gcc/d/intrinsics.cc

   1 /* intrinsics.cc -- D language compiler intrinsics.
   2    Copyright (C) 2006-2020 Free Software Foundation, Inc.
   3
   4 GCC is free software; you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation; either version 3, or (at your option)
   7 any later version.
   8
   9 GCC is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with GCC; see the file COPYING3.  If not see
  16 <http://www.gnu.org/licenses/>.  */
  17
  18 #include "config.h"
  19 #include "system.h"
  20 #include "coretypes.h"
  21
  22 #include "dmd/declaration.h"
  23 #include "dmd/identifier.h"
  24 #include "dmd/mangle.h"
  25 #include "dmd/mangle.h"
  26 #include "dmd/module.h"
  27 #include "dmd/template.h"
  28
  29 #include "tm.h"
  30 #include "function.h"
  31 #include "tree.h"
  32 #include "fold-const.h"
  33 #include "stringpool.h"
  34 #include "builtins.h"
  35
  36 #include "d-tree.h"
  37
  38
  39 /* An internal struct used to hold information on D intrinsics.  */
  40
  41 struct intrinsic_decl
  42 {
  43   /* The DECL_INTRINSIC_CODE of this decl.  */
  44   intrinsic_code code;
  45
  46   /* The DECL_FUNCTION_CODE of this decl, if it directly maps to any.  */
  47   built_in_function built_in;
  48
  49   /* The name of the intrinsic.  */
  50   const char *name;
  51
  52   /* The module where the intrinsic is located.  */
  53   const char *module;
  54
  55   /* The mangled signature decoration of the intrinsic.  */
  56   const char *deco;
  57
  58   /* True if the intrinsic is only handled in CTFE.  */
  59   bool ctfeonly;
  60 };
  61
  62 static const intrinsic_decl intrinsic_decls[] =
  63 {
  64 #define DEF_D_INTRINSIC(CODE, BUILTIN, NAME, MODULE, DECO, CTFE) \
  65     { INTRINSIC_ ## CODE, BUILT_IN_ ## BUILTIN, NAME, MODULE, DECO, CTFE },
  66
  67 #include "intrinsics.def"
  68
  69 #undef DEF_D_INTRINSIC
  70 };
  71
  72 /* Checks if DECL is an intrinsic or run time library function that requires
  73    special processing.  Sets DECL_INTRINSIC_CODE so it can be identified
  74    later in maybe_expand_intrinsic.  */
  75
  76 void
  77 maybe_set_intrinsic (FuncDeclaration *decl)
  78 {
  79   if (!decl->ident || decl->builtin != BUILTINunknown)
  80     return;
  81
  82   /* The builtin flag is updated only if we can evaluate the intrinsic
  83      at compile-time.  Such as the math or bitop intrinsics.  */
  84   decl->builtin = BUILTINno;
  85
  86   /* Check if it's a compiler intrinsic.  We only require that any
  87      internally recognised intrinsics are declared in a module with
  88      an explicit module declaration.  */
  89   Module *m = decl->getModule ();
  90
  91   if (!m || !m->md)
  92     return;
  93
  94   TemplateInstance *ti = decl->isInstantiated ();
  95   TemplateDeclaration *td = ti ? ti->tempdecl->isTemplateDeclaration () : NULL;
  96
  97   const char *tname = decl->ident->toChars ();
  98   const char *tmodule = m->md->toChars ();
  99   const char *tdeco = (td == NULL) ? decl->type->deco : NULL;
 100
 101   /* Look through all D intrinsics.  */
 102   for (size_t i = 0; i < (int) INTRINSIC_LAST; i++)
 103     {
 104       if (!intrinsic_decls[i].name)
 105         continue;
 106
 107       if (strcmp (intrinsic_decls[i].name, tname) != 0
 108           || strcmp (intrinsic_decls[i].module, tmodule) != 0)
 109         continue;
 110
 111       /* Instantiated functions would have the wrong type deco, get it from the
 112          template member instead.  */
 113       if (tdeco == NULL)
 114         {
 115           if (!td || !td->onemember)
 116             return;
 117
 118           FuncDeclaration *fd = td->onemember->isFuncDeclaration ();
 119           if (fd == NULL)
 120             return;
 121
 122           OutBuffer buf;
 123           mangleToBuffer (fd->type, &buf);
 124           tdeco = buf.extractChars ();
 125         }
 126
 127       /* Matching the type deco may be a bit too strict, as it means that all
 128          function attributes that end up in the signature must be kept aligned
 129          between the compiler and library declaration.  */
 130       if (strcmp (intrinsic_decls[i].deco, tdeco) == 0)
 131         {
 132           intrinsic_code code = intrinsic_decls[i].code;
 133
 134           if (decl->csym == NULL)
 135             get_symbol_decl (decl);
 136
 137           /* If there is no function body, then the implementation is always
 138              provided by the compiler.  */
