diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr77768.c | 13 | ||||
| -rw-r--r-- | gcc/tree-ssa-pre.c | 6 |
4 files changed, 28 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6b832ed..26dc3f9 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2016-09-29 Richard Biener <rguenther@suse.de> + PR tree-optimization/77768 + * tree-ssa-pre.c (eliminate_dom_walker::before_dom_children): + Handle stores to readonly memory when removing redundant stores. + +2016-09-29 Richard Biener <rguenther@suse.de> + PR middle-end/77407 * match.pd: Add X / abs (X) -> X < 0 ? -1 : 1 and X / -X -> -1 simplifications. diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 9269d58..2fd9e97 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-09-29 Richard Biener <rguenther@suse.de> + + PR tree-optimization/77768 + * gcc.dg/torture/pr77768.c: New testcase. + 2016-09-28 Richard Biener <rguenther@suse.de> PR middle-end/77407 diff --git a/gcc/testsuite/gcc.dg/torture/pr77768.c b/gcc/testsuite/gcc.dg/torture/pr77768.c new file mode 100644 index 0000000..47e1484 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr77768.c @@ -0,0 +1,13 @@ +/* { dg-do run } */ + +static const int a; +int b; +int *c, *d; +int main() +{ + c = (int *)&a; + c == d ?: __builtin_exit(0); + for (; b; b++ >= (*d = a)) + ; + return 0; +} diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index 3675fb9..39bc254 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -4443,9 +4443,11 @@ eliminate_dom_walker::before_dom_children (basic_block b) && operand_equal_p (val, rhs, 0)) { /* We can only remove the later store if the former aliases - at least all accesses the later one does. */ + at least all accesses the later one does or if the store + was to readonly memory storing the same value. */ alias_set_type set = get_alias_set (lhs); - if (vnresult->set == set + if (! vnresult + || vnresult->set == set || alias_set_subset_of (set, vnresult->set)) { if (dump_file && (dump_flags & TDF_DETAILS)) |