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| author | Jeff Law <law@redhat.com> | 2006-02-10 12:22:58 -0700 |
|---|---|---|
| committer | Jeff Law <law@gcc.gnu.org> | 2006-02-10 12:22:58 -0700 |
| commit | 61864771af6d7a5834f9df225b4ddd5542d656b0 (patch) | |
| tree | 5d6054da917dffe6c192e92e66570bbe9eaddf9d /gcc/tree-ssa-threadedge.c | |
| parent | def661340610359e6eea3cdd4189089b3b9b7acd (diff) | |
| download | gcc-61864771af6d7a5834f9df225b4ddd5542d656b0.zip gcc-61864771af6d7a5834f9df225b4ddd5542d656b0.tar.gz gcc-61864771af6d7a5834f9df225b4ddd5542d656b0.tar.bz2 | |
re PR tree-optimization/26213 (new (within last few days) infinite loop with -O1)
PR tree-optimization/26213
* tree-ssa-threadedge.c (simplify_control_stmt_condition): Do not
loop trying to follow SSA_NAME_VALUE chains.
* gcc.c-torture/compile/pr26213.c: New test.
From-SVN: r110846
Diffstat (limited to 'gcc/tree-ssa-threadedge.c')
| -rw-r--r-- | gcc/tree-ssa-threadedge.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/gcc/tree-ssa-threadedge.c b/gcc/tree-ssa-threadedge.c index b8d4b13..cc98867 100644 --- a/gcc/tree-ssa-threadedge.c +++ b/gcc/tree-ssa-threadedge.c @@ -441,10 +441,14 @@ simplify_control_stmt_condition (edge e, { cached_lhs = cond; - /* Get the variable's current value from the equivalency chains. */ - while (cached_lhs - && TREE_CODE (cached_lhs) == SSA_NAME - && SSA_NAME_VALUE (cached_lhs)) + /* Get the variable's current value from the equivalency chains. + + It is possible to get loops in the SSA_NAME_VALUE chains + (consider threading the backedge of a loop where we have + a loop invariant SSA_NAME used in the condition. */ + if (cached_lhs + && TREE_CODE (cached_lhs) == SSA_NAME + && SSA_NAME_VALUE (cached_lhs)) cached_lhs = SSA_NAME_VALUE (cached_lhs); /* If we're dominated by a suitable ASSERT_EXPR, then |