gcc/convert.c

   1 /* Utility routines for data type conversion for GCC.
   2    Copyright (C) 1987-2016 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
  21 /* These routines are somewhat language-independent utility function
  22    intended to be called by the language-specific convert () functions.  */
  23
  24 #include "config.h"
  25 #include "system.h"
  26 #include "coretypes.h"
  27 #include "target.h"
  28 #include "tree.h"
  29 #include "diagnostic-core.h"
  30 #include "fold-const.h"
  31 #include "stor-layout.h"
  32 #include "convert.h"
  33 #include "langhooks.h"
  34 #include "builtins.h"
  35 #include "ubsan.h"
  36
  37 #define maybe_fold_build1_loc(FOLD_P, LOC, CODE, TYPE, EXPR) \
  38   ((FOLD_P) ? fold_build1_loc (LOC, CODE, TYPE, EXPR)        \
  39    : build1_loc (LOC, CODE, TYPE, EXPR))
  40 #define maybe_fold_build2_loc(FOLD_P, LOC, CODE, TYPE, EXPR1, EXPR2) \
  41   ((FOLD_P) ? fold_build2_loc (LOC, CODE, TYPE, EXPR1, EXPR2)        \
  42    : build2_loc (LOC, CODE, TYPE, EXPR1, EXPR2))
  43
  44 /* Convert EXPR to some pointer or reference type TYPE.
  45    EXPR must be pointer, reference, integer, enumeral, or literal zero;
  46    in other cases error is called.  If FOLD_P is true, try to fold the
  47    expression.  */
  48
  49 static tree
  50 convert_to_pointer_1 (tree type, tree expr, bool fold_p)
  51 {
  52   location_t loc = EXPR_LOCATION (expr);
  53   if (TREE_TYPE (expr) == type)
  54     return expr;
  55
  56   switch (TREE_CODE (TREE_TYPE (expr)))
  57     {
  58     case POINTER_TYPE:
  59     case REFERENCE_TYPE:
  60       {
  61         /* If the pointers point to different address spaces, conversion needs
  62            to be done via a ADDR_SPACE_CONVERT_EXPR instead of a NOP_EXPR.  */
  63         addr_space_t to_as = TYPE_ADDR_SPACE (TREE_TYPE (type));
  64         addr_space_t from_as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (expr)));
  65
  66         if (to_as == from_as)
  67           return maybe_fold_build1_loc (fold_p, loc, NOP_EXPR, type, expr);
  68         else
  69           return maybe_fold_build1_loc (fold_p, loc, ADDR_SPACE_CONVERT_EXPR,
  70                                         type, expr);
  71       }
  72
  73     case INTEGER_TYPE:
  74     case ENUMERAL_TYPE:
  75     case BOOLEAN_TYPE:
  76       {
  77         /* If the input precision differs from the target pointer type
  78            precision, first convert the input expression to an integer type of
  79            the target precision.  Some targets, e.g. VMS, need several pointer
  80            sizes to coexist so the latter isn't necessarily POINTER_SIZE.  */
  81         unsigned int pprec = TYPE_PRECISION (type);
  82         unsigned int eprec = TYPE_PRECISION (TREE_TYPE (expr));
  83
  84         if (eprec != pprec)
  85           expr
  86             = maybe_fold_build1_loc (fold_p, loc, NOP_EXPR,
  87                                      lang_hooks.types.type_for_size (pprec, 0),
  88                                      expr);
  89       }
  90       return maybe_fold_build1_loc (fold_p, loc, CONVERT_EXPR, type, expr);
  91
  92     default:
  93       error ("cannot convert to a pointer type");
  94       return convert_to_pointer_1 (type, integer_zero_node, fold_p);
  95     }
  96 }
  97
  98 /* A wrapper around convert_to_pointer_1 that always folds the
  99    expression.  */
 100
 101 tree
 102 convert_to_pointer (tree type, tree expr)
 103 {
 104   return convert_to_pointer_1 (type, expr, true);
 105 }
 106
 107 /* A wrapper around convert_to_pointer_1 that only folds the
 108    expression if DOFOLD, or if it is CONSTANT_CLASS_P.  */
 109
 110 tree
 111 convert_to_pointer_maybe_fold (tree type, tree expr, bool dofold)
 112 {
 113   return convert_to_pointer_1 (type, expr, dofold || CONSTANT_CLASS_P (expr));
 114 }
 115
 116 /* Convert EXPR to some floating-point type TYPE.
