2010-12-02 Richard Guenther <rguenther@suse.de>

[pf3gnuchains/gcc-fork.git] / gcc / tree-ssa-sink.c

diff --git a/gcc/tree-ssa-sink.c b/gcc/tree-ssa-sink.c
index ac31781..bfa1a31 100644 (file)
--- a/gcc/tree-ssa-sink.c
+++ b/gcc/tree-ssa-sink.c
@@ -190,8 +190,12 @@ is_hidden_global_store (gimple stmt)
            return true;
 
        }
-      else if (INDIRECT_REF_P (lhs))
+      else if (INDIRECT_REF_P (lhs)
+              || TREE_CODE (lhs) == MEM_REF
+              || TREE_CODE (lhs) == TARGET_MEM_REF)
        return ptr_deref_may_alias_global_p (TREE_OPERAND (lhs, 0));
+      else if (CONSTANT_CLASS_P (lhs))
+       return true;
       else
        gcc_unreachable ();
     }
@@ -425,6 +429,12 @@ statement_sink_location (gimple stmt, basic_block frombb,
       || sinkbb->loop_father != frombb->loop_father)
     return false;
 
+  /* If the latch block is empty, don't make it non-empty by sinking
+     something into it.  */
+  if (sinkbb == frombb->loop_father->latch
+      && empty_block_p (sinkbb))
+    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))