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 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
);
352 case BUILT_IN_ROUND
: case BUILT_IN_ROUNDF
: case BUILT_IN_ROUNDL
:
353 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (long_long_integer_type_node
))
354 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLROUND
);
356 fn
= mathfn_built_in (s_intype
, BUILT_IN_LROUND
);
359 case BUILT_IN_RINT
: case BUILT_IN_RINTF
: case BUILT_IN_RINTL
:
360 /* Only convert rint* if we can ignore math exceptions. */
361 if (flag_trapping_math
)
363 /* ... Fall through ... */
364 case BUILT_IN_NEARBYINT
: case BUILT_IN_NEARBYINTF
: case BUILT_IN_NEARBYINTL
:
365 if (TYPE_MAIN_VARIANT (type
) == TYPE_MAIN_VARIANT (long_long_integer_type_node
))
366 fn
= mathfn_built_in (s_intype
, BUILT_IN_LLRINT
);
368 fn
= mathfn_built_in (s_intype
, BUILT_IN_LRINT
);
376 tree arglist
= TREE_OPERAND (s_expr
, 1);
377 tree newexpr
= build_function_call_expr (fn
, arglist
);
378 return convert_to_integer (type
, newexpr
);
382 switch (TREE_CODE (intype
))
386 if (integer_zerop (expr
))
387 expr
= integer_zero_node
;
389 expr
= fold (build1 (CONVERT_EXPR
,
390 lang_hooks
.types
.type_for_size
391 (POINTER_SIZE
, TYPE_UNSIGNED (type
)),
394 return convert_to_integer (type
, expr
);
400 /* If this is a logical operation, which just returns 0 or 1, we can
401 change the type of the expression. */
403 if (TREE_CODE_CLASS (ex_form
) == tcc_comparison
)
405 expr
= copy_node (expr
);
406 TREE_TYPE (expr
) = type
;
410 /* If we are widening the type, put in an explicit conversion.
411 Similarly if we are not changing the width. After this, we know
412 we are truncating EXPR. */
414 else if (outprec
>= inprec
)
418 /* If the precision of the EXPR's type is K bits and the
419 destination mode has more bits, and the sign is changing,
420 it is not safe to use a NOP_EXPR. For example, suppose
421 that EXPR's type is a 3-bit unsigned integer type, the
422 TYPE is a 3-bit signed integer type, and the machine mode
423 for the types is 8-bit QImode. In that case, the
424 conversion necessitates an explicit sign-extension. In
425 the signed-to-unsigned case the high-order bits have to
427 if (TYPE_UNSIGNED (type
) != TYPE_UNSIGNED (TREE_TYPE (expr
))
428 && (TYPE_PRECISION (TREE_TYPE (expr
))
429 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr
)))))
434 return build1 (code
, type
, expr
);
437 /* If TYPE is an enumeral type or a type with a precision less
438 than the number of bits in its mode, do the conversion to the
439 type corresponding to its mode, then do a nop conversion
441 else if (TREE_CODE (type
) == ENUMERAL_TYPE
442 || outprec
!= GET_MODE_BITSIZE (TYPE_MODE (type
)))
443 return build1 (NOP_EXPR
, type
,
444 convert (lang_hooks
.types
.type_for_mode
445 (TYPE_MODE (type
), TYPE_UNSIGNED (type
)),
448 /* Here detect when we can distribute the truncation down past some
449 arithmetic. For example, if adding two longs and converting to an
450 int, we can equally well convert both to ints and then add.
451 For the operations handled here, such truncation distribution
453 It is desirable in these cases:
454 1) when truncating down to full-word from a larger size
455 2) when truncating takes no work.
456 3) when at least one operand of the arithmetic has been extended
457 (as by C's default conversions). In this case we need two conversions
458 if we do the arithmetic as already requested, so we might as well
459 truncate both and then combine. Perhaps that way we need only one.