 117
 118    EXPR must be float, fixed-point, integer, or enumeral;
 119    in other cases error is called.  If FOLD_P is true, try to fold
 120    the expression.  */
 121
 122 static tree
 123 convert_to_real_1 (tree type, tree expr, bool fold_p)
 124 {
 125   enum built_in_function fcode = builtin_mathfn_code (expr);
 126   tree itype = TREE_TYPE (expr);
 127   location_t loc = EXPR_LOCATION (expr);
 128
 129   if (TREE_CODE (expr) == COMPOUND_EXPR)
 130     {
 131       tree t = convert_to_real_1 (type, TREE_OPERAND (expr, 1), fold_p);
 132       if (t == TREE_OPERAND (expr, 1))
 133         return expr;
 134       return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, TREE_TYPE (t),
 135                          TREE_OPERAND (expr, 0), t);
 136     }
 137
 138   /* Disable until we figure out how to decide whether the functions are
 139      present in runtime.  */
 140   /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */
 141   if (optimize
 142       && (TYPE_MODE (type) == TYPE_MODE (double_type_node)
 143           || TYPE_MODE (type) == TYPE_MODE (float_type_node)))
 144     {
 145       switch (fcode)
 146         {
 147 #define CASE_MATHFN(FN) case BUILT_IN_##FN: case BUILT_IN_##FN##L:
 148           CASE_MATHFN (COSH)
 149           CASE_MATHFN (EXP)
 150           CASE_MATHFN (EXP10)
 151           CASE_MATHFN (EXP2)
 152           CASE_MATHFN (EXPM1)
 153           CASE_MATHFN (GAMMA)
 154           CASE_MATHFN (J0)
 155           CASE_MATHFN (J1)
 156           CASE_MATHFN (LGAMMA)
 157           CASE_MATHFN (POW10)
 158           CASE_MATHFN (SINH)
 159           CASE_MATHFN (TGAMMA)
 160           CASE_MATHFN (Y0)
 161           CASE_MATHFN (Y1)
 162             /* The above functions may set errno differently with float
 163                input or output so this transformation is not safe with
 164                -fmath-errno.  */
 165             if (flag_errno_math)
 166               break;
 167           CASE_MATHFN (ACOS)
 168           CASE_MATHFN (ACOSH)
 169           CASE_MATHFN (ASIN)
 170           CASE_MATHFN (ASINH)
 171           CASE_MATHFN (ATAN)
 172           CASE_MATHFN (ATANH)
 173           CASE_MATHFN (CBRT)
 174           CASE_MATHFN (COS)
 175           CASE_MATHFN (ERF)
 176           CASE_MATHFN (ERFC)
 177           CASE_MATHFN (LOG)
 178           CASE_MATHFN (LOG10)
 179           CASE_MATHFN (LOG2)
 180           CASE_MATHFN (LOG1P)
 181           CASE_MATHFN (SIN)
 182           CASE_MATHFN (TAN)
 183           CASE_MATHFN (TANH)
 184             /* The above functions are not safe to do this conversion.  */
 185             if (!flag_unsafe_math_optimizations)
 186               break;
 187           CASE_MATHFN (SQRT)
 188           CASE_MATHFN (FABS)
 189           CASE_MATHFN (LOGB)
 190 #undef CASE_MATHFN
 191             {
 192               tree arg0 = strip_float_extensions (CALL_EXPR_ARG (expr, 0));
 193               tree newtype = type;
 194
 195               /* We have (outertype)sqrt((innertype)x).  Choose the wider mode from
 196                  the both as the safe type for operation.  */
 197               if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (type))
 198                 newtype = TREE_TYPE (arg0);
 199
 200               /* We consider to convert
 201
 202                      (T1) sqrtT2 ((T2) exprT3)
 203                  to
 204                      (T1) sqrtT4 ((T4) exprT3)
 205
 206                   , where T1 is TYPE, T2 is ITYPE, T3 is TREE_TYPE (ARG0),
 207                  and T4 is NEWTYPE.  All those types are of floating point types.
 208                  T4 (NEWTYPE) should be narrower than T2 (ITYPE). This conversion
 209                  is safe only if P1 >= P2*2+2, where P1 and P2 are precisions of
 210                  T2 and T4.  See the following URL for a reference:
 211                  http://stackoverflow.com/questions/9235456/determining-
 212                  floating-point-square-root
 213                  */
 214               if ((fcode == BUILT_IN_SQRT || fcode == BUILT_IN_SQRTL)
 215                   && !flag_unsafe_math_optimizations)
 216                 {
 217                   /* The following conversion is unsafe even the precision condition
 218                      below is satisfied:
 219
 220                      (float) sqrtl ((long double) double_val) -> (float) sqrt (double_val)
 221                     */
 222                   if (TYPE_MODE (type) != TYPE_MODE (newtype))
 223                     break;
 224
 225                   int p1 = REAL_MODE_FORMAT (TYPE_MODE (itype))->p;
 226                   int p2 = REAL_MODE_FORMAT (TYPE_MODE (newtype))->p;
 227                   if (p1 < p2 * 2 + 2)
 228                     break;
 229                 }
 230
 231               /* Be careful about integer to fp conversions.
 232                  These may overflow still.  */
 233               if (FLOAT_TYPE_P (TREE_TYPE (arg0))
 234                   && TYPE_PRECISION (newtype) < TYPE_PRECISION (itype)
 235                   && (TYPE_MODE (newtype) == TYPE_MODE (double_type_node)
 236                       || TYPE_MODE (newtype) == TYPE_MODE (float_type_node)))
 237                 {
 238                   tree fn = mathfn_built_in (newtype, fcode);
 239                   if (fn)
 240                     {
 241                       tree arg = convert_to_real_1 (newtype, arg0, fold_p);
 242                       expr = build_call_expr (fn, 1, arg);
 243                       if (newtype == type)
 244                         return expr;
 245                     }
 246                 }
 247             }
 248         default:
 249           break;
 250         }
 251     }
 252
 253   /* Propagate the cast into the operation.  */
 254   if (itype != type && FLOAT_TYPE_P (type))
 255     switch (TREE_CODE (expr))
 256       {
 257         /* Convert (float)-x into -(float)x.  This is safe for
 258            round-to-nearest rounding mode when the inner type is float.  */
 259         case ABS_EXPR:
 260         case NEGATE_EXPR:
 261           if (!flag_rounding_math
 262               && FLOAT_TYPE_P (itype)
 263               && TYPE_PRECISION (type) < TYPE_PRECISION (itype))
 264             {
 265               tree arg = convert_to_real_1 (type, TREE_OPERAND (expr, 0),
 266                                             fold_p);
 267               return build1 (TREE_CODE (expr), type, arg);
 268             }
 269           break;
 270         /* Convert (outertype)((innertype0)a+(innertype1)b)
 271            into ((newtype)a+(newtype)b) where newtype
 272            is the widest mode from all of these.  */
 273         case PLUS_EXPR:
 274         case MINUS_EXPR:
 275         case MULT_EXPR:
 276         case RDIV_EXPR:
 277            {
 278              tree arg0 = strip_float_extensions (TREE_OPERAND (expr, 0));
