1 /* Utility routines for data type conversion for GCC.
2 Copyright (C) 1987-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
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
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
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/>. */
21 /* These routines are somewhat language-independent utility function
22 intended to be called by the language-specific convert () functions. */
26 #include "coretypes.h"
29 #include "diagnostic-core.h"
30 #include "fold-const.h"
31 #include "stor-layout.h"
33 #include "langhooks.h"
36 #include "stringpool.h"
40 #define maybe_fold_build1_loc(FOLD_P, LOC, CODE, TYPE, EXPR) \
41 ((FOLD_P) ? fold_build1_loc (LOC, CODE, TYPE, EXPR) \
42 : build1_loc (LOC, CODE, TYPE, EXPR))
43 #define maybe_fold_build2_loc(FOLD_P, LOC, CODE, TYPE, EXPR1, EXPR2) \
44 ((FOLD_P) ? fold_build2_loc (LOC, CODE, TYPE, EXPR1, EXPR2) \
45 : build2_loc (LOC, CODE, TYPE, EXPR1, EXPR2))
47 /* Convert EXPR to some pointer or reference type TYPE.
48 EXPR must be pointer, reference, integer, enumeral, or literal zero;
49 in other cases error is called. If FOLD_P is true, try to fold the
53 convert_to_pointer_1 (tree type
, tree expr
, bool fold_p
)
55 location_t loc
= EXPR_LOCATION (expr
);
56 if (TREE_TYPE (expr
) == type
)
59 switch (TREE_CODE (TREE_TYPE (expr
)))
64 /* If the pointers point to different address spaces, conversion needs
65 to be done via a ADDR_SPACE_CONVERT_EXPR instead of a NOP_EXPR. */
66 addr_space_t to_as
= TYPE_ADDR_SPACE (TREE_TYPE (type
));
67 addr_space_t from_as
= TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (expr
)));
70 return maybe_fold_build1_loc (fold_p
, loc
, NOP_EXPR
, type
, expr
);
72 return maybe_fold_build1_loc (fold_p
, loc
, ADDR_SPACE_CONVERT_EXPR
,
80 /* If the input precision differs from the target pointer type
81 precision, first convert the input expression to an integer type of
82 the target precision. Some targets, e.g. VMS, need several pointer
83 sizes to coexist so the latter isn't necessarily POINTER_SIZE. */
84 unsigned int pprec
= TYPE_PRECISION (type
);
85 unsigned int eprec
= TYPE_PRECISION (TREE_TYPE (expr
));
89 = maybe_fold_build1_loc (fold_p
, loc
, NOP_EXPR
,
90 lang_hooks
.types
.type_for_size (pprec
, 0),
93 return maybe_fold_build1_loc (fold_p
, loc
, CONVERT_EXPR
, type
, expr
);
96 error ("cannot convert to a pointer type");
97 return convert_to_pointer_1 (type
, integer_zero_node
, fold_p
);
101 /* A wrapper around convert_to_pointer_1 that always folds the
105 convert_to_pointer (tree type
, tree expr
)
107 return convert_to_pointer_1 (type
, expr
, true);
110 /* A wrapper around convert_to_pointer_1 that only folds the
111 expression if DOFOLD, or if it is CONSTANT_CLASS_P. */
114 convert_to_pointer_maybe_fold (tree type
, tree expr
, bool dofold
)
116 return convert_to_pointer_1 (type
, expr
, dofold
|| CONSTANT_CLASS_P (expr
));
119 /* Convert EXPR to some floating-point type TYPE.
121 EXPR must be float, fixed-point, integer, or enumeral;
122 in other cases error is called. If FOLD_P is true, try to fold
126 convert_to_real_1 (tree type
, tree expr
, bool fold_p
)
128 enum built_in_function fcode
= builtin_mathfn_code (expr
);
129 tree itype
= TREE_TYPE (expr
);
130 location_t loc
= EXPR_LOCATION (expr
);
132 if (TREE_CODE (expr
) == COMPOUND_EXPR
)
134 tree t
= convert_to_real_1 (type
, TREE_OPERAND (expr
, 1), fold_p
);
135 if (t
== TREE_OPERAND (expr
, 1))
137 return build2_loc (EXPR_LOCATION (expr
), COMPOUND_EXPR
, TREE_TYPE (t
),
138 TREE_OPERAND (expr
, 0), t
);
141 /* Disable until we figure out how to decide whether the functions are
142 present in runtime. */
143 /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */
145 && (TYPE_MODE (type
) == TYPE_MODE (double_type_node
)
146 || TYPE_MODE (type
) == TYPE_MODE (float_type_node
)))
150 #define CASE_MATHFN(FN) case BUILT_IN_##FN: case BUILT_IN_##FN##L:
165 /* The above functions may set errno differently with float
166 input or output so this transformation is not safe with
188 /* The above functions are not safe to do this conversion. */
189 if (!flag_unsafe_math_optimizations
)
197 tree arg0
= strip_float_extensions (CALL_EXPR_ARG (expr
, 0));
200 /* We have (outertype)sqrt((innertype)x). Choose the wider mode from
201 the both as the safe type for operation. */
202 if (TYPE_PRECISION (TREE_TYPE (arg0
)) > TYPE_PRECISION (type
))
203 newtype
= TREE_TYPE (arg0
);
205 /* We consider to convert
207 (T1) sqrtT2 ((T2) exprT3)
209 (T1) sqrtT4 ((T4) exprT3)
211 , where T1 is TYPE, T2 is ITYPE, T3 is TREE_TYPE (ARG0),
212 and T4 is NEWTYPE. All those types are of floating point types.
