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 /* But now perhaps TYPEX is as wide as INPREC.
438 In that case, do nothing special here.
439 (Otherwise would recurse infinitely in convert. */
440 if (TYPE_PRECISION (typex
) != inprec
)
442 /* Don't do unsigned arithmetic where signed was wanted,
444 Exception: if both of the original operands were
445 unsigned then we can safely do the work as unsigned.
446 Exception: shift operations take their type solely
447 from the first argument.
448 Exception: the LSHIFT_EXPR case above requires that
449 we perform this operation unsigned lest we produce
450 signed-overflow undefinedness.
451 And we may need to do it as unsigned
452 if we truncate to the original size. */
453 if (TYPE_UNSIGNED (TREE_TYPE (expr
))
454 || (TYPE_UNSIGNED (TREE_TYPE (arg0
))
455 && (TYPE_UNSIGNED (TREE_TYPE (arg1
))
456 || ex_form
== LSHIFT_EXPR
457 || ex_form
== RSHIFT_EXPR
458 || ex_form
== LROTATE_EXPR
459 || ex_form
== RROTATE_EXPR
))
460 || ex_form
== LSHIFT_EXPR
461 /* If we have !flag_wrapv, and either ARG0 or
462 ARG1 is of a signed type, we have to do
463 PLUS_EXPR, MINUS_EXPR or MULT_EXPR in an unsigned
464 type in case the operation in outprec precision
465 could overflow. Otherwise, we would introduce
466 signed-overflow undefinedness. */
467 || ((!TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg0
))
468 || !TYPE_OVERFLOW_WRAPS (TREE_TYPE (arg1
)))
469 && ((TYPE_PRECISION (TREE_TYPE (arg0
)) * 2u
471 || (TYPE_PRECISION (TREE_TYPE (arg1
)) * 2u
473 && (ex_form
== PLUS_EXPR
474 || ex_form
== MINUS_EXPR
475 || ex_form
== MULT_EXPR
)))
477 if (!TYPE_UNSIGNED (typex
))
478 typex
= unsigned_type_for (typex
);
482 if (TYPE_UNSIGNED (typex
))
483 typex
= signed_type_for (typex
);
485 /* We should do away with all this once we have a proper
486 type promotion/demotion pass, see PR45397. */
487 expr
= maybe_fold_build2_loc (dofold
, loc
, ex_form
, typex
,
488 convert (typex
, arg0
),
489 convert (typex
, arg1
));
490 return convert (type
, expr
);
496 /* Convert EXPR to some integer (or enum) type TYPE.
498 EXPR must be pointer, integer, discrete (enum, char, or bool), float,
499 fixed-point or vector; in other cases error is called.
501 If DOFOLD is TRUE, we try to simplify newly-created patterns by folding.
503 The result of this is always supposed to be a newly created tree node
504 not in use in any existing structure. */
507 convert_to_integer_1 (tree type
, tree expr
, bool dofold
)
509 enum tree_code ex_form
= TREE_CODE (expr
);
510 tree intype
= TREE_TYPE (expr
);
511 unsigned int inprec
= element_precision (intype
);
512 unsigned int outprec
= element_precision (type
);
513 location_t loc
= EXPR_LOCATION (expr
);
515 /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
516 be. Consider `enum E = { a, b = (enum E) 3 };'. */
517 if (!COMPLETE_TYPE_P (type
))
519 error ("conversion to incomplete type");
520 return error_mark_node
;
523 if (ex_form
== COMPOUND_EXPR
)
525 tree t
= convert_to_integer_1 (type
, TREE_OPERAND (expr
, 1), dofold
);
526 if (t
== TREE_OPERAND (expr
, 1))
528 return build2_loc (EXPR_LOCATION (expr
), COMPOUND_EXPR
, TREE_TYPE (t
),
529 TREE_OPERAND (expr
, 0), t
);
532 /* Convert e.g. (long)round(d) -> lround(d). */
533 /* If we're converting to char, we may encounter differing behavior
534 between converting from double->char vs double->long->char.