 279              tree arg1 = strip_float_extensions (TREE_OPERAND (expr, 1));
 280
 281              if (FLOAT_TYPE_P (TREE_TYPE (arg0))
 282                  && FLOAT_TYPE_P (TREE_TYPE (arg1))
 283                  && DECIMAL_FLOAT_TYPE_P (itype) == DECIMAL_FLOAT_TYPE_P (type))
 284                {
 285                   tree newtype = type;
 286
 287                   if (TYPE_MODE (TREE_TYPE (arg0)) == SDmode
 288                       || TYPE_MODE (TREE_TYPE (arg1)) == SDmode
 289                       || TYPE_MODE (type) == SDmode)
 290                     newtype = dfloat32_type_node;
 291                   if (TYPE_MODE (TREE_TYPE (arg0)) == DDmode
 292                       || TYPE_MODE (TREE_TYPE (arg1)) == DDmode
 293                       || TYPE_MODE (type) == DDmode)
 294                     newtype = dfloat64_type_node;
 295                   if (TYPE_MODE (TREE_TYPE (arg0)) == TDmode
 296                       || TYPE_MODE (TREE_TYPE (arg1)) == TDmode
 297                       || TYPE_MODE (type) == TDmode)
 298                     newtype = dfloat128_type_node;
 299                   if (newtype == dfloat32_type_node
 300                       || newtype == dfloat64_type_node
 301                       || newtype == dfloat128_type_node)
 302                     {
 303                       expr = build2 (TREE_CODE (expr), newtype,
 304                                      convert_to_real_1 (newtype, arg0,
 305                                                         fold_p),
 306                                      convert_to_real_1 (newtype, arg1,
 307                                                         fold_p));
 308                       if (newtype == type)
 309                         return expr;
 310                       break;
 311                     }
 312
 313                   if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (newtype))
 314                     newtype = TREE_TYPE (arg0);
 315                   if (TYPE_PRECISION (TREE_TYPE (arg1)) > TYPE_PRECISION (newtype))
 316                     newtype = TREE_TYPE (arg1);
 317                   /* Sometimes this transformation is safe (cannot
 318                      change results through affecting double rounding
 319                      cases) and sometimes it is not.  If NEWTYPE is
 320                      wider than TYPE, e.g. (float)((long double)double
 321                      + (long double)double) converted to
 322                      (float)(double + double), the transformation is
 323                      unsafe regardless of the details of the types
 324                      involved; double rounding can arise if the result
 325                      of NEWTYPE arithmetic is a NEWTYPE value half way
 326                      between two representable TYPE values but the
 327                      exact value is sufficiently different (in the
 328                      right direction) for this difference to be
 329                      visible in ITYPE arithmetic.  If NEWTYPE is the
 330                      same as TYPE, however, the transformation may be
 331                      safe depending on the types involved: it is safe
 332                      if the ITYPE has strictly more than twice as many
 333                      mantissa bits as TYPE, can represent infinities
 334                      and NaNs if the TYPE can, and has sufficient
 335                      exponent range for the product or ratio of two
 336                      values representable in the TYPE to be within the
 337                      range of normal values of ITYPE.  */
 338                   if (TYPE_PRECISION (newtype) < TYPE_PRECISION (itype)
 339                       && (flag_unsafe_math_optimizations
 340                           || (TYPE_PRECISION (newtype) == TYPE_PRECISION (type)
 341                               && real_can_shorten_arithmetic (TYPE_MODE (itype),
 342                                                               TYPE_MODE (type))
 343                               && !excess_precision_type (newtype))))
 344                     {
 345                       expr = build2 (TREE_CODE (expr), newtype,
 346                                      convert_to_real_1 (newtype, arg0,
 347                                                         fold_p),
 348                                      convert_to_real_1 (newtype, arg1,
 349                                                         fold_p));
 350                       if (newtype == type)
 351                         return expr;
 352                     }
 353                }
 354            }
 355           break;
 356         default:
 357           break;
 358       }
 359
 360   switch (TREE_CODE (TREE_TYPE (expr)))
 361     {
 362     case REAL_TYPE:
 363       /* Ignore the conversion if we don't need to store intermediate
 364          results and neither type is a decimal float.  */
 365       return build1_loc (loc,
 366                          (flag_float_store
 367                           || DECIMAL_FLOAT_TYPE_P (type)
 368                           || DECIMAL_FLOAT_TYPE_P (itype))
 369                          ? CONVERT_EXPR : NOP_EXPR, type, expr);
 370
 371     case INTEGER_TYPE:
 372     case ENUMERAL_TYPE:
 373     case BOOLEAN_TYPE:
 374       return build1 (FLOAT_EXPR, type, expr);
 375
 376     case FIXED_POINT_TYPE:
 377       return build1 (FIXED_CONVERT_EXPR, type, expr);
 378
 379     case COMPLEX_TYPE:
 380       return convert (type,
 381                       maybe_fold_build1_loc (fold_p, loc, REALPART_EXPR,
 382                                              TREE_TYPE (TREE_TYPE (expr)),
 383                                              expr));
 384
 385     case POINTER_TYPE:
 386     case REFERENCE_TYPE:
 387       error ("pointer value used where a floating point value was expected");
 388       return convert_to_real_1 (type, integer_zero_node, fold_p);
 389
 390     default:
 391       error ("aggregate value used where a float was expected");
 392       return convert_to_real_1 (type, integer_zero_node, fold_p);
 393     }
 394 }
 395
 396 /* A wrapper around convert_to_real_1 that always folds the
 397    expression.  */
 398
 399 tree
 400 convert_to_real (tree type, tree expr)
 401 {
 402   return convert_to_real_1 (type, expr, true);
 403 }
 404
 405 /* A wrapper around convert_to_real_1 that only folds the
 406    expression if DOFOLD, or if it is CONSTANT_CLASS_P.  */
 407
 408 tree
 409 convert_to_real_maybe_fold (tree type, tree expr, bool dofold)
 410 {
 411   return convert_to_real_1 (type, expr, dofold || CONSTANT_CLASS_P (expr));
 412 }
 413
 414 /* Convert EXPR to some integer (or enum) type TYPE.
 415
 416    EXPR must be pointer, integer, discrete (enum, char, or bool), float,
 417    fixed-point or vector; in other cases error is called.
