1 /* Utility routines for data type conversion for GCC.
2 Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1997, 1998,
3 2000, 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
23 /* These routines are somewhat language-independent utility function
24 intended to be called by the language-specific convert () functions. */
28 #include "coretypes.h"
34 #include "langhooks.h"
36 /* Convert EXPR to some pointer or reference type TYPE.
38 EXPR must be pointer, reference, integer, enumeral, or literal zero;
39 in other cases error is called. */
42 convert_to_pointer (tree type
, tree expr
)
44 if (integer_zerop (expr
))
46 expr
= build_int_cst (type
, 0);
50 switch (TREE_CODE (TREE_TYPE (expr
)))
54 return build1 (NOP_EXPR
, type
, expr
);
60 if (TYPE_PRECISION (TREE_TYPE (expr
)) == POINTER_SIZE
)
61 return build1 (CONVERT_EXPR
, type
, expr
);
64 convert_to_pointer (type
,
65 convert (lang_hooks
.types
.type_for_size
66 (POINTER_SIZE
, 0), expr
));
69 error ("cannot convert to a pointer type");
70 return convert_to_pointer (type
, integer_zero_node
);
74 /* Avoid any floating point extensions from EXP. */
76 strip_float_extensions (tree exp
)
80 /* For floating point constant look up the narrowest type that can hold
81 it properly and handle it like (type)(narrowest_type)constant.
82 This way we can optimize for instance a=a*2.0 where "a" is float
83 but 2.0 is double constant. */
84 if (TREE_CODE (exp
) == REAL_CST
)
89 orig
= TREE_REAL_CST (exp
);
90 if (TYPE_PRECISION (TREE_TYPE (exp
)) > TYPE_PRECISION (float_type_node
)
91 && exact_real_truncate (TYPE_MODE (float_type_node
), &orig
))
92 type
= float_type_node
;
93 else if (TYPE_PRECISION (TREE_TYPE (exp
))
94 > TYPE_PRECISION (double_type_node
)
95 && exact_real_truncate (TYPE_MODE (double_type_node
), &orig
))
96 type
= double_type_node
;
98 return build_real (type
, real_value_truncate (TYPE_MODE (type
), orig
));
101 if (TREE_CODE (exp
) != NOP_EXPR
102 && TREE_CODE (exp
) != CONVERT_EXPR
)
105 sub
= TREE_OPERAND (exp
, 0);
106 subt
= TREE_TYPE (sub
);
107 expt
= TREE_TYPE (exp
);
109 if (!FLOAT_TYPE_P (subt
))
112 if (TYPE_PRECISION (subt
) > TYPE_PRECISION (expt
))
115 return strip_float_extensions (sub
);
119 /* Convert EXPR to some floating-point type TYPE.
121 EXPR must be float, integer, or enumeral;
122 in other cases error is called. */
125 convert_to_real (tree type
, tree expr
)
127 enum built_in_function fcode
= builtin_mathfn_code (expr
);
128 tree itype
= TREE_TYPE (expr
);
130 /* Disable until we figure out how to decide whether the functions are
131 present in runtime. */
132 /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */
134 && (TYPE_MODE (type
) == TYPE_MODE (double_type_node
)
135 || TYPE_MODE (type
) == TYPE_MODE (float_type_node
)))
139 #define CASE_MATHFN(FN) case BUILT_IN_##FN: case BUILT_IN_##FN##L:
176 tree arg0
= strip_float_extensions (TREE_VALUE (TREE_OPERAND (expr
, 1)));
179 /* We have (outertype)sqrt((innertype)x). Choose the wider mode from
180 the both as the safe type for operation. */
181 if (TYPE_PRECISION (TREE_TYPE (arg0
)) > TYPE_PRECISION (type
))
182 newtype
= TREE_TYPE (arg0
);
184 /* Be careful about integer to fp conversions.