535 We're in "undefined" territory but we prefer to be conservative,
536 so only proceed in "unsafe" math mode. */
538 && (flag_unsafe_math_optimizations
539 || (long_integer_type_node
540 && outprec
>= TYPE_PRECISION (long_integer_type_node
))))
542 tree s_expr
= strip_float_extensions (expr
);
543 tree s_intype
= TREE_TYPE (s_expr
);
544 const enum built_in_function fcode
= builtin_mathfn_code (s_expr
);
549 CASE_FLT_FN (BUILT_IN_CEIL
):
550 /* Only convert in ISO C99 mode. */
551 if (!targetm
.libc_has_function (function_c99_misc
))
553 if (outprec
< TYPE_PRECISION (integer_type_node
)
554 || (outprec
== TYPE_PRECISION (integer_type_node
)
555 && !TYPE_UNSIGNED (type
)))
556 fn
= mathfn_built_in (s_intype
, BUILT_IN_ICEIL
);
557 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
558 && !TYPE_UNSIGNED (type
))
559 fn
= mathfn_built_in (s_intype
, BUILT_IN_LCEIL
);
560 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
561 && !TYPE_UNSIGNED (type
))
562 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLCEIL
);
565 CASE_FLT_FN (BUILT_IN_FLOOR
):
566 /* Only convert in ISO C99 mode. */
567 if (!targetm
.libc_has_function (function_c99_misc
))
569 if (outprec
< TYPE_PRECISION (integer_type_node
)
570 || (outprec
== TYPE_PRECISION (integer_type_node
)
571 && !TYPE_UNSIGNED (type
)))
572 fn
= mathfn_built_in (s_intype
, BUILT_IN_IFLOOR
);
573 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
574 && !TYPE_UNSIGNED (type
))
575 fn
= mathfn_built_in (s_intype
, BUILT_IN_LFLOOR
);
576 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
577 && !TYPE_UNSIGNED (type
))
578 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLFLOOR
);
581 CASE_FLT_FN (BUILT_IN_ROUND
):
582 /* Only convert in ISO C99 mode and with -fno-math-errno. */
583 if (!targetm
.libc_has_function (function_c99_misc
) || flag_errno_math
)
585 if (outprec
< TYPE_PRECISION (integer_type_node
)
586 || (outprec
== TYPE_PRECISION (integer_type_node
)
587 && !TYPE_UNSIGNED (type
)))
588 fn
= mathfn_built_in (s_intype
, BUILT_IN_IROUND
);
589 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
590 && !TYPE_UNSIGNED (type
))
591 fn
= mathfn_built_in (s_intype
, BUILT_IN_LROUND
);
592 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
593 && !TYPE_UNSIGNED (type
))
594 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLROUND
);
597 CASE_FLT_FN (BUILT_IN_NEARBYINT
):
598 /* Only convert nearbyint* if we can ignore math exceptions. */
599 if (flag_trapping_math
)
602 CASE_FLT_FN (BUILT_IN_RINT
):
603 /* Only convert in ISO C99 mode and with -fno-math-errno. */
604 if (!targetm
.libc_has_function (function_c99_misc
) || flag_errno_math
)
606 if (outprec
< TYPE_PRECISION (integer_type_node
)
607 || (outprec
== TYPE_PRECISION (integer_type_node
)
608 && !TYPE_UNSIGNED (type
)))
609 fn
= mathfn_built_in (s_intype
, BUILT_IN_IRINT
);
610 else if (outprec
== TYPE_PRECISION (long_integer_type_node
)
611 && !TYPE_UNSIGNED (type
))
612 fn
= mathfn_built_in (s_intype
, BUILT_IN_LRINT
);
613 else if (outprec
== TYPE_PRECISION (long_long_integer_type_node
)
614 && !TYPE_UNSIGNED (type
))
615 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLRINT
);
618 CASE_FLT_FN (BUILT_IN_TRUNC
):
619 return convert_to_integer_1 (type
, CALL_EXPR_ARG (s_expr
, 0), dofold
);
627 tree newexpr
= build_call_expr (fn
, 1, CALL_EXPR_ARG (s_expr
, 0));
628 return convert_to_integer_1 (type
, newexpr
, dofold
);
632 /* Convert (int)logb(d) -> ilogb(d). */
