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| author | Richard Biener <rguenther@suse.de> | 2016-11-28 15:03:55 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-11-28 15:03:55 +0000 |
| commit | 6522add29b65f7fe572202b2a1e83a8cd00b07fa (patch) | |
| tree | 1372289a2cbe9345b5231abe32c44b42be707a59 /gcc | |
| parent | 6a6951b1bf77ab4d1c0fbffc361ad047e3aa0b98 (diff) | |
| download | gcc-6522add29b65f7fe572202b2a1e83a8cd00b07fa.zip gcc-6522add29b65f7fe572202b2a1e83a8cd00b07fa.tar.gz gcc-6522add29b65f7fe572202b2a1e83a8cd00b07fa.tar.bz2 | |
re PR tree-optimization/78542 (wrong code at -Og results in endless loop)
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
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/pr78542.c | 23 | ||||
| -rw-r--r-- | gcc/tree-ssa-ccp.c | 7 |
4 files changed, 40 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 83615ed..15129d9 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -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 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0374608..8535df4 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,5 +1,10 @@ 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 * gcc.dg/tree-ssa/20030808-1.c: Fix dump to generate. * gcc.dg/tree-ssa/20040305-1.c: Likewise. diff --git a/gcc/testsuite/gcc.dg/torture/pr78542.c b/gcc/testsuite/gcc.dg/torture/pr78542.c new file mode 100644 index 0000000..bae42b6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr78542.c @@ -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; +} diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c index f89da70..084b2e1 100644 --- a/gcc/tree-ssa-ccp.c +++ b/gcc/tree-ssa-ccp.c @@ -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) |