gcc/fold-const-call.cc

   1 /* Constant folding for calls to built-in and internal functions.
   2    Copyright (C) 1988-2023 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "realmpfr.h"
  24 #include "tree.h"
  25 #include "stor-layout.h"
  26 #include "options.h"
  27 #include "fold-const.h"
  28 #include "fold-const-call.h"
  29 #include "case-cfn-macros.h"
  30 #include "tm.h" /* For C[LT]Z_DEFINED_AT_ZERO.  */
  31 #include "builtins.h"
  32 #include "gimple-expr.h"
  33 #include "tree-vector-builder.h"
  34
  35 /* Functions that test for certain constant types, abstracting away the
  36    decision about whether to check for overflow.  */
  37
  38 static inline bool
  39 integer_cst_p (tree t)
  40 {
  41   return TREE_CODE (t) == INTEGER_CST && !TREE_OVERFLOW (t);
  42 }
  43
  44 static inline bool
  45 real_cst_p (tree t)
  46 {
  47   return TREE_CODE (t) == REAL_CST && !TREE_OVERFLOW (t);
  48 }
  49
  50 static inline bool
  51 complex_cst_p (tree t)
  52 {
  53   return TREE_CODE (t) == COMPLEX_CST;
  54 }
  55
  56 /* Return true if ARG is a size_type_node constant.
  57    Store it in *SIZE_OUT if so.  */
  58
  59 static inline bool
  60 size_t_cst_p (tree t, unsigned HOST_WIDE_INT *size_out)
  61 {
  62   if (types_compatible_p (size_type_node, TREE_TYPE (t))
  63       && integer_cst_p (t)
  64       && tree_fits_uhwi_p (t))
  65     {
  66       *size_out = tree_to_uhwi (t);
  67       return true;
  68     }
  69   return false;
  70 }
  71
  72 /* RES is the result of a comparison in which < 0 means "less", 0 means
  73    "equal" and > 0 means "more".  Canonicalize it to -1, 0 or 1 and
  74    return it in type TYPE.  */
  75
  76 tree
  77 build_cmp_result (tree type, int res)
  78 {
  79   return build_int_cst (type, res < 0 ? -1 : res > 0 ? 1 : 0);
  80 }
  81
  82 /* M is the result of trying to constant-fold an expression (starting
  83    with clear MPFR flags) and INEXACT says whether the result in M is
  84    exact or inexact.  Return true if M can be used as a constant-folded
  85    result in format FORMAT, storing the value in *RESULT if so.  */
  86
  87 static bool
  88 do_mpfr_ckconv (real_value *result, mpfr_srcptr m, bool inexact,
  89                 const real_format *format)
  90 {
  91   /* Proceed iff we get a normal number, i.e. not NaN or Inf and no
  92      overflow/underflow occurred.  If -frounding-math, proceed iff the
  93      result of calling FUNC was exact.  */
  94   if (!mpfr_number_p (m)
  95       || mpfr_overflow_p ()
  96       || mpfr_underflow_p ()
  97       || (flag_rounding_math && inexact))
  98     return false;
  99
 100   REAL_VALUE_TYPE tmp;
 101   real_from_mpfr (&tmp, m, format, MPFR_RNDN);
 102
 103   /* Proceed iff GCC's REAL_VALUE_TYPE can hold the MPFR values.
 104      If the REAL_VALUE_TYPE is zero but the mpft_t is not, then we
 105      underflowed in the conversion.  */
 106   if (!real_isfinite (&tmp)
 107       || ((tmp.cl == rvc_zero) != (mpfr_zero_p (m) != 0)))
 108     return false;
 109
 110   real_convert (result, format, &tmp);
 111   return real_identical (result, &tmp);
 112 }
 113
 114 /* Try to evaluate:
 115
 116       *RESULT = f (*ARG)
 117
 118    in format FORMAT, given that FUNC is the MPFR implementation of f.
 119    Return true on success.  */
 120
 121 static bool
 122 do_mpfr_arg1 (real_value *result,
 123               int (*func) (mpfr_ptr, mpfr_srcptr, mpfr_rnd_t),
 124               const real_value *arg, const real_format *format)
 125 {
 126   /* To proceed, MPFR must exactly represent the target floating point
 127      format, which only happens when the target base equals two.  */
 128   if (format->b != 2 || !real_isfinite (arg))
 129     return false;
 130
 131   int prec = format->p;
 132   mpfr_rnd_t rnd = format->round_towards_zero ? MPFR_RNDZ : MPFR_RNDN;
 133
 134   auto_mpfr m (prec);
 135   mpfr_from_real (m, arg, MPFR_RNDN);
 136   mpfr_clear_flags ();
 137   bool inexact = func (m, m, rnd);
 138   bool ok = do_mpfr_ckconv (result, m, inexact, format);
 139
 140   return ok;
 141 }
 142
 143 /* Try to evaluate:
 144
 145       *RESULT_SIN = sin (*ARG);
 146       *RESULT_COS = cos (*ARG);
 147
 148    for format FORMAT.  Return true on success.  */
 149
 150 static bool
 151 do_mpfr_sincos (real_value *result_sin, real_value *result_cos,
 152                 const real_value *arg, const real_format *format)
 153 {
 154   /* To proceed, MPFR must exactly represent the target floating point
 155      format, which only happens when the target base equals two.  */
 156   if (format->b != 2 || !real_isfinite (arg))
 157     return false;
 158
 159   int prec = format->p;
 160   mpfr_rnd_t rnd = format->round_towards_zero ? MPFR_RNDZ : MPFR_RNDN;
 161   mpfr_t m, ms, mc;
 162
 163   mpfr_inits2 (prec, m, ms, mc, NULL);
 164   mpfr_from_real (m, arg, MPFR_RNDN);
 165   mpfr_clear_flags ();
 166   bool inexact = mpfr_sin_cos (ms, mc, m, rnd);
 167   bool ok = (do_mpfr_ckconv (result_sin, ms, inexact, format)
 168              && do_mpfr_ckconv (result_cos, mc, inexact, format));
 169   mpfr_clears (m, ms, mc, NULL);
 170
 171   return ok;
 172 }
 173
 174 /* Try to evaluate:
 175
 176       *RESULT = f (*ARG0, *ARG1)
 177
 178    in format FORMAT, given that FUNC is the MPFR implementation of f.
 179    Return true on success.  */
 180
 181 static bool
 182 do_mpfr_arg2 (real_value *result,
 183               int (*func) (mpfr_ptr, mpfr_srcptr, mpfr_srcptr, mpfr_rnd_t),
 184               const real_value *arg0, const real_value *arg1,
 185               const real_format *format)
 186 {
 187   /* To proceed, MPFR must exactly represent the target floating point
 188      format, which only happens when the target base equals two.  */
 189   if (format->b != 2 || !real_isfinite (arg0) || !real_isfinite (arg1))
 190     return false;
 191
 192   int prec = format->p;
 193   mpfr_rnd_t rnd = format->round_towards_zero ? MPFR_RNDZ : MPFR_RNDN;
 194   mpfr_t m0, m1;
 195
 196   mpfr_inits2 (prec, m0, m1, NULL);
 197   mpfr_from_real (m0, arg0, MPFR_RNDN);
 198   mpfr_from_real (m1, arg1, MPFR_RNDN);
 199   mpfr_clear_flags ();
 200   bool inexact = func (m0, m0, m1, rnd);
 201   bool ok = do_mpfr_ckconv (result, m0, inexact, format);
 202   mpfr_clears (m0, m1, NULL);
 203
 204   return ok;
 205 }
 206
 207 /* Try to evaluate:
 208
 209       *RESULT = f (ARG0, *ARG1)
 210
 211    in format FORMAT, given that FUNC is the MPFR implementation of f.
 212    Return true on success.  */
 213
 214 static bool
 215 do_mpfr_arg2 (real_value *result,
 216               int (*func) (mpfr_ptr, long, mpfr_srcptr, mpfr_rnd_t),
 217               const wide_int_ref &arg0, const real_value *arg1,
 218               const real_format *format)
 219 {
 220   if (format->b != 2 || !real_isfinite (arg1))
 221     return false;
 222
 223   int prec = format->p;
 224   mpfr_rnd_t rnd = format->round_towards_zero ? MPFR_RNDZ : MPFR_RNDN;
 225
 226   auto_mpfr m (prec);
 227   mpfr_from_real (m, arg1, MPFR_RNDN);
 228   mpfr_clear_flags ();
 229   bool inexact = func (m, arg0.to_shwi (), m, rnd);
 230   bool ok = do_mpfr_ckconv (result, m, inexact, format);
 231
 232   return ok;
 233 }
 234
 235 /* Try to evaluate:
 236
 237       *RESULT = f (*ARG0, *ARG1, *ARG2)
 238
 239    in format FORMAT, given that FUNC is the MPFR implementation of f.