634 && flag_unsafe_math_optimizations
635 && !flag_trapping_math
&& !flag_errno_math
&& flag_finite_math_only
637 && (outprec
> TYPE_PRECISION (integer_type_node
)
638 || (outprec
== TYPE_PRECISION (integer_type_node
)
639 && !TYPE_UNSIGNED (type
))))
641 tree s_expr
= strip_float_extensions (expr
);
642 tree s_intype
= TREE_TYPE (s_expr
);
643 const enum built_in_function fcode
= builtin_mathfn_code (s_expr
);
648 CASE_FLT_FN (BUILT_IN_LOGB
):
649 fn
= mathfn_built_in (s_intype
, BUILT_IN_ILOGB
);
658 tree newexpr
= build_call_expr (fn
, 1, CALL_EXPR_ARG (s_expr
, 0));
659 return convert_to_integer_1 (type
, newexpr
, dofold
);
663 switch (TREE_CODE (intype
))
667 if (integer_zerop (expr
))
668 return build_int_cst (type
, 0);
670 /* Convert to an unsigned integer of the correct width first, and from
671 there widen/truncate to the required type. Some targets support the
672 coexistence of multiple valid pointer sizes, so fetch the one we need
675 return build1 (CONVERT_EXPR
, type
, expr
);
676 expr
= fold_build1 (CONVERT_EXPR
,
677 lang_hooks
.types
.type_for_size
678 (TYPE_PRECISION (intype
), 0),
680 return fold_convert (type
, expr
);
686 /* If this is a logical operation, which just returns 0 or 1, we can
687 change the type of the expression. */
689 if (TREE_CODE_CLASS (ex_form
) == tcc_comparison
)
691 expr
= copy_node (expr
);
692 TREE_TYPE (expr
) = type
;
696 /* If we are widening the type, put in an explicit conversion.
697 Similarly if we are not changing the width. After this, we know
698 we are truncating EXPR. */
700 else if (outprec
>= inprec
)
704 /* If the precision of the EXPR's type is K bits and the
705 destination mode has more bits, and the sign is changing,
706 it is not safe to use a NOP_EXPR. For example, suppose
707 that EXPR's type is a 3-bit unsigned integer type, the
708 TYPE is a 3-bit signed integer type, and the machine mode
709 for the types is 8-bit QImode. In that case, the
710 conversion necessitates an explicit sign-extension. In
711 the signed-to-unsigned case the high-order bits have to
713 if (TYPE_UNSIGNED (type
) != TYPE_UNSIGNED (TREE_TYPE (expr
))
714 && (TYPE_PRECISION (TREE_TYPE (expr
))
715 != GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (expr
)))))
720 return maybe_fold_build1_loc (dofold
, loc
, code
, type
, expr
);
723 /* If TYPE is an enumeral type or a type with a precision less
724 than the number of bits in its mode, do the conversion to the
725 type corresponding to its mode, then do a nop conversion
727 else if (TREE_CODE (type
) == ENUMERAL_TYPE
728 || outprec
!= GET_MODE_PRECISION (TYPE_MODE (type
)))
730 expr
= convert (lang_hooks
.types
.type_for_mode
731 (TYPE_MODE (type
), TYPE_UNSIGNED (type
)), expr
);
732 return maybe_fold_build1_loc (dofold
, loc
, NOP_EXPR
, type
, expr
);
735 /* Here detect when we can distribute the truncation down past some
736 arithmetic. For example, if adding two longs and converting to an
737 int, we can equally well convert both to ints and then add.
738 For the operations handled here, such truncation distribution
740 It is desirable in these cases:
741 1) when truncating down to full-word from a larger size
742 2) when truncating takes no work.
743 3) when at least one operand of the arithmetic has been extended
744 (as by C's default conversions). In this case we need two conversions
745 if we do the arithmetic as already requested, so we might as well
746 truncate both and then combine. Perhaps that way we need only one.