 139           if (!decl->fbody)
 140             set_decl_built_in_function (decl->csym, BUILT_IN_FRONTEND, code);
 141
 142           /* Infer whether the intrinsic can be used for CTFE, let the
 143              front-end know that it can be evaluated at compile-time.  */
 144           switch (code)
 145             {
 146             case INTRINSIC_VA_ARG:
 147             case INTRINSIC_C_VA_ARG:
 148             case INTRINSIC_VASTART:
 149             case INTRINSIC_ADDS:
 150             case INTRINSIC_ADDSL:
 151             case INTRINSIC_ADDU:
 152             case INTRINSIC_ADDUL:
 153             case INTRINSIC_SUBS:
 154             case INTRINSIC_SUBSL:
 155             case INTRINSIC_SUBU:
 156             case INTRINSIC_SUBUL:
 157             case INTRINSIC_MULS:
 158             case INTRINSIC_MULSL:
 159             case INTRINSIC_MULU:
 160             case INTRINSIC_MULUI:
 161             case INTRINSIC_MULUL:
 162             case INTRINSIC_NEGS:
 163             case INTRINSIC_NEGSL:
 164             case INTRINSIC_VLOAD8:
 165             case INTRINSIC_VLOAD16:
 166             case INTRINSIC_VLOAD32:
 167             case INTRINSIC_VLOAD64:
 168             case INTRINSIC_VSTORE8:
 169             case INTRINSIC_VSTORE16:
 170             case INTRINSIC_VSTORE32:
 171             case INTRINSIC_VSTORE64:
 172               break;
 173
 174             case INTRINSIC_POW:
 175             {
 176               /* Check that this overload of pow() is has an equivalent
 177                  built-in function.  It could be `int pow(int, int)'.  */
 178               tree rettype = TREE_TYPE (TREE_TYPE (decl->csym));
 179               if (mathfn_built_in (rettype, BUILT_IN_POW) != NULL_TREE)
 180                 decl->builtin = BUILTINyes;
 181               break;
 182             }
 183
 184             default:
 185               decl->builtin = BUILTINyes;
 186               break;
 187             }
 188
 189           /* The intrinsic was marked as CTFE-only.  */
 190           if (intrinsic_decls[i].ctfeonly)
 191             DECL_BUILT_IN_CTFE (decl->csym) = 1;
 192
 193           DECL_INTRINSIC_CODE (decl->csym) = code;
 194           break;
 195         }
 196     }
 197 }
 198
 199 /* Construct a function call to the built-in function CODE, N is the number of
 200    arguments, and the `...' parameters are the argument expressions.
 201    The original call expression is held in CALLEXP.  */
 202
 203 static tree
 204 call_builtin_fn (tree callexp, built_in_function code, int n, ...)
 205 {
 206   tree *argarray = XALLOCAVEC (tree, n);
 207   va_list ap;
 208
 209   va_start (ap, n);
 210   for (int i = 0; i < n; i++)
 211     argarray[i] = va_arg (ap, tree);
 212   va_end (ap);
 213
 214   tree exp = build_call_expr_loc_array (EXPR_LOCATION (callexp),
 215                                         builtin_decl_explicit (code),
 216                                         n, argarray);
 217   return convert (TREE_TYPE (callexp), fold (exp));
 218 }
 219
 220 /* Expand a front-end instrinsic call to bsf().  This takes one argument,
 221    the signature to which can be either:
 222
 223         int bsf (uint arg);
 224         int bsf (ulong arg);
 225
 226    This scans all bits in the given argument starting with the first,
 227    returning the bit number of the first bit set.  The original call
 228    expression is held in CALLEXP.  */
 229
 230 static tree
 231 expand_intrinsic_bsf (tree callexp)
 232 {
 233   /* The bsr() intrinsic gets turned into __builtin_ctz(arg).
 234      The return value is supposed to be undefined if arg is zero.  */
 235   tree arg = CALL_EXPR_ARG (callexp, 0);
 236   int argsize = TYPE_PRECISION (TREE_TYPE (arg));
 237
 238   /* Which variant of __builtin_ctz* should we call?  */
 239   built_in_function code = (argsize <= INT_TYPE_SIZE) ? BUILT_IN_CTZ
 240     : (argsize <= LONG_TYPE_SIZE) ? BUILT_IN_CTZL
 241     : (argsize <= LONG_LONG_TYPE_SIZE) ? BUILT_IN_CTZLL
 242     : END_BUILTINS;
 243
 244   gcc_assert (code != END_BUILTINS);
 245
 246   return call_builtin_fn (callexp, code, 1, arg);
 247 }
 248
 249 /* Expand a front-end instrinsic call to bsr().  This takes one argument,
 250    the signature to which can be either:
 251
 252         int bsr (uint arg);
 253         int bsr (ulong arg);
 254
 255    This scans all bits in the given argument from the most significant bit
 256    to the least significant, returning the bit number of the first bit set.