 418
 419    If DOFOLD is TRUE, we try to simplify newly-created patterns by folding.
 420
 421    The result of this is always supposed to be a newly created tree node
 422    not in use in any existing structure.  */
 423
 424 static tree
 425 convert_to_integer_1 (tree type, tree expr, bool dofold)
 426 {
 427   enum tree_code ex_form = TREE_CODE (expr);
 428   tree intype = TREE_TYPE (expr);
 429   unsigned int inprec = element_precision (intype);
 430   unsigned int outprec = element_precision (type);
 431   location_t loc = EXPR_LOCATION (expr);
 432
 433   /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
 434      be.  Consider `enum E = { a, b = (enum E) 3 };'.  */
 435   if (!COMPLETE_TYPE_P (type))
 436     {
 437       error ("conversion to incomplete type");
 438       return error_mark_node;
 439     }
 440
 441   if (ex_form == COMPOUND_EXPR)
 442     {
 443       tree t = convert_to_integer_1 (type, TREE_OPERAND (expr, 1), dofold);
 444       if (t == TREE_OPERAND (expr, 1))
 445         return expr;
 446       return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR, TREE_TYPE (t),
 447                          TREE_OPERAND (expr, 0), t);
 448     }
 449
 450   /* Convert e.g. (long)round(d) -> lround(d).  */
 451   /* If we're converting to char, we may encounter differing behavior
 452      between converting from double->char vs double->long->char.
 453      We're in "undefined" territory but we prefer to be conservative,
 454      so only proceed in "unsafe" math mode.  */
 455   if (optimize
 456       && (flag_unsafe_math_optimizations
 457           || (long_integer_type_node
 458               && outprec >= TYPE_PRECISION (long_integer_type_node))))
 459     {
 460       tree s_expr = strip_float_extensions (expr);
 461       tree s_intype = TREE_TYPE (s_expr);
 462       const enum built_in_function fcode = builtin_mathfn_code (s_expr);
 463       tree fn = 0;
 464
 465       switch (fcode)
 466         {
 467         CASE_FLT_FN (BUILT_IN_CEIL):
 468           /* Only convert in ISO C99 mode.  */
 469           if (!targetm.libc_has_function (function_c99_misc))
 470             break;
 471           if (outprec < TYPE_PRECISION (integer_type_node)
 472               || (outprec == TYPE_PRECISION (integer_type_node)
 473                   && !TYPE_UNSIGNED (type)))
 474             fn = mathfn_built_in (s_intype, BUILT_IN_ICEIL);
 475           else if (outprec == TYPE_PRECISION (long_integer_type_node)
 476                    && !TYPE_UNSIGNED (type))
 477             fn = mathfn_built_in (s_intype, BUILT_IN_LCEIL);
 478           else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
 479                    && !TYPE_UNSIGNED (type))
 480             fn = mathfn_built_in (s_intype, BUILT_IN_LLCEIL);
 481           break;
 482
 483         CASE_FLT_FN (BUILT_IN_FLOOR):
 484           /* Only convert in ISO C99 mode.  */
 485           if (!targetm.libc_has_function (function_c99_misc))
 486             break;
 487           if (outprec < TYPE_PRECISION (integer_type_node)
 488               || (outprec == TYPE_PRECISION (integer_type_node)
 489                   && !TYPE_UNSIGNED (type)))
 490             fn = mathfn_built_in (s_intype, BUILT_IN_IFLOOR);
 491           else if (outprec == TYPE_PRECISION (long_integer_type_node)
 492                    && !TYPE_UNSIGNED (type))
 493             fn = mathfn_built_in (s_intype, BUILT_IN_LFLOOR);
 494           else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
 495                    && !TYPE_UNSIGNED (type))
 496             fn = mathfn_built_in (s_intype, BUILT_IN_LLFLOOR);
 497           break;
 498
 499         CASE_FLT_FN (BUILT_IN_ROUND):
 500           /* Only convert in ISO C99 mode and with -fno-math-errno.  */
 501           if (!targetm.libc_has_function (function_c99_misc) || flag_errno_math)
 502             break;
 503           if (outprec < TYPE_PRECISION (integer_type_node)
 504               || (outprec == TYPE_PRECISION (integer_type_node)
 505                   && !TYPE_UNSIGNED (type)))
 506             fn = mathfn_built_in (s_intype, BUILT_IN_IROUND);
 507           else if (outprec == TYPE_PRECISION (long_integer_type_node)
 508                    && !TYPE_UNSIGNED (type))
 509             fn = mathfn_built_in (s_intype, BUILT_IN_LROUND);
 510           else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
 511                    && !TYPE_UNSIGNED (type))
 512             fn = mathfn_built_in (s_intype, BUILT_IN_LLROUND);
 513           break;
 514
 515         CASE_FLT_FN (BUILT_IN_NEARBYINT):
 516           /* Only convert nearbyint* if we can ignore math exceptions.  */
 517           if (flag_trapping_math)
 518             break;
 519           /* ... Fall through ...  */
 520         CASE_FLT_FN (BUILT_IN_RINT):
 521           /* Only convert in ISO C99 mode and with -fno-math-errno.  */
 522           if (!targetm.libc_has_function (function_c99_misc) || flag_errno_math)
 523             break;
 524           if (outprec < TYPE_PRECISION (integer_type_node)
 525               || (outprec == TYPE_PRECISION (integer_type_node)
 526                   && !TYPE_UNSIGNED (type)))
 527             fn = mathfn_built_in (s_intype, BUILT_IN_IRINT);
 528           else if (outprec == TYPE_PRECISION (long_integer_type_node)
 529                    && !TYPE_UNSIGNED (type))
 530             fn = mathfn_built_in (s_intype, BUILT_IN_LRINT);
 531           else if (outprec == TYPE_PRECISION (long_long_integer_type_node)
 532                    && !TYPE_UNSIGNED (type))