213 T4 (NEWTYPE) should be narrower than T2 (ITYPE). This conversion
214 is safe only if P1 >= P2*2+2, where P1 and P2 are precisions of
215 T2 and T4. See the following URL for a reference:
216 http://stackoverflow.com/questions/9235456/determining-
217 floating-point-square-root
219 if ((fcode
== BUILT_IN_SQRT
|| fcode
== BUILT_IN_SQRTL
)
220 && !flag_unsafe_math_optimizations
)
222 /* The following conversion is unsafe even the precision condition
225 (float) sqrtl ((long double) double_val) -> (float) sqrt (double_val)
227 if (TYPE_MODE (type
) != TYPE_MODE (newtype
))
230 int p1
= REAL_MODE_FORMAT (TYPE_MODE (itype
))->p
;
231 int p2
= REAL_MODE_FORMAT (TYPE_MODE (newtype
))->p
;
236 /* Be careful about integer to fp conversions.
237 These may overflow still. */
238 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
239 && TYPE_PRECISION (newtype
) < TYPE_PRECISION (itype
)
240 && (TYPE_MODE (newtype
) == TYPE_MODE (double_type_node
)
241 || TYPE_MODE (newtype
) == TYPE_MODE (float_type_node
)))
243 tree fn
= mathfn_built_in (newtype
, fcode
);
246 tree arg
= convert_to_real_1 (newtype
, arg0
, fold_p
);
247 expr
= build_call_expr (fn
, 1, arg
);
258 /* Propagate the cast into the operation. */
259 if (itype
!= type
&& FLOAT_TYPE_P (type
))
260 switch (TREE_CODE (expr
))
262 /* Convert (float)-x into -(float)x. This is safe for
263 round-to-nearest rounding mode when the inner type is float. */
266 if (!flag_rounding_math
267 && FLOAT_TYPE_P (itype
)
268 && TYPE_PRECISION (type
) < TYPE_PRECISION (itype
))
270 tree arg
= convert_to_real_1 (type
, TREE_OPERAND (expr
, 0),
272 return build1 (TREE_CODE (expr
), type
, arg
);
275 /* Convert (outertype)((innertype0)a+(innertype1)b)
276 into ((newtype)a+(newtype)b) where newtype
277 is the widest mode from all of these. */
283 tree arg0
= strip_float_extensions (TREE_OPERAND (expr
, 0));
284 tree arg1
= strip_float_extensions (TREE_OPERAND (expr
, 1));
286 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
287 && FLOAT_TYPE_P (TREE_TYPE (arg1
))
288 && DECIMAL_FLOAT_TYPE_P (itype
) == DECIMAL_FLOAT_TYPE_P (type
))
292 if (TYPE_MODE (TREE_TYPE (arg0
)) == SDmode
293 || TYPE_MODE (TREE_TYPE (arg1
)) == SDmode
294 || TYPE_MODE (type
) == SDmode
)
295 newtype
= dfloat32_type_node
;
296 if (TYPE_MODE (TREE_TYPE (arg0
)) == DDmode
297 || TYPE_MODE (TREE_TYPE (arg1
)) == DDmode
298 || TYPE_MODE (type
) == DDmode
)
299 newtype
= dfloat64_type_node
;
300 if (TYPE_MODE (TREE_TYPE (arg0
)) == TDmode
301 || TYPE_MODE (TREE_TYPE (arg1
)) == TDmode
302 || TYPE_MODE (type
) == TDmode
)
303 newtype
= dfloat128_type_node
;
304 if (newtype
== dfloat32_type_node
305 || newtype
== dfloat64_type_node
306 || newtype
== dfloat128_type_node
)
308 expr
= build2 (TREE_CODE (expr
), newtype
,
309 convert_to_real_1 (newtype
, arg0
,
311 convert_to_real_1 (newtype
, arg1
,
318 if (TYPE_PRECISION (TREE_TYPE (arg0
)) > TYPE_PRECISION (newtype
))
319 newtype
= TREE_TYPE (arg0
);
320 if (TYPE_PRECISION (TREE_TYPE (arg1
)) > TYPE_PRECISION (newtype
))
321 newtype
= TREE_TYPE (arg1
);
322 /* Sometimes this transformation is safe (cannot
323 change results through affecting double rounding
324 cases) and sometimes it is not. If NEWTYPE is
325 wider than TYPE, e.g. (float)((long double)double
326 + (long double)double) converted to
327 (float)(double + double), the transformation is
328 unsafe regardless of the details of the types
329 involved; double rounding can arise if the result
330 of NEWTYPE arithmetic is a NEWTYPE value half way
331 between two representable TYPE values but the
332 exact value is sufficiently different (in the