 257    The original call expression is held in CALLEXP.  */
 258
 259 static tree
 260 expand_intrinsic_bsr (tree callexp)
 261 {
 262   /* The bsr() intrinsic gets turned into (size - 1) - __builtin_clz(arg).
 263      The return value is supposed to be undefined if arg is zero.  */
 264   tree arg = CALL_EXPR_ARG (callexp, 0);
 265   tree type = TREE_TYPE (arg);
 266   int argsize = TYPE_PRECISION (type);
 267
 268   /* Which variant of __builtin_clz* should we call?  */
 269   built_in_function code = (argsize <= INT_TYPE_SIZE) ? BUILT_IN_CLZ
 270     : (argsize <= LONG_TYPE_SIZE) ? BUILT_IN_CLZL
 271     : (argsize <= LONG_LONG_TYPE_SIZE) ? BUILT_IN_CLZLL
 272     : END_BUILTINS;
 273
 274   gcc_assert (code != END_BUILTINS);
 275
 276   tree result = call_builtin_fn (callexp, code, 1, arg);
 277
 278   /* Handle int -> long conversions.  */
 279   if (TREE_TYPE (result) != type)
 280     result = fold_convert (type, result);
 281
 282   result = fold_build2 (MINUS_EXPR, type,
 283                         build_integer_cst (argsize - 1, type), result);
 284   return fold_convert (TREE_TYPE (callexp), result);
 285 }
 286
 287 /* Expand a front-end intrinsic call to INTRINSIC, which is either a call to
 288    bt(), btc(), btr(), or bts().  These intrinsics expect to take two arguments,
 289    the signature to which is:
 290
 291         int bt (size_t* ptr, size_t bitnum);
 292
 293    All intrinsics test if a bit is set and return the result of that condition.
 294    Variants of `bt' will then update that bit. `btc' compliments the bit, `bts'
 295    sets the bit, and `btr' resets the bit.  The original call expression is
 296    held in CALLEXP.  */
 297
 298 static tree
 299 expand_intrinsic_bt (intrinsic_code intrinsic, tree callexp)
 300 {
 301   tree ptr = CALL_EXPR_ARG (callexp, 0);
 302   tree bitnum = CALL_EXPR_ARG (callexp, 1);
 303   tree type = TREE_TYPE (TREE_TYPE (ptr));
 304
 305   /* size_t bitsize = sizeof(*ptr) * BITS_PER_UNIT;  */
 306   tree bitsize = fold_convert (type, TYPE_SIZE (TREE_TYPE (ptr)));
 307
 308   /* ptr[bitnum / bitsize]  */
 309   ptr = build_array_index (ptr, fold_build2 (TRUNC_DIV_EXPR, type,
 310                                              bitnum, bitsize));
 311   ptr = indirect_ref (type, ptr);
 312
 313   /* mask = 1 << (bitnum % bitsize);  */
 314   bitnum = fold_build2 (TRUNC_MOD_EXPR, type, bitnum, bitsize);
 315   bitnum = fold_build2 (LSHIFT_EXPR, type, build_one_cst (type), bitnum);
 316
 317   /* cond = ptr[bitnum / size] & mask;  */
 318   tree cond = fold_build2 (BIT_AND_EXPR, type, ptr, bitnum);
 319
 320   /* cond ? -1 : 0;  */
 321   cond = build_condition (TREE_TYPE (callexp), d_truthvalue_conversion (cond),
 322                           build_minus_one_cst (TREE_TYPE (callexp)),
 323                           build_zero_cst (TREE_TYPE (callexp)));
 324
 325   /* Update the bit as needed, only testing the bit for bt().  */
 326   tree_code code;
 327
 328   switch (intrinsic)
 329     {
 330     case INTRINSIC_BT:
 331     case INTRINSIC_BT64:
 332       return cond;
 333
 334     case INTRINSIC_BTC:
 335     case INTRINSIC_BTC64:
 336       code = BIT_XOR_EXPR;
 337       break;
 338
 339     case INTRINSIC_BTR:
 340     case INTRINSIC_BTR64:
 341       bitnum = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (bitnum), bitnum);
 342       code = BIT_AND_EXPR;
 343       break;
 344
 345     case INTRINSIC_BTS:
 346     case INTRINSIC_BTS64:
 347       code = BIT_IOR_EXPR;
 348       break;
 349
 350     default:
 351       gcc_unreachable ();
 352     }
 353
 354   /* ptr[bitnum / size] op= mask;  */
 355   ptr = modify_expr (ptr, fold_build2 (code, TREE_TYPE (ptr), ptr, bitnum));
 356
 357   /* Store the condition result in a temporary, and return expressions in
 358      correct order of evaluation.  */
 359   tree tmp = build_local_temp (TREE_TYPE (callexp));
 360   cond = modify_expr (tmp, cond);
 361
 362   return compound_expr (cond, compound_expr (ptr, tmp));
 363 }
 364
 365 /* Expand a front-end intrinsic call to popcnt().  This takes one argument, the
 366    signature to which can be either:
 367
 368         int popcnt (uint arg);
 369         int popcnt (ulong arg);