185 These may overflow still. */
186 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
187 && TYPE_PRECISION (newtype
) < TYPE_PRECISION (itype
)
188 && (TYPE_MODE (newtype
) == TYPE_MODE (double_type_node
)
189 || TYPE_MODE (newtype
) == TYPE_MODE (float_type_node
)))
192 tree fn
= mathfn_built_in (newtype
, fcode
);
196 arglist
= build_tree_list (NULL_TREE
, fold (convert_to_real (newtype
, arg0
)));
197 expr
= build_function_call_expr (fn
, arglist
);
208 && (((fcode
== BUILT_IN_FLOORL
209 || fcode
== BUILT_IN_CEILL
210 || fcode
== BUILT_IN_ROUNDL
211 || fcode
== BUILT_IN_RINTL
212 || fcode
== BUILT_IN_TRUNCL
213 || fcode
== BUILT_IN_NEARBYINTL
)
214 && (TYPE_MODE (type
) == TYPE_MODE (double_type_node
)
215 || TYPE_MODE (type
) == TYPE_MODE (float_type_node
)))
216 || ((fcode
== BUILT_IN_FLOOR
217 || fcode
== BUILT_IN_CEIL
218 || fcode
== BUILT_IN_ROUND
219 || fcode
== BUILT_IN_RINT
220 || fcode
== BUILT_IN_TRUNC
221 || fcode
== BUILT_IN_NEARBYINT
)
222 && (TYPE_MODE (type
) == TYPE_MODE (float_type_node
)))))
224 tree fn
= mathfn_built_in (type
, fcode
);
228 tree arg0
= strip_float_extensions (TREE_VALUE (TREE_OPERAND (expr
,
230 tree arglist
= build_tree_list (NULL_TREE
,
231 fold (convert_to_real (type
, arg0
)));
233 return build_function_call_expr (fn
, arglist
);
237 /* Propagate the cast into the operation. */
238 if (itype
!= type
&& FLOAT_TYPE_P (type
))
239 switch (TREE_CODE (expr
))
241 /* Convert (float)-x into -(float)x. This is always safe. */
244 if (TYPE_PRECISION (type
) < TYPE_PRECISION (TREE_TYPE (expr
)))
245 return build1 (TREE_CODE (expr
), type
,
246 fold (convert_to_real (type
,
247 TREE_OPERAND (expr
, 0))));
249 /* Convert (outertype)((innertype0)a+(innertype1)b)
250 into ((newtype)a+(newtype)b) where newtype
251 is the widest mode from all of these. */
257 tree arg0
= strip_float_extensions (TREE_OPERAND (expr
, 0));
258 tree arg1
= strip_float_extensions (TREE_OPERAND (expr
, 1));
260 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
261 && FLOAT_TYPE_P (TREE_TYPE (arg1
)))
264 if (TYPE_PRECISION (TREE_TYPE (arg0
)) > TYPE_PRECISION (newtype
))
265 newtype
= TREE_TYPE (arg0
);
266 if (TYPE_PRECISION (TREE_TYPE (arg1
)) > TYPE_PRECISION (newtype
))
267 newtype
= TREE_TYPE (arg1
);
268 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (itype
))
270 expr
= build2 (TREE_CODE (expr
), newtype
,
271 fold (convert_to_real (newtype
, arg0
)),
272 fold (convert_to_real (newtype
, arg1
)));
283 switch (TREE_CODE (TREE_TYPE (expr
)))
286 return build1 (flag_float_store
? CONVERT_EXPR
: NOP_EXPR
,
293 return build1 (FLOAT_EXPR
, type
, expr
);
296 return convert (type
,
297 fold (build1 (REALPART_EXPR
,
298 TREE_TYPE (TREE_TYPE (expr
)), expr
)));
302 error ("pointer value used where a floating point value was expected");
303 return convert_to_real (type
, integer_zero_node
);
306 error ("aggregate value used where a float was expected");
307 return convert_to_real (type
, integer_zero_node
);
311 /* Convert EXPR to some integer (or enum) type TYPE.
313 EXPR must be pointer, integer, discrete (enum, char, or bool), float, or
314 vector; in other cases error is called.
316 The result of this is always supposed to be a newly created tree node
317 not in use in any existing structure. */
320 convert_to_integer (tree type
, tree expr
)
322 enum tree_code ex_form
= TREE_CODE (expr
);
323 tree intype
= TREE_TYPE (expr
);
324 unsigned int inprec
= TYPE_PRECISION (intype
);
325 unsigned int outprec
= TYPE_PRECISION (type
);
327 /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
328 be. Consider `enum E = { a, b = (enum E) 3 };'. */
329 if (!COMPLETE_TYPE_P (type
))
331 error ("conversion to incomplete type");
332 return error_mark_node
;
335 /* Convert e.g. (long)round(d) -> lround(d). */
336 /* If we're converting to char, we may encounter differing behavior
337 between converting from double->char vs double->long->char.