333 right direction) for this difference to be
334 visible in ITYPE arithmetic. If NEWTYPE is the
335 same as TYPE, however, the transformation may be
336 safe depending on the types involved: it is safe
337 if the ITYPE has strictly more than twice as many
338 mantissa bits as TYPE, can represent infinities
339 and NaNs if the TYPE can, and has sufficient
340 exponent range for the product or ratio of two
341 values representable in the TYPE to be within the
342 range of normal values of ITYPE. */
343 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (itype
)
344 && (flag_unsafe_math_optimizations
345 || (TYPE_PRECISION (newtype
) == TYPE_PRECISION (type
)
346 && real_can_shorten_arithmetic (TYPE_MODE (itype
),
348 && !excess_precision_type (newtype
))))
350 expr
= build2 (TREE_CODE (expr
), newtype
,
351 convert_to_real_1 (newtype
, arg0
,
353 convert_to_real_1 (newtype
, arg1
,
365 switch (TREE_CODE (TREE_TYPE (expr
)))
368 /* Ignore the conversion if we don't need to store intermediate
369 results and neither type is a decimal float. */
370 return build1_loc (loc
,
372 || DECIMAL_FLOAT_TYPE_P (type
)
373 || DECIMAL_FLOAT_TYPE_P (itype
))
374 ? CONVERT_EXPR
: NOP_EXPR
, type
, expr
);
379 return build1 (FLOAT_EXPR
, type
, expr
);
381 case FIXED_POINT_TYPE
:
382 return build1 (FIXED_CONVERT_EXPR
, type
, expr
);
385 return convert (type
,
386 maybe_fold_build1_loc (fold_p
, loc
, REALPART_EXPR
,
387 TREE_TYPE (TREE_TYPE (expr
)),
392 error ("pointer value used where a floating point value was expected");
393 return convert_to_real_1 (type
, integer_zero_node
, fold_p
);
396 error ("aggregate value used where a float was expected");
397 return convert_to_real_1 (type
, integer_zero_node
, fold_p
);
401 /* A wrapper around convert_to_real_1 that always folds the
405 convert_to_real (tree type
, tree expr
)
407 return convert_to_real_1 (type
, expr
, true);
410 /* A wrapper around convert_to_real_1 that only folds the
411 expression if DOFOLD, or if it is CONSTANT_CLASS_P. */
414 convert_to_real_maybe_fold (tree type
, tree expr
, bool dofold
)
416 return convert_to_real_1 (type
, expr
, dofold
|| CONSTANT_CLASS_P (expr
));
419 /* Try to narrow EX_FORM ARG0 ARG1 in narrowed arg types producing a
423 do_narrow (location_t loc
,
424 enum tree_code ex_form
, tree type
, tree arg0
, tree arg1
,
425 tree expr
, unsigned inprec
, unsigned outprec
, bool dofold
)
427 /* Do the arithmetic in type TYPEX,
428 then convert result to TYPE. */
431 /* Can't do arithmetic in enumeral types
432 so use an integer type that will hold the values. */
433 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
434 typex
= lang_hooks
.types
.type_for_size (TYPE_PRECISION (typex
),
435 TYPE_UNSIGNED (typex
));
437 /* The type demotion below might cause doing unsigned arithmetic
438 instead of signed, and thus hide overflow bugs. */
439 if ((ex_form
== PLUS_EXPR
|| ex_form
== MINUS_EXPR
)
440 && !TYPE_UNSIGNED (typex
)
441 && sanitize_flags_p (SANITIZE_SI_OVERFLOW
))
444 /* But now perhaps TYPEX is as wide as INPREC.
445 In that case, do nothing special here.
446 (Otherwise would recurse infinitely in convert. */
447 if (TYPE_PRECISION (typex
) != inprec
)
449 /* Don't do unsigned arithmetic where signed was wanted,
451 Exception: if both of the original operands were
452 unsigned then we can safely do the work as unsigned.
453 Exception: shift operations take their type solely
454 from the first argument.
455 Exception: the LSHIFT_EXPR case above requires that
456 we perform this operation unsigned lest we produce
457 signed-overflow undefinedness.
