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| author | Jakub Jelinek <jakub@redhat.com> | 2011-05-20 16:19:05 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2011-05-20 16:19:05 +0200 |
| commit | 6c66f73369dacc9889cfaa05f8a08813e7c45f1f (patch) | |
| tree | 940cae516f3f04771fe6a0abd862dd3ee83bd9da /gcc/gimple-fold.c | |
| parent | 57b4d355a187943b042ca3e9a86bccf74c0e0d84 (diff) | |
| download | gcc-6c66f73369dacc9889cfaa05f8a08813e7c45f1f.zip gcc-6c66f73369dacc9889cfaa05f8a08813e7c45f1f.tar.gz gcc-6c66f73369dacc9889cfaa05f8a08813e7c45f1f.tar.bz2 | |
re PR tree-optimization/49073 (g++ optimizer breaks do-while code)
PR tree-optimization/49073
* gimple-fold.c (and_comparisons_1, or_comparisons_1): Return
NULL if PHI argument is SSA_NAME, whose def_stmt is dominated
by the PHI.
* tree-ssa-ifcombine.c (tree_ssa_ifcombine): Calculate dominators.
* gcc.c-torture/execute/pr49073.c: New test.
From-SVN: r173948
Diffstat (limited to 'gcc/gimple-fold.c')
| -rw-r--r-- | gcc/gimple-fold.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index e5303e3..933a47b 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -1,5 +1,5 @@ /* Statement simplification on GIMPLE. - Copyright (C) 2010 Free Software Foundation, Inc. + Copyright (C) 2010, 2011 Free Software Foundation, Inc. Split out from tree-ssa-ccp.c. This file is part of GCC. @@ -2278,8 +2278,19 @@ and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, } else if (TREE_CODE (arg) == SSA_NAME) { - tree temp = and_var_with_comparison (arg, invert, - code2, op2a, op2b); + tree temp; + gimple def_stmt = SSA_NAME_DEF_STMT (arg); + /* In simple cases we can look through PHI nodes, + but we have to be careful with loops. + See PR49073. */ + if (! dom_info_available_p (CDI_DOMINATORS) + || gimple_bb (def_stmt) == gimple_bb (stmt) + || dominated_by_p (CDI_DOMINATORS, + gimple_bb (def_stmt), + gimple_bb (stmt))) + return NULL_TREE; + temp = and_var_with_comparison (arg, invert, code2, + op2a, op2b); if (!temp) return NULL_TREE; else if (!result) @@ -2728,8 +2739,19 @@ or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, } else if (TREE_CODE (arg) == SSA_NAME) { - tree temp = or_var_with_comparison (arg, invert, - code2, op2a, op2b); + tree temp; + gimple def_stmt = SSA_NAME_DEF_STMT (arg); + /* In simple cases we can look through PHI nodes, + but we have to be careful with loops. + See PR49073. */ + if (! dom_info_available_p (CDI_DOMINATORS) + || gimple_bb (def_stmt) == gimple_bb (stmt) + || dominated_by_p (CDI_DOMINATORS, + gimple_bb (def_stmt), + gimple_bb (stmt))) + return NULL_TREE; + temp = or_var_with_comparison (arg, invert, code2, + op2a, op2b); if (!temp) return NULL_TREE; else if (!result) |