[PATCH] Remove fold () dispatch from fold_gimple_assign

[Richard Biener]

After

Index: gcc/gimple-fold.c
===================================================================
--- gcc/gimple-fold.c   (revision 229518)
+++ gcc/gimple-fold.c   (working copy)
@@ -398,7 +398,10 @@ fold_gimple_assign (gimple_stmt_iterator
         /* If we couldn't fold the RHS, hand over to the generic
            fold routines.  */
         if (result == NULL_TREE)
-          result = fold (rhs);
+         {
+           result = fold (rhs);
+           gcc_assert (result == rhs);
+         }
 
         /* Strip away useless type conversions.  Both the NON_LVALUE_EXPR
            that may have been added by fold, and "useless" type

passed bootstrap and regtest on x86_64-unknown-linux-gnu I am now
testing the following.

There is still GIMPLE_TERNARY_RHS handling going via fold_ternary,
mostly for [VEC_]COND_EXPR handling not moved to match.pd
(and some others).

Richard.

2015-10-29  Richard Biener  <rguenther@suse.de>

	* gimple-fold.c (fold_gimple_assign): Do not dispatch to
	fold () on single RHSs.

Index: gcc/gimple-fold.c
===================================================================
--- gcc/gimple-fold.c	(revision 229520)
+++ gcc/gimple-fold.c	(working copy)
@@ -355,8 +355,8 @@ fold_gimple_assign (gimple_stmt_iterator
 		    return val;
 		  }
 	      }
-
 	  }
+
 	else if (TREE_CODE (rhs) == ADDR_EXPR)
 	  {
 	    tree ref = TREE_OPERAND (rhs, 0);
@@ -371,6 +371,18 @@ fold_gimple_assign (gimple_stmt_iterator
 	    else if (TREE_CODE (ref) == MEM_REF
 		     && integer_zerop (TREE_OPERAND (ref, 1)))
 	      result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0));
+
+	    if (result)
+	      {
+		/* Strip away useless type conversions.  Both the
+		   NON_LVALUE_EXPR that may have been added by fold, and
+		   "useless" type conversions that might now be apparent
+		   due to propagation.  */
+		STRIP_USELESS_TYPE_CONVERSION (result);
+
+		if (result != rhs && valid_gimple_rhs_p (result))
+		  return result;
+	      }
 	  }
 
 	else if (TREE_CODE (rhs) == CONSTRUCTOR
@@ -394,21 +406,6 @@ fold_gimple_assign (gimple_stmt_iterator
 
 	else if (DECL_P (rhs))
 	  return get_symbol_constant_value (rhs);
-
-        /* If we couldn't fold the RHS, hand over to the generic
-           fold routines.  */
-        if (result == NULL_TREE)
-          result = fold (rhs);
-
-        /* Strip away useless type conversions.  Both the NON_LVALUE_EXPR
-           that may have been added by fold, and "useless" type
-           conversions that might now be apparent due to propagation.  */
-        STRIP_USELESS_TYPE_CONVERSION (result);
-
-        if (result != rhs && valid_gimple_rhs_p (result))
-	  return result;
-
-	return NULL_TREE;
       }
       break;