* tree-ssa-sink.c (statement_sink_location): Stop sinking expression

	if the target bb post dominates from bb.

	* config/i386/i386.c (memory_address_length): Check existence of base
	register before using it.

	* gcc.dg/tree-ssa/ssa-sink-5.c: New testcase.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@149082 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 10 insertions, 0 deletions

diff --git a/gcc/tree-ssa-sink.c b/gcc/tree-ssa-sink.c
index 227ad11253c..4f16addb323 100644
--- a/gcc/tree-ssa-sink.c
+++ b/gcc/tree-ssa-sink.c
@@ -384,6 +384,11 @@ statement_sink_location (gimple stmt, basic_block frombb,
 	  || sinkbb->loop_father != frombb->loop_father)
 	return false;
 
+      /* Move the expression to a post dominator can't reduce the number of
+         executions.  */
+      if (dominated_by_p (CDI_POST_DOMINATORS, frombb, sinkbb))
+        return false;
+
       *togsi = gsi_for_stmt (use);
       return true;
     }
@@ -411,6 +416,11 @@ statement_sink_location (gimple stmt, basic_block frombb,
       || sinkbb->loop_father != frombb->loop_father)
     return false;
 
+  /* Move the expression to a post dominator can't reduce the number of
+     executions.  */
+  if (dominated_by_p (CDI_POST_DOMINATORS, frombb, sinkbb))
+    return false;
+
   *togsi = gsi_after_labels (sinkbb);
 
   return true;