OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR tree-optimization/93156 (abused nonnull attribute evokes new segfault in gcc 10 since Nov 4 commit, 0fb958ab8aa)

Browse Source 
PR tree-optimization/93156
	* tree-ssa-ccp.c (bit_value_binop): For x * x note that the second
	least significant bit is always clear.

	* gcc.dg/tree-ssa/pr93156.c: New test.

From-SVN: r279951
This commit is contained in:
Jakub Jelinek 2020-01-07 11:05:14 +01:00 committed by Jakub Jelinek
parent f26916c2ac
commit fb862fdfb5
4 changed files with 43 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
gcc/ChangeLog
View File

@ -1,4 +1,8 @@
2019-01-07 Jakub Jelinek <jakub@redhat.com>
2020-01-07 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/93156
* tree-ssa-ccp.c (bit_value_binop): For x * x note that the second
least significant bit is always clear.
PR tree-optimization/93118
* match.pd ((x >> c) << c -> x & (-1<<c)): Add nop_convert?. Add new

5
gcc/testsuite/ChangeLog
View File

@ -1,4 +1,7 @@
2019-01-07 Jakub Jelinek <jakub@redhat.com>
2020-01-07 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/93156
* gcc.dg/tree-ssa/pr93156.c: New test.
PR tree-optimization/93118
* gcc.dg/tree-ssa/pr93118.c: New test.

23
gcc/testsuite/gcc.dg/tree-ssa/pr93156.c Normal file
View File

@ -0,0 +1,23 @@
/* PR tree-optimization/93156 */
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-optimized" } */
/* { dg-final { scan-tree-dump-times "return 0;" 3 "optimized" } } */
int
foo (int x)
{
return (x * x) & 2;
}
unsigned long long
bar (unsigned long long x)
{
return (x * x) & 2;
}
int
baz (int x)
{
x &= -2;
return (x * x) & 3;
}

11
gcc/tree-ssa-ccp.c
View File

@ -1650,6 +1650,17 @@ bit_value_binop (enum tree_code code, tree type, tree rhs1, tree rhs2)
TYPE_SIGN (TREE_TYPE (rhs2)), TYPE_PRECISION (TREE_TYPE (rhs2)),
value_to_wide_int (r2val), r2val.mask);
/* (x * x) & 2 == 0. */
if (code == MULT_EXPR && rhs1 == rhs2 && TYPE_PRECISION (type) > 1)
{
widest_int m = 2;
if (wi::sext (mask, TYPE_PRECISION (type)) != -1)
value = wi::bit_and_not (value, m);
else
value = 0;
mask = wi::bit_and_not (mask, m);
}
if (wi::sext (mask, TYPE_PRECISION (type)) != -1)
{
val.lattice_val = CONSTANT;