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| author | dberlin <dberlin@138bc75d-0d04-0410-961f-82ee72b054a4> | 2005-01-22 16:48:23 +0000 |
|---|---|---|
| committer | dberlin <dberlin@138bc75d-0d04-0410-961f-82ee72b054a4> | 2005-01-22 16:48:23 +0000 |
| commit | 652a5bec83dabc21abe6bf9848cb24f4e02afc09 (patch) | |
| tree | 0a76779a7881d888f227491e074bdc5063b828ae /gcc/tree-ssa-dom.c | |
| parent | 33db115fe91a3750a83e883d475635db3a4b4d0c (diff) | |
| download | gcc-652a5bec83dabc21abe6bf9848cb24f4e02afc09.tar.gz | |
2005-01-20 Daniel Berlin <dberlin@dberlin.org>
Fix PR tree-optimization/19038
* tree-ssa-dom.c (cprop_operand): Don't replace loop invaeriant
copies with loop variant ones.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@94069 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index 35847ec3f28..68147989e49 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -2819,6 +2819,14 @@ cprop_operand (tree stmt, use_operand_p op_p) extensions. */ else if (!may_propagate_copy (op, val)) return false; + + /* Do not propagate copies if the propagated value is at a deeper loop + depth than the propagatee. Otherwise, this may move loop variant + variables outside of their loops and prevent coalescing + opportunities. If the value was loop invariant, it will be hoisted + by LICM and exposed for copy propagation. */ + if (loop_depth_of_name (val) > loop_depth_of_name (op)) + return false; /* Dump details. */ if (dump_file && (dump_flags & TDF_DETAILS)) |