{XFmode}. Similarly, the integer types @code{int} 35and @code{@w{unsigned int}} correspond to @code{SImode}; @code{long} and 36@code{@w{unsigned long}} to @code{DImode}; and @code{@w{long long}} and 37@code{@w{unsigned long long}} to @code{TImode}. 38 39@menu 40* Integer library routines:: 41* Soft float library routines:: 42* Exception handling routines:: 43* Miscellaneous routines:: 44@end menu 45 46@node Integer library routines 47@section Routines for integer arithmetic 48 49The integer arithmetic routines are used on platforms that don't provide 50hardware support for arithmetic operations on some modes. 51 52@subsection Arithmetic functions 53 54@deftypefn {Runtime Function} int __ashlsi3 (int @var{a}, int @var{b}) 55@deftypefnx {Runtime Function} long __ashldi3 (long @var{a}, int @var{b}) 56@deftypefnx {Runtime Function} {long long} __ashlti3 (long long @var{a}, int @var{b}) 57These functions return the result of shifting @var{a} left by @var{b} bits. 58@end deftypefn 59 60@deftypefn {Runtime Function} int __ashrsi3 (int @var{a}, int @var{b}) 61@deftypefnx {Runtime Function} long __ashrdi3 (long @var{a}, int @var{b}) 62@deftypefnx {Runtime Function} {long long} __ashrti3 (long long @var{a}, int @var{b}) 63These functions return the result of arithmetically shifting @var{a} right 64by @var{b} bits. 65@end deftypefn 66 67@deftypefn {Runtime Function} int __divsi3 (int @var{a}, int @var{b}) 68@deftypefnx {Runtime Function} long __divdi3 (long @var{a}, long @var{b}) 69@deftypefnx {Runtime Function} {long long} __divti3 (long long @var{a}, long long @var{b}) 70These functions return the quotient of the signed division of @var{a} and 71@var{b}. 72@end deftypefn 73 74@deftypefn {Runtime Function} int __lshrsi3 (int @var{a}, int @var{b}) 75@deftypefnx {Runtime Function} long __lshrdi3 (long @var{a}, int @var{b}) 76@deftypefnx {Runtime Function} {long long} __lshrti3 (long long @var{a}, int @var{b}) 77These functions return the result of logically shifting @var{a} right by 78@var{b} bits. 79@end deftypefn 80 81@deftypefn {Runtime Function} int __modsi3 (int @var{a}, int @var{b}) 82@deftypefnx {Runtime Function} long __moddi3 (long @var{a}, long @var{b}) 83@deftypefnx {Runtime Function} {long long} __modti3 (long long @var{a}, long long @var{b}) 84These functions return the remainder of the signed division of @var{a} 85and @var{b}. 86@end deftypefn 87 88@deftypefn {Runtime Function} int __mulsi3 (int @var{a}, int @var{b}) 89@deftypefnx {Runtime Function} long __muldi3 (long @var{a}, long @var{b}) 90@deftypefnx {Runtime Function} {long long} __multi3 (long long @var{a}, long long @var{b}) 91These functions return the product of @var{a} and @var{b}. 92@end deftypefn 93 94@deftypefn {Runtime Function} long __negdi2 (long @var{a}) 95@deftypefnx {Runtime Function} {long long} __negti2 (long long @var{a}) 96These functions return the negation of @var{a}. 97@end deftypefn 98 99@deftypefn {Runtime Function} {unsigned int} __udivsi3 (unsigned int @var{a}, unsigned int @var{b}) 100@deftypefnx {Runtime Function} {unsigned long} __udivdi3 (unsigned long @var{a}, unsigned long @var{b}) 101@deftypefnx {Runtime Function} {unsigned long long} __udivti3 (unsigned long long @var{a}, unsigned long long @var{b}) 102These functions return the quotient of the unsigned division of @var{a} 103and @var{b}. 104@end deftypefn 105 106@deftypefn {Runtime Function} {unsigned long} __udivmoddi3 (unsigned long @var{a}, unsigned long @var{b}, unsigned long *@var{c}) 107@deftypefnx {Runtime Function} {unsigned long long} __udivti3 (unsigned long long @var{a}, unsigned long long @var{b}, unsigned long long *@var{c}) 108These functions calculate both the quotient and remainder of the unsigned 109division of @var{a} and @var{b}. The return value is the quotient, and 110the remainder is placed in variable pointed to by @var{c}. 