tree-ssa-sccvn.c (visit_reference_op_store): Do not insert struct copies into the expression table.

2008-03-03  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-sccvn.c (visit_reference_op_store): Do not insert
	struct copies into the expression table.
	(simplify_unary_expression): Handle VIEW_CONVERT_EXPR.
	(try_to_simplify): Likewise.
	* fold-const.c (fold_unary): Fold VIEW_CONVERT_EXPR of
	integral and pointer arguments which do not change the
	precision to NOP_EXPRs.
	* tree-ssa-loop-ivopts.c (may_be_nonaddressable_p): Adjust
	VIEW_CONVERT_EXPR case.

From-SVN: r132836

gcc/ChangeLog

+2008-03-03  Richard Guenther  <rguenther@suse.de>
+
+	* tree-ssa-sccvn.c (visit_reference_op_store): Do not insert
+	struct copies into the expression table.
+	(simplify_unary_expression): Handle VIEW_CONVERT_EXPR.
+	(try_to_simplify): Likewise.
+	* fold-const.c (fold_unary): Fold VIEW_CONVERT_EXPR of
+	integral and pointer arguments which do not change the
+	precision to NOP_EXPRs.
+	* tree-ssa-loop-ivopts.c (may_be_nonaddressable_p): Adjust
+	VIEW_CONVERT_EXPR case.
+
 2008-03-02  Sebastian Pop  <sebastian.pop@amd.com>
 
 	* tree-scalar-evolution.c (instantiate_parameters_1): An SSA_NAME

gcc/fold-const.c

@@ -8277,13 +8277,28 @@ fold_unary (enum tree_code code, tree type, tree op0)
     case VIEW_CONVERT_EXPR:
       if (TREE_TYPE (op0) == type)
 	return op0;
-      if (TREE_CODE (op0) == VIEW_CONVERT_EXPR
-	  || (TREE_CODE (op0) == NOP_EXPR
-	      && INTEGRAL_TYPE_P (TREE_TYPE (op0))
-	      && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
-	      && TYPE_PRECISION (TREE_TYPE (op0))
-		 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
+      if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
 	return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
+
+      /* For integral conversions with the same precision or pointer
+	 conversions use a NOP_EXPR instead.  */
+      if ((INTEGRAL_TYPE_P (type) && INTEGRAL_TYPE_P (TREE_TYPE (op0))
+	   && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0))
+	   /* Do not muck with VIEW_CONVERT_EXPRs that convert from
+	      a sub-type to its base type as generated by the Ada FE.  */
+	   && !TREE_TYPE (TREE_TYPE (op0)))
+	  || (POINTER_TYPE_P (type) && POINTER_TYPE_P (TREE_TYPE (op0))))
+	return fold_convert (type, op0);
+
+      /* Strip inner integral conversions that do not change the precision.  */
+      if ((TREE_CODE (op0) == NOP_EXPR
+	   || TREE_CODE (op0) == CONVERT_EXPR)
+	  && INTEGRAL_TYPE_P (TREE_TYPE (op0))
+	  && INTEGRAL_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0)))
+	  && (TYPE_PRECISION (TREE_TYPE (op0))
+	      == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op0, 0)))))
+	return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
+
       return fold_view_convert_expr (type, op0);
 
     case NEGATE_EXPR:

gcc/tree-ssa-loop-ivopts.c

@@ -1525,8 +1525,8 @@ may_be_nonaddressable_p (tree expr)
 	 and make them look addressable.  After some processing the
 	 non-addressability may be uncovered again, causing ADDR_EXPRs
 	 of inappropriate objects to be built.  */
-      if (AGGREGATE_TYPE_P (TREE_TYPE (expr))
-	  && !AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
+      if (is_gimple_reg (TREE_OPERAND (expr, 0))
+	  || is_gimple_min_invariant (TREE_OPERAND (expr, 0)))
 	return true;
 
       /* ... fall through ... */

gcc/tree-ssa-sccvn.c

@@ -1259,7 +1259,10 @@ visit_reference_op_store (tree lhs, tree op, tree stmt)
 	  changed |= set_ssa_val_to (vdef, vdef);
 	}
 
-      vn_reference_insert (lhs, op, vdefs);
+      /* Do not insert structure copies into the tables.  */
+      if (is_gimple_min_invariant (op)
+	  || is_gimple_reg (op))
+        vn_reference_insert (lhs, op, vdefs);
     }
   else
     {
@@ -1497,13 +1500,15 @@ simplify_unary_expression (tree rhs)
   else if (TREE_CODE (rhs) == NOP_EXPR
 	   || TREE_CODE (rhs) == CONVERT_EXPR
 	   || TREE_CODE (rhs) == REALPART_EXPR
-	   || TREE_CODE (rhs) == IMAGPART_EXPR)
+	   || TREE_CODE (rhs) == IMAGPART_EXPR
+	   || TREE_CODE (rhs) == VIEW_CONVERT_EXPR)
     {
       /* We want to do tree-combining on conversion-like expressions.
          Make sure we feed only SSA_NAMEs or constants to fold though.  */
       tree tem = valueize_expr (VN_INFO (op0)->expr);
       if (UNARY_CLASS_P (tem)
 	  || BINARY_CLASS_P (tem)
+	  || TREE_CODE (tem) == VIEW_CONVERT_EXPR
 	  || TREE_CODE (tem) == SSA_NAME
 	  || is_gimple_min_invariant (tem))
 	op0 = tem;
@@ -1555,7 +1560,8 @@ try_to_simplify (tree stmt, tree rhs)
 
 	  /* Fallthrough for some codes that can operate on registers.  */
 	  if (!(TREE_CODE (rhs) == REALPART_EXPR
-	        || TREE_CODE (rhs) == IMAGPART_EXPR))
+	        || TREE_CODE (rhs) == IMAGPART_EXPR
+		|| TREE_CODE (rhs) == VIEW_CONVERT_EXPR))
 	    break;
 	  /* We could do a little more with unary ops, if they expand
 	     into binary ops, but it's debatable whether it is worth it. */