 370
 371    Calculates the number of set bits in an integer.  The original call
 372    expression is held in CALLEXP.  */
 373
 374 static tree
 375 expand_intrinsic_popcnt (tree callexp)
 376 {
 377   tree arg = CALL_EXPR_ARG (callexp, 0);
 378   int argsize = TYPE_PRECISION (TREE_TYPE (arg));
 379
 380   /* Which variant of __builtin_popcount* should we call?  */
 381   built_in_function code = (argsize <= INT_TYPE_SIZE) ? BUILT_IN_POPCOUNT
 382     : (argsize <= LONG_TYPE_SIZE) ? BUILT_IN_POPCOUNTL
 383     : (argsize <= LONG_LONG_TYPE_SIZE) ? BUILT_IN_POPCOUNTLL
 384     : END_BUILTINS;
 385
 386   gcc_assert (code != END_BUILTINS);
 387
 388   return call_builtin_fn (callexp, code, 1, arg);
 389 }
 390
 391 /* Expand a front-end intrinsic call to INTRINSIC, which is either a call to
 392    rol() or ror().  These intrinsics expect to take one or two arguments,
 393    the signature to which can be either:
 394
 395         T rol(T) (const T value, const uint count);
 396         T rol(uint count, T) (const T value);
 397         T ror(T) (const T value, const uint count);
 398         T ror(uint count, T) (const T value);
 399
 400    This bitwise rotates VALUE left or right by COUNT bit positions.  */
 401
 402 static tree
 403 expand_intrinsic_rotate (intrinsic_code intrinsic, tree callexp)
 404 {
 405   tree type = TREE_TYPE (callexp);
 406   tree value = CALL_EXPR_ARG (callexp, 0);
 407   tree count;
 408   tree_code code;
 409
 410   /* Get the equivalent tree code for the intrinsic.  */
 411   if (intrinsic == INTRINSIC_ROL || intrinsic == INTRINSIC_ROL_TIARG)
 412     code = LROTATE_EXPR;
 413   else if (intrinsic == INTRINSIC_ROR || intrinsic == INTRINSIC_ROR_TIARG)
 414     code = RROTATE_EXPR;
 415   else
 416     gcc_unreachable ();
 417
 418   /* Get the COUNT parameter.  Either from the call expression arguments or the
 419      template instantiation arguments.  */
 420   if (intrinsic == INTRINSIC_ROL || intrinsic == INTRINSIC_ROR)
 421     count = CALL_EXPR_ARG (callexp, 1);
 422   else
 423     {
 424       tree callee = CALL_EXPR_FN (callexp);
 425
 426       if (TREE_CODE (callee) == ADDR_EXPR)
 427         callee = TREE_OPERAND (callee, 0);
 428
 429       /* Retrieve from the encoded template instantation.  */
 430       TemplateInstance *ti = DECL_LANG_FRONTEND (callee)->isInstantiated ();
 431       gcc_assert (ti && ti->tiargs && ti->tiargs->length == 2);
 432
 433       Expression *e = isExpression ((*ti->tiargs)[0]);
 434       gcc_assert (e && e->op == TOKint64);
 435       count = build_expr (e, true);
 436     }
 437
 438   return fold_build2 (code, type, value, count);
 439 }
 440
 441 /* Expand a front-end intrinsic call to copysign().  This takes two arguments,
 442    the signature to which can be either:
 443
 444         float copysign (T to, float from);
 445         double copysign (T to, double from);
 446         real copysign (T to, real from);
 447
 448    This computes a value composed of TO with the sign bit of FROM.  The original
 449    call expression is held in CALLEXP.  */
 450
 451 static tree
 452 expand_intrinsic_copysign (tree callexp)
 453 {
 454   tree to = CALL_EXPR_ARG (callexp, 0);
 455   tree from = CALL_EXPR_ARG (callexp, 1);
 456   tree type = TREE_TYPE (to);
 457
 458   /* Convert parameters to the same type.  Prefer the first parameter unless it
 459      is an integral type.  */
 460   if (INTEGRAL_TYPE_P (type))
 461     {
 462       to = fold_convert (TREE_TYPE (from), to);
 463       type = TREE_TYPE (to);
 464     }
 465   else
 466     from = fold_convert (type, from);
 467
 468   /* Which variant of __builtin_copysign* should we call?  */
 469   tree builtin = mathfn_built_in (type, BUILT_IN_COPYSIGN);
 470   gcc_assert (builtin != NULL_TREE);
 471
 472   return call_builtin_fn (callexp, DECL_FUNCTION_CODE (builtin), 2,
 473                           to, from);
 474 }
 475
 476 /* Expand a front-end intrinsic call to pow().  This takes two arguments, the
 477    signature to which can be either:
 478
 479         float pow (float base, T exponent);
 480         double pow (double base, T exponent);
 481         real pow (real base, T exponent);