111@end deftypefn 112 113@deftypefn {Runtime Function} {unsigned int} __umodsi3 (unsigned int @var{a}, unsigned int @var{b}) 114@deftypefnx {Runtime Function} {unsigned long} __umoddi3 (unsigned long @var{a}, unsigned long @var{b}) 115@deftypefnx {Runtime Function} {unsigned long long} __umodti3 (unsigned long long @var{a}, unsigned long long @var{b}) 116These functions return the remainder of the unsigned division of @var{a} 117and @var{b}. 118@end deftypefn 119 120@subsection Comparison functions 121 122The following functions implement integral comparisons. These functions 123implement a low-level compare, upon which the higher level comparison 124operators (such as less than and greater than or equal to) can be 125constructed. The returned values lie in the range zero to two, to allow 126the high-level operators to be implemented by testing the returned 127result using either signed or unsigned comparison. 128 129@deftypefn {Runtime Function} int __cmpdi2 (long @var{a}, long @var{b}) 130@deftypefnx {Runtime Function} int __cmpti2 (long long @var{a}, long long @var{b}) 131These functions perform a signed comparison of @var{a} and @var{b}. If 132@var{a} is less than @var{b}, they return 0; if @var{a} is greater than 133@var{b}, they return 2; and if @var{a} and @var{b} are equal they return 1. 134@end deftypefn 135 136@deftypefn {Runtime Function} int __ucmpdi2 (unsigned long @var{a}, unsigned long @var{b}) 137@deftypefnx {Runtime Function} int __ucmpti2 (unsigned long long @var{a}, unsigned long long @var{b}) 138These functions perform an unsigned comparison of @var{a} and @var{b}. 139If @var{a} is less than @var{b}, they return 0; if @var{a} is greater than 140@var{b}, they return 2; and if @var{a} and @var{b} are equal they return 1. 141@end deftypefn 142 143@subsection Trapping arithmetic functions 144 145The following functions implement trapping arithmetic. These functions 146call the libc function @code{abort} upon signed arithmetic overflow. 147 148@deftypefn {Runtime Function} int __absvsi2 (int @var{a}) 149@deftypefnx {Runtime Function} long __absvdi2 (long @var{a}) 150These functions return the absolute value of @var{a}. 151@end deftypefn 152 153@deftypefn {Runtime Function} int __addvsi3 (int @var{a}, int @var{b}) 154@deftypefnx {Runtime Function} long __addvdi3 (long @var{a}, long @var{b}) 155These functions return the sum of @var{a} and @var{b}; that is 156@code{@var{a} + @var{b}}. 157@end deftypefn 158 159@deftypefn {Runtime Function} int __mulvsi3 (int @var{a}, int @var{b}) 160@deftypefnx {Runtime Function} long __mulvdi3 (long @var{a}, long @var{b}) 161The functions return the product of @var{a} and @var{b}; that is 162@code{@var{a} * @var{b}}. 163@end deftypefn 164 165@deftypefn {Runtime Function} int __negvsi2 (int @var{a}) 166@deftypefnx {Runtime Function} long __negvdi2 (long @var{a}) 167These functions return the negation of @var{a}; that is @code{-@var{a}}. 168@end deftypefn 169 170@deftypefn {Runtime Function} int __subvsi3 (int @var{a}, int @var{b}) 171@deftypefnx {Runtime Function} long __subvdi3 (long @var{a}, long @var{b}) 172These functions return the difference between @var{b} and @var{a}; 173that is @code{@var{a} - @var{b}}. 174@end deftypefn 175 176@subsection Bit operations 177 178@deftypefn {Runtime Function} int __clzsi2 (int @var{a}) 179@deftypefnx {Runtime Function} int __clzdi2 (long @var{a}) 180@deftypefnx {Runtime Function} int __clzti2 (long long @var{a}) 181These functions return the number of leading 0-bits in @var{a}, starting 182at the most significant bit position. If @var{a} is zero, the result is 183undefined. 