748 Note that in general we cannot do the arithmetic in a type
749 shorter than the desired result of conversion, even if the operands
750 are both extended from a shorter type, because they might overflow
751 if combined in that type. The exceptions to this--the times when
752 two narrow values can be combined in their narrow type even to
753 make a wider result--are handled by "shorten" in build_binary_op. */
759 /* We can pass truncation down through right shifting
760 when the shift count is a nonpositive constant. */
761 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
762 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) <= 0)
767 /* We can pass truncation down through left shifting
768 when the shift count is a nonnegative constant and
769 the target type is unsigned. */
770 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
771 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) >= 0
772 && TYPE_UNSIGNED (type
)
773 && TREE_CODE (TYPE_SIZE (type
)) == INTEGER_CST
)
775 /* If shift count is less than the width of the truncated type,
777 if (tree_int_cst_lt (TREE_OPERAND (expr
, 1), TYPE_SIZE (type
)))
778 /* In this case, shifting is like multiplication. */
782 /* If it is >= that width, result is zero.
783 Handling this with trunc1 would give the wrong result:
784 (int) ((long long) a << 32) is well defined (as 0)
785 but (int) a << 32 is undefined and would get a
788 tree t
= build_int_cst (type
, 0);
790 /* If the original expression had side-effects, we must
792 if (TREE_SIDE_EFFECTS (expr
))
793 return build2 (COMPOUND_EXPR
, type
, expr
, t
);
802 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), NULL_TREE
);
803 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), NULL_TREE
);
805 /* Don't distribute unless the output precision is at least as
806 big as the actual inputs and it has the same signedness. */
807 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
808 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
809 /* If signedness of arg0 and arg1 don't match,
810 we can't necessarily find a type to compare them in. */
811 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
812 == TYPE_UNSIGNED (TREE_TYPE (arg1
)))
813 /* Do not change the sign of the division. */
814 && (TYPE_UNSIGNED (TREE_TYPE (expr
))
815 == TYPE_UNSIGNED (TREE_TYPE (arg0
)))
816 /* Either require unsigned division or a division by
817 a constant that is not -1. */
818 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
819 || (TREE_CODE (arg1
) == INTEGER_CST
820 && !integer_all_onesp (arg1
))))
822 tree tem
= do_narrow (loc
, ex_form
, type
, arg0
, arg1
,
823 expr
, inprec
, outprec
, dofold
);
834 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
835 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
837 /* Don't distribute unless the output precision is at least as
838 big as the actual inputs. Otherwise, the comparison of the
839 truncated values will be wrong. */
840 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
841 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
842 /* If signedness of arg0 and arg1 don't match,
843 we can't necessarily find a type to compare them in. */
844 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
845 == TYPE_UNSIGNED (TREE_TYPE (arg1
))))
857 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
858 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
860 /* Do not try to narrow operands of pointer subtraction;
861 that will interfere with other folding. */
862 if (ex_form
== MINUS_EXPR
863 && CONVERT_EXPR_P (arg0
)
864 && CONVERT_EXPR_P (arg1
)
865 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0)))
866 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg1
, 0))))
869 if (outprec
>= BITS_PER_WORD
870 || TRULY_NOOP_TRUNCATION (outprec
, inprec
)
871 || inprec
> TYPE_PRECISION (TREE_TYPE (arg0
))
872 || inprec
> TYPE_PRECISION (TREE_TYPE (arg1
)))
874 tree tem
= do_narrow (loc
, ex_form
, type
, arg0
, arg1
,
875 expr
, inprec
, outprec
, dofold
);
884 /* This is not correct for ABS_EXPR,
885 since we must test the sign before truncation. */
887 /* Do the arithmetic in type TYPEX,
888 then convert result to TYPE. */
891 /* Can't do arithmetic in enumeral types
892 so use an integer type that will hold the values. */
893 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
895 = lang_hooks
.types
.type_for_size (TYPE_PRECISION (typex
),
896 TYPE_UNSIGNED (typex
));
898 if (!TYPE_UNSIGNED (typex
))
899 typex
= unsigned_type_for (typex
);
900 return convert (type
,
901 fold_build1 (ex_form
, typex
,
903 TREE_OPERAND (expr
, 0))));
907 /* Don't introduce a "can't convert between vector values of
908 different size" error. */
909 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == VECTOR_TYPE
910 && (GET_MODE_SIZE (TYPE_MODE
911 (TREE_TYPE (TREE_OPERAND (expr
, 0))))
912 != GET_MODE_SIZE (TYPE_MODE (type
))))
914 /* If truncating after truncating, might as well do all at once.
