diff options
| author | steven <steven@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-05-31 10:18:36 +0000 |
|---|---|---|
| committer | steven <steven@138bc75d-0d04-0410-961f-82ee72b054a4> | 2004-05-31 10:18:36 +0000 |
| commit | b787f5e5aec4e644f4dbfb9b4038f65821bf569a (patch) | |
| tree | 03546cea2e85d029b448847ecd142555b3ffec6e /gcc/tree-ssa-dom.c | |
| parent | 0f50072e9a93b49d0510128adafe9c5f22813e73 (diff) | |
| download | gcc-b787f5e5aec4e644f4dbfb9b4038f65821bf569a.tar.gz | |
* tree-ssa-dom.c (record_equivalences_from_incoming_edge):
Only look at case labels if the immediate dominator is also
the only predecessor. Don't look for more case labels if the
first seen is a case range.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@82480 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, 6 insertions, 2 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index c74dd5d5325..0ca36b09c80 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -1450,9 +1450,12 @@ record_equivalences_from_incoming_edge (struct dom_walk_data *walk_data, &bd->avail_exprs, bb, &bd->vrp_variables); - /* Similarly when the parent block ended in a SWITCH_EXPR. */ + /* Similarly when the parent block ended in a SWITCH_EXPR. + We can only know the value of the switch's condition if the dominator + parent is also the only predecessor of this block. */ else if (parent_block_last_stmt && bb->pred->pred_next == NULL + && bb->pred->src == parent && TREE_CODE (parent_block_last_stmt) == SWITCH_EXPR) { tree switch_cond = SWITCH_COND (parent_block_last_stmt); @@ -1473,7 +1476,7 @@ record_equivalences_from_incoming_edge (struct dom_walk_data *walk_data, tree elt = TREE_VEC_ELT (switch_vec, i); if (label_to_block (CASE_LABEL (elt)) == bb) { - if (++case_count > 1) + if (++case_count > 1 || CASE_HIGH (elt)) break; match_case = elt; } @@ -1484,6 +1487,7 @@ record_equivalences_from_incoming_edge (struct dom_walk_data *walk_data, the exact value of SWITCH_COND which caused us to get to this block. Record that equivalence in EQ_EXPR_VALUE. */ if (case_count == 1 + && match_case && CASE_LOW (match_case) && !CASE_HIGH (match_case)) { |