re PR tree-optimization/69467 (Pattern X * C1 CMP 0 to X CMP 0 causes…

re PR tree-optimization/69467 (Pattern X * C1 CMP 0 to X CMP 0 causes performance drop on 32-bit x86.)

2016-01-26  Richard Biener  <rguenther@suse.de>

	PR middle-end/69467
	* match.pd: Guard X * CST CMP 0 pattern with single_use.

From-SVN: r232821

gcc/ChangeLog

 2016-01-26  Richard Biener  <rguenther@suse.de>
 
+	PR middle-end/69467
+	* match.pd: Guard X * CST CMP 0 pattern with single_use.
+
+2016-01-26  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/69452
 	* tree-ssa-loop-im.c (move_computations_dom_walker): Remove.
 	(move_computations_dom_walker::before_dom_children): Rename

gcc/match.pd

@@ -1821,12 +1821,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
 (for cmp (simple_comparison)
      scmp (swapped_simple_comparison)
  (simplify
-  (cmp (mult @0 INTEGER_CST@1) integer_zerop@2)
+  (cmp (mult@3 @0 INTEGER_CST@1) integer_zerop@2)
   /* Handle unfolded multiplication by zero.  */
   (if (integer_zerop (@1))
    (cmp @1 @2)
    (if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
-	&& TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
+	&& TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))
+	&& single_use (@3))
     /* If @1 is negative we swap the sense of the comparison.  */
     (if (tree_int_cst_sgn (@1) < 0)
      (scmp @0 @2)