From: Steven Bosscher Date: Mon, 31 May 2004 10:18:36 +0000 (+0000) Subject: tree-ssa-dom.c (record_equivalences_from_incoming_edge): Only look at case labels... X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1c052514f657db4f56b876814fee2ffd564fae59;p=gcc.git tree-ssa-dom.c (record_equivalences_from_incoming_edge): Only look at case labels if the immediate dominator is also the only predecessor. * 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. From-SVN: r82480 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 28c70ec38eb..ca109d99911 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2004-05-31 Steven Bosscher + + * 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. + 2004-05-31 Kazu Hirata * builtins.c: Add a prototype for fold_builtin_strchr(). 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)) {