184@end deftypefn 185 186@deftypefn {Runtime Function} int __ctzsi2 (int @var{a}) 187@deftypefnx {Runtime Function} int __ctzdi2 (long @var{a}) 188@deftypefnx {Runtime Function} int __ctzti2 (long long @var{a}) 189These functions return the number of trailing 0-bits in @var{a}, starting 190at the least significant bit position. If @var{a} is zero, the result is 191undefined. 192@end deftypefn 193 194@deftypefn {Runtime Function} int __ffsdi2 (long @var{a}) 195@deftypefnx {Runtime Function} int __ffsti2 (long long @var{a}) 196These functions return the index of the least significant 1-bit in @var{a}, 197or the value zero if @var{a} is zero. The least significant bit is index 198one. 199@end deftypefn 200 201@deftypefn {Runtime Function} int __paritysi2 (int @var{a}) 202@deftypefnx {Runtime Function} int __paritydi2 (long @var{a}) 203@deftypefnx {Runtime Function} int __parityti2 (long long @var{a}) 204These functions return the value zero if the number of bits set in 205@var{a} is even, and the value one otherwise. 206@end deftypefn 207 208@deftypefn {Runtime Function} int __popcountsi2 (int @var{a}) 209@deftypefnx {Runtime Function} int __popcountdi2 (long @var{a}) 210@deftypefnx {Runtime Function} int __popcountti2 (long long @var{a}) 211These functions return the number of bits set in @var{a}. 212@end deftypefn 213 214@node Soft float library routines 215@section Routines for floating point emulation 216@cindex soft float library 217@cindex arithmetic library 218@cindex math library 219@opindex msoft-float 220 221The software floating point library is used on machines which do not 222have hardware support for floating point. It is also used whenever 223@option{-msoft-float} is used to disable generation of floating point 224instructions. (Not all targets support this switch.) 225 226For compatibility with other compilers, the floating point emulation 227routines can be renamed with the @code{DECLARE_LIBRARY_RENAMES} macro 228(@pxref{Library Calls}). In this section, the default names are used. 229 230Presently the library does not support @code{XFmode}, which is used 231for @code{long double} on some architectures. 232 233@subsection Arithmetic functions 234 235@deftypefn {Runtime Function} float __addsf3 (float @var{a}, float @var{b}) 236@deftypefnx {Runtime Function} double __adddf3 (double @var{a}, double @var{b}) 237@deftypefnx {Runtime Function} {long double} __addtf3 (long double @var{a}, long double @var{b}) 238@deftypefnx {Runtime Function} {long double} __addxf3 (long double @var{a}, long double @var{b}) 239These functions return the sum of @var{a} and @var{b}. 240@end deftypefn 241 242@deftypefn {Runtime Function} float __subsf3 (float @var{a}, float @var{b}) 243@deftypefnx {Runtime Function} double __subdf3 (double @var{a}, double @var{b}) 244@deftypefnx {Runtime Function} {long double} __subtf3 (long double @var{a}, long double @var{b}) 245@deftypefnx {Runtime Function} {long double} __subxf3 (long double @var{a}, long double @var{b}) 246These functions return the difference between @var{b} and @var{a}; 247that is, @w{@math{@var{a} - @var{b}}}. 248@end deftypefn 249 250@deftypefn {Runtime Function} float __mulsf3 (float @var{a}, float @var{b}) 251@deftypefnx {Runtime Function} double __muldf3 (double @var{a}, double @var{b}) 252@deftypefnx {Runtime Function} {long double} __multf3 (long double @var{a}, long double @var{b}) 253@deftypefnx {Runtime Function} {long double} __mulxf3 (long double @var{a}, long double @var{b}) 254These functions return the product of @var{a} and @var{b}. 