461 Note that in general we cannot do the arithmetic in a type
462 shorter than the desired result of conversion, even if the operands
463 are both extended from a shorter type, because they might overflow
464 if combined in that type. The exceptions to this--the times when
465 two narrow values can be combined in their narrow type even to
466 make a wider result--are handled by "shorten" in build_binary_op. */
471 /* We can pass truncation down through right shifting
472 when the shift count is a nonpositive constant. */
473 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
474 && tree_int_cst_lt (TREE_OPERAND (expr
, 1),
475 convert (TREE_TYPE (TREE_OPERAND (expr
, 1)),
481 /* We can pass truncation down through left shifting
482 when the shift count is a nonnegative constant and
483 the target type is unsigned. */
484 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
485 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) >= 0
486 && TYPE_UNSIGNED (type
)
487 && TREE_CODE (TYPE_SIZE (type
)) == INTEGER_CST
)
489 /* If shift count is less than the width of the truncated type,
491 if (tree_int_cst_lt (TREE_OPERAND (expr
, 1), TYPE_SIZE (type
)))
492 /* In this case, shifting is like multiplication. */
496 /* If it is >= that width, result is zero.
497 Handling this with trunc1 would give the wrong result:
498 (int) ((long long) a << 32) is well defined (as 0)
499 but (int) a << 32 is undefined and would get a
502 tree t
= convert_to_integer (type
, integer_zero_node
);
504 /* If the original expression had side-effects, we must
506 if (TREE_SIDE_EFFECTS (expr
))
507 return build2 (COMPOUND_EXPR
, type
, expr
, t
);
518 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
519 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
521 /* Don't distribute unless the output precision is at least as big
522 as the actual inputs. Otherwise, the comparison of the
523 truncated values will be wrong. */
524 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
525 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
526 /* If signedness of arg0 and arg1 don't match,
527 we can't necessarily find a type to compare them in. */
528 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
529 == TYPE_UNSIGNED (TREE_TYPE (arg1
))))
541 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
542 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
544 if (outprec
>= BITS_PER_WORD
545 || TRULY_NOOP_TRUNCATION (outprec
, inprec
)
546 || inprec
> TYPE_PRECISION (TREE_TYPE (arg0
))
547 || inprec
> TYPE_PRECISION (TREE_TYPE (arg1
)))
549 /* Do the arithmetic in type TYPEX,
550 then convert result to TYPE. */
553 /* Can't do arithmetic in enumeral types
554 so use an integer type that will hold the values. */
555 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
556 typex
= lang_hooks
.types
.type_for_size
557 (TYPE_PRECISION (typex
), TYPE_UNSIGNED (typex
));
559 /* But now perhaps TYPEX is as wide as INPREC.
560 In that case, do nothing special here.
561 (Otherwise would recurse infinitely in convert. */
562 if (TYPE_PRECISION (typex
) != inprec
)
564 /* Don't do unsigned arithmetic where signed was wanted,
566 Exception: if both of the original operands were
567 unsigned then we can safely do the work as unsigned.
568 Exception: shift operations take their type solely
569 from the first argument.
570 Exception: the LSHIFT_EXPR case above requires that
571 we perform this operation unsigned lest we produce
572 signed-overflow undefinedness.
573 And we may need to do it as unsigned
574 if we truncate to the original size. */
575 if (TYPE_UNSIGNED (TREE_TYPE (expr
))
576 || (TYPE_UNSIGNED (TREE_TYPE (arg0
))
577 && (TYPE_UNSIGNED (TREE_TYPE (arg1
))
578 || ex_form
== LSHIFT_EXPR
579 || ex_form
== RSHIFT_EXPR
580 || ex_form
== LROTATE_EXPR
581 || ex_form
== RROTATE_EXPR
))
582 || ex_form
== LSHIFT_EXPR
)
583 typex
= lang_hooks
.types
.unsigned_type (typex
);
585 typex
= lang_hooks
.types
.signed_type (typex
);
586 return convert (type
,
587 fold (build2 (ex_form
, typex
,
588 convert (typex
, arg0
),
589 convert (typex
, arg1
))));
597 /* This is not correct for ABS_EXPR,
598 since we must test the sign before truncation. */
602 /* Can't do arithmetic in enumeral types
603 so use an integer type that will hold the values. */
604 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
605 typex
= lang_hooks
.types
.type_for_size
606 (TYPE_PRECISION (typex
), TYPE_UNSIGNED (typex
));
608 /* But now perhaps TYPEX is as wide as INPREC.