 240    Return true on success.  */
 241
 242 static bool
 243 do_mpfr_arg3 (real_value *result,
 244               int (*func) (mpfr_ptr, mpfr_srcptr, mpfr_srcptr,
 245                            mpfr_srcptr, mpfr_rnd_t),
 246               const real_value *arg0, const real_value *arg1,
 247               const real_value *arg2, const real_format *format)
 248 {
 249   /* To proceed, MPFR must exactly represent the target floating point
 250      format, which only happens when the target base equals two.  */
 251   if (format->b != 2
 252       || !real_isfinite (arg0)
 253       || !real_isfinite (arg1)
 254       || !real_isfinite (arg2))
 255     return false;
 256
 257   int prec = format->p;
 258   mpfr_rnd_t rnd = format->round_towards_zero ? MPFR_RNDZ : MPFR_RNDN;
 259   mpfr_t m0, m1, m2;
 260
 261   mpfr_inits2 (prec, m0, m1, m2, NULL);
 262   mpfr_from_real (m0, arg0, MPFR_RNDN);
 263   mpfr_from_real (m1, arg1, MPFR_RNDN);
 264   mpfr_from_real (m2, arg2, MPFR_RNDN);
 265   mpfr_clear_flags ();
 266   bool inexact = func (m0, m0, m1, m2, rnd);
 267   bool ok = do_mpfr_ckconv (result, m0, inexact, format);
 268   mpfr_clears (m0, m1, m2, NULL);
 269
 270   return ok;
 271 }
 272
 273 /* M is the result of trying to constant-fold an expression (starting
 274    with clear MPFR flags) and INEXACT says whether the result in M is
 275    exact or inexact.  Return true if M can be used as a constant-folded
 276    result in which the real and imaginary parts have format FORMAT.
 277    Store those parts in *RESULT_REAL and *RESULT_IMAG if so.  */
 278
 279 static bool
 280 do_mpc_ckconv (real_value *result_real, real_value *result_imag,
 281                mpc_srcptr m, bool inexact, const real_format *format)
 282 {
 283   /* Proceed iff we get a normal number, i.e. not NaN or Inf and no
 284      overflow/underflow occurred.  If -frounding-math, proceed iff the
 285      result of calling FUNC was exact.  */
 286   if (!mpfr_number_p (mpc_realref (m))
 287       || !mpfr_number_p (mpc_imagref (m))
 288       || mpfr_overflow_p ()
 289       || mpfr_underflow_p ()
 290       || (flag_rounding_math && inexact))
 291     return false;
 292
 293   REAL_VALUE_TYPE tmp_real, tmp_imag;
 294   real_from_mpfr (&tmp_real, mpc_realref (m), format, MPFR_RNDN);
 295   real_from_mpfr (&tmp_imag, mpc_imagref (m), format, MPFR_RNDN);
 296
 297   /* Proceed iff GCC's REAL_VALUE_TYPE can hold the MPFR values.
 298      If the REAL_VALUE_TYPE is zero but the mpft_t is not, then we
 299      underflowed in the conversion.  */
 300   if (!real_isfinite (&tmp_real)
 301       || !real_isfinite (&tmp_imag)
 302       || (tmp_real.cl == rvc_zero) != (mpfr_zero_p (mpc_realref (m)) != 0)
 303       || (tmp_imag.cl == rvc_zero) != (mpfr_zero_p (mpc_imagref (m)) != 0))
 304     return false;
 305
 306   real_convert (result_real, format, &tmp_real);
 307   real_convert (result_imag, format, &tmp_imag);
 308
 309   return (real_identical (result_real, &tmp_real)
 310           && real_identical (result_imag, &tmp_imag));
 311 }
 312
 313 /* Try to evaluate:
 314
 315       RESULT = f (ARG)
 316
 317    in format FORMAT, given that FUNC is the mpc implementation of f.
 318    Return true on success.  Both RESULT and ARG are represented as
 319    real and imaginary pairs.  */
 320
 321 static bool
 322 do_mpc_arg1 (real_value *result_real, real_value *result_imag,
 323              int (*func) (mpc_ptr, mpc_srcptr, mpc_rnd_t),
 324              const real_value *arg_real, const real_value *arg_imag,
 325              const real_format *format)
 326 {
 327   /* To proceed, MPFR must exactly represent the target floating point
 328      format, which only happens when the target base equals two.  */
 329   if (format->b != 2
 330       || !real_isfinite (arg_real)
 331       || !real_isfinite (arg_imag))
 332     return false;
 333
 334   int prec = format->p;
 335   mpc_rnd_t crnd = format->round_towards_zero ? MPC_RNDZZ : MPC_RNDNN;
 336   mpc_t m;
 337
 338   mpc_init2 (m, prec);
 339   mpfr_from_real (mpc_realref (m), arg_real, MPFR_RNDN);
 340   mpfr_from_real (mpc_imagref (m), arg_imag, MPFR_RNDN);
 341   mpfr_clear_flags ();
 342   bool inexact = func (m, m, crnd);
 343   bool ok = do_mpc_ckconv (result_real, result_imag, m, inexact, format);
 344   mpc_clear (m);
 345
 346   return ok;
 347 }
 348
 349 /* Try to evaluate:
 350
 351       RESULT = f (ARG0, ARG1)
 352
 353    in format FORMAT, given that FUNC is the mpc implementation of f.
 354    Return true on success.  RESULT, ARG0 and ARG1 are represented as
 355    real and imaginary pairs.  */
 356
 357 static bool
 358 do_mpc_arg2 (real_value *result_real, real_value *result_imag,
 359              int (*func)(mpc_ptr, mpc_srcptr, mpc_srcptr, mpc_rnd_t),
 360              const real_value *arg0_real, const real_value *arg0_imag,
 361              const real_value *arg1_real, const real_value *arg1_imag,
 362              const real_format *format)
 363 {
 364   if (!real_isfinite (arg0_real)
 365       || !real_isfinite (arg0_imag)
 366       || !real_isfinite (arg1_real)
 367       || !real_isfinite (arg1_imag))
 368     return false;
 369
 370   int prec = format->p;
 371   mpc_rnd_t crnd = format->round_towards_zero ? MPC_RNDZZ : MPC_RNDNN;
 372   mpc_t m0, m1;
 373
 374   mpc_init2 (m0, prec);
 375   mpc_init2 (m1, prec);
 376   mpfr_from_real (mpc_realref (m0), arg0_real, MPFR_RNDN);
 377   mpfr_from_real (mpc_imagref (m0), arg0_imag, MPFR_RNDN);
 378   mpfr_from_real (mpc_realref (m1), arg1_real, MPFR_RNDN);
 379   mpfr_from_real (mpc_imagref (m1), arg1_imag, MPFR_RNDN);
 380   mpfr_clear_flags ();
 381   bool inexact = func (m0, m0, m1, crnd);
 382   bool ok = do_mpc_ckconv (result_real, result_imag, m0, inexact, format);
 383   mpc_clear (m0);
 384   mpc_clear (m1);
 385
 386   return ok;
 387 }
 388
 389 /* Try to evaluate:
 390
 391       *RESULT = logb (*ARG)
 392
 393    in format FORMAT.  Return true on success.  */
 394
 395 static bool
 396 fold_const_logb (real_value *result, const real_value *arg,
 397                  const real_format *format)
 398 {
 399   switch (arg->cl)
 400     {
 401     case rvc_nan:
 402       /* If arg is +-NaN, then return it.  */
 403       *result = *arg;
 404       return true;
 405
 406     case rvc_inf:
 407       /* If arg is +-Inf, then return +Inf.  */
 408       *result = *arg;
 409       result->sign = 0;
 410       return true;
 411
 412     case rvc_zero:
 413       /* Zero may set errno and/or raise an exception.  */
 414       return false;
 415
 416     case rvc_normal:
 417       /* For normal numbers, proceed iff radix == 2.  In GCC,
 418          normalized significands are in the range [0.5, 1.0).  We
 419          want the exponent as if they were [1.0, 2.0) so get the
 420          exponent and subtract 1.  */
 421       if (format->b == 2)
 422         {
 423           real_from_integer (result, format, REAL_EXP (arg) - 1, SIGNED);
 424           return true;
 425         }
 426       return false;
 427     }
 428 }
 429
 430 /* Try to evaluate:
 431
 432       *RESULT = significand (*ARG)
 433
 434    in format FORMAT.  Return true on success.  */
 435
 436 static bool
 437 fold_const_significand (real_value *result, const real_value *arg,
 438                         const real_format *format)
 439 {
 440   switch (arg->cl)
 441     {
 442     case rvc_zero:
 443     case rvc_nan:
 444     case rvc_inf:
 445       /* If arg is +-0, +-Inf or +-NaN, then return it.  */
 446       *result = *arg;
 447       return true;
 448
 449     case rvc_normal:
 450       /* For normal numbers, proceed iff radix == 2.  */
 451       if (format->b == 2)
 452         {
 453           *result = *arg;
 454           /* In GCC, normalized significands are in the range [0.5, 1.0).