458 And we may need to do it as unsigned
459 if we truncate to the original size. */
460 if (TYPE_UNSIGNED (TREE_TYPE (expr
))
461 || (TYPE_UNSIGNED (TREE_TYPE (arg0
))
462 && (TYPE_UNSIGNED (TREE_TYPE (arg1
))
463 || ex_form
== LSHIFT_EXPR
464 || ex_form
== RSHIFT_EXPR
465 || ex_form
== LROTATE_EXPR
466 || ex_form
== RROTATE_EXPR
))
467 || ex_form
== LSHIFT_EXPR
468 /* If we have !flag_wrapv, and either ARG0 or
469 ARG1 is of a signed type, we have to do
470 PLUS_EXPR, MINUS_EXPR or MULT_EXPR in an unsigned
471 type in case the operation in outprec precision
472 could overflow. Otherwise, we would introduce
473 signed-overflow undefinedness. */
474 || ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0
))
475 || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1
)))
476 && ((TYPE_PRECISION (TREE_TYPE (arg0
)) * 2u
478 || (TYPE_PRECISION (TREE_TYPE (arg1
)) * 2u
480 && (ex_form
== PLUS_EXPR
481 || ex_form
== MINUS_EXPR
482 || ex_form
== MULT_EXPR
)))
484 if (!TYPE_UNSIGNED (typex
))
485 typex
= unsigned_type_for (typex
);
489 if (TYPE_UNSIGNED (typex
))
490 typex
= signed_type_for (typex
);
492 /* We should do away with all this once we have a proper
493 type promotion/demotion pass, see PR45397. */
494 expr
= maybe_fold_build2_loc (dofold
, loc
, ex_form
, typex
,
495 convert (typex
, arg0
),
496 convert (typex
, arg1
));
497 return convert (type
, expr
);
503 /* Convert EXPR to some integer (or enum) type TYPE.
505 EXPR must be pointer, integer, discrete (enum, char, or bool), float,
506 fixed-point or vector; in other cases error is called.
508 If DOFOLD is TRUE, we try to simplify newly-created patterns by folding.
510 The result of this is always supposed to be a newly created tree node
511 not in use in any existing structure. */
514 convert_to_integer_1 (tree type
, tree expr
, bool dofold
)
516 enum tree_code ex_form
= TREE_CODE (expr
);
517 tree intype
= TREE_TYPE (expr
);
518 unsigned int inprec
= element_precision (intype
);
519 unsigned int outprec
= element_precision (type
);
520 location_t loc
= EXPR_LOCATION (expr
);
522 /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
523 be. Consider `enum E = { a, b = (enum E) 3 };'. */
524 if (!COMPLETE_TYPE_P (type
))
526 error ("conversion to incomplete type");
527 return error_mark_node
;
530 if (ex_form
== COMPOUND_EXPR
)
532 tree t
= convert_to_integer_1 (type
, TREE_OPERAND (expr
, 1), dofold
);
533 if (t
== TREE_OPERAND (expr
, 1))
535 return build2_loc (EXPR_LOCATION (expr
), COMPOUND_EXPR
, TREE_TYPE (t
),
536 TREE_OPERAND (expr
, 0), t
);
539 /* Convert e.g. (long)round(d) -> lround(d). */
540 /* If we're converting to char, we may encounter differing behavior
541 between converting from double->char vs double->long->char.
542 We're in "undefined" territory but we prefer to be conservative,
543 so only proceed in "unsafe" math mode. */
545 && (flag_unsafe_math_optimizations
546 || (long_integer_type_node
547 && outprec
>= TYPE_PRECISION (long_integer_type_node
))))
549 tree s_expr
= strip_float_extensions (expr
);
550 tree s_intype
= TREE_TYPE (s_expr
);
551 const enum built_in_function fcode
= builtin_mathfn_code (s_expr
);
556 CASE_FLT_FN (BUILT_IN_CEIL
):
557 CASE_FLT_FN_FLOATN_NX (BUILT_IN_CEIL
):
558 /* Only convert in ISO C99 mode. */
559 if (!targetm
.libc_has_function (function_c99_misc
))
561 if (outprec
< TYPE_PRECISION (integer_type_node
)
562 || (outprec
== TYPE_PRECISION (integer_type_node
)
563 && !TYPE_UNSIGNED (type
)))
564 fn
= mathfn_built_in (s_intype
, BUILT_IN_ICEIL
);
565 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
566 && !TYPE_UNSIGNED (type
))
567 fn
= mathfn_built_in (s_intype
, BUILT_IN_LCEIL
);
568 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
569 && !TYPE_UNSIGNED (type
))
570 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLCEIL
);
573 CASE_FLT_FN (BUILT_IN_FLOOR
):
574 CASE_FLT_FN_FLOATN_NX (BUILT_IN_FLOOR
):
575 /* Only convert in ISO C99 mode. */
576 if (!targetm