915 If truncating after extending, we may get rid of wasted work. */
916 return convert (type
, get_unwidened (TREE_OPERAND (expr
, 0), type
));
919 /* It is sometimes worthwhile to push the narrowing down through
920 the conditional and never loses. A COND_EXPR may have a throw
921 as one operand, which then has void type. Just leave void
922 operands as they are. */
924 fold_build3 (COND_EXPR
, type
, TREE_OPERAND (expr
, 0),
925 VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 1)))
926 ? TREE_OPERAND (expr
, 1)
927 : convert (type
, TREE_OPERAND (expr
, 1)),
928 VOID_TYPE_P (TREE_TYPE (TREE_OPERAND (expr
, 2)))
929 ? TREE_OPERAND (expr
, 2)
930 : convert (type
, TREE_OPERAND (expr
, 2)));
936 /* When parsing long initializers, we might end up with a lot of casts.
938 if (TREE_CODE (expr
) == INTEGER_CST
)
939 return fold_convert (type
, expr
);
940 return build1 (CONVERT_EXPR
, type
, expr
);
943 if (sanitize_flags_p (SANITIZE_FLOAT_CAST
)
944 && current_function_decl
!= NULL_TREE
)
946 expr
= save_expr (expr
);
947 tree check
= ubsan_instrument_float_cast (loc
, type
, expr
);
948 expr
= build1 (FIX_TRUNC_EXPR
, type
, expr
);
949 if (check
== NULL_TREE
)
951 return maybe_fold_build2_loc (dofold
, loc
, COMPOUND_EXPR
,
952 TREE_TYPE (expr
), check
, expr
);
955 return build1 (FIX_TRUNC_EXPR
, type
, expr
);
957 case FIXED_POINT_TYPE
:
958 return build1 (FIXED_CONVERT_EXPR
, type
, expr
);
961 expr
= maybe_fold_build1_loc (dofold
, loc
, REALPART_EXPR
,
962 TREE_TYPE (TREE_TYPE (expr
)), expr
);
963 return convert (type
, expr
);
966 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
968 error ("can%'t convert a vector of type %qT"
969 " to type %qT which has different size",
970 TREE_TYPE (expr
), type
);
971 return error_mark_node
;
973 return build1 (VIEW_CONVERT_EXPR
, type
, expr
);
976 error ("aggregate value used where an integer was expected");
977 return convert (type
, integer_zero_node
);
981 /* Convert EXPR to some integer (or enum) type TYPE.
983 EXPR must be pointer, integer, discrete (enum, char, or bool), float,
984 fixed-point or vector; in other cases error is called.