 533             fn = mathfn_built_in (s_intype, BUILT_IN_LLRINT);
 534           break;
 535
 536         CASE_FLT_FN (BUILT_IN_TRUNC):
 537           return convert_to_integer_1 (type, CALL_EXPR_ARG (s_expr, 0), dofold);
 538
 539         default:
 540           break;
 541         }
 542
 543       if (fn)
 544         {
 545           tree newexpr = build_call_expr (fn, 1, CALL_EXPR_ARG (s_expr, 0));
 546           return convert_to_integer_1 (type, newexpr, dofold);
 547         }
 548     }
 549
 550   /* Convert (int)logb(d) -> ilogb(d).  */
 551   if (optimize
 552       && flag_unsafe_math_optimizations
 553       && !flag_trapping_math && !flag_errno_math && flag_finite_math_only
 554       && integer_type_node
 555       && (outprec > TYPE_PRECISION (integer_type_node)
 556           || (outprec == TYPE_PRECISION (integer_type_node)
 557               && !TYPE_UNSIGNED (type))))
 558     {
 559       tree s_expr = strip_float_extensions (expr);
 560       tree s_intype = TREE_TYPE (s_expr);
 561       const enum built_in_function fcode = builtin_mathfn_code (s_expr);
 562       tree fn = 0;
 563
 564       switch (fcode)
 565         {
 566         CASE_FLT_FN (BUILT_IN_LOGB):
 567           fn = mathfn_built_in (s_intype, BUILT_IN_ILOGB);
 568           break;
 569
 570         default:
 571           break;
 572         }
 573
 574       if (fn)
 575         {
 576           tree newexpr = build_call_expr (fn, 1, CALL_EXPR_ARG (s_expr, 0));
 577           return convert_to_integer_1 (type, newexpr, dofold);
 578         }
 579     }
 580
 581   switch (TREE_CODE (intype))
 582     {
 583     case POINTER_TYPE:
 584     case REFERENCE_TYPE:
 585       if (integer_zerop (expr))
 586         return build_int_cst (type, 0);
 587
 588       /* Convert to an unsigned integer of the correct width first, and from
 589          there widen/truncate to the required type.  Some targets support the
 590          coexistence of multiple valid pointer sizes, so fetch the one we need
 591          from the type.  */
 592       if (!dofold)
 593         return build1 (CONVERT_EXPR, type, expr);
 594       expr = fold_build1 (CONVERT_EXPR,
 595                           lang_hooks.types.type_for_size
 596                             (TYPE_PRECISION (intype), 0),
 597                           expr);
 598       return fold_convert (type, expr);
 599
 600     case INTEGER_TYPE:
 601     case ENUMERAL_TYPE:
 602     case BOOLEAN_TYPE:
 603     case OFFSET_TYPE:
 604       /* If this is a logical operation, which just returns 0 or 1, we can
 605          change the type of the expression.  */
 606
 607       if (TREE_CODE_CLASS (ex_form) == tcc_comparison)
 608         {
 609           expr = copy_node (expr);
 610           TREE_TYPE (expr) = type;
 611           return expr;
 612         }
 613
 614       /* If we are widening the type, put in an explicit conversion.
 615          Similarly if we are not changing the width.  After this, we know
 616          we are truncating EXPR.  */
 617
 618       else if (outprec >= inprec)
 619         {
 620           enum tree_code code;
 621
 622           /* If the precision of the EXPR's type is K bits and the
 623              destination mode has more bits, and the sign is changing,
 624              it is not safe to use a NOP_EXPR.  For example, suppose
 625              that EXPR's type is a 3-bit unsigned integer type, the
 626              TYPE is a 3-bit signed integer type, and the machine mode
 627              for the types is 8-bit QImode.  In that case, the
 628              conversion necessitates an explicit sign-extension.  In
 629              the signed-to-unsigned case the high-order bits have to
 630              be cleared.  */
 631           if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (TREE_TYPE (expr))
 632               && (TYPE_PRECISION (TREE_TYPE (expr))
 633                   != GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (expr)))))
 634             code = CONVERT_EXPR;
 635           else
 636             code = NOP_EXPR;
 637
 638           return maybe_fold_build1_loc (dofold, loc, code, type, expr);
 639         }
 640
 641       /* If TYPE is an enumeral type or a type with a precision less
 642          than the number of bits in its mode, do the conversion to the
 643          type corresponding to its mode, then do a nop conversion
 644          to TYPE.  */
 645       else if (TREE_CODE (type) == ENUMERAL_TYPE
 646                || outprec != GET_MODE_PRECISION (TYPE_MODE (type)))
 647         return build1 (NOP_EXPR, type,
 648                        convert (lang_hooks.types.type_for_mode
 649                                 (TYPE_MODE (type), TYPE_UNSIGNED (type)),
 650                                 expr));
 651
 652       /* Here detect when we can distribute the truncation down past some
 653          arithmetic.  For example, if adding two longs and converting to an
 654          int, we can equally well convert both to ints and then add.
 655          For the operations handled here, such truncation distribution
 656          is always safe.
 657          It is desirable in these cases:
 658          1) when truncating down to full-word from a larger size
 659          2) when truncating takes no work.
 660          3) when at least one operand of the arithmetic has been extended
 661          (as by C's default conversions).  In this case we need two conversions
 662          if we do the arithmetic as already requested, so we might as well
 663          truncate both and then combine.  Perhaps that way we need only one.