 455              We want them to be [1.0, 2.0) so set the exponent to 1.  */
 456           SET_REAL_EXP (result, 1);
 457           return true;
 458         }
 459       return false;
 460     }
 461 }
 462
 463 /* Try to evaluate:
 464
 465       *RESULT = f (*ARG)
 466
 467    where FORMAT is the format of *ARG and PRECISION is the number of
 468    significant bits in the result.  Return true on success.  */
 469
 470 static bool
 471 fold_const_conversion (wide_int *result,
 472                        void (*fn) (real_value *, format_helper,
 473                                    const real_value *),
 474                        const real_value *arg, unsigned int precision,
 475                        const real_format *format)
 476 {
 477   if (!real_isfinite (arg))
 478     return false;
 479
 480   real_value rounded;
 481   fn (&rounded, format, arg);
 482
 483   bool fail = false;
 484   *result = real_to_integer (&rounded, &fail, precision);
 485   return !fail;
 486 }
 487
 488 /* Try to evaluate:
 489
 490       *RESULT = pow (*ARG0, *ARG1)
 491
 492    in format FORMAT.  Return true on success.  */
 493
 494 static bool
 495 fold_const_pow (real_value *result, const real_value *arg0,
 496                 const real_value *arg1, const real_format *format)
 497 {
 498   if (do_mpfr_arg2 (result, mpfr_pow, arg0, arg1, format))
 499     return true;
 500
 501   /* Check for an integer exponent.  */
 502   REAL_VALUE_TYPE cint1;
 503   HOST_WIDE_INT n1 = real_to_integer (arg1);
 504   real_from_integer (&cint1, VOIDmode, n1, SIGNED);
 505   /* Attempt to evaluate pow at compile-time, unless this should
 506      raise an exception.  */
 507   if (real_identical (arg1, &cint1)
 508       && (n1 > 0
 509           || (!flag_trapping_math && !flag_errno_math)
 510           || !real_equal (arg0, &dconst0)))
 511     {
 512       bool inexact = real_powi (result, format, arg0, n1);
 513       /* Avoid the folding if flag_signaling_nans is on.  */
 514       if (flag_unsafe_math_optimizations
 515           || (!inexact
 516               && !(flag_signaling_nans
 517                    && REAL_VALUE_ISSIGNALING_NAN (*arg0))))
 518         return true;
 519     }
 520
 521   return false;
 522 }
 523
 524 /* Try to evaluate:
 525
 526       *RESULT = nextafter (*ARG0, *ARG1)
 527
 528    or
 529
 530       *RESULT = nexttoward (*ARG0, *ARG1)
 531
 532    in format FORMAT.  Return true on success.  */
 533
 534 static bool
 535 fold_const_nextafter (real_value *result, const real_value *arg0,
 536                       const real_value *arg1, const real_format *format)
 537 {
 538   if (REAL_VALUE_ISSIGNALING_NAN (*arg0)
 539       || REAL_VALUE_ISSIGNALING_NAN (*arg1))
 540     return false;
 541
 542   /* Don't handle composite modes, nor decimal, nor modes without
 543      inf or denorm at least for now.  */
 544   if (format->pnan < format->p
 545       || format->b == 10
 546       || !format->has_inf
 547       || !format->has_denorm)
 548     return false;
 549
 550   if (real_nextafter (result, format, arg0, arg1)
 551       /* If raising underflow or overflow and setting errno to ERANGE,
 552          fail if we care about those side-effects.  */
 553       && (flag_trapping_math || flag_errno_math))
 554     return false;
 555   /* Similarly for nextafter (0, 1) raising underflow.  */
 556   else if (flag_trapping_math
 557            && arg0->cl == rvc_zero
 558            && result->cl != rvc_zero)
 559     return false;
 560
 561   real_convert (result, format, result);
 562
 563   return true;
 564 }
 565
 566 /* Try to evaluate:
 567
 568       *RESULT = ldexp (*ARG0, ARG1)
 569
 570    in format FORMAT.  Return true on success.  */
 571
 572 static bool
 573 fold_const_builtin_load_exponent (real_value *result, const real_value *arg0,
 574                                   const wide_int_ref &arg1,
 575                                   const real_format *format)
 576 {
 577   /* Bound the maximum adjustment to twice the range of the
 578      mode's valid exponents.  Use abs to ensure the range is
 579      positive as a sanity check.  */
 580   int max_exp_adj = 2 * labs (format->emax - format->emin);
 581
 582   /* The requested adjustment must be inside this range.  This
 583      is a preliminary cap to avoid things like overflow, we
 584      may still fail to compute the result for other reasons.  */
 585   if (wi::les_p (arg1, -max_exp_adj) || wi::ges_p (arg1, max_exp_adj))
 586     return false;
 587
 588   /* Don't perform operation if we honor signaling NaNs and
 589      operand is a signaling NaN.  */
 590   if (!flag_unsafe_math_optimizations
 591       && flag_signaling_nans
 592       && REAL_VALUE_ISSIGNALING_NAN (*arg0))
 593     return false;
 594
 595   REAL_VALUE_TYPE initial_result;
 596   real_ldexp (&initial_result, arg0, arg1.to_shwi ());
 597
 598   /* Ensure we didn't overflow.  */
 599   if (real_isinf (&initial_result))
 600     return false;
 601
 602   /* Only proceed if the target mode can hold the
 603      resulting value.  */
 604   *result = real_value_truncate (format, initial_result);
 605   return real_equal (&initial_result, result);
 606 }
 607
 608 /* Fold a call to __builtin_nan or __builtin_nans with argument ARG and
 609    return type TYPE.  QUIET is true if a quiet rather than signalling
 610    NaN is required.  */
 611
 612 static tree
 613 fold_const_builtin_nan (tree type, tree arg, bool quiet)
 614 {
 615   REAL_VALUE_TYPE real;
 616   const char *str = c_getstr (arg);
 617   if (str && real_nan (&real, str, quiet, TYPE_MODE (type)))
 618     return build_real (type, real);
 619   return NULL_TREE;
 620 }
 621
 622 /* Fold a call to IFN_REDUC_<CODE> (ARG), returning a value of type TYPE.  */
 623
 624 static tree
 625 fold_const_reduction (tree type, tree arg, tree_code code)
 626 {
 627   unsigned HOST_WIDE_INT nelts;
 628   if (TREE_CODE (arg) != VECTOR_CST
 629       || !VECTOR_CST_NELTS (arg).is_constant (&nelts))
 630     return NULL_TREE;
 631
 632   tree res = VECTOR_CST_ELT (arg, 0);
 633   for (unsigned HOST_WIDE_INT i = 1; i < nelts; i++)
 634     {
 635       res = const_binop (code, type, res, VECTOR_CST_ELT (arg, i));
 636       if (res == NULL_TREE || !CONSTANT_CLASS_P (res))
 637         return NULL_TREE;
 638     }
 639   return res;
 640 }
 641
 642 /* Fold a call to IFN_VEC_CONVERT (ARG) returning TYPE.  */
 643
 644 static tree
 645 fold_const_vec_convert (tree ret_type, tree arg)
 646 {
 647   enum tree_code code = NOP_EXPR;
 648   tree arg_type = TREE_TYPE (arg);
 649   if (TREE_CODE (arg) != VECTOR_CST)
 650     return NULL_TREE;
 651
 652   gcc_checking_assert (VECTOR_TYPE_P (ret_type) && VECTOR_TYPE_P (arg_type));
 653
 654   if (INTEGRAL_TYPE_P (TREE_TYPE (ret_type))
 655       && SCALAR_FLOAT_TYPE_P (TREE_TYPE (arg_type)))
 656     code = FIX_TRUNC_EXPR;
 657   else if (INTEGRAL_TYPE_P (TREE_TYPE (arg_type))
 658            && SCALAR_FLOAT_TYPE_P (TREE_TYPE (ret_type)))
 659     code = FLOAT_EXPR;
 660
 661   /* We can't handle steps directly when extending, since the
 662      values need to wrap at the original precision first.  */
 663   bool step_ok_p
 664     = (INTEGRAL_TYPE_P (TREE_TYPE (ret_type))
 665        && INTEGRAL_TYPE_P (TREE_TYPE (arg_type))
 666        && (TYPE_PRECISION (TREE_TYPE (ret_type))
 667            <= TYPE_PRECISION (TREE_TYPE (arg_type))));
 668   tree_vector_builder elts;
 669   if (!elts.new_unary_operation (ret_type, arg, step_ok_p))
 670     return NULL_TREE;
 671
 672   unsigned int count = elts.encoded_nelts ();
 673   for (unsigned int i = 0; i < count; ++i)
 674     {
 675       tree elt = fold_unary (code, TREE_TYPE (ret_type),
 676                              VECTOR_CST_ELT (arg, i));
 677       if (elt == NULL_TREE || !CONSTANT_CLASS_P (elt))
 678         return NULL_TREE;