609 In that case, do nothing special here.
610 (Otherwise would recurse infinitely in convert. */
611 if (TYPE_PRECISION (typex
) != inprec
)
613 /* Don't do unsigned arithmetic where signed was wanted,
615 if (TYPE_UNSIGNED (TREE_TYPE (expr
)))
616 typex
= lang_hooks
.types
.unsigned_type (typex
);
618 typex
= lang_hooks
.types
.signed_type (typex
);
619 return convert (type
,
620 fold (build1 (ex_form
, typex
,
622 TREE_OPERAND (expr
, 0)))));
628 "can't convert between vector values of different size" error. */
629 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == VECTOR_TYPE
630 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr
, 0))))
631 != GET_MODE_SIZE (TYPE_MODE (type
))))
633 /* If truncating after truncating, might as well do all at once.
634 If truncating after extending, we may get rid of wasted work. */
635 return convert (type
, get_unwidened (TREE_OPERAND (expr
, 0), type
));
638 /* It is sometimes worthwhile to push the narrowing down through
639 the conditional and never loses. */
640 return fold (build3 (COND_EXPR
, type
, TREE_OPERAND (expr
, 0),
641 convert (type
, TREE_OPERAND (expr
, 1)),
642 convert (type
, TREE_OPERAND (expr
, 2))));
648 return build1 (CONVERT_EXPR
, type
, expr
);
651 return build1 (FIX_TRUNC_EXPR
, type
, expr
);
654 return convert (type
,
655 fold (build1 (REALPART_EXPR
,
656 TREE_TYPE (TREE_TYPE (expr
)), expr
)));
659 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
661 error ("can't convert between vector values of different size");
662 return error_mark_node
;
664 return build1 (NOP_EXPR
, type
, expr
);
667 error ("aggregate value used where an integer was expected");
668 return convert (type
, integer_zero_node
);
672 /* Convert EXPR to the complex type TYPE in the usual ways. */
675 convert_to_complex (tree type
, tree expr
)
677 tree subtype
= TREE_TYPE (type
);
679 switch (TREE_CODE (TREE_TYPE (expr
)))
686 return build2 (COMPLEX_EXPR
, type
, convert (subtype
, expr
),
687 convert (subtype
, integer_zero_node
));
691 tree elt_type
= TREE_TYPE (TREE_TYPE (expr
));
693 if (TYPE_MAIN_VARIANT (elt_type
) == TYPE_MAIN_VARIANT (subtype
))
695 else if (TREE_CODE (expr
) == COMPLEX_EXPR
)
696 return fold (build2 (COMPLEX_EXPR
, type
,
697 convert (subtype
, TREE_OPERAND (expr
, 0)),
698 convert (subtype
, TREE_OPERAND (expr
, 1))));
701 expr
= save_expr (expr
);
703 fold (build2 (COMPLEX_EXPR
, type
,
705 fold (build1 (REALPART_EXPR
,
706 TREE_TYPE (TREE_TYPE (expr
)),
709 fold (build1 (IMAGPART_EXPR
,
710 TREE_TYPE (TREE_TYPE (expr
)),
717 error ("pointer value used where a complex was expected");
718 return convert_to_complex (type
, integer_zero_node
);
721 error ("aggregate value used where a complex was expected");
722 return convert_to_complex (type
, integer_zero_node
);
726 /* Convert EXPR to the vector type TYPE in the usual ways. */
729 convert_to_vector (tree type
, tree expr
)
731 switch (TREE_CODE (TREE_TYPE (expr
)))
735 if (!tree_int_cst_equal (TYPE_SIZE (type
), TYPE_SIZE (TREE_TYPE (expr
))))
737 error ("can't convert between vector values of different size");
738 return error_mark_node
;
740 return build1 (NOP_EXPR
, type
, expr
);
743 error ("can't convert value to a vector");
744 return error_mark_node
;