 482
 483    This computes the value of BASE raised to the power of EXPONENT.
 484    The original call expression is held in CALLEXP.  */
 485
 486 static tree
 487 expand_intrinsic_pow (tree callexp)
 488 {
 489   tree base = CALL_EXPR_ARG (callexp, 0);
 490   tree exponent = CALL_EXPR_ARG (callexp, 1);
 491   tree exptype = TREE_TYPE (exponent);
 492
 493   /* Which variant of __builtin_pow* should we call?  */
 494   built_in_function code = SCALAR_FLOAT_TYPE_P (exptype) ? BUILT_IN_POW
 495     : INTEGRAL_TYPE_P (exptype) ? BUILT_IN_POWI
 496     : END_BUILTINS;
 497   gcc_assert (code != END_BUILTINS);
 498
 499   tree builtin = mathfn_built_in (TREE_TYPE (base), code);
 500   gcc_assert (builtin != NULL_TREE);
 501
 502   return call_builtin_fn (callexp, DECL_FUNCTION_CODE (builtin), 2,
 503                           base, exponent);
 504 }
 505
 506 /* Expand a front-end intrinsic call to toPrec().  This takes one argument, the
 507    signature to which can be either:
 508
 509         T toPrec(T)(float f);
 510         T toPrec(T)(double f);
 511         T toPrec(T)(real f);
 512
 513     This rounds the argument F to the precision of the specified floating
 514     point type T.  The original call expression is held in CALLEXP.  */
 515
 516 static tree
 517 expand_intrinsic_toprec (tree callexp)
 518 {
 519   tree f = CALL_EXPR_ARG (callexp, 0);
 520   tree type = TREE_TYPE (callexp);
 521
 522   return convert (type, f);
 523 }
 524
 525 /* Expand a front-end intrinsic call to va_arg().  This takes either one or two
 526    arguments, the signature to which can be either:
 527
 528         T va_arg(T) (ref va_list ap);
 529         void va_arg(T) (va_list ap, ref T parmn);
 530
 531    This retrieves the next variadic parameter that is type T from the given
 532    va_list.  If also given, store the value into parmn, otherwise return it.
 533    The original call expression is held in CALLEXP.  */
 534
 535 static tree
 536 expand_intrinsic_vaarg (tree callexp)
 537 {
 538   tree ap = CALL_EXPR_ARG (callexp, 0);
 539   tree parmn = NULL_TREE;
 540   tree type;
 541
 542   STRIP_NOPS (ap);
 543
 544   if (call_expr_nargs (callexp) == 1)
 545     type = TREE_TYPE (callexp);
 546   else
 547     {
 548       parmn = CALL_EXPR_ARG (callexp, 1);
 549       STRIP_NOPS (parmn);
 550
 551       /* The `ref' argument to va_arg is either an address or reference,
 552          get the value of it.  */
 553       if (TREE_CODE (parmn) == PARM_DECL && POINTER_TYPE_P (TREE_TYPE (parmn)))
 554         parmn = build_deref (parmn);
 555       else
 556         {
 557           gcc_assert (TREE_CODE (parmn) == ADDR_EXPR);
 558           parmn = TREE_OPERAND (parmn, 0);
 559         }
 560
 561       type = TREE_TYPE (parmn);
 562     }
 563
 564   /* (T) VA_ARG_EXP<ap>;  */
 565   tree exp = build1_loc (EXPR_LOCATION (callexp), VA_ARG_EXPR, type, ap);
 566
 567   /* parmn = (T) VA_ARG_EXP<ap>;  */
 568   if (parmn != NULL_TREE)
 569     exp = modify_expr (parmn, exp);
 570
 571   return exp;
 572 }
 573
 574 /* Expand a front-end intrinsic call to va_start(), which takes two arguments,
 575    the signature to which is:
 576
 577         void va_start(T) (out va_list ap, ref T parmn);
 578
 579    This initializes the va_list type, where parmn should be the last named
 580    parameter.  The original call expression is held in CALLEXP.  */
 581
 582 static tree
 583 expand_intrinsic_vastart (tree callexp)
 584 {
 585   tree ap = CALL_EXPR_ARG (callexp, 0);
 586   tree parmn = CALL_EXPR_ARG (callexp, 1);
 587
 588   STRIP_NOPS (ap);
 589   STRIP_NOPS (parmn);
 590
 591   /* The va_list argument should already have its address taken.  The second