 679       elts.quick_push (elt);
 680     }
 681
 682   return elts.build ();
 683 }
 684
 685 /* Try to evaluate:
 686
 687       IFN_WHILE_ULT (ARG0, ARG1, (TYPE) { ... })
 688
 689    Return the value on success and null on failure.  */
 690
 691 static tree
 692 fold_while_ult (tree type, poly_uint64 arg0, poly_uint64 arg1)
 693 {
 694   if (known_ge (arg0, arg1))
 695     return build_zero_cst (type);
 696
 697   if (maybe_ge (arg0, arg1))
 698     return NULL_TREE;
 699
 700   poly_uint64 diff = arg1 - arg0;
 701   poly_uint64 nelts = TYPE_VECTOR_SUBPARTS (type);
 702   if (known_ge (diff, nelts))
 703     return build_all_ones_cst (type);
 704
 705   unsigned HOST_WIDE_INT const_diff;
 706   if (known_le (diff, nelts) && diff.is_constant (&const_diff))
 707     {
 708       tree minus_one = build_minus_one_cst (TREE_TYPE (type));
 709       tree zero = build_zero_cst (TREE_TYPE (type));
 710       return build_vector_a_then_b (type, const_diff, minus_one, zero);
 711     }
 712   return NULL_TREE;
 713 }
 714
 715 /* Try to evaluate:
 716
 717       *RESULT = FN (*ARG)
 718
 719    in format FORMAT.  Return true on success.  */
 720
 721 static bool
 722 fold_const_call_ss (real_value *result, combined_fn fn,
 723                     const real_value *arg, const real_format *format)
 724 {
 725   switch (fn)
 726     {
 727     CASE_CFN_SQRT:
 728     CASE_CFN_SQRT_FN:
 729       return (real_compare (GE_EXPR, arg, &dconst0)
 730               && do_mpfr_arg1 (result, mpfr_sqrt, arg, format));
 731
 732     CASE_CFN_CBRT:
 733     CASE_CFN_CBRT_FN:
 734       return do_mpfr_arg1 (result, mpfr_cbrt, arg, format);
 735
 736     CASE_CFN_ASIN:
 737     CASE_CFN_ASIN_FN:
 738       return (real_compare (GE_EXPR, arg, &dconstm1)
 739               && real_compare (LE_EXPR, arg, &dconst1)
 740               && do_mpfr_arg1 (result, mpfr_asin, arg, format));
 741
 742     CASE_CFN_ACOS:
 743     CASE_CFN_ACOS_FN:
 744       return (real_compare (GE_EXPR, arg, &dconstm1)
 745               && real_compare (LE_EXPR, arg, &dconst1)
 746               && do_mpfr_arg1 (result, mpfr_acos, arg, format));
 747
 748     CASE_CFN_ATAN:
 749     CASE_CFN_ATAN_FN:
 750       return do_mpfr_arg1 (result, mpfr_atan, arg, format);
 751
 752     CASE_CFN_ASINH:
 753     CASE_CFN_ASINH_FN:
 754       return do_mpfr_arg1 (result, mpfr_asinh, arg, format);
 755
 756     CASE_CFN_ACOSH:
 757     CASE_CFN_ACOSH_FN:
 758       return (real_compare (GE_EXPR, arg, &dconst1)
 759               && do_mpfr_arg1 (result, mpfr_acosh, arg, format));
 760
 761     CASE_CFN_ATANH:
 762     CASE_CFN_ATANH_FN:
 763       return (real_compare (GE_EXPR, arg, &dconstm1)
 764               && real_compare (LE_EXPR, arg, &dconst1)
 765               && do_mpfr_arg1 (result, mpfr_atanh, arg, format));
 766
 767     CASE_CFN_SIN:
 768     CASE_CFN_SIN_FN:
 769       return do_mpfr_arg1 (result, mpfr_sin, arg, format);
 770
 771     CASE_CFN_COS:
 772     CASE_CFN_COS_FN:
 773       return do_mpfr_arg1 (result, mpfr_cos, arg, format);
 774
 775     CASE_CFN_TAN:
 776     CASE_CFN_TAN_FN:
 777       return do_mpfr_arg1 (result, mpfr_tan, arg, format);
 778
 779     CASE_CFN_SINH:
 780     CASE_CFN_SINH_FN:
 781       return do_mpfr_arg1 (result, mpfr_sinh, arg, format);
 782
 783     CASE_CFN_COSH:
 784     CASE_CFN_COSH_FN:
 785       return do_mpfr_arg1 (result, mpfr_cosh, arg, format);
 786
 787     CASE_CFN_TANH:
 788     CASE_CFN_TANH_FN:
 789       return do_mpfr_arg1 (result, mpfr_tanh, arg, format);
 790
 791     CASE_CFN_ERF:
 792     CASE_CFN_ERF_FN:
 793       return do_mpfr_arg1 (result, mpfr_erf, arg, format);
 794
 795     CASE_CFN_ERFC:
 796     CASE_CFN_ERFC_FN:
 797       return do_mpfr_arg1 (result, mpfr_erfc, arg, format);
 798
 799     CASE_CFN_TGAMMA:
 800     CASE_CFN_TGAMMA_FN:
 801       return do_mpfr_arg1 (result, mpfr_gamma, arg, format);
 802
 803     CASE_CFN_EXP:
 804     CASE_CFN_EXP_FN:
 805       return do_mpfr_arg1 (result, mpfr_exp, arg, format);
 806
 807     CASE_CFN_EXP2:
 808     CASE_CFN_EXP2_FN:
 809       return do_mpfr_arg1 (result, mpfr_exp2, arg, format);
 810
 811     CASE_CFN_EXP10:
 812     CASE_CFN_POW10:
 813       return do_mpfr_arg1 (result, mpfr_exp10, arg, format);
 814
 815     CASE_CFN_EXPM1:
 816     CASE_CFN_EXPM1_FN:
 817       return do_mpfr_arg1 (result, mpfr_expm1, arg, format);
 818
 819     CASE_CFN_LOG:
 820     CASE_CFN_LOG_FN:
 821       return (real_compare (GT_EXPR, arg, &dconst0)
 822               && do_mpfr_arg1 (result, mpfr_log, arg, format));
 823
 824     CASE_CFN_LOG2:
 825     CASE_CFN_LOG2_FN:
 826       return (real_compare (GT_EXPR, arg, &dconst0)
 827               && do_mpfr_arg1 (result, mpfr_log2, arg, format));
 828
 829     CASE_CFN_LOG10:
 830     CASE_CFN_LOG10_FN:
 831       return (real_compare (GT_EXPR, arg, &dconst0)
 832               && do_mpfr_arg1 (result, mpfr_log10, arg, format));
 833
 834     CASE_CFN_LOG1P:
 835     CASE_CFN_LOG1P_FN:
 836       return (real_compare (GT_EXPR, arg, &dconstm1)
 837               && do_mpfr_arg1 (result, mpfr_log1p, arg, format));
 838
 839     CASE_CFN_J0:
 840       return do_mpfr_arg1 (result, mpfr_j0, arg, format);
 841
 842     CASE_CFN_J1:
 843       return do_mpfr_arg1 (result, mpfr_j1, arg, format);
 844
 845     CASE_CFN_Y0:
 846       return (real_compare (GT_EXPR, arg, &dconst0)
 847               && do_mpfr_arg1 (result, mpfr_y0, arg, format));
 848
 849     CASE_CFN_Y1:
 850       return (real_compare (GT_EXPR, arg, &dconst0)
 851               && do_mpfr_arg1 (result, mpfr_y1, arg, format));
 852
 853     CASE_CFN_FLOOR:
 854     CASE_CFN_FLOOR_FN:
 855       if (!REAL_VALUE_ISSIGNALING_NAN (*arg))
 856         {
 857           real_floor (result, format, arg);
 858           return true;
 859         }
 860       return false;
 861
 862     CASE_CFN_CEIL:
 863     CASE_CFN_CEIL_FN:
 864       if (!REAL_VALUE_ISSIGNALING_NAN (*arg))
 865         {
 866           real_ceil (result, format, arg);
 867           return true;
 868         }
 869       return false;
 870
 871     CASE_CFN_TRUNC:
 872     CASE_CFN_TRUNC_FN:
 873       if (!REAL_VALUE_ISSIGNALING_NAN (*arg))
 874         {
 875           real_trunc (result, format, arg);
 876           return true;
 877         }
 878       return false;
 879
 880     CASE_CFN_ROUND:
 881     CASE_CFN_ROUND_FN:
 882       if (!REAL_VALUE_ISSIGNALING_NAN (*arg))
 883         {
 884           real_round (result, format, arg);
 885           return true;
 886         }
 887       return false;
 888
 889     CASE_CFN_ROUNDEVEN:
 890     CASE_CFN_ROUNDEVEN_FN:
 891       if (!REAL_VALUE_ISSIGNALING_NAN (*arg))
 892         {
 893           real_roundeven (result, format, arg);
 894           return true;
 895         }
 896       return false;
 897
 898     CASE_CFN_LOGB:
 899     CASE_CFN_LOGB_FN:
 900       return fold_const_logb (result, arg, format);
 901
 902     CASE_CFN_SIGNIFICAND:
 903       return fold_const_significand (result, arg, format);
 904
 905     default:
 906       return false;
 907     }
 908 }
 909
 910 /* Try to evaluate:
 911
 912       *RESULT = FN (*ARG)
 913
 914    where FORMAT is the format of ARG and PRECISION is the number of
 915    significant bits in the result.  Return true on success.  */
 916
 917 static bool
 918 fold_const_call_ss (wide_int *result, combined_fn fn,
 919                     const real_value *arg, unsigned int precision,
 920                     const real_format *format)
 921 {
 922   switch (fn)
 923     {
 924     CASE_CFN_SIGNBIT:
 925       if (real_isneg (arg))
 926         *result = wi::one (precision);
 927       else
 928         *result = wi::zero (precision);
 929       return true;
 930
 931     CASE_CFN_ILOGB:
 932     CASE_CFN_ILOGB_FN:
 933       /* For ilogb we don't know FP_ILOGB0, so only handle normal values.