 664
 665          Note that in general we cannot do the arithmetic in a type
 666          shorter than the desired result of conversion, even if the operands
 667          are both extended from a shorter type, because they might overflow
 668          if combined in that type.  The exceptions to this--the times when
 669          two narrow values can be combined in their narrow type even to
 670          make a wider result--are handled by "shorten" in build_binary_op.  */
 671
 672       if (dofold)
 673       switch (ex_form)
 674         {
 675         case RSHIFT_EXPR:
 676           /* We can pass truncation down through right shifting
 677              when the shift count is a nonpositive constant.  */
 678           if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST
 679               && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) <= 0)
 680             goto trunc1;
 681           break;
 682
 683         case LSHIFT_EXPR:
 684           /* We can pass truncation down through left shifting
 685              when the shift count is a nonnegative constant and
 686              the target type is unsigned.  */
 687           if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST
 688               && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) >= 0
 689               && TYPE_UNSIGNED (type)
 690               && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
 691             {
 692               /* If shift count is less than the width of the truncated type,
 693                  really shift.  */
 694               if (tree_int_cst_lt (TREE_OPERAND (expr, 1), TYPE_SIZE (type)))
 695                 /* In this case, shifting is like multiplication.  */
 696                 goto trunc1;
 697               else
 698                 {
 699                   /* If it is >= that width, result is zero.
 700                      Handling this with trunc1 would give the wrong result:
 701                      (int) ((long long) a << 32) is well defined (as 0)
 702                      but (int) a << 32 is undefined and would get a
 703                      warning.  */
 704
 705                   tree t = build_int_cst (type, 0);
 706
 707                   /* If the original expression had side-effects, we must
 708                      preserve it.  */
 709                   if (TREE_SIDE_EFFECTS (expr))
 710                     return build2 (COMPOUND_EXPR, type, expr, t);
 711                   else
 712                     return t;
 713                 }
 714             }
 715           break;
 716
 717         case TRUNC_DIV_EXPR:
 718           {
 719             tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
 720             tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);
 721
 722             /* Don't distribute unless the output precision is at least as big
 723                as the actual inputs and it has the same signedness.  */
 724             if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0))
 725                 && outprec >= TYPE_PRECISION (TREE_TYPE (arg1))
 726                 /* If signedness of arg0 and arg1 don't match,
 727                    we can't necessarily find a type to compare them in.  */
 728                 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
 729                     == TYPE_UNSIGNED (TREE_TYPE (arg1)))
 730                 /* Do not change the sign of the division.  */
 731                 && (TYPE_UNSIGNED (TREE_TYPE (expr))
 732                     == TYPE_UNSIGNED (TREE_TYPE (arg0)))
 733                 /* Either require unsigned division or a division by
 734                    a constant that is not -1.  */
 735                 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
 736                     || (TREE_CODE (arg1) == INTEGER_CST
 737                         && !integer_all_onesp (arg1))))
 738               goto trunc1;
 739             break;
 740           }
 741
 742         case MAX_EXPR:
 743         case MIN_EXPR:
 744         case MULT_EXPR:
 745           {
 746             tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
 747             tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);
 748
 749             /* Don't distribute unless the output precision is at least as big
 750                as the actual inputs.  Otherwise, the comparison of the
 751                truncated values will be wrong.  */
 752             if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0))
 753                 && outprec >= TYPE_PRECISION (TREE_TYPE (arg1))
 754                 /* If signedness of arg0 and arg1 don't match,
 755                    we can't necessarily find a type to compare them in.  */
 756                 && (TYPE_UNSIGNED (TREE_TYPE (arg0))
 757                     == TYPE_UNSIGNED (TREE_TYPE (arg1))))
 758               goto trunc1;
 759             break;
 760           }
 761
 762         case PLUS_EXPR:
 763         case MINUS_EXPR:
 764         case BIT_AND_EXPR:
 765         case BIT_IOR_EXPR:
 766         case BIT_XOR_EXPR:
 767         trunc1:
 768           {
 769             tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
 770             tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);
 771
 772             /* Do not try to narrow operands of pointer subtraction;
 773                that will interfere with other folding.  */
 774             if (ex_form == MINUS_EXPR
 775                 && CONVERT_EXPR_P (arg0)
 776                 && CONVERT_EXPR_P (arg1)
 777                 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
 778                 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1, 0))))
 779               break;
 780
 781             if (outprec >= BITS_PER_WORD
 782                 || TRULY_NOOP_TRUNCATION (outprec, inprec)
 783                 || inprec > TYPE_PRECISION (TREE_TYPE (arg0))
 784                 || inprec > TYPE_PRECISION (TREE_TYPE (arg1)))
 785               {
 786                 /* Do the arithmetic in type TYPEX,
 787                    then convert result to TYPE.  */
 788                 tree typex = type;
 789
 790                 /* Can't do arithmetic in enumeral types
 791                    so use an integer type that will hold the values.  */
 792                 if (TREE_CODE (typex) == ENUMERAL_TYPE)
 793                   typex
 794                     = lang_hooks.types.type_for_size (TYPE_PRECISION (typex),
 795                                                       TYPE_UNSIGNED (typex));
 796
 797                 /* But now perhaps TYPEX is as wide as INPREC.
 798                    In that case, do nothing special here.
 799                    (Otherwise would recurse infinitely in convert.  */
 800                 if (TYPE_PRECISION (typex) != inprec)
 801                   {
 802                     /* Don't do unsigned arithmetic where signed was wanted,
 803                        or vice versa.
 804                        Exception: if both of the original operands were
 805                        unsigned then we can safely do the work as unsigned.
 806                        Exception: shift operations take their type solely
 807                        from the first argument.
 808                        Exception: the LSHIFT_EXPR case above requires that
 809                        we perform this operation unsigned lest we produce
 810                        signed-overflow undefinedness.
