procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

re PR tree-optimization/78542 (wrong code at -Og results in endless loop)

Browse source 
2016-11-28  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/78542
	* tree-ssa-ccp.c (evaluate_stmt): Only valueize simplification
	if allowed.

	* gcc.dg/torture/pr78542.c: New testcase.

From-SVN: r242920
This commit is contained in:
Richard Biener 2016-11-28 15:03:55 +00:00 • committed by Richard Biener
parent 6a6951b1bf
commit 6522add29b
4 changed files with 40 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2016-11-28 Richard Biener <rguenther@suse.de>
PR tree-optimization/78542
* tree-ssa-ccp.c (evaluate_stmt): Only valueize simplification
if allowed.
2016-11-28 Paolo Bonzini <bonzini@gnu.org>
* combine.c (simplify_if_then_else): Simplify IF_THEN_ELSE

5
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,8 @@
2016-11-28 Richard Biener <rguenther@suse.de>
PR tree-optimization/78542
* gcc.dg/torture/pr78542.c: New testcase.
2016-11-28 Richard Biener <rguenther@suse.de>
PR tree-optimization/78343

23
gcc/testsuite/gcc.dg/torture/pr78542.c Normal file
View file

@ -0,0 +1,23 @@
/* { dg-do run } */
/* { dg-additional-options "-w -Wno-psabi" } */
typedef unsigned V __attribute__ ((vector_size (16)));
V
foo (unsigned x, V v)
{
do {
v %= x;
x = 1;
} while (v[1]);
return v;
}
int
main ()
{
V x = foo (5, (V) { 0, 1 });
if (x[0] || x[1] || x[2] || x[3])
__builtin_abort();
return 0;
}

7
gcc/tree-ssa-ccp.c
View file

@ -1744,7 +1744,12 @@ evaluate_stmt (gimple *stmt)
{
fold_defer_overflow_warnings ();
simplified = ccp_fold (stmt);
if (simplified && TREE_CODE (simplified) == SSA_NAME)
if (simplified
&& TREE_CODE (simplified) == SSA_NAME
/* We may not use values of something that may be simulated again,
see valueize_op_1. */
&& (SSA_NAME_IS_DEFAULT_DEF (simplified)
|| ! prop_simulate_again_p (SSA_NAME_DEF_STMT (simplified))))
{
ccp_prop_value_t *val = get_value (simplified);
if (val && val->lattice_val != VARYING)