 934          Proceed iff radix == 2.  In GCC, normalized significands are in
 935          the range [0.5, 1.0).  We want the exponent as if they were
 936          [1.0, 2.0) so get the exponent and subtract 1.  */
 937       if (arg->cl == rvc_normal && format->b == 2)
 938         {
 939           *result = wi::shwi (REAL_EXP (arg) - 1, precision);
 940           return true;
 941         }
 942       return false;
 943
 944     CASE_CFN_ICEIL:
 945     CASE_CFN_LCEIL:
 946     CASE_CFN_LLCEIL:
 947       return fold_const_conversion (result, real_ceil, arg,
 948                                     precision, format);
 949
 950     CASE_CFN_LFLOOR:
 951     CASE_CFN_IFLOOR:
 952     CASE_CFN_LLFLOOR:
 953       return fold_const_conversion (result, real_floor, arg,
 954                                     precision, format);
 955
 956     CASE_CFN_IROUND:
 957     CASE_CFN_LROUND:
 958     CASE_CFN_LROUND_FN:
 959     CASE_CFN_LLROUND:
 960     CASE_CFN_LLROUND_FN:
 961       return fold_const_conversion (result, real_round, arg,
 962                                     precision, format);
 963
 964     CASE_CFN_IRINT:
 965     CASE_CFN_LRINT:
 966     CASE_CFN_LRINT_FN:
 967     CASE_CFN_LLRINT:
 968     CASE_CFN_LLRINT_FN:
 969       /* Not yet folded to a constant.  */
 970       return false;
 971
 972     CASE_CFN_FINITE:
 973     case CFN_BUILT_IN_FINITED32:
 974     case CFN_BUILT_IN_FINITED64:
 975     case CFN_BUILT_IN_FINITED128:
 976     case CFN_BUILT_IN_ISFINITE:
 977       *result = wi::shwi (real_isfinite (arg) ? 1 : 0, precision);
 978       return true;
 979
 980     case CFN_BUILT_IN_ISSIGNALING:
 981       *result = wi::shwi (real_issignaling_nan (arg) ? 1 : 0, precision);
 982       return true;
 983
 984     CASE_CFN_ISINF:
 985     case CFN_BUILT_IN_ISINFD32:
 986     case CFN_BUILT_IN_ISINFD64:
 987     case CFN_BUILT_IN_ISINFD128:
 988       if (real_isinf (arg))
 989         *result = wi::shwi (arg->sign ? -1 : 1, precision);
 990       else
 991         *result = wi::shwi (0, precision);
 992       return true;
 993
 994     CASE_CFN_ISNAN:
 995     case CFN_BUILT_IN_ISNAND32:
 996     case CFN_BUILT_IN_ISNAND64:
 997     case CFN_BUILT_IN_ISNAND128:
 998       *result = wi::shwi (real_isnan (arg) ? 1 : 0, precision);
 999       return true;
1000
1001     default:
1002       return false;
1003     }
1004 }
1005
1006 /* Try to evaluate:
1007
1008       *RESULT = FN (ARG)
1009
1010    where ARG_TYPE is the type of ARG and PRECISION is the number of bits
1011    in the result.  Return true on success.  */
1012
1013 static bool
1014 fold_const_call_ss (wide_int *result, combined_fn fn, const wide_int_ref &arg,
1015                     unsigned int precision, tree arg_type)
1016 {
1017   switch (fn)
1018     {
1019     CASE_CFN_FFS:
1020       *result = wi::shwi (wi::ffs (arg), precision);
1021       return true;
1022
1023     CASE_CFN_CLZ:
1024       {
1025         int tmp;
1026         if (wi::ne_p (arg, 0))
1027           tmp = wi::clz (arg);
1028         else if (!CLZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (arg_type),
1029                                              tmp))
1030           tmp = TYPE_PRECISION (arg_type);
1031         *result = wi::shwi (tmp, precision);
1032         return true;
1033       }
1034
1035     CASE_CFN_CTZ:
1036       {
1037         int tmp;
1038         if (wi::ne_p (arg, 0))
1039           tmp = wi::ctz (arg);
1040         else if (!CTZ_DEFINED_VALUE_AT_ZERO (SCALAR_INT_TYPE_MODE (arg_type),
1041                                              tmp))
1042           tmp = TYPE_PRECISION (arg_type);
1043         *result = wi::shwi (tmp, precision);
1044         return true;
1045       }
1046
1047     CASE_CFN_CLRSB:
1048       *result = wi::shwi (wi::clrsb (arg), precision);
1049       return true;
1050
1051     CASE_CFN_POPCOUNT:
1052       *result = wi::shwi (wi::popcount (arg), precision);
1053       return true;
1054
1055     CASE_CFN_PARITY:
1056       *result = wi::shwi (wi::parity (arg), precision);
1057       return true;
1058
1059     case CFN_BUILT_IN_BSWAP16:
1060     case CFN_BUILT_IN_BSWAP32:
1061     case CFN_BUILT_IN_BSWAP64:
1062     case CFN_BUILT_IN_BSWAP128:
1063       *result = wide_int::from (arg, precision, TYPE_SIGN (arg_type)).bswap ();
1064       return true;
1065
1066     default:
1067       return false;
1068     }
1069 }
1070
1071 /* Try to evaluate:
1072
1073       RESULT = FN (*ARG)
1074
1075    where FORMAT is the format of ARG and of the real and imaginary parts
1076    of RESULT, passed as RESULT_REAL and RESULT_IMAG respectively.  Return
1077    true on success.  */
1078
1079 static bool
1080 fold_const_call_cs (real_value *result_real, real_value *result_imag,
1081                     combined_fn fn, const real_value *arg,
1082                     const real_format *format)
1083 {
1084   switch (fn)
1085     {
1086     CASE_CFN_CEXPI:
1087       /* cexpi(x+yi) = cos(x)+sin(y)*i.  */
1088       return do_mpfr_sincos (result_imag, result_real, arg, format);
1089
1090     default:
1091       return false;
1092     }
1093 }
1094
1095 /* Try to evaluate:
1096
1097       *RESULT = fn (ARG)
1098
1099    where FORMAT is the format of RESULT and of the real and imaginary parts
1100    of ARG, passed as ARG_REAL and ARG_IMAG respectively.  Return true on
1101    success.  */
1102
1103 static bool
1104 fold_const_call_sc (real_value *result, combined_fn fn,
1105                     const real_value *arg_real, const real_value *arg_imag,
1106                     const real_format *format)
1107 {
1108   switch (fn)
1109     {
1110     CASE_CFN_CABS:
1111     CASE_CFN_CABS_FN:
1112       return do_mpfr_arg2 (result, mpfr_hypot, arg_real, arg_imag, format);
1113
1114     default:
1115       return false;
1116     }
1117 }
1118
1119 /* Try to evaluate:
1120
1121       RESULT = fn (ARG)
1122
1123    where FORMAT is the format of the real and imaginary parts of RESULT
1124    (RESULT_REAL and RESULT_IMAG) and of ARG (ARG_REAL and ARG_IMAG).
1125    Return true on success.  */
1126
1127 static bool
1128 fold_const_call_cc (real_value *result_real, real_value *result_imag,
1129                     combined_fn fn, const real_value *arg_real,
1130                     const real_value *arg_imag, const real_format *format)
1131 {
1132   switch (fn)
1133     {
1134     CASE_CFN_CCOS:
1135     CASE_CFN_CCOS_FN:
1136       return do_mpc_arg1 (result_real, result_imag, mpc_cos,
1137                           arg_real, arg_imag, format);
1138
1139     CASE_CFN_CCOSH:
1140     CASE_CFN_CCOSH_FN:
1141       return do_mpc_arg1 (result_real, result_imag, mpc_cosh,
1142                           arg_real, arg_imag, format);
1143
1144     CASE_CFN_CPROJ:
1145     CASE_CFN_CPROJ_FN:
1146       if (real_isinf (arg_real) || real_isinf (arg_imag))
1147         {
1148           *result_real = dconstinf;
1149           *result_imag = dconst0;
1150           result_imag->sign = arg_imag->sign;
1151         }
1152       else
1153         {
1154           *result_real = *arg_real;
1155           *result_imag = *arg_imag;
1156         }
1157       return true;
1158
1159     CASE_CFN_CSIN:
1160     CASE_CFN_CSIN_FN:
1161       return do_mpc_arg1 (result_real, result_imag, mpc_sin,
1162                           arg_real, arg_imag, format);
1163
1164     CASE_CFN_CSINH:
1165     CASE_CFN_CSINH_FN:
1166       return do_mpc_arg1 (result_real, result_imag, mpc_sinh,
1167                           arg_real, arg_imag, format);
1168
1169     CASE_CFN_CTAN:
1170     CASE_CFN_CTAN_FN:
1171       return do_mpc_arg1 (result_real, result_imag, mpc_tan,
1172                           arg_real, arg_imag, format);
1173
1174     CASE_CFN_CTANH:
1175     CASE_CFN_CTANH_FN:
1176       return do_mpc_arg1 (result_real, result_imag, mpc_tanh,
1177                           arg_real, arg_imag, format);
1178
1179     CASE_CFN_CLOG:
1180     CASE_CFN_CLOG_FN:
1181       return do_mpc_arg1 (result_real, result_imag, mpc_log,
1182                           arg_real, arg_imag, format);
1183
1184     CASE_CFN_CSQRT:
1185     CASE_CFN_CSQRT_FN:
1186       return do_mpc_arg1 (result_real, result_imag, mpc_sqrt,
1187                           arg_real, arg_imag, format);
1188
1189     CASE_CFN_CASIN:
1190     CASE_CFN_CASIN_FN:
1191       return do_mpc_arg1 (result_real, result_imag, mpc_asin,