.libc_has_function (function_c99_misc
))
578 if (outprec
< TYPE_PRECISION (integer_type_node
)
579 || (outprec
== TYPE_PRECISION (integer_type_node
)
580 && !TYPE_UNSIGNED (type
)))
581 fn
= mathfn_built_in (s_intype
, BUILT_IN_IFLOOR
);
582 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
583 && !TYPE_UNSIGNED (type
))
584 fn
= mathfn_built_in (s_intype
, BUILT_IN_LFLOOR
);
585 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
586 && !TYPE_UNSIGNED (type
))
587 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLFLOOR
);
590 CASE_FLT_FN (BUILT_IN_ROUND
):
591 CASE_FLT_FN_FLOATN_NX (BUILT_IN_ROUND
):
592 /* Only convert in ISO C99 mode and with -fno-math-errno. */
593 if (!targetm
.libc_has_function (function_c99_misc
) || flag_errno_math
)
595 if (outprec
< TYPE_PRECISION (integer_type_node
)
596 || (outprec
== TYPE_PRECISION (integer_type_node
)
597 && !TYPE_UNSIGNED (type
)))
598 fn
= mathfn_built_in (s_intype
, BUILT_IN_IROUND
);
599 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
600 && !TYPE_UNSIGNED (type
))
601 fn
= mathfn_built_in (s_intype
, BUILT_IN_LROUND
);
602 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
603 && !TYPE_UNSIGNED (type
))
604 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLROUND
);
607 CASE_FLT_FN (BUILT_IN_NEARBYINT
):
608 CASE_FLT_FN_FLOATN_NX (BUILT_IN_NEARBYINT
):
609 /* Only convert nearbyint* if we can ignore math exceptions. */
610 if (flag_trapping_math
)
613 CASE_FLT_FN (BUILT_IN_RINT
):
614 CASE_FLT_FN_FLOATN_NX (BUILT_IN_RINT
):
615 /* Only convert in ISO C99 mode and with -fno-math-errno. */
616 if (!targetm
.libc_has_function (function_c99_misc
) || flag_errno_math
)
618 if (outprec
< TYPE_PRECISION (integer_type_node
)
619 || (outprec
== TYPE_PRECISION (integer_type_node
)
620 && !TYPE_UNSIGNED (type
)))
621 fn
= mathfn_built_in (s_intype
, BUILT_IN_IRINT
);
622 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
623 && !TYPE_UNSIGNED (type
))
624 fn
= mathfn_built_in (s_intype
, BUILT_IN_LRINT
);
625 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
626 && !TYPE_UNSIGNED (type
))
627 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLRINT
);
630 CASE_FLT_FN (BUILT_IN_TRUNC
):
631 CASE_FLT_FN_FLOATN_NX (BUILT_IN_TRUNC
):
632 return convert_to_integer_1 (type
, CALL_EXPR_ARG (s_expr
, 0), dofold
);
640 tree newexpr
= build_call_expr (fn
, 1, CALL_EXPR_ARG (s_expr
, 0));
641 return convert_to_integer_1 (type
, newexpr
, dofold
);
645 /* Convert (int)logb(d) -> ilogb(d). */
647 && flag_unsafe_math_optimizations
648 && !flag_trapping_math
&& !flag_errno_math
&& flag_finite_math_only
650 && (outprec
> TYPE_PRECISION (integer_type_node
)
651 || (outprec
== TYPE_PRECISION (integer_type_node
)
652 && !TYPE_UNSIGNED (type
))))
654 tree s_expr
= strip_float_extensions (expr
);
655 tree s_intype
= TREE_TYPE (s_expr
);
656 const enum built_in_function fcode
= builtin_mathfn_code (s_expr
);
661 CASE_FLT_FN (BUILT_IN_LOGB
):
662 fn
= mathfn_built_in (s_intype
, BUILT_IN_ILOGB
);
671 tree newexpr
= build_call_expr (fn
, 1, CALL_EXPR_ARG (s_expr
, 0));
672 return convert_to_integer_1 (type
, newexpr
, dofold
);
676 switch (TREE_CODE (intype
))
680 if (integer_zerop (expr
) && !TREE_OVERFLOW (expr
))
681 return build_int_cst (type
, 0);
683 /* Convert to an unsigned integer of the correct width first, and from
684 there widen/truncate to the required type. Some targets support the
685 coexistence of multiple valid pointer sizes, so fetch the one we need
688 return build1 (CONVERT_EXPR
, type
, expr
);
689 expr
= fold_build1 (CONVERT_EXPR
,
690 lang_hooks
.types
.type_for_size
691 (TYPE_PRECISION (intype
), 0),
693 return fold_convert (type
, expr
);
699 /* If this is a logical operation, which just returns 0 or 1, we can
700 change the type of the expression. */
702 if (TREE_CODE_CLASS (ex_form
) == tcc_comparison
)
704 expr
= copy_node (expr
);
705 TREE_TYPE (expr
) = type
;
709 /* If we are widening the type, put in an explicit conversion.
