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_2 (0, 0);
47 TREE_TYPE (expr
) = type
;
51 switch (TREE_CODE (TREE_TYPE (expr
)))
55 return build1 (NOP_EXPR
, type
, expr
);
61 if (TYPE_PRECISION (TREE_TYPE (expr
)) == POINTER_SIZE
)
62 return build1 (CONVERT_EXPR
, type
, expr
);
65 convert_to_pointer (type
,
66 convert (lang_hooks
.types
.type_for_size
67 (POINTER_SIZE
, 0), expr
));
70 error ("cannot convert to a pointer type");
71 return convert_to_pointer (type
, integer_zero_node
);
75 /* Avoid any floating point extensions from EXP. */
77 strip_float_extensions (tree exp
)
81 /* For floating point constant look up the narrowest type that can hold
82 it properly and handle it like (type)(narrowest_type)constant.
83 This way we can optimize for instance a=a*2.0 where "a" is float
84 but 2.0 is double constant. */
85 if (TREE_CODE (exp
) == REAL_CST
)
90 orig
= TREE_REAL_CST (exp
);
91 if (TYPE_PRECISION (TREE_TYPE (exp
)) > TYPE_PRECISION (float_type_node
)
92 && exact_real_truncate (TYPE_MODE (float_type_node
), &orig
))
93 type
= float_type_node
;
94 else if (TYPE_PRECISION (TREE_TYPE (exp
))
95 > TYPE_PRECISION (double_type_node
)
96 && exact_real_truncate (TYPE_MODE (double_type_node
), &orig
))
97 type
= double_type_node
;
99 return build_real (type
, real_value_truncate (TYPE_MODE (type
), orig
));
102 if (TREE_CODE (exp
) != NOP_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
= build (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 switch (TREE_CODE (intype
))
339 if (integer_zerop (expr
))
340 expr
= integer_zero_node
;
342 expr
= fold (build1 (CONVERT_EXPR
,
343 lang_hooks
.types
.type_for_size (POINTER_SIZE
, 0),
346 return convert_to_integer (type
, expr
);
352 /* If this is a logical operation, which just returns 0 or 1, we can
353 change the type of the expression. For some logical operations,
354 we must also change the types of the operands to maintain type
357 if (TREE_CODE_CLASS (ex_form
) == '<')
359 expr
= copy_node (expr
);
360 TREE_TYPE (expr
) = type
;
364 else if (ex_form
== TRUTH_AND_EXPR
|| ex_form
== TRUTH_ANDIF_EXPR
365 || ex_form
== TRUTH_OR_EXPR
|| ex_form
== TRUTH_ORIF_EXPR
366 || ex_form
== TRUTH_XOR_EXPR
)
368 expr
= copy_node (expr
);
369 TREE_OPERAND (expr
, 0) = convert (type
, TREE_OPERAND (expr
, 0));
370 TREE_OPERAND (expr
, 1) = convert (type
, TREE_OPERAND (expr
, 1));
371 TREE_TYPE (expr
) = type
;
375 else if (ex_form
== TRUTH_NOT_EXPR
)
377 expr
= copy_node (expr
);
378 TREE_OPERAND (expr
, 0) = convert (type
, TREE_OPERAND (expr
, 0));
379 TREE_TYPE (expr
) = type
;
383 /* If we are widening the type, put in an explicit conversion.
384 Similarly if we are not changing the width. After this, we know
385 we are truncating EXPR. */
387 else if (outprec
>= inprec
)
391 /* If the precision of the EXPR's type is K bits and the
392 destination mode has more bits, and the sign is changing,
393 it is not safe to use a NOP_EXPR. For example, suppose
394 that EXPR's type is a 3-bit unsigned integer type, the
395 TYPE is a 3-bit signed integer type, and the machine mode
396 for the types is 8-bit QImode. In that case, the
397 conversion necessitates an explicit sign-extension. In
398 the signed-to-unsigned case the high-order bits have to
400 if (TYPE_UNSIGNED (type
) != TYPE_UNSIGNED (TREE_TYPE (expr
))
401 && (TYPE_PRECISION (TREE_TYPE (expr
))
402 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr
)))))
407 return build1 (code
, type
, expr
);
410 /* If TYPE is an enumeral type or a type with a precision less
411 than the number of bits in its mode, do the conversion to the
412 type corresponding to its mode, then do a nop conversion
414 else if (TREE_CODE (type
) == ENUMERAL_TYPE
415 || outprec
!= GET_MODE_BITSIZE (TYPE_MODE (type
)))
416 return build1 (NOP_EXPR
, type
,
417 convert (lang_hooks
.types
.type_for_mode
418 (TYPE_MODE (type
), TYPE_UNSIGNED (type
)),
421 /* Here detect when we can distribute the truncation down past some
422 arithmetic. For example, if adding two longs and converting to an
423 int, we can equally well convert both to ints and then add.