1192                           arg_real, arg_imag, format);
1193
1194     CASE_CFN_CACOS:
1195     CASE_CFN_CACOS_FN:
1196       return do_mpc_arg1 (result_real, result_imag, mpc_acos,
1197                           arg_real, arg_imag, format);
1198
1199     CASE_CFN_CATAN:
1200     CASE_CFN_CATAN_FN:
1201       return do_mpc_arg1 (result_real, result_imag, mpc_atan,
1202                           arg_real, arg_imag, format);
1203
1204     CASE_CFN_CASINH:
1205     CASE_CFN_CASINH_FN:
1206       return do_mpc_arg1 (result_real, result_imag, mpc_asinh,
1207                           arg_real, arg_imag, format);
1208
1209     CASE_CFN_CACOSH:
1210     CASE_CFN_CACOSH_FN:
1211       return do_mpc_arg1 (result_real, result_imag, mpc_acosh,
1212                           arg_real, arg_imag, format);
1213
1214     CASE_CFN_CATANH:
1215     CASE_CFN_CATANH_FN:
1216       return do_mpc_arg1 (result_real, result_imag, mpc_atanh,
1217                           arg_real, arg_imag, format);
1218
1219     CASE_CFN_CEXP:
1220     CASE_CFN_CEXP_FN:
1221       return do_mpc_arg1 (result_real, result_imag, mpc_exp,
1222                           arg_real, arg_imag, format);
1223
1224     default:
1225       return false;
1226     }
1227 }
1228
1229 /* Subroutine of fold_const_call, with the same interface.  Handle cases
1230    where the arguments and result are numerical.  */
1231
1232 static tree
1233 fold_const_call_1 (combined_fn fn, tree type, tree arg)
1234 {
1235   machine_mode mode = TYPE_MODE (type);
1236   machine_mode arg_mode = TYPE_MODE (TREE_TYPE (arg));
1237
1238   if (integer_cst_p (arg))
1239     {
1240       if (SCALAR_INT_MODE_P (mode))
1241         {
1242           wide_int result;
1243           if (fold_const_call_ss (&result, fn, wi::to_wide (arg),
1244                                   TYPE_PRECISION (type), TREE_TYPE (arg)))
1245             return wide_int_to_tree (type, result);
1246         }
1247       return NULL_TREE;
1248     }
1249
1250   if (real_cst_p (arg))
1251     {
1252       gcc_checking_assert (SCALAR_FLOAT_MODE_P (arg_mode));
1253       if (mode == arg_mode)
1254         {
1255           /* real -> real.  */
1256           REAL_VALUE_TYPE result;
1257           if (fold_const_call_ss (&result, fn, TREE_REAL_CST_PTR (arg),
1258                                   REAL_MODE_FORMAT (mode)))
1259             return build_real (type, result);
1260         }
1261       else if (COMPLEX_MODE_P (mode)
1262                && GET_MODE_INNER (mode) == arg_mode)
1263         {
1264           /* real -> complex real.  */
1265           REAL_VALUE_TYPE result_real, result_imag;
1266           if (fold_const_call_cs (&result_real, &result_imag, fn,
1267                                   TREE_REAL_CST_PTR (arg),
1268                                   REAL_MODE_FORMAT (arg_mode)))
1269             return build_complex (type,
1270                                   build_real (TREE_TYPE (type), result_real),
1271                                   build_real (TREE_TYPE (type), result_imag));
1272         }
1273       else if (INTEGRAL_TYPE_P (type))
1274         {
1275           /* real -> int.  */
1276           wide_int result;
1277           if (fold_const_call_ss (&result, fn,
1278                                   TREE_REAL_CST_PTR (arg),
1279                                   TYPE_PRECISION (type),
1280                                   REAL_MODE_FORMAT (arg_mode)))
1281             return wide_int_to_tree (type, result);
1282         }
1283       return NULL_TREE;
1284     }
1285
1286   if (complex_cst_p (arg))
1287     {
1288       gcc_checking_assert (COMPLEX_MODE_P (arg_mode));
1289       machine_mode inner_mode = GET_MODE_INNER (arg_mode);
1290       tree argr = TREE_REALPART (arg);
1291       tree argi = TREE_IMAGPART (arg);
1292       if (mode == arg_mode
1293           && real_cst_p (argr)
1294           && real_cst_p (argi))
1295         {
1296           /* complex real -> complex real.  */
1297           REAL_VALUE_TYPE result_real, result_imag;
1298           if (fold_const_call_cc (&result_real, &result_imag, fn,
1299                                   TREE_REAL_CST_PTR (argr),
1300                                   TREE_REAL_CST_PTR (argi),
1301                                   REAL_MODE_FORMAT (inner_mode)))
1302             return build_complex (type,
1303                                   build_real (TREE_TYPE (type), result_real),
1304                                   build_real (TREE_TYPE (type), result_imag));
1305         }
1306       if (mode == inner_mode
1307           && real_cst_p (argr)
1308           && real_cst_p (argi))
1309         {
1310           /* complex real -> real.  */
1311           REAL_VALUE_TYPE result;
1312           if (fold_const_call_sc (&result, fn,
1313                                   TREE_REAL_CST_PTR (argr),
1314                                   TREE_REAL_CST_PTR (argi),
1315                                   REAL_MODE_FORMAT (inner_mode)))
1316             return build_real (type, result);
1317         }
1318       return NULL_TREE;
1319     }
1320
1321   return NULL_TREE;
1322 }
1323
1324 /* Try to fold FN (ARG) to a constant.  Return the constant on success,
1325    otherwise return null.  TYPE is the type of the return value.  */
1326
1327 tree
1328 fold_const_call (combined_fn fn, tree type, tree arg)
1329 {
1330   switch (fn)
1331     {
1332     case CFN_BUILT_IN_STRLEN:
1333       if (const char *str = c_getstr (arg))
1334         return build_int_cst (type, strlen (str));
1335       return NULL_TREE;
1336
1337     CASE_CFN_NAN:
1338     CASE_FLT_FN_FLOATN_NX (CFN_BUILT_IN_NAN):
1339     case CFN_BUILT_IN_NAND32:
1340     case CFN_BUILT_IN_NAND64:
1341     case CFN_BUILT_IN_NAND128:
1342       return fold_const_builtin_nan (type, arg, true);
1343
1344     CASE_CFN_NANS:
1345     CASE_FLT_FN_FLOATN_NX (CFN_BUILT_IN_NANS):
1346     case CFN_BUILT_IN_NANSF16B:
1347     case CFN_BUILT_IN_NANSD32:
1348     case CFN_BUILT_IN_NANSD64:
1349     case CFN_BUILT_IN_NANSD128:
1350       return fold_const_builtin_nan (type, arg, false);
1351
1352     case CFN_REDUC_PLUS:
1353       return fold_const_reduction (type, arg, PLUS_EXPR);
1354
1355     case CFN_REDUC_MAX:
1356       return fold_const_reduction (type, arg, MAX_EXPR);
1357
1358     case CFN_REDUC_MIN:
1359       return fold_const_reduction (type, arg, MIN_EXPR);
1360
1361     case CFN_REDUC_AND:
1362       return fold_const_reduction (type, arg, BIT_AND_EXPR);
1363
1364     case CFN_REDUC_IOR:
1365       return fold_const_reduction (type, arg, BIT_IOR_EXPR);
1366
1367     case CFN_REDUC_XOR:
1368       return fold_const_reduction (type, arg, BIT_XOR_EXPR);
1369
1370     case CFN_VEC_CONVERT:
1371       return fold_const_vec_convert (type, arg);
1372
1373     default:
1374       return fold_const_call_1 (fn, type, arg);
1375     }
1376 }
1377
1378 /* Fold a call to IFN_FOLD_LEFT_<CODE> (ARG0, ARG1), returning a value
1379    of type TYPE.  */
1380
1381 static tree
1382 fold_const_fold_left (tree type, tree arg0, tree arg1, tree_code code)
1383 {
1384   if (TREE_CODE (arg1) != VECTOR_CST)
1385     return NULL_TREE;
1386
1387   unsigned HOST_WIDE_INT nelts;
1388   if (!VECTOR_CST_NELTS (arg1).is_constant (&nelts))
1389     return NULL_TREE;
1390
1391   for (unsigned HOST_WIDE_INT i = 0; i < nelts; i++)
1392     {
1393       arg0 = const_binop (code, type, arg0, VECTOR_CST_ELT (arg1, i));
1394       if (arg0 == NULL_TREE || !CONSTANT_CLASS_P (arg0))
1395         return NULL_TREE;
1396     }
1397   return arg0;
1398 }
1399
1400 /* Try to evaluate:
1401
1402       *RESULT = FN (*ARG0, *ARG1)
1403
1404    in format FORMAT.  Return true on success.  */
1405
1406 static bool
1407 fold_const_call_sss (real_value *result, combined_fn fn,
1408                      const real_value *arg0, const real_value *arg1,
1409                      const real_format *format)
1410 {
1411   switch (fn)
1412     {
1413     CASE_CFN_DREM:
1414     CASE_CFN_REMAINDER:
1415     CASE_CFN_REMAINDER_FN:
1416       return do_mpfr_arg2 (result, mpfr_remainder, arg0, arg1, format);
1417
1418     CASE_CFN_ATAN2:
1419     CASE_CFN_ATAN2_FN:
1420       return do_mpfr_arg2 (result, mpfr_atan2, arg0, arg1, format);
1421
1422     CASE_CFN_FDIM:
1423     CASE_CFN_FDIM_FN:
1424       return do_mpfr_arg2 (result, mpfr_dim, arg0, arg1, format);
