re PR tree-optimization/37662 (ice: tree check: expected ssa_name, have…

re PR tree-optimization/37662 (ice: tree check: expected ssa_name, have integer_cst in get_value_range, at tree-vrp.c:612)

2008-09-30  Paolo Bonzini  <bonzini@gnu.org>

	PR tree-optimization/37662
	* tree-ssa-ccp.c (fold_gimple_assign): Invert the operands of a
	commutative binary operation if they are in the wrong order and
	fold_build2 produces non-GIMPLE.

From-SVN: r140809

gcc/ChangeLog

+2008-09-30  Paolo Bonzini  <bonzini@gnu.org>
+
+	PR tree-optimization/37662
+	* tree-ssa-ccp.c (fold_gimple_assign): Invert the operands of a
+	commutative binary operation if they are in the wrong order and
+	fold_build2 produces non-GIMPLE.
+
 2008-09-30  Jakub Jelinek  <jakub@redhat.com>
 
 	PR tree-optimization/37662

gcc/tree-ssa-ccp.c

@@ -2711,6 +2711,17 @@ fold_gimple_assign (gimple_stmt_iterator *si)
           STRIP_USELESS_TYPE_CONVERSION (result);
           if (valid_gimple_rhs_p (result))
 	    return result;
+
+	  /* Fold might have produced non-GIMPLE, so if we trust it blindly
+	     we lose canonicalization opportunities.  Do not go again
+	     through fold here though, or the same non-GIMPLE will be
+	     produced.  */
+          if (commutative_tree_code (subcode)
+              && tree_swap_operands_p (gimple_assign_rhs1 (stmt),
+                                       gimple_assign_rhs2 (stmt), false))
+            return build2 (subcode, TREE_TYPE (gimple_assign_lhs (stmt)),
+                           gimple_assign_rhs2 (stmt),
+                           gimple_assign_rhs1 (stmt));
         }
       break;