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| author | Richard Biener <rguenther@suse.de> | 2017-09-26 07:29:51 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2017-09-26 07:29:51 +0000 |
| commit | 09fdb7014c9b121d4f695b1ce63d13f7e43a45c8 (patch) | |
| tree | f0340b9988503b0649b09dc8a759ee36ef684ec4 /gcc/tree-ssa-sccvn.c | |
| parent | df2a1a265d13222bd4d109eeebbb7662f24fd5b1 (diff) | |
| download | gcc-09fdb7014c9b121d4f695b1ce63d13f7e43a45c8.zip gcc-09fdb7014c9b121d4f695b1ce63d13f7e43a45c8.tar.gz gcc-09fdb7014c9b121d4f695b1ce63d13f7e43a45c8.tar.bz2 | |
re PR tree-optimization/82320 (Compile time hog w/ -O)
2017-09-26 Richard Biener <rguenther@suse.de>
PR tree-optimization/82320
* tree-ssa-sccvn.c (set_ssa_val_to): Changing undef to undef
isn't a change.
* gcc.dg/torture/pr82320.c: New testcase.
From-SVN: r253188
Diffstat (limited to 'gcc/tree-ssa-sccvn.c')
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index ca78e2d..5939749 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -3355,6 +3355,12 @@ set_ssa_val_to (tree from, tree to) if (currval != to && !operand_equal_p (currval, to, 0) + /* Different undefined SSA names are not actually different. See + PR82320 for a testcase were we'd otherwise not terminate iteration. */ + && !(TREE_CODE (currval) == SSA_NAME + && TREE_CODE (to) == SSA_NAME + && ssa_undefined_value_p (currval, false) + && ssa_undefined_value_p (to, false)) /* ??? For addresses involving volatile objects or types operand_equal_p does not reliably detect ADDR_EXPRs as equal. We know we are only getting invariant gimple addresses here, so can use |