2008-11-05 Richard Guenther <rguenther@suse.de>

	PR middle-end/37742
	* tree-ssa.c (useless_type_conversion_p_1): Check different restrict
	qualified pointer conversion before stripping qualifiers.
	* gimplify.c (create_tmp_from_val): Use correctly qualified type.
	* tree-flow.h (may_propagate_address_into_dereference): Declare.
	* tree-ssa-ccp.c (may_propagate_address_into_dereference): New function.
	(ccp_fold): Use it.
	* tree-ssa-forwprop.c (rhs_to_tree): Remove useless conversions,
	properly canonicalize binary ops.
	(forward_propagate_addr_expr_1): Use
	may_propagate_address_into_dereference.

	cp/
	* decl.c (start_preparsed_function): Use the correct type for
	building the RESULT_DECL.

	* gcc.c-torture/compile/pr37742.c: New testcase.
	* g++.dg/pr37742.C: Likewise.
	* gcc.dg/tree-ssa/forwprop-7.c: Check for two volatile loads.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@141606 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 5 insertions, 15 deletions

diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 7a5233bd1f8..a04e7ca4404 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -334,10 +334,10 @@ rhs_to_tree (tree type, gimple stmt)
 {
   enum tree_code code = gimple_assign_rhs_code (stmt);
   if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS)
-    return fold_convert (type, build2 (code, type, gimple_assign_rhs1 (stmt),
-                         gimple_assign_rhs2 (stmt)));
+    return fold_build2 (code, type, gimple_assign_rhs1 (stmt),
+			gimple_assign_rhs2 (stmt));
   else if (get_gimple_rhs_class (code) == GIMPLE_UNARY_RHS)
-    return fold_convert (type, build1 (code, type, gimple_assign_rhs1 (stmt)));
+    return build1 (code, type, gimple_assign_rhs1 (stmt));
   else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS)
     return gimple_assign_rhs1 (stmt);
   else
@@ -719,12 +719,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
      propagate the ADDR_EXPR into the use of NAME and fold the result.  */
   if (TREE_CODE (lhs) == INDIRECT_REF
       && TREE_OPERAND (lhs, 0) == name
-      && useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (lhs, 0)),
-				    TREE_TYPE (def_rhs))
-      /* ???  This looks redundant, but is required for bogus types
-	 that can sometimes occur.  */
-      && useless_type_conversion_p (TREE_TYPE (lhs),
-				    TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
+      && may_propagate_address_into_dereference (def_rhs, lhs))
     {
       *lhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
       fold_stmt_inplace (use_stmt);
@@ -747,12 +742,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
      propagate the ADDR_EXPR into the use of NAME and fold the result.  */
   if (TREE_CODE (rhs) == INDIRECT_REF
       && TREE_OPERAND (rhs, 0) == name
-      && useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (rhs, 0)),
-				    TREE_TYPE (def_rhs))
-      /* ???  This looks redundant, but is required for bogus types
-	 that can sometimes occur.  */
-      && useless_type_conversion_p (TREE_TYPE (rhs),
-				    TREE_TYPE (TREE_OPERAND (def_rhs, 0))))
+      && may_propagate_address_into_dereference (def_rhs, rhs))
     {
       *rhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
       fold_stmt_inplace (use_stmt);