338 We're in "undefined" territory but we prefer to be conservative,
339 so only proceed in "unsafe" math mode. */
341 && (flag_unsafe_math_optimizations
342 || (long_integer_type_node
343 && outprec
>= TYPE_PRECISION (long_integer_type_node
))))
345 tree s_expr
= strip_float_extensions (expr
);
346 tree s_intype
= TREE_TYPE (s_expr
);
347 const enum built_in_function fcode
= builtin_mathfn_code (s_expr
);
354 /* Only convert in ISO C99 mode. */
355 if (!TARGET_C99_FUNCTIONS
)
357 /* ... Fall through ... */
359 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (long_long_integer_type_node
))
360 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLCEIL
);
362 fn
= mathfn_built_in (s_intype
, BUILT_IN_LCEIL
);
365 case BUILT_IN_FLOORF
:
366 case BUILT_IN_FLOORL
:
367 /* Only convert in ISO C99 mode. */
368 if (!TARGET_C99_FUNCTIONS
)
370 /* ... Fall through ... */
372 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (long_long_integer_type_node
))
373 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLFLOOR
);
375 fn
= mathfn_built_in (s_intype
, BUILT_IN_LFLOOR
);
378 case BUILT_IN_ROUND
: case BUILT_IN_ROUNDF
: case BUILT_IN_ROUNDL
:
379 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (long_long_integer_type_node
))
380 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLROUND
);
382 fn
= mathfn_built_in (s_intype
, BUILT_IN_LROUND
);
385 case BUILT_IN_RINT
: case BUILT_IN_RINTF
: case BUILT_IN_RINTL
:
386 /* Only convert rint* if we can ignore math exceptions. */
387 if (flag_trapping_math
)
389 /* ... Fall through ... */
390 case BUILT_IN_NEARBYINT
: case BUILT_IN_NEARBYINTF
: case BUILT_IN_NEARBYINTL
:
391 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (long_long_integer_type_node
))
392 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLRINT
);
394 fn
= mathfn_built_in (s_intype
, BUILT_IN_LRINT
);
397 case BUILT_IN_TRUNC
: case BUILT_IN_TRUNCF
: case BUILT_IN_TRUNCL
:
399 tree arglist
= TREE_OPERAND (s_expr
, 1);
400 return convert_to_integer (type
, TREE_VALUE (arglist
));
409 tree arglist
= TREE_OPERAND (s_expr
, 1);
410 tree newexpr
= build_function_call_expr (fn
, arglist
);
411 return convert_to_integer (type
, newexpr
);
415 switch (TREE_CODE (intype
))
419 if (integer_zerop (expr
))
420 expr
= integer_zero_node
;
422 expr
= fold (build1 (CONVERT_EXPR
,
423 lang_hooks
.types
.type_for_size (POINTER_SIZE
, 0),
426 return convert_to_integer (type
, expr
);
432 /* If this is a logical operation, which just returns 0 or 1, we can
433 change the type of the expression. */
435 if (TREE_CODE_CLASS (ex_form
) == tcc_comparison
)
437 expr
= copy_node (expr
);
438 TREE_TYPE (expr
) = type
;
442 /* If we are widening the type, put in an explicit conversion.
443 Similarly if we are not changing the width. After this, we know
444 we are truncating EXPR. */
446 else if (outprec
>= inprec
)
450 /* If the precision of the EXPR's type is K bits and the
451 destination mode has more bits, and the sign is changing,
452 it is not safe to use a NOP_EXPR. For example, suppose
453 that EXPR's type is a 3-bit unsigned integer type, the
454 TYPE is a 3-bit signed integer type, and the machine mode
455 for the types is 8-bit QImode. In that case, the
456 conversion necessitates an explicit sign-extension. In
457 the signed-to-unsigned case the high-order bits have to
459 if (TYPE_UNSIGNED (type
) != TYPE_UNSIGNED (TREE_TYPE (expr
))
460 && (TYPE_PRECISION (TREE_TYPE (expr
))
461 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr
)))))
466 return build1 (code
, type
, expr
);
469 /* If TYPE is an enumeral type or a type with a precision less
470 than the number of bits in its mode, do the conversion to the
471 type corresponding to its mode, then do a nop conversion
473 else if (TREE_CODE (type
) == ENUMERAL_TYPE
474 || outprec
!= GET_MODE_BITSIZE (TYPE_MODE (type
)))
475 return build1 (NOP_EXPR
, type
,
476 convert (lang_hooks
.types
.type_for_mode
477 (TYPE_MODE (type
), TYPE_UNSIGNED (type
)),
480 /* Here detect when we can distribute the truncation down past some
481 arithmetic. For example, if adding two longs and converting to an
482 int, we can equally well convert both to ints and then add.