1425
1426     CASE_CFN_FMOD:
1427     CASE_CFN_FMOD_FN:
1428       return do_mpfr_arg2 (result, mpfr_fmod, arg0, arg1, format);
1429
1430     CASE_CFN_HYPOT:
1431     CASE_CFN_HYPOT_FN:
1432       return do_mpfr_arg2 (result, mpfr_hypot, arg0, arg1, format);
1433
1434     CASE_CFN_COPYSIGN:
1435     CASE_CFN_COPYSIGN_FN:
1436       *result = *arg0;
1437       real_copysign (result, arg1);
1438       return true;
1439
1440     CASE_CFN_FMIN:
1441     CASE_CFN_FMIN_FN:
1442       return do_mpfr_arg2 (result, mpfr_min, arg0, arg1, format);
1443
1444     CASE_CFN_FMAX:
1445     CASE_CFN_FMAX_FN:
1446       return do_mpfr_arg2 (result, mpfr_max, arg0, arg1, format);
1447
1448     CASE_CFN_POW:
1449     CASE_CFN_POW_FN:
1450       return fold_const_pow (result, arg0, arg1, format);
1451
1452     CASE_CFN_NEXTAFTER:
1453     CASE_CFN_NEXTAFTER_FN:
1454     case CFN_BUILT_IN_NEXTAFTERF16B:
1455     CASE_CFN_NEXTTOWARD:
1456       return fold_const_nextafter (result, arg0, arg1, format);
1457
1458     default:
1459       return false;
1460     }
1461 }
1462
1463 /* Try to evaluate:
1464
1465       *RESULT = FN (*ARG0, ARG1)
1466
1467    where FORMAT is the format of *RESULT and *ARG0.  Return true on
1468    success.  */
1469
1470 static bool
1471 fold_const_call_sss (real_value *result, combined_fn fn,
1472                      const real_value *arg0, const wide_int_ref &arg1,
1473                      const real_format *format)
1474 {
1475   switch (fn)
1476     {
1477     CASE_CFN_LDEXP:
1478     CASE_CFN_LDEXP_FN:
1479       return fold_const_builtin_load_exponent (result, arg0, arg1, format);
1480
1481     CASE_CFN_SCALBN:
1482     CASE_CFN_SCALBN_FN:
1483     CASE_CFN_SCALBLN:
1484     CASE_CFN_SCALBLN_FN:
1485       return (format->b == 2
1486               && fold_const_builtin_load_exponent (result, arg0, arg1,
1487                                                    format));
1488
1489     CASE_CFN_POWI:
1490       /* Avoid the folding if flag_signaling_nans is on and
1491          operand is a signaling NaN.  */
1492       if (!flag_unsafe_math_optimizations
1493           && flag_signaling_nans
1494           && REAL_VALUE_ISSIGNALING_NAN (*arg0))
1495         return false;
1496
1497       real_powi (result, format, arg0, arg1.to_shwi ());
1498       return true;
1499
1500     default:
1501       return false;
1502     }
1503 }
1504
1505 /* Try to evaluate:
1506
1507       *RESULT = FN (ARG0, *ARG1)
1508
1509    where FORMAT is the format of *RESULT and *ARG1.  Return true on
1510    success.  */
1511
1512 static bool
1513 fold_const_call_sss (real_value *result, combined_fn fn,
1514                      const wide_int_ref &arg0, const real_value *arg1,
1515                      const real_format *format)
1516 {
1517   switch (fn)
1518     {
1519     CASE_CFN_JN:
1520       return do_mpfr_arg2 (result, mpfr_jn, arg0, arg1, format);
1521
1522     CASE_CFN_YN:
1523       return (real_compare (GT_EXPR, arg1, &dconst0)
1524               && do_mpfr_arg2 (result, mpfr_yn, arg0, arg1, format));
1525
1526     default:
1527       return false;
1528     }
1529 }
1530
1531 /* Try to evaluate:
1532
1533       RESULT = fn (ARG0, ARG1)
1534
1535    where FORMAT is the format of the real and imaginary parts of RESULT
1536    (RESULT_REAL and RESULT_IMAG), of ARG0 (ARG0_REAL and ARG0_IMAG)
1537    and of ARG1 (ARG1_REAL and ARG1_IMAG).  Return true on success.  */
1538
1539 static bool
1540 fold_const_call_ccc (real_value *result_real, real_value *result_imag,
1541                      combined_fn fn, const real_value *arg0_real,
1542                      const real_value *arg0_imag, const real_value *arg1_real,
1543                      const real_value *arg1_imag, const real_format *format)
1544 {
1545   switch (fn)
1546     {
1547     CASE_CFN_CPOW:
1548     CASE_CFN_CPOW_FN:
1549       return do_mpc_arg2 (result_real, result_imag, mpc_pow,
1550                           arg0_real, arg0_imag, arg1_real, arg1_imag, format);
1551
1552     default:
1553       return false;
1554     }
1555 }
1556
1557 /* Subroutine of fold_const_call, with the same interface.  Handle cases
1558    where the arguments and result are numerical.  */
1559
1560 static tree
1561 fold_const_call_1 (combined_fn fn, tree type, tree arg0, tree arg1)
1562 {
1563   machine_mode mode = TYPE_MODE (type);
1564   machine_mode arg0_mode = TYPE_MODE (TREE_TYPE (arg0));
1565   machine_mode arg1_mode = TYPE_MODE (TREE_TYPE (arg1));
1566
1567   if (mode == arg0_mode
1568       && real_cst_p (arg0)
1569       && real_cst_p (arg1))
1570     {
1571       gcc_checking_assert (SCALAR_FLOAT_MODE_P (arg0_mode));
1572       REAL_VALUE_TYPE result;
1573       if (arg0_mode == arg1_mode)
1574         {
1575           /* real, real -> real.  */
1576           if (fold_const_call_sss (&result, fn, TREE_REAL_CST_PTR (arg0),
1577                                    TREE_REAL_CST_PTR (arg1),
1578                                    REAL_MODE_FORMAT (mode)))
1579             return build_real (type, result);
1580         }
1581       else if (arg1_mode == TYPE_MODE (long_double_type_node))
1582         switch (fn)
1583           {
1584           CASE_CFN_NEXTTOWARD:
1585             /* real, long double -> real.  */
1586             if (fold_const_call_sss (&result, fn, TREE_REAL_CST_PTR (arg0),
1587                                      TREE_REAL_CST_PTR (arg1),
1588                                      REAL_MODE_FORMAT (mode)))
1589               return build_real (type, result);
1590             break;
1591           default:
1592             break;
1593           }
1594       return NULL_TREE;
1595     }
1596
1597   if (real_cst_p (arg0)
1598       && integer_cst_p (arg1))
1599     {
1600       gcc_checking_assert (SCALAR_FLOAT_MODE_P (arg0_mode));
1601       if (mode == arg0_mode)
1602         {
1603           /* real, int -> real.  */
1604           REAL_VALUE_TYPE result;
1605           if (fold_const_call_sss (&result, fn, TREE_REAL_CST_PTR (arg0),
1606                                    wi::to_wide (arg1),
1607                                    REAL_MODE_FORMAT (mode)))
1608             return build_real (type, result);
1609         }
1610       return NULL_TREE;
1611     }
1612
1613   if (integer_cst_p (arg0)
1614       && real_cst_p (arg1))
1615     {
1616       gcc_checking_assert (SCALAR_FLOAT_MODE_P (arg1_mode));
1617       if (mode == arg1_mode)
1618         {
1619           /* int, real -> real.  */
1620           REAL_VALUE_TYPE result;
1621           if (fold_const_call_sss (&result, fn, wi::to_wide (arg0),
1622                                    TREE_REAL_CST_PTR (arg1),
1623                                    REAL_MODE_FORMAT (mode)))
1624             return build_real (type, result);
1625         }
1626       return NULL_TREE;
1627     }
1628
1629   if (arg0_mode == arg1_mode
1630       && complex_cst_p (arg0)
1631       && complex_cst_p (arg1))
1632     {
1633       gcc_checking_assert (COMPLEX_MODE_P (arg0_mode));
1634       machine_mode inner_mode = GET_MODE_INNER (arg0_mode);
1635       tree arg0r = TREE_REALPART (arg0);
1636       tree arg0i = TREE_IMAGPART (arg0);
1637       tree arg1r = TREE_REALPART (arg1);
1638       tree arg1i = TREE_IMAGPART (arg1);
1639       if (mode == arg0_mode
1640           && real_cst_p (arg0r)
1641           && real_cst_p (arg0i)
1642           && real_cst_p (arg1r)
1643           && real_cst_p (arg1i))
1644         {
1645           /* complex real, complex real -> complex real.  */
1646           REAL_VALUE_TYPE result_real, result_imag;
1647           if (fold_const_call_ccc (&result_real, &result_imag, fn,
1648                                    TREE_REAL_CST_PTR (arg0r),
1649                                    TREE_REAL_CST_PTR (arg0i),
1650                                    TREE_REAL_CST_PTR (arg1r),
1651                                    TREE_REAL_CST_PTR (arg1i),
1652                                    REAL_MODE_FORMAT (inner_mode)))
1653             return build_complex (type,
1654                                   build_real (TREE_TYPE (type), result_real),
1655                                   build_real (TREE_TYPE (type), result_imag));
1656         }
1657       return NULL_TREE;
1658     }
1659
1660   return NULL_TREE;
1661 }
1662
1663 /* Try to fold FN (ARG0, ARG1) to a constant.  Return the constant on success,