424 For the operations handled here, such truncation distribution
426 It is desirable in these cases:
427 1) when truncating down to full-word from a larger size
428 2) when truncating takes no work.
429 3) when at least one operand of the arithmetic has been extended
430 (as by C's default conversions). In this case we need two conversions
431 if we do the arithmetic as already requested, so we might as well
432 truncate both and then combine. Perhaps that way we need only one.
434 Note that in general we cannot do the arithmetic in a type
435 shorter than the desired result of conversion, even if the operands
436 are both extended from a shorter type, because they might overflow
437 if combined in that type. The exceptions to this--the times when
438 two narrow values can be combined in their narrow type even to
439 make a wider result--are handled by "shorten" in build_binary_op. */
444 /* We can pass truncation down through right shifting
445 when the shift count is a nonpositive constant. */
446 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
447 && tree_int_cst_lt (TREE_OPERAND (expr
, 1),
448 convert (TREE_TYPE (TREE_OPERAND (expr
, 1)),
454 /* We can pass truncation down through left shifting
455 when the shift count is a nonnegative constant and
456 the target type is unsigned. */
457 if (TREE_CODE (TREE_OPERAND (expr
, 1)) == INTEGER_CST
458 && tree_int_cst_sgn (TREE_OPERAND (expr
, 1)) >= 0
459 && TYPE_UNSIGNED (type
)
460 && TREE_CODE (TYPE_SIZE (type
)) == INTEGER_CST
)
462 /* If shift count is less than the width of the truncated type,
464 if (tree_int_cst_lt (TREE_OPERAND (expr
, 1), TYPE_SIZE (type
)))
465 /* In this case, shifting is like multiplication. */
469 /* If it is >= that width, result is zero.
470 Handling this with trunc1 would give the wrong result:
471 (int) ((long long) a << 32) is well defined (as 0)
472 but (int) a << 32 is undefined and would get a
475 tree t
= convert_to_integer (type
, integer_zero_node
);
477 /* If the original expression had side-effects, we must
479 if (TREE_SIDE_EFFECTS (expr
))
480 return build (COMPOUND_EXPR
, type
, expr
, t
);
491 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
492 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
494 /* Don't distribute unless the output precision is at least as big
495 as the actual inputs. Otherwise, the comparison of the
496 truncated values will be wrong. */
497 if (outprec
>= TYPE_PRECISION (TREE_TYPE (arg0
))
498 && outprec
>= TYPE_PRECISION (TREE_TYPE (arg1
))
499 /* If signedness of arg0 and arg1 don't match,
500 we can't necessarily find a type to compare them in. */
501 && (TYPE_UNSIGNED (TREE_TYPE (arg0
))
502 == TYPE_UNSIGNED (TREE_TYPE (arg1
))))
514 tree arg0
= get_unwidened (TREE_OPERAND (expr
, 0), type
);
515 tree arg1
= get_unwidened (TREE_OPERAND (expr
, 1), type
);
517 if (outprec
>= BITS_PER_WORD
518 || TRULY_NOOP_TRUNCATION (outprec
, inprec
)
519 || inprec
> TYPE_PRECISION (TREE_TYPE (arg0
))
520 || inprec
> TYPE_PRECISION (TREE_TYPE (arg1
)))
522 /* Do the arithmetic in type TYPEX,
523 then convert result to TYPE. */
526 /* Can't do arithmetic in enumeral types
527 so use an integer type that will hold the values. */
528 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
529 typex
= lang_hooks
.types
.type_for_size
530 (TYPE_PRECISION (typex
), TYPE_UNSIGNED (typex
));
532 /* But now perhaps TYPEX is as wide as INPREC.
533 In that case, do nothing special here.
534 (Otherwise would recurse infinitely in convert. */
535 if (TYPE_PRECISION (typex
) != inprec
)
537 /* Don't do unsigned arithmetic where signed was wanted,
539 Exception: if both of the original operands were
540 unsigned then we can safely do the work as unsigned.
541 Exception: shift operations take their type solely
542 from the first argument.
543 Exception: the LSHIFT_EXPR case above requires that
544 we perform this operation unsigned lest we produce
545 signed-overflow undefinedness.