710 Similarly if we are not changing the width. After this, we know
711 we are truncating EXPR. */
713 else if (outprec
>= inprec
)
717 /* If the precision of the EXPR's type is K bits and the
718 destination mode has more bits, and the sign is changing,
719 it is not safe to use a NOP_EXPR. For example, suppose
720 that EXPR's type is a 3-bit unsigned integer type, the
721 TYPE is a 3-bit signed integer type, and the machine mode
722 for the types is 8-bit QImode. In that case, the
723 conversion necessitates an explicit sign-extension. In
724 the signed-to-unsigned case the high-order bits have to
726 if (TYPE_UNSIGNED (type
) != TYPE_UNSIGNED (TREE_TYPE (expr
))
727 && !type_has_mode_precision_p (TREE_TYPE (expr
)))
732 return maybe_fold_build1_loc (dofold
, loc
, code
, type
, expr
);
735 /* If TYPE is an enumeral type or a type with a precision less
736 than the number of bits in its mode, do the conversion to the
737 type corresponding to its mode, then do a nop conversion
739 else if (TREE_CODE (type
) == ENUMERAL_TYPE
740 || outprec
!= GET_MODE_PRECISION (TYPE_MODE (type
)))
742 expr
= convert (lang_hooks
.types
.type_for_mode
743 (TYPE_MODE (type
), TYPE_UNSIGNED (type
)), expr
);
744 return maybe_fold_build1_loc (dofold
, loc
, NOP_EXPR
, type
, expr
);
747 /* Here detect when we can distribute the truncation down past some
748 arithmetic. For example, if adding two longs and converting to an
749 int, we can equally well convert both to ints and then add.
750 For the operations handled here, such truncation distribution
752 It is desirable in these cases:
753 1) when truncating down to full-word from a larger size
754 2) when truncating takes no work.
755 3) when at least one operand of the arithmetic has been extended
756 (as by C's default conversions). In this case we need two conversions
757 if we do the arithmetic as already requested, so we might as well
758 truncate both and then combine. Perhaps that way we need only one.
760 Note that in general we cannot do the arithmetic in a type
761 shorter than the desired result of conversion, even if the operands
762 are both extended from a shorter type, because they might overflow
763 if combined in that type. The exceptions to this--the times when
764 two narrow values can be combined in their narrow type even to
765 make a wider result--are handled by "shorten" in build_binary_op. */
771 /* We can pass truncation down through right shifting
772 when the shift count is a nonpositive constant. */
773 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
774 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) <= 0)
779 /* We can pass truncation down through left shifting
780 when the shift count is a nonnegative constant and
781 the target type is unsigned. */
782 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
783 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) >= 0
784 && TYPE_UNSIGNED (type
)
785 && TREE_CODE (TYPE_SIZE (type
)) == INTEGER_CST
)
787 /* If shift count is less than the width of the truncated type,
789 if (tree_int_cst_lt (TREE_OPERAND (expr
, 1), TYPE_SIZE (type
)))
790 /* In this case, shifting is like multiplication. */
794 /* If it is >= that width, result is zero.
795 Handling this with trunc1 would give the wrong result:
796 (int) ((long long) a << 32) is well defined (as 0)
797 but (int) a << 32 is undefined and would get a
800 tree t
= build_int_cst (type
, 0);
802 /* If the original expression had side-effects, we must
804 if (TREE_SIDE_EFFECTS (expr
))
805 return build2 (COMPOUND_EXPR
, type
, expr
, t
);
814 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), NULL_TREE
);
815 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), NULL_TREE
);
817 /* Don't distribute unless the output precision is at least as
818 big as the actual inputs and it has the same signedness. */
819 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
820 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
821 /* If signedness of arg0 and arg1 don't match,
822 we can't necessarily find a type to compare them in. */
823 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
824 == TYPE_UNSIGNED (TREE_TYPE (arg1
)))
825 /* Do not change the sign of the division. */
826 && (TYPE_UNSIGNED (TREE_TYPE (expr
))
827 == TYPE_UNSIGNED (TREE_TYPE (arg0
)))
828 /* Either require unsigned division or a division by
829 a constant that is not -1. */
830 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
831 || (TREE_CODE (arg1
) == INTEGER_CST
832 && !integer_all_onesp (arg1
))))
834 tree tem
= do_narrow (loc
, ex_form
, type
, arg0
, arg1
,
835 expr
, inprec
, outprec
, dofold
);