 811                        And we may need to do it as unsigned
 812                        if we truncate to the original size.  */
 813                     if (TYPE_UNSIGNED (TREE_TYPE (expr))
 814                         || (TYPE_UNSIGNED (TREE_TYPE (arg0))
 815                             && (TYPE_UNSIGNED (TREE_TYPE (arg1))
 816                                 || ex_form == LSHIFT_EXPR
 817                                 || ex_form == RSHIFT_EXPR
 818                                 || ex_form == LROTATE_EXPR
 819                                 || ex_form == RROTATE_EXPR))
 820                         || ex_form == LSHIFT_EXPR
 821                         /* If we have !flag_wrapv, and either ARG0 or
 822                            ARG1 is of a signed type, we have to do
 823                            PLUS_EXPR, MINUS_EXPR or MULT_EXPR in an unsigned
 824                            type in case the operation in outprec precision
 825                            could overflow.  Otherwise, we would introduce
 826                            signed-overflow undefinedness.  */
 827                         || ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0))
 828                              || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1)))
 829                             && ((TYPE_PRECISION (TREE_TYPE (arg0)) * 2u
 830                                  > outprec)
 831                                 || (TYPE_PRECISION (TREE_TYPE (arg1)) * 2u
 832                                     > outprec))
 833                             && (ex_form == PLUS_EXPR
 834                                 || ex_form == MINUS_EXPR
 835                                 || ex_form == MULT_EXPR)))
 836                       {
 837                         if (!TYPE_UNSIGNED (typex))
 838                           typex = unsigned_type_for (typex);
 839                       }
 840                     else
 841                       {
 842                         if (TYPE_UNSIGNED (typex))
 843                           typex = signed_type_for (typex);
 844                       }
 845                     /* We should do away with all this once we have a proper
 846                        type promotion/demotion pass, see PR45397.  */
 847                     expr = maybe_fold_build2_loc (dofold, loc, ex_form, typex,
 848                                                   convert (typex, arg0),
 849                                                   convert (typex, arg1));
 850                     return convert (type, expr);
 851                   }
 852               }
 853           }
 854           break;
 855
 856         case NEGATE_EXPR:
 857         case BIT_NOT_EXPR:
 858           /* This is not correct for ABS_EXPR,
 859              since we must test the sign before truncation.  */
 860           {
 861             /* Do the arithmetic in type TYPEX,
 862                then convert result to TYPE.  */
 863             tree typex = type;
 864
 865             /* Can't do arithmetic in enumeral types
 866                so use an integer type that will hold the values.  */
 867             if (TREE_CODE (typex) == ENUMERAL_TYPE)
 868               typex
 869                 = lang_hooks.types.type_for_size (TYPE_PRECISION (typex),
 870                                                   TYPE_UNSIGNED (typex));
 871
 872             if (!TYPE_UNSIGNED (typex))
 873               typex = unsigned_type_for (typex);
 874             return convert (type,
 875                             fold_build1 (ex_form, typex,
 876                                          convert (typex,
 877                                                   TREE_OPERAND (expr, 0))));
 878           }
 879
 880         CASE_CONVERT:
 881           /* Don't introduce a
 882              "can't convert between vector values of different size" error.  */
 883           if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == VECTOR_TYPE
 884               && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0))))
 885                   != GET_MODE_SIZE (TYPE_MODE (type))))
 886             break;
 887           /* If truncating after truncating, might as well do all at once.
 888              If truncating after extending, we may get rid of wasted work.  */
 889           return convert (type, get_unwidened (TREE_OPERAND (expr, 0), type));
 890
 891         case COND_EXPR:
 892           /* It is sometimes worthwhile to push the narrowing down through
 893              the conditional and never loses.  A COND_EXPR may have a throw
 894              as one operand, which then has void type.  Just leave void
 895              operands as they are.  */
 896             return
 897               fold_build3 (COND_EXPR, type, TREE_OPERAND (expr, 0),
 898                            VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 1)))
 899                            ? TREE_OPERAND (expr, 1)
 900                            : convert (type, TREE_OPERAND (expr, 1)),
 901                            VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 2)))
 902                            ? TREE_OPERAND (expr, 2)
 903                            : convert (type, TREE_OPERAND (expr, 2)));
 904
 905         default:
 906           break;
 907         }
 908
 909       /* When parsing long initializers, we might end up with a lot of casts.
 910          Shortcut this.  */
 911       if (TREE_CODE (expr) == INTEGER_CST)
 912         return fold_convert (type, expr);
 913       return build1 (CONVERT_EXPR, type, expr);
 914
 915     case REAL_TYPE:
 916       if (flag_sanitize & SANITIZE_FLOAT_CAST
 917           && do_ubsan_in_current_function ())
 918         {
 919           expr = save_expr (expr);
 920           tree check = ubsan_instrument_float_cast (loc, type, expr);
 921           expr = build1 (FIX_TRUNC_EXPR, type, expr);
 922           if (check == NULL_TREE)
 923             return expr;
 924           return maybe_fold_build2_loc (dofold, loc, COMPOUND_EXPR,
 925                                         TREE_TYPE (expr), check, expr);
 926         }
 927       else
 928         return build1 (FIX_TRUNC_EXPR, type, expr);
 929
 930     case FIXED_POINT_TYPE:
 931       return build1 (FIXED_CONVERT_EXPR, type, expr);
 932
 933     case COMPLEX_TYPE:
 934       expr = maybe_fold_build1_loc (dofold, loc, REALPART_EXPR,
 935                                     TREE_TYPE (TREE_TYPE (expr)), expr);
 936       return convert (type, expr);
 937
 938     case VECTOR_TYPE:
 939       if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr))))
 940         {
 941           error ("can%'t convert a vector of type %qT"
 942                  " to type %qT which has different size",
 943                  TREE_TYPE (expr), type);
 944           return error_mark_node;
 945         }
 946       return build1 (VIEW_CONVERT_EXPR, type, expr);
 947
 948     default:
 949       error ("aggregate value used where an integer was expected");
 950       return convert (type, integer_zero_node);
 951     }
 952 }
 953
 954 /* Convert EXPR to some integer (or enum) type TYPE.
 955
 956    EXPR must be pointer, integer, discrete (enum, char, or bool), float,
 957    fixed-point or vector; in other cases error is called.