 592      argument, however, is inout and that needs to be fixed to prevent a
 593      warning.  Could be casting, so need to check type too?  */
 594   gcc_assert (TREE_CODE (ap) == ADDR_EXPR
 595               || (TREE_CODE (ap) == PARM_DECL
 596                   && POINTER_TYPE_P (TREE_TYPE (ap))));
 597
 598   /* Assuming nobody tries to change the return type.  */
 599   if (TREE_CODE (parmn) != PARM_DECL)
 600     {
 601       gcc_assert (TREE_CODE (parmn) == ADDR_EXPR);
 602       parmn = TREE_OPERAND (parmn, 0);
 603     }
 604
 605   return call_builtin_fn (callexp, BUILT_IN_VA_START, 2, ap, parmn);
 606 }
 607
 608 /* Expand a front-end instrinsic call to INTRINSIC, which is either a call to
 609    adds(), addu(), subs(), subu(), negs(), muls(), or mulu().  These intrinsics
 610    expect to take two or three arguments, the signature to which can be either:
 611
 612         int adds (int x, int y, ref bool overflow);
 613         long adds (long x, long y, ref bool overflow);
 614         int negs (int x, ref bool overflow);
 615         long negs (long x, ref bool overflow);
 616
 617    This performs an operation on two signed or unsigned integers, checking for
 618    overflow.  The overflow is sticky, meaning that a sequence of operations
 619    can be done and overflow need only be checked at the end.  The original call
 620    expression is held in CALLEXP.  */
 621
 622 static tree
 623 expand_intrinsic_checkedint (intrinsic_code intrinsic, tree callexp)
 624 {
 625   tree type = TREE_TYPE (callexp);
 626   tree x;
 627   tree y;
 628   tree overflow;
 629   internal_fn icode;
 630
 631   /* Which variant of *_OVERFLOW should we generate?  */
 632   switch (intrinsic)
 633     {
 634     case INTRINSIC_ADDS:
 635     case INTRINSIC_ADDSL:
 636     case INTRINSIC_ADDU:
 637     case INTRINSIC_ADDUL:
 638       x = CALL_EXPR_ARG (callexp, 0);
 639       y = CALL_EXPR_ARG (callexp, 1);
 640       overflow = CALL_EXPR_ARG (callexp, 2);
 641       icode = IFN_ADD_OVERFLOW;
 642       break;
 643
 644     case INTRINSIC_SUBS:
 645     case INTRINSIC_SUBSL:
 646     case INTRINSIC_SUBU:
 647     case INTRINSIC_SUBUL:
 648       x = CALL_EXPR_ARG (callexp, 0);
 649       y = CALL_EXPR_ARG (callexp, 1);
 650       overflow = CALL_EXPR_ARG (callexp, 2);
 651       icode = IFN_SUB_OVERFLOW;
 652       break;
 653
 654     case INTRINSIC_MULS:
 655     case INTRINSIC_MULSL:
 656     case INTRINSIC_MULU:
 657     case INTRINSIC_MULUI:
 658     case INTRINSIC_MULUL:
 659       x = CALL_EXPR_ARG (callexp, 0);
 660       y = CALL_EXPR_ARG (callexp, 1);
 661       overflow = CALL_EXPR_ARG (callexp, 2);
 662       icode = IFN_MUL_OVERFLOW;
 663       break;
 664
 665     case INTRINSIC_NEGS:
 666     case INTRINSIC_NEGSL:
 667       /* The negs() intrinsic gets turned into SUB_OVERFLOW (0, y).  */
 668       x = fold_convert (type, integer_zero_node);
 669       y = CALL_EXPR_ARG (callexp, 0);
 670       overflow = CALL_EXPR_ARG (callexp, 1);
 671       icode = IFN_SUB_OVERFLOW;
 672       break;
 673
 674     default:
 675       gcc_unreachable ();
 676     }
 677
 678   tree result
 679     = build_call_expr_internal_loc (EXPR_LOCATION (callexp), icode,
 680                                     build_complex_type (type), 2, x, y);
 681
 682   STRIP_NOPS (overflow);
 683   overflow = build_deref (overflow);
 684
 685   /* Assign returned result to overflow parameter, however if overflow is
 686      already true, maintain its value.  */
 687   type = TREE_TYPE (overflow);
 688   result = save_expr (result);
 689
 690   tree exp = fold_build2 (BIT_IOR_EXPR, type, overflow,
 691                           fold_convert (type, imaginary_part (result)));
 692   exp = modify_expr (overflow, exp);
