2011-10-19 Tom de Vries <tom@codesourcery.com>

	PR tree-optimization/50769
	* tree-ssa-tail-merge.c (replace_block_by): Calculate phi_vuse2
	unconditionally.  Handle case that phi_vuse2 is not an SSA_NAME.  Add
	dummy argument .MEM to phi when increasing number of arguments of phi by
	redirecting edges to the block with phi.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@180197 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e67dcbf..e4a45f4 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2011-10-19  Tom de Vries  <tom@codesourcery.com>
+
+       PR tree-optimization/50769
+       * tree-ssa-tail-merge.c (replace_block_by): Calculate phi_vuse2
+       unconditionally.  Handle case that phi_vuse2 is not an SSA_NAME.  Add
+       dummy argument .MEM to phi when increasing number of arguments of phi by
+       redirecting edges to the block with phi.
+
 2011-10-19  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
        PR bootstrap/50777

diff --git a/gcc/tree-ssa-tail-merge.c b/gcc/tree-ssa-tail-merge.c
index 529388c..2a47dc6 100644 (file)
--- a/gcc/tree-ssa-tail-merge.c
+++ b/gcc/tree-ssa-tail-merge.c
@@ -1508,11 +1508,14 @@ replace_block_by (basic_block bb1, basic_block bb2, bool update_vops)
   edge e;
   edge_iterator ei;
 
+  phi_vuse2 = vop_at_entry (bb2);
+  if (phi_vuse2 != NULL_TREE && TREE_CODE (phi_vuse2) != SSA_NAME)
+    phi_vuse2 = NULL_TREE;
+
   if (update_vops)
     {
       /* Find the vops at entry of bb1 and bb2.  */
       phi_vuse1 = vop_at_entry (bb1);
-      phi_vuse2 = vop_at_entry (bb2);
 
       /* If one of the 2 not found, it means there's no need to update.  */
       update_vops = phi_vuse1 != NULL_TREE && phi_vuse2 != NULL_TREE;
@@ -1545,6 +1548,9 @@ replace_block_by (basic_block bb1, basic_block bb2, bool update_vops)
       gcc_assert (pred_edge != NULL);
       if (update_vops)
        VEC_safe_push (edge, heap, redirected_edges, pred_edge);
+      else if (phi_vuse2 && gimple_bb (SSA_NAME_DEF_STMT (phi_vuse2)) == bb2)
+       add_phi_arg (SSA_NAME_DEF_STMT (phi_vuse2), SSA_NAME_VAR (phi_vuse2),
+                    pred_edge, UNKNOWN_LOCATION);
     }
 
   /* Update the vops.  */