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re PR middle-end/61725 (__builtin_ffs(0) leads to wrong code generation)

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PR tree-optimization/61725
	* tree-vrp.c (extract_range_basic): Don't assume vr0 is unsigned
	range, use range_includes_zerop_p instead of integer_zerop on
	vr0->min, only use log2 of max if min is not negative.

	* gcc.dg/tree-ssa/vrp93.c: New test.
	* gcc.c-torture/execute/pr61725.c: New test.

From-SVN: r212353
This commit is contained in:
Jakub Jelinek 2014-07-08 11:39:57 +02:00 • committed by Jakub Jelinek
parent a59d8e8eb6
commit b48e3948be
5 changed files with 69 additions and 3 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2014-07-08 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/61725
* tree-vrp.c (extract_range_basic): Don't assume vr0 is unsigned
range, use range_includes_zerop_p instead of integer_zerop on
vr0->min, only use log2 of max if min is not negative.
2014-07-08 Richard Biener <rguenther@suse.de>
* tree-ssa-dom.h (loop_depth_of_name): Remove.

6
gcc/testsuite/ChangeLog
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@ -1,3 +1,9 @@
2014-07-08 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/61725
* gcc.dg/tree-ssa/vrp93.c: New test.
* gcc.c-torture/execute/pr61725.c: New test.
2014-07-08 Richard Biener <rguenther@suse.de>
* tree-ssa-dom.h (loop_depth_of_name): Remove.

14
gcc/testsuite/gcc.c-torture/execute/pr61725.c Normal file
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@ -0,0 +1,14 @@
/* PR tree-optimization/61725 */
int
main ()
{
int x;
for (x = -128; x <= 128; x++)
{
int a = __builtin_ffs (x);
if (x == 0 && a != 0)
__builtin_abort ();
}
return 0;
}

36
gcc/testsuite/gcc.dg/tree-ssa/vrp93.c Normal file
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@ -0,0 +1,36 @@
/* PR target/29776 */
/* PR tree-optimization/61725 */
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-vrp1" } */
/* { dg-final { scan-tree-dump-not "link_error" "vrp1"} } */
/* { dg-final { cleanup-tree-dump "vrp1" } } */
#define A(fn, arg, min, max) \
if (__builtin_##fn (arg) < min || __builtin_##fn (arg) > max) \
link_error ();
#define B(fn, min, max) \
A (fn, a, min, max) A (fn##l, b, min, max) A (fn##ll, c, min, max)
#define C(fn, min, sub) \
A (fn, a, min, ((int) sizeof (a) * __CHAR_BIT__ - sub)) \
A (fn##l, b, min, ((int) sizeof (b) * __CHAR_BIT__ - sub)) \
A (fn##ll, c, min, ((int) sizeof (c) * __CHAR_BIT__ - sub))
extern void link_error (void);
unsigned int d;
unsigned long e;
unsigned long long f;
void
foo (int a, long b, long long c)
{
C (ffs, 0, 0)
a &= 63; b &= 63; c &= 63;
B (ffs, 0, 6)
a++; b++; c++;
B (ffs, 1, 7)
a -= 2; b -= 2; c -= 2;
C (ffs, 0, 0)
a -= 63; b -= 63; c -= 63;
C (ffs, 1, 0)
}

9
gcc/tree-vrp.c
View file

@ -3536,15 +3536,18 @@ extract_range_basic (value_range_t *vr, gimple stmt)
/* If arg is non-zero, then ffs or popcount
are non-zero. */
if (((vr0->type == VR_RANGE
&& integer_nonzerop (vr0->min))
&& range_includes_zero_p (vr0->min, vr0->max) == 0)
|| (vr0->type == VR_ANTI_RANGE
&& integer_zerop (vr0->min)))
&& !is_overflow_infinity (vr0->min))
&& range_includes_zero_p (vr0->min, vr0->max) == 1))
&& !is_overflow_infinity (vr0->min)
&& !is_overflow_infinity (vr0->max))
mini = 1;
/* If some high bits are known to be zero,
we can decrease the maximum. */
if (vr0->type == VR_RANGE
&& TREE_CODE (vr0->max) == INTEGER_CST
&& !operand_less_p (vr0->min,
build_zero_cst (TREE_TYPE (vr0->min)))
&& !is_overflow_infinity (vr0->max))
maxi = tree_floor_log2 (vr0->max) + 1;
}