846 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
847 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
849 /* Don't distribute unless the output precision is at least as
850 big as the actual inputs. Otherwise, the comparison of the
851 truncated values will be wrong. */
852 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
853 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
854 /* If signedness of arg0 and arg1 don't match,
855 we can't necessarily find a type to compare them in. */
856 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
857 == TYPE_UNSIGNED (TREE_TYPE (arg1
))))
869 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
870 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
872 /* Do not try to narrow operands of pointer subtraction;
873 that will interfere with other folding. */
874 if (ex_form
== MINUS_EXPR
875 && CONVERT_EXPR_P (arg0
)
876 && CONVERT_EXPR_P (arg1
)
877 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0)))
878 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1
, 0))))
881 if (outprec
>= BITS_PER_WORD
882 || targetm
.truly_noop_truncation (outprec
, inprec
)
883 || inprec
> TYPE_PRECISION (TREE_TYPE (arg0
))
884 || inprec
> TYPE_PRECISION (TREE_TYPE (arg1
)))
886 tree tem
= do_narrow (loc
, ex_form
, type
, arg0
, arg1
,
887 expr
, inprec
, outprec
, dofold
);
895 /* Using unsigned arithmetic for signed types may hide overflow
897 if (!TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (expr
, 0)))
898 && sanitize_flags_p (SANITIZE_SI_OVERFLOW
))
902 /* This is not correct for ABS_EXPR,
903 since we must test the sign before truncation. */
905 /* Do the arithmetic in type TYPEX,
906 then convert result to TYPE. */
909 /* Can't do arithmetic in enumeral types
910 so use an integer type that will hold the values. */
911 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
913 = lang_hooks
.types
.type_for_size (TYPE_PRECISION (typex
),
914 TYPE_UNSIGNED (typex
));
916 if (!TYPE_UNSIGNED (typex
))
917 typex
= unsigned_type_for (typex
);
918 return convert (type
,
919 fold_build1 (ex_form
, typex
,
921 TREE_OPERAND (expr
, 0))));
925 /* Don't introduce a "can't convert between vector values of
926 different size" error. */
927 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == VECTOR_TYPE
928 && (GET_MODE_SIZE (TYPE_MODE
929 (TREE_TYPE (TREE_OPERAND (expr
, 0))))
930 != GET_MODE_SIZE (TYPE_MODE (type
))))
932 /* If truncating after truncating, might as well do all at once.
933 If truncating after extending, we may get rid of wasted work. */
934 return convert (type
, get_unwidened (TREE_OPERAND (expr
, 0), type
));
937 /* It is sometimes worthwhile to push the narrowing down through
938 the conditional and never loses. A COND_EXPR may have a throw
939 as one operand, which then has void type. Just leave void
940 operands as they are. */
942 fold_build3 (COND_EXPR
, type
, TREE_OPERAND (expr
, 0),
943 VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 1)))
944 ? TREE_OPERAND (expr
, 1)
945 : convert (type
, TREE_OPERAND (expr
, 1)),
946 VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 2)))
947 ? TREE_OPERAND (expr
, 2)
948 : convert (type
, TREE_OPERAND (expr
, 2)));
954 /* When parsing long initializers, we might end up with a lot of casts.
956 if (TREE_CODE (expr
) == INTEGER_CST
)
957 return fold_convert (type
, expr
);
958 return build1 (CONVERT_EXPR
, type
, expr
);
961 if (sanitize_flags_p (SANITIZE_FLOAT_CAST
)
962 && current_function_decl
!= NULL_TREE
)
964 expr
= save_expr (expr
);
965 tree check
= ubsan_instrument_float_cast (loc
, type
, expr
);
966 expr
= build1 (FIX_TRUNC_EXPR
, type
, expr
);
967 if (check
== NULL_TREE
)
969 return maybe_fold_build2_loc (dofold
, loc
, COMPOUND_EXPR
,
970 TREE_TYPE (expr
), check
, expr
);
973 return build1 (FIX_TRUNC_EXPR
, type
, expr
);
975 case FIXED_POINT_TYPE
:
976 return build1 (FIXED_CONVERT_EXPR
, type
, expr
);
979 expr
= maybe_fold_build1_loc (dofold
, loc
, REALPART_EXPR
,
980 TREE_TYPE (TREE_TYPE (expr
)), expr
);
981 return convert (type
, expr
);
984 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
986 error ("can%'t convert a vector of type %qT"
987 " to type %qT which has different size",
988 TREE_TYPE (expr
), type
);
989 return error_mark_node
;
991 return build1 (VIEW_CONVERT_EXPR
, type
, expr
);
994 error ("aggregate value used where an integer was expected");
995 return convert (type
, integer_zero_node
);
999 /* Convert EXPR to some integer (or enum) type TYPE.
1001 EXPR must be pointer, integer, discrete (enum, char, or bool), float,
1002 fixed-point or vector; in other cases error is called.