483 For the operations handled here, such truncation distribution
485 It is desirable in these cases:
486 1) when truncating down to full-word from a larger size
487 2) when truncating takes no work.
488 3) when at least one operand of the arithmetic has been extended
489 (as by C's default conversions). In this case we need two conversions
490 if we do the arithmetic as already requested, so we might as well
491 truncate both and then combine. Perhaps that way we need only one.
493 Note that in general we cannot do the arithmetic in a type
494 shorter than the desired result of conversion, even if the operands
495 are both extended from a shorter type, because they might overflow
496 if combined in that type. The exceptions to this--the times when
497 two narrow values can be combined in their narrow type even to
498 make a wider result--are handled by "shorten" in build_binary_op. */
503 /* We can pass truncation down through right shifting
504 when the shift count is a nonpositive constant. */
505 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
506 && tree_int_cst_lt (TREE_OPERAND (expr
, 1),
507 convert (TREE_TYPE (TREE_OPERAND (expr
, 1)),
513 /* We can pass truncation down through left shifting
514 when the shift count is a nonnegative constant and
515 the target type is unsigned. */
516 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
517 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) >= 0
518 && TYPE_UNSIGNED (type
)
519 && TREE_CODE (TYPE_SIZE (type
)) == INTEGER_CST
)
521 /* If shift count is less than the width of the truncated type,
523 if (tree_int_cst_lt (TREE_OPERAND (expr
, 1), TYPE_SIZE (type
)))
524 /* In this case, shifting is like multiplication. */
528 /* If it is >= that width, result is zero.
529 Handling this with trunc1 would give the wrong result:
530 (int) ((long long) a << 32) is well defined (as 0)
531 but (int) a << 32 is undefined and would get a
534 tree t
= convert_to_integer (type
, integer_zero_node
);
536 /* If the original expression had side-effects, we must
538 if (TREE_SIDE_EFFECTS (expr
))
539 return build2 (COMPOUND_EXPR
, type
, expr
, t
);
550 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
551 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
553 /* Don't distribute unless the output precision is at least as big
554 as the actual inputs. Otherwise, the comparison of the
555 truncated values will be wrong. */
556 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
557 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
558 /* If signedness of arg0 and arg1 don't match,
559 we can't necessarily find a type to compare them in. */
560 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
561 == TYPE_UNSIGNED (TREE_TYPE (arg1
))))
573 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
574 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
576 if (outprec
>= BITS_PER_WORD
577 || TRULY_NOOP_TRUNCATION (outprec
, inprec
)
578 || inprec
> TYPE_PRECISION (TREE_TYPE (arg0
))
579 || inprec
> TYPE_PRECISION (TREE_TYPE (arg1
)))
581 /* Do the arithmetic in type TYPEX,
582 then convert result to TYPE. */
585 /* Can't do arithmetic in enumeral types
586 so use an integer type that will hold the values. */
587 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
588 typex
= lang_hooks
.types
.type_for_size
589 (TYPE_PRECISION (typex
), TYPE_UNSIGNED (typex
));
591 /* But now perhaps TYPEX is as wide as INPREC.
592 In that case, do nothing special here.
593 (Otherwise would recurse infinitely in convert. */
594 if (TYPE_PRECISION (typex
) != inprec
)
596 /* Don't do unsigned arithmetic where signed was wanted,
598 Exception: if both of the original operands were
599 unsigned then we can safely do the work as unsigned.
600 Exception: shift operations take their type solely
601 from the first argument.
602 Exception: the LSHIFT_EXPR case above requires that
603 we perform this operation unsigned lest we produce
604 signed-overflow undefinedness.
