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authorRichard Kenner <kenner@vlsi1.ultra.nyu.edu>2004-08-31 22:28:44 +0000
committerRichard Kenner <kenner@gcc.gnu.org>2004-08-31 18:28:44 -0400
commit631b67ce1f819a4122eaf8b46f725dc5ff5ebd1d (patch)
tree364c3bbaa6a3d5a7c6377b0c8fe299b0e9f34921 /gcc/tree-cfg.c
parent149a42dd2de169de9252db751ec1200db50c23aa (diff)
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tree-cfg.c (cfg_remove_useless_stmts_bb): Also invalidate if VAL gets modified.
* tree-cfg.c (cfg_remove_useless_stmts_bb): Also invalidate if VAL gets modified. Co-Authored-By: Jeff Law <law@redhat.com> From-SVN: r86847
Diffstat (limited to 'gcc/tree-cfg.c')
-rw-r--r--gcc/tree-cfg.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index dab9125..ae9521e 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -1738,10 +1738,14 @@ cfg_remove_useless_stmts_bb (basic_block bb)
continue;
}
- /* Invalidate the var if we encounter something that could modify it. */
+ /* Invalidate the var if we encounter something that could modify it.
+ Likewise for the value it was previously set to. Note that we only
+ consider values that are either a VAR_DECL or PARM_DECL so we
+ can test for conflict very simply. */
if (TREE_CODE (stmt) == ASM_EXPR
|| (TREE_CODE (stmt) == MODIFY_EXPR
- && TREE_OPERAND (stmt, 0) == var))
+ && (TREE_OPERAND (stmt, 0) == var
+ || TREE_OPERAND (stmt, 0) == val)))
return;
bsi_next (&bsi);