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re PR middle-end/87623 (bytes swapped in register when comparing cause fail when compiled with -O1 or higher)

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PR middle-end/87623
	* fold-const.c (fold_truth_andor_1): If the right side is not constant,
	bail out if both sides do not have the same storage order.

From-SVN: r265242
This commit is contained in:
Eric Botcazou 2018-10-17 17:49:28 +00:00
parent 54994253d3
commit 1906e1a607
4 changed files with 48 additions and 3 deletions
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8
gcc/ChangeLog
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@ -1,4 +1,10 @@
2018-10-09 Aldy Hernandez <aldyh@redhat.com>
2018-10-17 Eric Botcazou <ebotcazou@adacore.com>
PR middle-end/87623
* fold-const.c (fold_truth_andor_1): If the right side is not constant,
bail out if both sides do not have the same storage order.
2018-10-17 Aldy Hernandez <aldyh@redhat.com>
* bitmap.c (bitmap_head::dump): New.
* bitmap.h (bitmap_head): Add dump().

5
gcc/fold-const.c
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@ -6009,12 +6009,13 @@ fold_truth_andor_1 (location_t loc, enum tree_code code, tree truth_type,
}
/* If the right sides are not constant, do the same for it. Also,
disallow this optimization if a size or signedness mismatch occurs
between the left and right sides. */
disallow this optimization if a size, signedness or storage order
mismatch occurs between the left and right sides. */
if (l_const == 0)
{
if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
|| ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
|| ll_reversep != lr_reversep
/* Make sure the two fields on the right
correspond to the left without being swapped. */
|| ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)

4
gcc/testsuite/ChangeLog
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@ -1,3 +1,7 @@
2018-10-17 Eric Botcazou <ebotcazou@adacore.com>
* gcc.c-torture/execute/pr87623.c: New test.
2018-10-17 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/84705

34
gcc/testsuite/gcc.c-torture/execute/pr87623.c Normal file
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@ -0,0 +1,34 @@
/* PR middle-end/87623 */
/* Testcase by George Thopas <george.thopas@gmail.com> */
struct be {
unsigned short pad[1];
unsigned char a;
unsigned char b;
} __attribute__((scalar_storage_order("big-endian")));
typedef struct be t_be;
struct le {
unsigned short pad[3];
unsigned char a;
unsigned char b;
};
typedef struct le t_le;
int a_or_b_different(t_be *x,t_le *y)
{
return (x->a != y->a) || (x->b != y->b);
}
int main (void)
{
t_be x = { .a=1, .b=2 };
t_le y = { .a=1, .b=2 };
if (a_or_b_different(&x,&y))
__builtin_abort ();
return 0;
}