1004 The result of this is always supposed to be a newly created tree node
1005 not in use in any existing structure. */
1008 convert_to_integer (tree type
, tree expr
)
1010 return convert_to_integer_1 (type
, expr
, true);
1013 /* A wrapper around convert_to_complex_1 that only folds the
1014 expression if DOFOLD, or if it is CONSTANT_CLASS_P. */
1017 convert_to_integer_maybe_fold (tree type
, tree expr
, bool dofold
)
1019 return convert_to_integer_1 (type
, expr
, dofold
|| CONSTANT_CLASS_P (expr
));
1022 /* Convert EXPR to the complex type TYPE in the usual ways. If FOLD_P is
1023 true, try to fold the expression. */
1026 convert_to_complex_1 (tree type
, tree expr
, bool fold_p
)
1028 location_t loc
= EXPR_LOCATION (expr
);
1029 tree subtype
= TREE_TYPE (type
);
1031 switch (TREE_CODE (TREE_TYPE (expr
)))
1034 case FIXED_POINT_TYPE
:
1038 return build2 (COMPLEX_EXPR
, type
, convert (subtype
, expr
),
1039 convert (subtype
, integer_zero_node
));
1043 tree elt_type
= TREE_TYPE (TREE_TYPE (expr
));
1045 if (TYPE_MAIN_VARIANT (elt_type
) == TYPE_MAIN_VARIANT (subtype
))
1047 else if (TREE_CODE (expr
) == COMPOUND_EXPR
)
1049 tree t
= convert_to_complex_1 (type
, TREE_OPERAND (expr
, 1),
1051 if (t
== TREE_OPERAND (expr
, 1))
1053 return build2_loc (EXPR_LOCATION (expr
), COMPOUND_EXPR
,
1054 TREE_TYPE (t
), TREE_OPERAND (expr
, 0), t
);
1056 else if (TREE_CODE (expr
) == COMPLEX_EXPR
)
1057 return maybe_fold_build2_loc (fold_p
, loc
, COMPLEX_EXPR
, type
,
1059 TREE_OPERAND (expr
, 0)),
1061 TREE_OPERAND (expr
, 1)));
1064 expr
= save_expr (expr
);
1065 tree realp
= maybe_fold_build1_loc (fold_p
, loc
, REALPART_EXPR
,
1066 TREE_TYPE (TREE_TYPE (expr
)),
1068 tree imagp
= maybe_fold_build1_loc (fold_p
, loc
, IMAGPART_EXPR
,
1069 TREE_TYPE (TREE_TYPE (expr
)),
1071 return maybe_fold_build2_loc (fold_p
, loc
, COMPLEX_EXPR
, type
,
1072 convert (subtype
, realp
),
1073 convert (subtype
, imagp
));
1078 case REFERENCE_TYPE
:
1079 error ("pointer value used where a complex was expected");
1080 return convert_to_complex_1 (type
, integer_zero_node
, fold_p
);
1083 error ("aggregate value used where a complex was expected");
1084 return convert_to_complex_1 (type
, integer_zero_node
, fold_p
);
1088 /* A wrapper around convert_to_complex_1 that always folds the
1092 convert_to_complex (tree type
, tree expr
)
1094 return convert_to_complex_1 (type
, expr
, true);
1097 /* A wrapper around convert_to_complex_1 that only folds the
1098 expression if DOFOLD, or if it is CONSTANT_CLASS_P. */
1101 convert_to_complex_maybe_fold (tree type
, tree expr
, bool dofold
)
1103 return convert_to_complex_1 (type
, expr
, dofold
|| CONSTANT_CLASS_P (expr
));
1106 /* Convert EXPR to the vector type TYPE in the usual ways. */
1109 convert_to_vector (tree type
, tree expr
)
1111 switch (TREE_CODE (TREE_TYPE (expr
)))
1115 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
1117 error ("can%'t convert a value of type %qT"
1118 " to vector type %qT which has different size",
1119 TREE_TYPE (expr
), type
);
1120 return error_mark_node
;
1122 return build1 (VIEW_CONVERT_EXPR
, type
, expr
);
1125 error ("can%'t convert value to a vector");
1126 return error_mark_node
;
1130 /* Convert EXPR to some fixed-point type TYPE.
1132 EXPR must be fixed-point, float, integer, or enumeral;
1133 in other cases error is called. */
1136 convert_to_fixed (tree type
, tree expr
)
1138 if (integer_zerop (expr
))
1140 tree fixed_zero_node
= build_fixed (type
, FCONST0 (TYPE_MODE (type
)));
1141 return fixed_zero_node
;
1143 else if (integer_onep (expr
) && ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type
)))
1145 tree fixed_one_node
= build_fixed (type
, FCONST1 (TYPE_MODE (type
)));
1146 return fixed_one_node
;
1149 switch (TREE_CODE (TREE_TYPE (expr
)))
1151 case FIXED_POINT_TYPE
:
1156 return build1 (FIXED_CONVERT_EXPR
, type
, expr
);
1159 return convert (type
,
1160 fold_build1 (REALPART_EXPR
,
1161 TREE_TYPE (TREE_TYPE (expr
)), expr
));
1164 error ("aggregate value used where a fixed-point was expected");
1165 return error_mark_node
;