tree-ssa-dom.c (tree_ssa_dominator_optimize): Be more selective about when to iterate.

        * tree-ssa-dom.c (tree_ssa_dominator_optimize): Be more selective
        about when to iterate.

From-SVN: r104658

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4d6dd1646d97794f2fcb829b9317698d60ea5760..90efa60da0a4850adc5d2e48fd66395c0908837a 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2005-09-26  Jeff Law  <law@redhat.com>
+
+       * tree-ssa-dom.c (tree_ssa_dominator_optimize): Be more selective
+       about when to iterate.
+
 2005-09-23  Fariborz Jahanian <fjahanian@apple.com>
 
        PR target/23847

diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c
index 6d99e54364008e158c83fb22e3fa173650c1e3eb..1b78b6d5f3971b5875e90fcc8411ee4aaf2b9d57 100644 (file)
--- a/gcc/tree-ssa-dom.c
+++ b/gcc/tree-ssa-dom.c
@@ -479,7 +479,11 @@ tree_ssa_dominator_optimize (void)
       if (cfg_altered)
         free_dominance_info (CDI_DOMINATORS);
 
-      cfg_altered = cleanup_tree_cfg ();
+      /* Only iterate if we threaded jumps AND the CFG cleanup did
+        something interesting.  Other cases generate far fewer
+        optimization opportunities and thus are not worth another
+        full DOM iteration.  */
+      cfg_altered &= cleanup_tree_cfg ();
 
       if (rediscover_loops_after_threading)
        {