 693
 694   /* Return the value of result.  */
 695   return compound_expr (exp, real_part (result));
 696 }
 697
 698 /* Expand a front-end instrinsic call to volatileLoad().  This takes one
 699    argument, the signature to which can be either:
 700
 701         ubyte volatileLoad (ubyte* ptr);
 702         ushort volatileLoad (ushort* ptr);
 703         uint volatileLoad (uint* ptr);
 704         ulong volatileLoad (ulong* ptr);
 705
 706    This reads a value from the memory location indicated by ptr.  Calls to
 707    them are be guaranteed to not be removed (such as during DCE) or reordered
 708    in the same thread.  The original call expression is held in CALLEXP.  */
 709
 710 static tree
 711 expand_volatile_load (tree callexp)
 712 {
 713   tree ptr = CALL_EXPR_ARG (callexp, 0);
 714   tree ptrtype = TREE_TYPE (ptr);
 715   gcc_assert (POINTER_TYPE_P (ptrtype));
 716
 717   /* (T) *(volatile T *) ptr;  */
 718   tree type = build_qualified_type (TREE_TYPE (ptrtype), TYPE_QUAL_VOLATILE);
 719   tree result = indirect_ref (type, ptr);
 720   TREE_THIS_VOLATILE (result) = 1;
 721
 722   return result;
 723 }
 724
 725 /* Expand a front-end instrinsic call to volatileStore().  This takes two
 726    arguments, the signature to which can be either:
 727
 728         void volatileStore (ubyte* ptr, ubyte value);
 729         void volatileStore (ushort* ptr, ushort value);
 730         void volatileStore (uint* ptr, uint value);
 731         void volatileStore (ulong* ptr, ulong value);
 732
 733    This writes a value to the memory location indicated by ptr.  Calls to
 734    them are be guaranteed to not be removed (such as during DCE) or reordered
 735    in the same thread.  The original call expression is held in CALLEXP.  */
 736
 737 static tree
 738 expand_volatile_store (tree callexp)
 739 {
 740   tree ptr = CALL_EXPR_ARG (callexp, 0);
 741   tree ptrtype = TREE_TYPE (ptr);
 742   gcc_assert (POINTER_TYPE_P (ptrtype));
 743
 744   /* (T) *(volatile T *) ptr;  */
 745   tree type = build_qualified_type (TREE_TYPE (ptrtype), TYPE_QUAL_VOLATILE);
 746   tree result = indirect_ref (type, ptr);
 747   TREE_THIS_VOLATILE (result) = 1;
 748
 749   /* (*(volatile T *) ptr) = value;  */
 750   tree value = CALL_EXPR_ARG (callexp, 1);
 751   return modify_expr (result, value);
 752 }
 753
 754 /* If CALLEXP is for an intrinsic , expand and return inlined compiler
 755    generated instructions.  Most map directly to GCC builtins, others
 756    require a little extra work around them.  */
 757
 758 tree
 759 maybe_expand_intrinsic (tree callexp)
 760 {
 761   tree callee = CALL_EXPR_FN (callexp);
 762
 763   if (TREE_CODE (callee) == ADDR_EXPR)
 764     callee = TREE_OPERAND (callee, 0);
 765
 766   if (TREE_CODE (callee) != FUNCTION_DECL)
 767     return callexp;
 768
 769   /* Don't expand CTFE-only intrinsics outside of semantic processing.  */
 770   if (DECL_BUILT_IN_CTFE (callee) && !doing_semantic_analysis_p)
 771     return callexp;
 772
 773   intrinsic_code intrinsic = DECL_INTRINSIC_CODE (callee);
 774   built_in_function code;
 775
 776   switch (intrinsic)
 777     {
 778     case INTRINSIC_NONE:
 779       return callexp;
 780
 781     case INTRINSIC_BSF:
 782     case INTRINSIC_BSF64:
 783       return expand_intrinsic_bsf (callexp);
 784
 785     case INTRINSIC_BSR:
 786     case INTRINSIC_BSR64:
 787       return expand_intrinsic_bsr (callexp);
 788
 789     case INTRINSIC_BT:
 790     case INTRINSIC_BT64:
 791     case INTRINSIC_BTC:
 792     case INTRINSIC_BTC64:
 793     case INTRINSIC_BTR:
 794     case INTRINSIC_BTR64:
 795     case INTRINSIC_BTS:
 796     case INTRINSIC_BTS64:
 797       return expand_intrinsic_bt (intrinsic, callexp);
 798
