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re PR tree-optimization/80426 (wrong manipulation of range based on INT_MIN)

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PR tree-optimization/80426
	* tree-vrp.c (extract_range_from_binary_expr_1): For an additive
	operation on symbolic operands, also compute the overflow for the
	invariant part when the operation degenerates into a negation.

	PR tree-optimization/80426
	* gcc.c-torture/execute/20170419-1.c: New test.

Co-Authored-By: Jakub Jelinek <jakub@redhat.com>

From-SVN: r247007
This commit is contained in:
Eric Botcazou 2017-04-19 19:27:09 +00:00 committed by Jeff Law
parent 52744dd73c
commit fe1e7d0e9b
4 changed files with 65 additions and 2 deletions
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8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2017-04-19 Eric Botcazou <ebotcazou@adacore.com>
Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/80426
* tree-vrp.c (extract_range_from_binary_expr_1): For an additive
operation on symbolic operands, also compute the overflow for the
invariant part when the operation degenerates into a negation.
2017-04-19 Jakub Jelinek <jakub@redhat.com>
PR debug/80461

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2017-04-19 Eric Botcazou <ebotcazou@adacore.com>
PR tree-optimization/80426
* gcc.c-torture/execute/20170419-1.c: New test.
2017-04-19 Jakub Jelinek <jakub@redhat.com>
PR debug/80461

24
gcc/testsuite/gcc.c-torture/execute/20170429-1.c Normal file
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@ -0,0 +1,24 @@
/* PR tree-optimization/80426 */
/* Testcase by <ishiura-compiler@ml.kwansei.ac.jp> */
#define INT_MAX 0x7fffffff
#define INT_MIN (-INT_MAX-1)
int x;
int main (void)
{
volatile int a = 0;
volatile int b = -INT_MAX;
int j;
for(j = 0; j < 18; j += 1) {
x = ( (a == 0) != (b - (int)(INT_MIN) ) );
}
if (x != 0)
__builtin_abort ();
return 0;
}

30
gcc/tree-vrp.c
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@ -2461,7 +2461,20 @@ extract_range_from_binary_expr_1 (value_range *vr,
else if (min_op0)
wmin = min_op0;
else if (min_op1)
wmin = minus_p ? wi::neg (min_op1) : min_op1;
{
if (minus_p)
{
wmin = wi::neg (min_op1);
/* Check for overflow. */
if (sgn == SIGNED && wi::neg_p (min_op1) && wi::neg_p (wmin))
min_ovf = 1;
else if (sgn == UNSIGNED && wi::ne_p (min_op1, 0))
min_ovf = -1;
}
else
wmin = min_op1;
}
else
wmin = wi::shwi (0, prec);
@ -2489,7 +2502,20 @@ extract_range_from_binary_expr_1 (value_range *vr,
else if (max_op0)
wmax = max_op0;
else if (max_op1)
wmax = minus_p ? wi::neg (max_op1) : max_op1;
{
if (minus_p)
{
wmax = wi::neg (max_op1);
/* Check for overflow. */
if (sgn == SIGNED && wi::neg_p (max_op1) && wi::neg_p (wmax))
max_ovf = 1;
else if (sgn == UNSIGNED && wi::ne_p (max_op1, 0))
max_ovf = -1;
}
else
wmax = max_op1;
}
else
wmax = wi::shwi (0, prec);