255@end deftypefn 256 257@deftypefn {Runtime Function} float __divsf3 (float @var{a}, float @var{b}) 258@deftypefnx {Runtime Function} double __divdf3 (double @var{a}, double @var{b}) 259@deftypefnx {Runtime Function} {long double} __divtf3 (long double @var{a}, long double @var{b}) 260@deftypefnx {Runtime Function} {long double} __divxf3 (long double @var{a}, long double @var{b}) 261These functions return the quotient of @var{a} and @var{b}; that is, 262@w{@math{@var{a} / @var{b}}}. 263@end deftypefn 264 265@deftypefn {Runtime Function} float __negsf2 (float @var{a}) 266@deftypefnx {Runtime Function} double __negdf2 (double @var{a}) 267@deftypefnx {Runtime Function} {long double} __negtf2 (long double @var{a}) 268@deftypefnx {Runtime Function} {long double} __negxf2 (long double @var{a}) 269These functions return the negation of @var{a}. They simply flip the 270sign bit, so they can produce negative zero and negative NaN. 271@end deftypefn 272 273@subsection Conversion functions 274 275@deftypefn {Runtime Function} double __extendsfdf2 (float @var{a}) 276@deftypefnx {Runtime Function} {long double} __extendsftf2 (float @var{a}) 277@deftypefnx {Runtime Function} {long double} __extendsfxf2 (float @var{a}) 278@deftypefnx {Runtime Function} {long double} __extenddftf2 (double @var{a}) 279@deftypefnx {Runtime Function} {long double} __extenddfxf2 (double @var{a}) 280These functions extend @var{a} to the wider mode of their return 281type. 282@end deftypefn 283 284@deftypefn {Runtime Function} double __truncxfdf2 (long double @var{a}) 285@deftypefnx {Runtime Function} double __trunctfdf2 (long double @var{a}) 286@deftypefnx {Runtime Function} float __truncxfsf2 (long double @var{a}) 287@deftypefnx {Runtime Function} float __trunctfsf2 (long double @var{a}) 288@deftypefnx {Runtime Function} float __truncdfsf2 (double @var{a}) 289These functions truncate @var{a} to the narrower mode of their return 290type, rounding toward zero. 291@end deftypefn 292 293@deftypefn {Runtime Function} int __fixsfsi (float @var{a}) 294@deftypefnx {Runtime Function} int __fixdfsi (double @var{a}) 295@deftypefnx {Runtime Function} int __fixtfsi (long double @var{a}) 296@deftypefnx {Runtime Function} int __fixxfsi (long double @var{a}) 297These functions convert @var{a} to a signed integer, rounding toward zero. 298@end deftypefn 299 300@deftypefn {Runtime Function} long __fixsfdi (float @var{a}) 301@deftypefnx {Runtime Function} long __fixdfdi (double @var{a}) 302@deftypefnx {Runtime Function} long __fixtfdi (long double @var{a}) 303@deftypefnx {Runtime Function} long __fixxfdi (long double @var{a}) 304These functions convert @var{a} to a signed long, rounding toward zero. 305@end deftypefn 306 307@deftypefn {Runtime Function} {long long} __fixsfti (float @var{a}) 308@deftypefnx {Runtime Function} {long long} __fixdfti (double @var{a}) 309@deftypefnx {Runtime Function} {long long} __fixtfti (long double @var{a}) 310@deftypefnx {Runtime Function} {long long} __fixxfti (long double @var{a}) 311These functions convert @var{a} to a signed long long, rounding toward zero. 312@end deftypefn 313 314@deftypefn {Runtime Function} {unsigned int} __fixunssfsi (float @var{a}) 315@deftypefnx {Runtime Function} {unsigned int} __fixunsdfsi (double @var{a}) 316@deftypefnx {Runtime Function} {unsigned int} __fixunstfsi (long double @var{a}) 317@deftypefnx {Runtime Function} {unsigned int} __fixunsxfsi (long double @var{a}) 318These functions convert @var{a} to an unsigned integer, rounding 319toward zero. Negative values all become zero. 320@end deftypefn 321 322@deftypefn {Runtime Function} {unsigned long} __fixunssfdi (float @var{a}) 323@deftypefnx {Runtime Function} {unsigned