re PR tree-optimization/70310 (wrong code with vector compare at -O0)

2016-03-21  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/70310
	* tree-vect-generic.c (expand_vector_condition): Fold the built
	condition.

	* gcc.dg/torture/pr70310.c: New testcase.

From-SVN: r234369

gcc/ChangeLog

+2016-03-21  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70310
+	* tree-vect-generic.c (expand_vector_condition): Fold the built
+	condition.
+
 2016-03-21  Kirill Yukhin  <kirill.yukhin@intel.com>
 
 	PR target/70293

gcc/testsuite/ChangeLog

+2016-03-21  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/70310
+	* gcc.dg/torture/pr70310.c: New testcase.
+
 2016-03-21  Kirill Yukhin  <kirill.yukhin@intel.com>
 
 	PR target/70293

gcc/testsuite/gcc.dg/torture/pr70310.c

+/* { dg-do run } */
+
+typedef unsigned char v32u8 __attribute__ ((vector_size (32)));
+
+unsigned __attribute__((noinline, noclone))
+foo(unsigned u)
+{
+  v32u8 v32u8_0 = (v32u8){} > (v32u8){-u};
+  return v32u8_0[31] + v32u8_0[0];
+}
+
+int
+main ()
+{
+  unsigned x = foo(0);
+  __builtin_printf ("%08x\n",x);
+  if (x != 0)
+    __builtin_abort();
+  return 0;
+}

gcc/tree-vect-generic.c

@@ -897,7 +897,7 @@ expand_vector_condition (gimple_stmt_iterator *gsi)
 	{
 	  tree aa1 = tree_vec_extract (gsi, comp_inner_type, a1, width, index);
 	  tree aa2 = tree_vec_extract (gsi, comp_inner_type, a2, width, index);
-	  aa = build2 (TREE_CODE (a), cond_type, aa1, aa2);
+	  aa = fold_build2 (TREE_CODE (a), cond_type, aa1, aa2);
 	}
       else
 	aa = tree_vec_extract (gsi, cond_type, a, width, index);