1664    otherwise return null.  TYPE is the type of the return value.  */
1665
1666 tree
1667 fold_const_call (combined_fn fn, tree type, tree arg0, tree arg1)
1668 {
1669   const char *p0, *p1;
1670   char c;
1671   switch (fn)
1672     {
1673     case CFN_BUILT_IN_STRSPN:
1674       if ((p0 = c_getstr (arg0)) && (p1 = c_getstr (arg1)))
1675         return build_int_cst (type, strspn (p0, p1));
1676       return NULL_TREE;
1677
1678     case CFN_BUILT_IN_STRCSPN:
1679       if ((p0 = c_getstr (arg0)) && (p1 = c_getstr (arg1)))
1680         return build_int_cst (type, strcspn (p0, p1));
1681       return NULL_TREE;
1682
1683     case CFN_BUILT_IN_STRCMP:
1684       if ((p0 = c_getstr (arg0)) && (p1 = c_getstr (arg1)))
1685         return build_cmp_result (type, strcmp (p0, p1));
1686       return NULL_TREE;
1687
1688     case CFN_BUILT_IN_STRCASECMP:
1689       if ((p0 = c_getstr (arg0)) && (p1 = c_getstr (arg1)))
1690         {
1691           int r = strcmp (p0, p1);
1692           if (r == 0)
1693             return build_cmp_result (type, r);
1694         }
1695       return NULL_TREE;
1696
1697     case CFN_BUILT_IN_INDEX:
1698     case CFN_BUILT_IN_STRCHR:
1699       if ((p0 = c_getstr (arg0)) && target_char_cst_p (arg1, &c))
1700         {
1701           const char *r = strchr (p0, c);
1702           if (r == NULL)
1703             return build_int_cst (type, 0);
1704           return fold_convert (type,
1705                                fold_build_pointer_plus_hwi (arg0, r - p0));
1706         }
1707       return NULL_TREE;
1708
1709     case CFN_BUILT_IN_RINDEX:
1710     case CFN_BUILT_IN_STRRCHR:
1711       if ((p0 = c_getstr (arg0)) && target_char_cst_p (arg1, &c))
1712         {
1713           const char *r = strrchr (p0, c);
1714           if (r == NULL)
1715             return build_int_cst (type, 0);
1716           return fold_convert (type,
1717                                fold_build_pointer_plus_hwi (arg0, r - p0));
1718         }
1719       return NULL_TREE;
1720
1721     case CFN_BUILT_IN_STRSTR:
1722       if ((p1 = c_getstr (arg1)))
1723         {
1724           if ((p0 = c_getstr (arg0)))
1725             {
1726               const char *r = strstr (p0, p1);
1727               if (r == NULL)
1728                 return build_int_cst (type, 0);
1729               return fold_convert (type,
1730                                    fold_build_pointer_plus_hwi (arg0, r - p0));
1731             }
1732           if (*p1 == '\0')
1733             return fold_convert (type, arg0);
1734         }
1735       return NULL_TREE;
1736
1737     case CFN_FOLD_LEFT_PLUS:
1738       return fold_const_fold_left (type, arg0, arg1, PLUS_EXPR);
1739
1740     default:
1741       return fold_const_call_1 (fn, type, arg0, arg1);
1742     }
1743 }
1744
1745 /* Try to evaluate:
1746
1747       *RESULT = FN (*ARG0, *ARG1, *ARG2)
1748
1749    in format FORMAT.  Return true on success.  */
1750
1751 static bool
1752 fold_const_call_ssss (real_value *result, combined_fn fn,
1753                       const real_value *arg0, const real_value *arg1,
1754                       const real_value *arg2, const real_format *format)
1755 {
1756   switch (fn)
1757     {
1758     CASE_CFN_FMA:
1759     CASE_CFN_FMA_FN:
1760       return do_mpfr_arg3 (result, mpfr_fma, arg0, arg1, arg2, format);
1761
1762     case CFN_FMS:
1763       {
1764         real_value new_arg2 = real_value_negate (arg2);
1765         return do_mpfr_arg3 (result, mpfr_fma, arg0, arg1, &new_arg2, format);
1766       }
1767
1768     case CFN_FNMA:
1769       {
1770         real_value new_arg0 = real_value_negate (arg0);
1771         return do_mpfr_arg3 (result, mpfr_fma, &new_arg0, arg1, arg2, format);
1772       }
1773
1774     case CFN_FNMS:
1775       {
1776         real_value new_arg0 = real_value_negate (arg0);
1777         real_value new_arg2 = real_value_negate (arg2);
1778         return do_mpfr_arg3 (result, mpfr_fma, &new_arg0, arg1,
1779                              &new_arg2, format);
1780       }
1781
1782     default:
1783       return false;
1784     }
1785 }
1786
1787 /* Subroutine of fold_const_call, with the same interface.  Handle cases
1788    where the arguments and result are numerical.  */
1789
1790 static tree
1791 fold_const_call_1 (combined_fn fn, tree type, tree arg0, tree arg1, tree arg2)
1792 {
1793   machine_mode mode = TYPE_MODE (type);
1794   machine_mode arg0_mode = TYPE_MODE (TREE_TYPE (arg0));
1795   machine_mode arg1_mode = TYPE_MODE (TREE_TYPE (arg1));
1796   machine_mode arg2_mode = TYPE_MODE (TREE_TYPE (arg2));
1797
1798   if (arg0_mode == arg1_mode
1799       && arg0_mode == arg2_mode
1800       && real_cst_p (arg0)
1801       && real_cst_p (arg1)
1802       && real_cst_p (arg2))
1803     {
1804       gcc_checking_assert (SCALAR_FLOAT_MODE_P (arg0_mode));
1805       if (mode == arg0_mode)
1806         {
1807           /* real, real, real -> real.  */
1808           REAL_VALUE_TYPE result;
1809           if (fold_const_call_ssss (&result, fn, TREE_REAL_CST_PTR (arg0),
1810                                     TREE_REAL_CST_PTR (arg1),
1811                                     TREE_REAL_CST_PTR (arg2),
1812                                     REAL_MODE_FORMAT (mode)))
1813             return build_real (type, result);
1814         }
1815       return NULL_TREE;
1816     }
1817
1818   return NULL_TREE;
1819 }
1820
1821 /* Try to fold FN (ARG0, ARG1, ARG2) to a constant.  Return the constant on
1822    success, otherwise return null.  TYPE is the type of the return value.  */
1823
1824 tree
1825 fold_const_call (combined_fn fn, tree type, tree arg0, tree arg1, tree arg2)
1826 {
1827   const char *p0, *p1;
1828   char c;
1829   unsigned HOST_WIDE_INT s0, s1, s2 = 0;
1830   switch (fn)
1831     {
1832     case CFN_BUILT_IN_STRNCMP:
1833       if (!size_t_cst_p (arg2, &s2))
1834         return NULL_TREE;
1835       if (s2 == 0
1836           && !TREE_SIDE_EFFECTS (arg0)
1837           && !TREE_SIDE_EFFECTS (arg1))
1838         return build_int_cst (type, 0);
1839       else if ((p0 = c_getstr (arg0)) && (p1 = c_getstr (arg1)))
1840         return build_int_cst (type, strncmp (p0, p1, MIN (s2, SIZE_MAX)));
1841       return NULL_TREE;
1842
1843     case CFN_BUILT_IN_STRNCASECMP:
1844       if (!size_t_cst_p (arg2, &s2))
1845         return NULL_TREE;
1846       if (s2 == 0
1847           && !TREE_SIDE_EFFECTS (arg0)
1848           && !TREE_SIDE_EFFECTS (arg1))
1849         return build_int_cst (type, 0);
1850       else if ((p0 = c_getstr (arg0))
1851                && (p1 = c_getstr (arg1))
1852                && strncmp (p0, p1, MIN (s2, SIZE_MAX)) == 0)
1853         return build_int_cst (type, 0);
1854       return NULL_TREE;
1855
1856     case CFN_BUILT_IN_BCMP:
1857     case CFN_BUILT_IN_MEMCMP:
1858       if (!size_t_cst_p (arg2, &s2))
1859         return NULL_TREE;
1860       if (s2 == 0
1861           && !TREE_SIDE_EFFECTS (arg0)
1862           && !TREE_SIDE_EFFECTS (arg1))
1863         return build_int_cst (type, 0);
1864       if ((p0 = getbyterep (arg0, &s0))
1865           && (p1 = getbyterep (arg1, &s1))
1866           && s2 <= s0
1867           && s2 <= s1)
1868         return build_cmp_result (type, memcmp (p0, p1, s2));
1869       return NULL_TREE;
1870
1871     case CFN_BUILT_IN_MEMCHR:
1872       if (!size_t_cst_p (arg2, &s2))
1873         return NULL_TREE;
1874       if (s2 == 0
1875           && !TREE_SIDE_EFFECTS (arg0)
1876           && !TREE_SIDE_EFFECTS (arg1))
1877         return build_int_cst (type, 0);
1878       if ((p0 = getbyterep (arg0, &s0))
1879           && s2 <= s0
1880           && target_char_cst_p (arg1, &c))
1881         {
1882           const char *r = (const char *) memchr (p0, c, s2);
1883           if (r == NULL)
1884             return build_int_cst (type, 0);
1885           return fold_convert (type,
1886                                fold_build_pointer_plus_hwi (arg0, r - p0));
1887         }
1888       return NULL_TREE;
1889
1890     case CFN_WHILE_ULT:
1891       {
1892         poly_uint64 parg0, parg1;
1893         if (poly_int_tree_p (arg0, &parg0) && poly_int_tree_p (arg1, &parg1))
1894           return fold_while_ult (type, parg0, parg1);
1895         return NULL_TREE;
1896       }
1897
1898     default:
1899       return fold_const_call_1 (fn, type, arg0, arg1, arg2);
1900     }
1901 }