[PATCH, PR middle-end/71279] Avoid folding vec_cond_expr into comparison

[Ilya Enkovich]

Hi,

This patch disable transformation of VEC_COND_EXPR into comparison
which became invalid after boolean vectors introduciton.

Bootstrapped and regtested for x86_64-pc-linux-gnu.  OK for trunk
and gcc-6?

Thanks,
Ilya
--
gcc/

2016-05-27  Ilya Enkovich  <ilya.enkov...@intel.com>

        PR middle-end/71279
        * fold-const.c (fold_ternary_loc): Don't fold VEC_COND_EXPR
        into comparison.

gcc/testsuite/

2016-05-27  Ilya Enkovich  <ilya.enkov...@intel.com>

        PR middle-end/71279
        * gcc.dg/pr71279.c: New test.


diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 556fc73..5058746 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -11515,9 +11515,9 @@ fold_ternary_loc (location_t loc, enum tree_code code, 
tree type,
       /* Convert A ? 0 : 1 to !A.  This prefers the use of NOT_EXPR
         over COND_EXPR in cases such as floating point comparisons.  */
       if (integer_zerop (op1)
-         && (code == VEC_COND_EXPR ? integer_all_onesp (op2)
-                                   : (integer_onep (op2)
-                                      && !VECTOR_TYPE_P (type)))
+         && code == COND_EXPR
+         && integer_onep (op2)
+         && !VECTOR_TYPE_P (type)
          && truth_value_p (TREE_CODE (arg0)))
        return pedantic_non_lvalue_loc (loc,
                                    fold_convert_loc (loc, type,
diff --git a/gcc/testsuite/gcc.dg/pr71279.c b/gcc/testsuite/gcc.dg/pr71279.c
new file mode 100644
index 0000000..4ecc84b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr71279.c
@@ -0,0 +1,14 @@
+/* PR middle-end/71279 */
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+/* { dg-additional-options "-march=knl" { target { i?86-*-* x86_64-*-* } } } */
+
+extern int a, b;
+long c[1][1][1];
+long d[1][1];
+
+void fn1 ()
+{
+  for (int e = 0; e < b; e = e + 1)
+    *(e + **c) = (a && *d[1]) - 1;
+}