long} __fixunsdfdi (double @var{a}) 324@deftypefnx {Runtime Function} {unsigned long} __fixunstfdi (long double @var{a}) 325@deftypefnx {Runtime Function} {unsigned long} __fixunsxfdi (long double @var{a}) 326These functions convert @var{a} to an unsigned long, rounding 327toward zero. Negative values all become zero. 328@end deftypefn 329 330@deftypefn {Runtime Function} {unsigned long long} __fixunssfti (float @var{a}) 331@deftypefnx {Runtime Function} {unsigned long long} __fixunsdfti (double @var{a}) 332@deftypefnx {Runtime Function} {unsigned long long} __fixunstfti (long double @var{a}) 333@deftypefnx {Runtime Function} {unsigned long long} __fixunsxfti (long double @var{a}) 334These functions convert @var{a} to an unsigned long long, rounding 335toward zero. Negative values all become zero. 336@end deftypefn 337 338@deftypefn {Runtime Function} float __floatsisf (int @var{i}) 339@deftypefnx {Runtime Function} double __floatsidf (int @var{i}) 340@deftypefnx {Runtime Function} {long double} __floatsitf (int @var{i}) 341@deftypefnx {Runtime Function} {long double} __floatsixf (int @var{i}) 342These functions convert @var{i}, a signed integer, to floating point. 343@end deftypefn 344 345@deftypefn {Runtime Function} float __floatdisf (long @var{i}) 346@deftypefnx {Runtime Function} double __floatdidf (long @var{i}) 347@deftypefnx {Runtime Function} {long double} __floatditf (long @var{i}) 348@deftypefnx {Runtime Function} {long double} __floatdixf (long @var{i}) 349These functions convert @var{i}, a signed long, to floating point. 350@end deftypefn 351 352@deftypefn {Runtime Function} float __floattisf (long long @var{i}) 353@deftypefnx {Runtime Function} double __floattidf (long long @var{i}) 354@deftypefnx {Runtime Function} {long double} __floattitf (long long @var{i}) 355@deftypefnx {Runtime Function} {long double} __floattixf (long long @var{i}) 356These functions convert @var{i}, a signed long long, to floating point. 357@end deftypefn 358 359@subsection Comparison functions 360 361There are two sets of basic comparison functions. 362 363@deftypefn {Runtime Function} int __cmpsf2 (float @var{a}, float @var{b}) 364@deftypefnx {Runtime Function} int __cmpdf2 (double @var{a}, double @var{b}) 365@deftypefnx {Runtime Function} int __cmptf2 (long double @var{a}, long double @var{b}) 366These functions calculate @math{a <=> b}. That is, if @var{a} is less 367than @var{b}, they return -1; if @var{a} is greater than @var{b}, they 368return 1; and if @var{a} and @var{b} are equal they return 0. If 369either argument is NaN they return 1, but you should not rely on this; 370if NaN is a possibility, use one of the higher-level comparison 371functions. 372@end deftypefn 373 374@deftypefn {Runtime Function} int __unordsf2 (float @var{a}, float @var{b}) 375@deftypefnx {Runtime Function} int __unorddf2 (double @var{a}, double @var{b}) 376@deftypefnx {Runtime Function} int __unordtf2 (long double @var{a}, long double @var{b}) 377These functions return a nonzero value if either argument is NaN, otherwise 0. 378@end deftypefn 379 380There is also a complete group of higher level functions which 381correspond directly to comparison operators. They implement the ISO C 382semantics for floating-point comparisons, taking NaN into account. 383Pay careful attention to the return values defined for each set. 384Under the hood, all of these routines are implemented as 385 386@smallexample 387 if (__unord@var{X}f2 (a, b)) 388 return @var{E}; 389 return __cmp@var{X}f2 (a, b); 390@end smallexample 391 392@noindent 393where @var{E} is a constant chosen to give the proper behavior for 394NaN. Thus, the meaning of the return value is different for each set. 395Do not rely on this implementation; only the semantics documented 396below are guaranteed. 