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| author | Jakub Jelinek <jakub@redhat.com> | 2012-01-17 11:38:38 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2012-01-17 11:38:38 +0100 |
| commit | e6fa9204e6c288f61751821d6ca23d360d6e2b5b (patch) | |
| tree | f7c316bdd47a7c81826047b8a1a4be5dcd48454f /gcc/tree-ssa-tail-merge.c | |
| parent | 6521d80a9b0372bb370bae90e1370fd88ff694c1 (diff) | |
| download | gcc-e6fa9204e6c288f61751821d6ca23d360d6e2b5b.zip gcc-e6fa9204e6c288f61751821d6ca23d360d6e2b5b.tar.gz gcc-e6fa9204e6c288f61751821d6ca23d360d6e2b5b.tar.bz2 | |
re PR tree-optimization/51877 (XEmacs miscompilation due to tail merging)
PR tree-optimization/51877
* tree-ssa-tail-merge.c (gimple_equal_p): Don't return true whenever
call arguments and fndecls compare equal, instead return false if they
don't. Return true only if lhs1 and lhs2 are either both NULL, or
both SSA_NAMEs that are valueized the same, or they satisfy
operand_equal_p.
* gcc.c-torture/execute/pr51877.c: New test.
From-SVN: r183237
Diffstat (limited to 'gcc/tree-ssa-tail-merge.c')
| -rw-r--r-- | gcc/tree-ssa-tail-merge.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c index 7452266..47dc0a6 100644 --- a/gcc/tree-ssa-tail-merge.c +++ b/gcc/tree-ssa-tail-merge.c @@ -1,5 +1,5 @@ /* Tail merging for gimple. - Copyright (C) 2011 Free Software Foundation, Inc. + Copyright (C) 2011, 2012 Free Software Foundation, Inc. Contributed by Tom de Vries (tom@codesourcery.com) This file is part of GCC. @@ -1071,14 +1071,18 @@ gimple_equal_p (same_succ same_succ, gimple s1, gimple s2) equal = false; break; } - if (equal) - return true; + if (!equal) + return false; lhs1 = gimple_get_lhs (s1); lhs2 = gimple_get_lhs (s2); - return (lhs1 != NULL_TREE && lhs2 != NULL_TREE - && TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME - && vn_valueize (lhs1) == vn_valueize (lhs2)); + if (lhs1 == NULL_TREE && lhs2 == NULL_TREE) + return true; + if (lhs1 == NULL_TREE || lhs2 == NULL_TREE) + return false; + if (TREE_CODE (lhs1) == SSA_NAME && TREE_CODE (lhs2) == SSA_NAME) + return vn_valueize (lhs1) == vn_valueize (lhs2); + return operand_equal_p (lhs1, lhs2, 0); case GIMPLE_ASSIGN: lhs1 = gimple_get_lhs (s1); |