 799     case INTRINSIC_POPCNT32:
 800     case INTRINSIC_POPCNT64:
 801       return expand_intrinsic_popcnt (callexp);
 802
 803     case INTRINSIC_ROL:
 804     case INTRINSIC_ROL_TIARG:
 805     case INTRINSIC_ROR:
 806     case INTRINSIC_ROR_TIARG:
 807       return expand_intrinsic_rotate (intrinsic, callexp);
 808
 809     case INTRINSIC_BSWAP32:
 810     case INTRINSIC_BSWAP64:
 811     case INTRINSIC_CEIL:
 812     case INTRINSIC_CEILF:
 813     case INTRINSIC_CEILL:
 814     case INTRINSIC_COSL:
 815     case INTRINSIC_EXP:
 816     case INTRINSIC_EXP2:
 817     case INTRINSIC_EXPM1:
 818     case INTRINSIC_FABSL:
 819     case INTRINSIC_FLOOR:
 820     case INTRINSIC_FLOORF:
 821     case INTRINSIC_FLOORL:
 822     case INTRINSIC_ISFINITE:
 823     case INTRINSIC_ISINFINITY:
 824     case INTRINSIC_ISNAN:
 825     case INTRINSIC_LOG:
 826     case INTRINSIC_LOG10:
 827     case INTRINSIC_LOG2:
 828     case INTRINSIC_RINTL:
 829     case INTRINSIC_RNDTOLL:
 830     case INTRINSIC_ROUND:
 831     case INTRINSIC_SINL:
 832     case INTRINSIC_SQRT:
 833     case INTRINSIC_SQRTF:
 834     case INTRINSIC_SQRTL:
 835     case INTRINSIC_TAN:
 836     case INTRINSIC_TRUNC:
 837       code = intrinsic_decls[intrinsic].built_in;
 838       gcc_assert (code != BUILT_IN_NONE);
 839       return call_builtin_fn (callexp, code, 1,
 840                               CALL_EXPR_ARG (callexp, 0));
 841
 842     case INTRINSIC_FMAX:
 843     case INTRINSIC_FMIN:
 844     case INTRINSIC_LDEXPL:
 845       code = intrinsic_decls[intrinsic].built_in;
 846       gcc_assert (code != BUILT_IN_NONE);
 847       return call_builtin_fn (callexp, code, 2,
 848                               CALL_EXPR_ARG (callexp, 0),
 849                               CALL_EXPR_ARG (callexp, 1));
 850
 851     case INTRINSIC_FMA:
 852       code = intrinsic_decls[intrinsic].built_in;
 853       gcc_assert (code != BUILT_IN_NONE);
 854       return call_builtin_fn (callexp, code, 3,
 855                               CALL_EXPR_ARG (callexp, 0),
 856                               CALL_EXPR_ARG (callexp, 1),
 857                               CALL_EXPR_ARG (callexp, 2));
 858
 859     case INTRINSIC_COPYSIGN:
 860     case INTRINSIC_COPYSIGNI:
 861       return expand_intrinsic_copysign (callexp);
 862
 863     case INTRINSIC_POW:
 864       return expand_intrinsic_pow (callexp);
 865
 866     case INTRINSIC_TOPREC:
 867     case INTRINSIC_TOPRECF:
 868     case INTRINSIC_TOPRECL:
 869       return expand_intrinsic_toprec (callexp);
 870
 871     case INTRINSIC_VA_ARG:
 872     case INTRINSIC_C_VA_ARG:
 873       return expand_intrinsic_vaarg (callexp);
 874
 875     case INTRINSIC_VASTART:
 876       return expand_intrinsic_vastart (callexp);
 877
 878     case INTRINSIC_ADDS:
 879     case INTRINSIC_ADDSL:
 880     case INTRINSIC_ADDU:
 881     case INTRINSIC_ADDUL:
 882     case INTRINSIC_SUBS:
 883     case INTRINSIC_SUBSL:
 884     case INTRINSIC_SUBU:
 885     case INTRINSIC_SUBUL:
 886     case INTRINSIC_MULS:
 887     case INTRINSIC_MULSL:
 888     case INTRINSIC_MULU:
 889     case INTRINSIC_MULUI:
 890     case INTRINSIC_MULUL:
 891     case INTRINSIC_NEGS:
 892     case INTRINSIC_NEGSL:
 893       return expand_intrinsic_checkedint (intrinsic, callexp);
 894
 895     case INTRINSIC_VLOAD8:
 896     case INTRINSIC_VLOAD16:
 897     case INTRINSIC_VLOAD32:
 898     case INTRINSIC_VLOAD64:
 899       return expand_volatile_load (callexp);
 900
 901     case INTRINSIC_VSTORE8:
 902     case INTRINSIC_VSTORE16:
 903     case INTRINSIC_VSTORE32:
 904     case INTRINSIC_VSTORE64:
 905       return expand_volatile_store (callexp);
 906
 907     default:
 908       gcc_unreachable ();
 909     }
 910 }