397 398@deftypefn {Runtime Function} int __eqsf2 (float @var{a}, float @var{b}) 399@deftypefnx {Runtime Function} int __eqdf2 (double @var{a}, double @var{b}) 400@deftypefnx {Runtime Function} int __eqtf2 (long double @var{a}, long double @var{b}) 401These functions return zero if neither argument is NaN, and @var{a} and 402@var{b} are equal. 403@end deftypefn 404 405@deftypefn {Runtime Function} int __nesf2 (float @var{a}, float @var{b}) 406@deftypefnx {Runtime Function} int __nedf2 (double @var{a}, double @var{b}) 407@deftypefnx {Runtime Function} int __netf2 (long double @var{a}, long double @var{b}) 408These functions return a nonzero value if either argument is NaN, or 409if @var{a} and @var{b} are unequal. 410@end deftypefn 411 412@deftypefn {Runtime Function} int __gesf2 (float @var{a}, float @var{b}) 413@deftypefnx {Runtime Function} int __gedf2 (double @var{a}, double @var{b}) 414@deftypefnx {Runtime Function} int __getf2 (long double @var{a}, long double @var{b}) 415These functions return a value greater than or equal to zero if 416neither argument is NaN, and @var{a} is greater than or equal to 417@var{b}. 418@end deftypefn 419 420@deftypefn {Runtime Function} int __ltsf2 (float @var{a}, float @var{b}) 421@deftypefnx {Runtime Function} int __ltdf2 (double @var{a}, double @var{b}) 422@deftypefnx {Runtime Function} int __lttf2 (long double @var{a}, long double @var{b}) 423These functions return a value less than zero if neither argument is 424NaN, and @var{a} is strictly less than @var{b}. 425@end deftypefn 426 427@deftypefn {Runtime Function} int __lesf2 (float @var{a}, float @var{b}) 428@deftypefnx {Runtime Function} int __ledf2 (double @var{a}, double @var{b}) 429@deftypefnx {Runtime Function} int __letf2 (long double @var{a}, long double @var{b}) 430These functions return a value less than or equal to zero if neither 431argument is NaN, and @var{a} is less than or equal to @var{b}. 432@end deftypefn 433 434@deftypefn {Runtime Function} int __gtsf2 (float @var{a}, float @var{b}) 435@deftypefnx {Runtime Function} int __gtdf2 (double @var{a}, double @var{b}) 436@deftypefnx {Runtime Function} int __gttf2 (long double @var{a}, long double @var{b}) 437These functions return a value greater than zero if neither argument 438is NaN, and @var{a} is strictly greater than @var{b}. 439@end deftypefn 440 441@node Exception handling routines 442@section Language-independent routines for exception handling 443 444document me! 445 446@smallexample 447 _Unwind_DeleteException 448 _Unwind_Find_FDE 449 _Unwind_ForcedUnwind 450 _Unwind_GetGR 451 _Unwind_GetIP 452 _Unwind_GetLanguageSpecificData 453 _Unwind_GetRegionStart 454 _Unwind_GetTextRelBase 455 _Unwind_GetDataRelBase 456 _Unwind_RaiseException 457 _Unwind_Resume 458 _Unwind_SetGR 459 _Unwind_SetIP 460 _Unwind_FindEnclosingFunction 461 _Unwind_SjLj_Register 462 _Unwind_SjLj_Unregister 463 _Unwind_SjLj_RaiseException 464 _Unwind_SjLj_ForcedUnwind 465 _Unwind_SjLj_Resume 466 __deregister_frame 467 __deregister_frame_info 468 __deregister_frame_info_bases 469 __register_frame 470 __register_frame_info 471 __register_frame_info_bases 472 __register_frame_info_table 473 __register_frame_info_table_bases 474 __register_frame_table 475@end smallexample 476 477@node Miscellaneous routines 478@section Miscellaneous runtime library routines 479 480@subsection Cache control functions 481@deftypefn {Runtime Function} void __clear_cache (char *@var{beg}, char *@var{end}) 482This function clears the instruction cache between @var{beg} and @var{end}. 483@end deftypefn 484 485