2012-09-24 Marc Glisse <marc.glisse@inria.fr>

gcc/
	* tree-ssa-forwprop.c: Include tree-ssa-propagate.h.
	(simplify_bitfield_ref): Handle constructors.
	* Makefile.in (tree-ssa-forwprop.o): Depend on tree-ssa-propagate.h.

gcc/testsuite/
	* gcc.dg/tree-ssa/forwprop-23.c: New testcase.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@191665 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 20 insertions, 9 deletions

diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 3b7991f8a1d..cd8f092915b 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -34,6 +34,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "expr.h"
 #include "cfgloop.h"
 #include "optabs.h"
+#include "tree-ssa-propagate.h"
 
 /* This pass propagates the RHS of assignment statements into use
    sites of the LHS of the assignment.  It's basically a specialized
@@ -2582,25 +2583,35 @@ simplify_bitfield_ref (gimple_stmt_iterator *gsi)
       || TREE_CODE (TREE_TYPE (op0)) != VECTOR_TYPE)
     return false;
 
+  def_stmt = get_prop_source_stmt (op0, false, NULL);
+  if (!def_stmt || !can_propagate_from (def_stmt))
+    return false;
+
+  op1 = TREE_OPERAND (op, 1);
+  op2 = TREE_OPERAND (op, 2);
+  code = gimple_assign_rhs_code (def_stmt);
+
+  if (code == CONSTRUCTOR)
+    {
+      tree tem = fold_ternary (BIT_FIELD_REF, TREE_TYPE (op),
+			       gimple_assign_rhs1 (def_stmt), op1, op2);
+      if (!tem || !valid_gimple_rhs_p (tem))
+	return false;
+      gimple_assign_set_rhs_from_tree (gsi, tem);
+      update_stmt (gsi_stmt (*gsi));
+      return true;
+    }
+
   elem_type = TREE_TYPE (TREE_TYPE (op0));
   if (TREE_TYPE (op) != elem_type)
     return false;
 
   size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type));
-  op1 = TREE_OPERAND (op, 1);
   n = TREE_INT_CST_LOW (op1) / size;
   if (n != 1)
     return false;
-
-  def_stmt = get_prop_source_stmt (op0, false, NULL);
-  if (!def_stmt || !can_propagate_from (def_stmt))
-    return false;
-
-  op2 = TREE_OPERAND (op, 2);
   idx = TREE_INT_CST_LOW (op2) / size;
 
-  code = gimple_assign_rhs_code (def_stmt);
-
   if (code == VEC_PERM_EXPR)
     {
       tree p, m, index, tem;