 958
 959    The result of this is always supposed to be a newly created tree node
 960    not in use in any existing structure.  */
 961
 962 tree
 963 convert_to_integer (tree type, tree expr)
 964 {
 965   return convert_to_integer_1 (type, expr, true);
 966 }
 967
 968 /* A wrapper around convert_to_complex_1 that only folds the
 969    expression if DOFOLD, or if it is CONSTANT_CLASS_P.  */
 970
 971 tree
 972 convert_to_integer_maybe_fold (tree type, tree expr, bool dofold)
 973 {
 974   return convert_to_integer_1 (type, expr, dofold || CONSTANT_CLASS_P (expr));
 975 }
 976
 977 /* Convert EXPR to the complex type TYPE in the usual ways.  If FOLD_P is
 978    true, try to fold the expression.  */
 979
 980 static tree
 981 convert_to_complex_1 (tree type, tree expr, bool fold_p)
 982 {
 983   location_t loc = EXPR_LOCATION (expr);
 984   tree subtype = TREE_TYPE (type);
 985
 986   switch (TREE_CODE (TREE_TYPE (expr)))
 987     {
 988     case REAL_TYPE:
 989     case FIXED_POINT_TYPE:
 990     case INTEGER_TYPE:
 991     case ENUMERAL_TYPE:
 992     case BOOLEAN_TYPE:
 993       return build2 (COMPLEX_EXPR, type, convert (subtype, expr),
 994                      convert (subtype, integer_zero_node));
 995
 996     case COMPLEX_TYPE:
 997       {
 998         tree elt_type = TREE_TYPE (TREE_TYPE (expr));
 999
1000         if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype))
1001           return expr;
1002         else if (TREE_CODE (expr) == COMPOUND_EXPR)
1003           {
1004             tree t = convert_to_complex_1 (type, TREE_OPERAND (expr, 1),
1005                                            fold_p);
1006             if (t == TREE_OPERAND (expr, 1))
1007               return expr;
1008             return build2_loc (EXPR_LOCATION (expr), COMPOUND_EXPR,
1009                                TREE_TYPE (t), TREE_OPERAND (expr, 0), t);
1010           }
1011         else if (TREE_CODE (expr) == COMPLEX_EXPR)
1012           return maybe_fold_build2_loc (fold_p, loc, COMPLEX_EXPR, type,
1013                                         convert (subtype,
1014                                                  TREE_OPERAND (expr, 0)),
1015                                         convert (subtype,
1016                                                  TREE_OPERAND (expr, 1)));
1017         else
1018           {
1019             expr = save_expr (expr);
1020             tree realp = maybe_fold_build1_loc (fold_p, loc, REALPART_EXPR,
1021                                                 TREE_TYPE (TREE_TYPE (expr)),
1022                                                 expr);
1023             tree imagp = maybe_fold_build1_loc (fold_p, loc, IMAGPART_EXPR,
1024                                                 TREE_TYPE (TREE_TYPE (expr)),
1025                                                 expr);
1026             return maybe_fold_build2_loc (fold_p, loc, COMPLEX_EXPR, type,
1027                                           convert (subtype, realp),
1028                                           convert (subtype, imagp));
1029           }
1030       }
1031
1032     case POINTER_TYPE:
1033     case REFERENCE_TYPE:
1034       error ("pointer value used where a complex was expected");
1035       return convert_to_complex_1 (type, integer_zero_node, fold_p);
1036
1037     default:
1038       error ("aggregate value used where a complex was expected");
1039       return convert_to_complex_1 (type, integer_zero_node, fold_p);
1040     }
1041 }
1042
1043 /* A wrapper around convert_to_complex_1 that always folds the
1044    expression.  */
1045
1046 tree
1047 convert_to_complex (tree type, tree expr)
1048 {
1049   return convert_to_complex_1 (type, expr, true);
1050 }
1051
1052 /* A wrapper around convert_to_complex_1 that only folds the
1053    expression if DOFOLD, or if it is CONSTANT_CLASS_P.  */
1054
1055 tree
1056 convert_to_complex_maybe_fold (tree type, tree expr, bool dofold)
1057 {
1058   return convert_to_complex_1 (type, expr, dofold || CONSTANT_CLASS_P (expr));
1059 }
1060
1061 /* Convert EXPR to the vector type TYPE in the usual ways.  */
1062
1063 tree
1064 convert_to_vector (tree type, tree expr)
1065 {
1066   switch (TREE_CODE (TREE_TYPE (expr)))
1067     {
1068     case INTEGER_TYPE:
1069     case VECTOR_TYPE:
1070       if (!tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (TREE_TYPE (expr))))
1071         {
1072           error ("can%'t convert a value of type %qT"
1073                  " to vector type %qT which has different size",
1074                  TREE_TYPE (expr), type);
1075           return error_mark_node;
1076         }
1077       return build1 (VIEW_CONVERT_EXPR, type, expr);
1078
1079     default:
1080       error ("can%'t convert value to a vector");
1081       return error_mark_node;
1082     }
1083 }
1084
1085 /* Convert EXPR to some fixed-point type TYPE.
1086
1087    EXPR must be fixed-point, float, integer, or enumeral;
1088    in other cases error is called.  */
1089
1090 tree
1091 convert_to_fixed (tree type, tree expr)
1092 {
1093   if (integer_zerop (expr))
1094     {
1095       tree fixed_zero_node = build_fixed (type, FCONST0 (TYPE_MODE (type)));
1096       return fixed_zero_node;
1097     }
1098   else if (integer_onep (expr) && ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type)))
1099     {
1100       tree fixed_one_node = build_fixed (type, FCONST1 (TYPE_MODE (type)));
1101       return fixed_one_node;
1102     }
1103
1104   switch (TREE_CODE (TREE_TYPE (expr)))
1105     {
1106     case FIXED_POINT_TYPE:
1107     case INTEGER_TYPE:
1108     case ENUMERAL_TYPE:
1109     case BOOLEAN_TYPE:
1110     case REAL_TYPE:
1111       return build1 (FIXED_CONVERT_EXPR, type, expr);
1112
1113     case COMPLEX_TYPE:
1114       return convert (type,
1115                       fold_build1 (REALPART_EXPR,
1116                                    TREE_TYPE (TREE_TYPE (expr)), expr));
1117
1118     default:
1119       error ("aggregate value used where a fixed-point was expected");
1120       return error_mark_node;
1121     }
1122 }