605 And we may need to do it as unsigned
606 if we truncate to the original size. */
607 if (TYPE_UNSIGNED (TREE_TYPE (expr
))
608 || (TYPE_UNSIGNED (TREE_TYPE (arg0
))
609 && (TYPE_UNSIGNED (TREE_TYPE (arg1
))
610 || ex_form
== LSHIFT_EXPR
611 || ex_form
== RSHIFT_EXPR
612 || ex_form
== LROTATE_EXPR
613 || ex_form
== RROTATE_EXPR
))
614 || ex_form
== LSHIFT_EXPR
)
615 typex
= lang_hooks
.types
.unsigned_type (typex
);
617 typex
= lang_hooks
.types
.signed_type (typex
);
618 return convert (type
,
619 fold (build2 (ex_form
, typex
,
620 convert (typex
, arg0
),
621 convert (typex
, arg1
))));
629 /* This is not correct for ABS_EXPR,
630 since we must test the sign before truncation. */
634 /* Can't do arithmetic in enumeral types
635 so use an integer type that will hold the values. */
636 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
637 typex
= lang_hooks
.types
.type_for_size
638 (TYPE_PRECISION (typex
), TYPE_UNSIGNED (typex
));
640 /* But now perhaps TYPEX is as wide as INPREC.
641 In that case, do nothing special here.
642 (Otherwise would recurse infinitely in convert. */
643 if (TYPE_PRECISION (typex
) != inprec
)
645 /* Don't do unsigned arithmetic where signed was wanted,
647 if (TYPE_UNSIGNED (TREE_TYPE (expr
)))
648 typex
= lang_hooks
.types
.unsigned_type (typex
);
650 typex
= lang_hooks
.types
.signed_type (typex
);
651 return convert (type
,
652 fold (build1 (ex_form
, typex
,
654 TREE_OPERAND (expr
, 0)))));
660 "can't convert between vector values of different size" error. */
661 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == VECTOR_TYPE
662 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr
, 0))))
663 != GET_MODE_SIZE (TYPE_MODE (type
))))
665 /* If truncating after truncating, might as well do all at once.
666 If truncating after extending, we may get rid of wasted work. */
667 return convert (type
, get_unwidened (TREE_OPERAND (expr
, 0), type
));
670 /* It is sometimes worthwhile to push the narrowing down through
671 the conditional and never loses. */
672 return fold (build3 (COND_EXPR
, type
, TREE_OPERAND (expr
, 0),
673 convert (type
, TREE_OPERAND (expr
, 1)),
674 convert (type
, TREE_OPERAND (expr
, 2))));
680 return build1 (CONVERT_EXPR
, type
, expr
);
683 return build1 (FIX_TRUNC_EXPR
, type
, expr
);
686 return convert (type
,
687 fold (build1 (REALPART_EXPR
,
688 TREE_TYPE (TREE_TYPE (expr
)), expr
)));
691 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
693 error ("can't convert between vector values of different size");
694 return error_mark_node
;
696 return build1 (NOP_EXPR
, type
, expr
);
699 error ("aggregate value used where an integer was expected");
700 return convert (type
, integer_zero_node
);
704 /* Convert EXPR to the complex type TYPE in the usual ways. */
707 convert_to_complex (tree type
, tree expr
)
709 tree subtype
= TREE_TYPE (type
);
711 switch (TREE_CODE (TREE_TYPE (expr
)))
718 return build2 (COMPLEX_EXPR
, type
, convert (subtype
, expr
),
719 convert (subtype
, integer_zero_node
));
723 tree elt_type
= TREE_TYPE (TREE_TYPE (expr
));
725 if (TYPE_MAIN_VARIANT (elt_type
) == TYPE_MAIN_VARIANT (subtype
))
727 else if (TREE_CODE (expr
) == COMPLEX_EXPR
)
728 return fold (build2 (COMPLEX_EXPR
, type
,
729 convert (subtype
, TREE_OPERAND (expr
, 0)),
730 convert (subtype
, TREE_OPERAND (expr
, 1))));
733 expr
= save_expr (expr
);
735 fold (build2 (COMPLEX_EXPR
, type
,
737 fold (build1 (REALPART_EXPR
,
738 TREE_TYPE (TREE_TYPE (expr
)),
741 fold (build1 (IMAGPART_EXPR
,
742 TREE_TYPE (TREE_TYPE (expr
)),
749 error ("pointer value used where a complex was expected");
750 return convert_to_complex (type
, integer_zero_node
);
753 error ("aggregate value used where a complex was expected");
754 return convert_to_complex (type
, integer_zero_node
);
758 /* Convert EXPR to the vector type TYPE in the usual ways. */
761 convert_to_vector (tree type
, tree expr
)
763 switch (TREE_CODE (TREE_TYPE (expr
)))
767 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
769 error ("can't convert between vector values of different size");
770 return error_mark_node
;
772 return build1 (NOP_EXPR
, type
, expr
);
775 error ("can't convert value to a vector");
776 return error_mark_node
;