546 And we may need to do it as unsigned
547 if we truncate to the original size. */
548 if (TYPE_UNSIGNED (TREE_TYPE (expr
))
549 || (TYPE_UNSIGNED (TREE_TYPE (arg0
))
550 && (TYPE_UNSIGNED (TREE_TYPE (arg1
))
551 || ex_form
== LSHIFT_EXPR
552 || ex_form
== RSHIFT_EXPR
553 || ex_form
== LROTATE_EXPR
554 || ex_form
== RROTATE_EXPR
))
555 || ex_form
== LSHIFT_EXPR
)
556 typex
= lang_hooks
.types
.unsigned_type (typex
);
558 typex
= lang_hooks
.types
.signed_type (typex
);
559 return convert (type
,
560 fold (build (ex_form
, typex
,
561 convert (typex
, arg0
),
562 convert (typex
, arg1
))));
570 /* This is not correct for ABS_EXPR,
571 since we must test the sign before truncation. */
575 /* Can't do arithmetic in enumeral types
576 so use an integer type that will hold the values. */
577 if (TREE_CODE (typex
) == ENUMERAL_TYPE
)
578 typex
= lang_hooks
.types
.type_for_size
579 (TYPE_PRECISION (typex
), TYPE_UNSIGNED (typex
));
581 /* But now perhaps TYPEX is as wide as INPREC.
582 In that case, do nothing special here.
583 (Otherwise would recurse infinitely in convert. */
584 if (TYPE_PRECISION (typex
) != inprec
)
586 /* Don't do unsigned arithmetic where signed was wanted,
588 if (TYPE_UNSIGNED (TREE_TYPE (expr
)))
589 typex
= lang_hooks
.types
.unsigned_type (typex
);
591 typex
= lang_hooks
.types
.signed_type (typex
);
592 return convert (type
,
593 fold (build1 (ex_form
, typex
,
595 TREE_OPERAND (expr
, 0)))));
601 "can't convert between vector values of different size" error. */
602 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == VECTOR_TYPE
603 && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr
, 0))))
604 != GET_MODE_SIZE (TYPE_MODE (type
))))
606 /* If truncating after truncating, might as well do all at once.
607 If truncating after extending, we may get rid of wasted work. */
608 return convert (type
, get_unwidened (TREE_OPERAND (expr
, 0), type
));
611 /* It is sometimes worthwhile to push the narrowing down through
612 the conditional and never loses. */
613 return fold (build (COND_EXPR
, type
, TREE_OPERAND (expr
, 0),
614 convert (type
, TREE_OPERAND (expr
, 1)),
615 convert (type
, TREE_OPERAND (expr
, 2))));
621 return build1 (NOP_EXPR
, type
, expr
);
624 return build1 (FIX_TRUNC_EXPR
, type
, expr
);
627 return convert (type
,
628 fold (build1 (REALPART_EXPR
,
629 TREE_TYPE (TREE_TYPE (expr
)), expr
)));
632 if (GET_MODE_SIZE (TYPE_MODE (type
))
633 != GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr
))))
635 error ("can't convert between vector values of different size");
636 return error_mark_node
;
638 return build1 (NOP_EXPR
, type
, expr
);
641 error ("aggregate value used where an integer was expected");
642 return convert (type
, integer_zero_node
);
646 /* Convert EXPR to the complex type TYPE in the usual ways. */
649 convert_to_complex (tree type
, tree expr
)
651 tree subtype
= TREE_TYPE (type
);
653 switch (TREE_CODE (TREE_TYPE (expr
)))
660 return build (COMPLEX_EXPR
, type
, convert (subtype
, expr
),
661 convert (subtype
, integer_zero_node
));
665 tree elt_type
= TREE_TYPE (TREE_TYPE (expr
));
667 if (TYPE_MAIN_VARIANT (elt_type
) == TYPE_MAIN_VARIANT (subtype
))
669 else if (TREE_CODE (expr
) == COMPLEX_EXPR
)
670 return fold (build (COMPLEX_EXPR
,
672 convert (subtype
, TREE_OPERAND (expr
, 0)),
673 convert (subtype
, TREE_OPERAND (expr
, 1))));
676 expr
= save_expr (expr
);
678 fold (build (COMPLEX_EXPR
,
679 type
, convert (subtype
,
680 fold (build1 (REALPART_EXPR
,
681 TREE_TYPE (TREE_TYPE (expr
)),
684 fold (build1 (IMAGPART_EXPR
,
685 TREE_TYPE (TREE_TYPE (expr
)),
692 error ("pointer value used where a complex was expected");
693 return convert_to_complex (type
, integer_zero_node
);
696 error ("aggregate value used where a complex was expected");
697 return convert_to_complex (type
, integer_zero_node
);
701 /* Convert EXPR to the vector type TYPE in the usual ways. */
704 convert_to_vector (tree type
, tree expr
)
706 switch (TREE_CODE (TREE_TYPE (expr
)))
710 if (GET_MODE_SIZE (TYPE_MODE (type
))
711 != GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr
))))
713 error ("can't convert between vector values of different size");
714 return error_mark_node
;
716 return build1 (NOP_EXPR
, type
, expr
);
719 error ("can't convert value to a vector");
720 return convert_to_vector (type
, integer_zero_node
);