re PR middle-end/54219 (__builtin_shuffle mask reversed)

2012-08-10  Richard Guenther  <rguenther@suse.de>

	PR middle-end/54219
	* fold-const.c (fold_ternary_loc): Do not reverse the mask
	when canonicalizing it when folding VEC_PERM_EXPR.

	* gcc.dg/torture/vector-shuffle1.c: New testcase.

From-SVN: r190297

gcc/ChangeLog

+2012-08-10  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/54219
+	* fold-const.c (fold_ternary_loc): Do not reverse the mask
+	when canonicalizing it when folding VEC_PERM_EXPR.
+
 2012-08-10  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	PR middle-end/54211

gcc/fold-const.c

@@ -14189,7 +14189,7 @@ fold_ternary_loc (location_t loc, enum tree_code code, tree type,
 	      tree *tsel = XALLOCAVEC (tree, nelts);
 	      tree eltype = TREE_TYPE (TREE_TYPE (arg2));
 	      for (i = 0; i < nelts; i++)
-		tsel[i] = build_int_cst (eltype, sel[nelts - i - 1]);
+		tsel[i] = build_int_cst (eltype, sel[i]);
 	      t = build_vector (TREE_TYPE (arg2), tsel);
 	      return build3_loc (loc, VEC_PERM_EXPR, type, op0, op1, t);
 	    }

gcc/testsuite/ChangeLog

+2012-08-10  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/54219
+	* gcc.dg/torture/vector-shuffle1.c: New testcase.
+
 2012-08-10  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>
 
 	PR middle-end/54211

gcc/testsuite/gcc.dg/torture/vector-shuffle1.c

+/* PR54219 */
+/* { dg-do run } */
+
+extern void abort (void);
+
+typedef int v2si __attribute__((vector_size(2*sizeof(int))));
+
+v2si f(v2si x)
+{
+  /* This requires canonicalization of the mask to { 1, 0 }.  */
+  return __builtin_shuffle(x,x, (v2si) { 5, 0 });
+}
+
+int main()
+{
+  v2si y = f((v2si) { 1, 2 });
+  if (y[0] != 2 || y[1] != 1)
+    abort ();
+  return 0;
+}