986 The result of this is always supposed to be a newly created tree node
987 not in use in any existing structure. */
990 convert_to_integer (tree type
, tree expr
)
992 return convert_to_integer_1 (type
, expr
, true);
995 /* A wrapper around convert_to_complex_1 that only folds the
996 expression if DOFOLD, or if it is CONSTANT_CLASS_P. */
999 convert_to_integer_maybe_fold (tree type
, tree expr
, bool dofold
)
1001 return convert_to_integer_1 (type
, expr
, dofold
|| CONSTANT_CLASS_P (expr
));
1004 /* Convert EXPR to the complex type TYPE in the usual ways. If FOLD_P is
1005 true, try to fold the expression. */
1008 convert_to_complex_1 (tree type
, tree expr
, bool fold_p
)
1010 location_t loc
= EXPR_LOCATION (expr
);
1011 tree subtype
= TREE_TYPE (type
);
1013 switch (TREE_CODE (TREE_TYPE (expr
)))
1016 case FIXED_POINT_TYPE
:
1020 return build2 (COMPLEX_EXPR
, type
, convert (subtype
, expr
),
1021 convert (subtype
, integer_zero_node
));
1025 tree elt_type
= TREE_TYPE (TREE_TYPE (expr
));
1027 if (TYPE_MAIN_VARIANT (elt_type
) == TYPE_MAIN_VARIANT (subtype
))
1029 else if (TREE_CODE (expr
) == COMPOUND_EXPR
)
1031 tree t
= convert_to_complex_1 (type
, TREE_OPERAND (expr
, 1),
1033 if (t
== TREE_OPERAND (expr
, 1))
1035 return build2_loc (EXPR_LOCATION (expr
), COMPOUND_EXPR
,
1036 TREE_TYPE (t
), TREE_OPERAND (expr
, 0), t
);
1038 else if (TREE_CODE (expr
) == COMPLEX_EXPR
)
1039 return maybe_fold_build2_loc (fold_p
, loc
, COMPLEX_EXPR
, type
,
1041 TREE_OPERAND (expr
, 0)),
1043 TREE_OPERAND (expr
, 1)));
1046 expr
= save_expr (expr
);
1047 tree realp
= maybe_fold_build1_loc (fold_p
, loc
, REALPART_EXPR
,
1048 TREE_TYPE (TREE_TYPE (expr
)),
1050 tree imagp
= maybe_fold_build1_loc (fold_p
, loc
, IMAGPART_EXPR
,
1051 TREE_TYPE (TREE_TYPE (expr
)),
1053 return maybe_fold_build2_loc (fold_p
, loc
, COMPLEX_EXPR
, type
,
1054 convert (subtype
, realp
),
1055 convert (subtype
, imagp
));
1060 case REFERENCE_TYPE
:
1061 error ("pointer value used where a complex was expected");
1062 return convert_to_complex_1 (type
, integer_zero_node
, fold_p
);
1065 error ("aggregate value used where a complex was expected");
1066 return convert_to_complex_1 (type
, integer_zero_node
, fold_p
);
1070 /* A wrapper around convert_to_complex_1 that always folds the
1074 convert_to_complex (tree type
, tree expr
)
1076 return convert_to_complex_1 (type
, expr
, true);
1079 /* A wrapper around convert_to_complex_1 that only folds the
1080 expression if DOFOLD, or if it is CONSTANT_CLASS_P. */
1083 convert_to_complex_maybe_fold (tree type
, tree expr
, bool dofold
)
1085 return convert_to_complex_1 (type
, expr
, dofold
|| CONSTANT_CLASS_P (expr
));
1088 /* Convert EXPR to the vector type TYPE in the usual ways. */
1091 convert_to_vector (tree type
, tree expr
)
1093 switch (TREE_CODE (TREE_TYPE (expr
)))
1097 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
1099 error ("can%'t convert a value of type %qT"
1100 " to vector type %qT which has different size",
1101 TREE_TYPE (expr
), type
);
1102 return error_mark_node
;
1104 return build1 (VIEW_CONVERT_EXPR
, type
, expr
);
1107 error ("can%'t convert value to a vector");
1108 return error_mark_node
;
1112 /* Convert EXPR to some fixed-point type TYPE.
1114 EXPR must be fixed-point, float, integer, or enumeral;
1115 in other cases error is called. */
1118 convert_to_fixed (tree type
, tree expr
)
1120 if (integer_zerop (expr
))
1122 tree fixed_zero_node
= build_fixed (type
, FCONST0 (TYPE_MODE (type
)));
1123 return fixed_zero_node
;
1125 else if (integer_onep (expr
) && ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type
)))
1127 tree fixed_one_node
= build_fixed (type
, FCONST1 (TYPE_MODE (type
)));
1128 return fixed_one_node
;
1131 switch (TREE_CODE (TREE_TYPE (expr
)))
1133 case FIXED_POINT_TYPE
:
1138 return build1 (FIXED_CONVERT_EXPR
, type
, expr
);
1141 return convert (type
,
1142 fold_build1 (REALPART_EXPR
,
1143 TREE_TYPE (TREE_TYPE (expr
)), expr
));
1146 error ("aggregate value used where a fixed-point was expected");
1147 return error_mark_node
;