[PATCH] Fix ix86_expand_vector_set (PR target/70421)

[Jakub Jelinek]

Hi!

The various blendm expanders look like:
(define_insn "<avx512>_blendm<mode>"
  [(set (match_operand:V48_AVX512VL 0 "register_operand" "=v")
        (vec_merge:V48_AVX512VL
          (match_operand:V48_AVX512VL 2 "nonimmediate_operand" "vm")
          (match_operand:V48_AVX512VL 1 "register_operand" "v")
          (match_operand:<avx512fmaskmode> 3 "register_operand" "Yk")))]
  "TARGET_AVX512F"
  "vblendm<ssemodesuffix>\t{%2, %1, %0%{%3%}|%0%{%3%}, %1, %2}"
  [(set_attr "type" "ssemov")
   (set_attr "prefix" "evex")
   (set_attr "mode" "<sseinsnmode>")])
(i.e. their operands[1] is the second argument of VEC_MERGE (aka the value
to take elements from for bits cleared in the mask), while operands[2]
is the first argument of VEC_MERGE (aka the value to take elements from for
bits set in the mask)), so the call to gen_blendm which want to insert a
single element (with index elt) into target by broadcasting val into a
temporary and using mask of 1 << elt uses wrong order of arguments.

Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux, ok for
trunk?

2016-03-27  Jakub Jelinek  <ja...@redhat.com>

        PR target/70421
        * config/i386/i386.c (ix86_expand_vector_set): Fix up argument order
        in gen_blendm expander.

        * gcc.dg/torture/pr70421.c: New test.
        * gcc.target/i386/avx512f-pr70421.c: New test.

--- gcc/config/i386/i386.c.jj   2016-03-23 10:41:12.000000000 +0100
+++ gcc/config/i386/i386.c      2016-03-27 22:32:51.748280358 +0200
@@ -46930,7 +46930,7 @@ half:
     {
       tmp = gen_reg_rtx (mode);
       emit_insn (gen_rtx_SET (tmp, gen_rtx_VEC_DUPLICATE (mode, val)));
-      emit_insn (gen_blendm (target, tmp, target,
+      emit_insn (gen_blendm (target, target, tmp,
                             force_reg (mmode,
                                        gen_int_mode (1 << elt, mmode))));
     }
--- gcc/testsuite/gcc.dg/torture/pr70421.c.jj   2016-03-29 09:25:37.015469084 
+0200
+++ gcc/testsuite/gcc.dg/torture/pr70421.c      2016-03-29 09:25:13.000000000 
+0200
@@ -0,0 +1,22 @@
+/* PR target/70421 */
+/* { dg-do run } */
+/* { dg-additional-options "-Wno-psabi -w" } */
+
+typedef unsigned V __attribute__ ((vector_size (64)));
+
+unsigned __attribute__ ((noinline, noclone))
+foo (unsigned x, V u, V v)
+{
+  v[1] ^= v[2];
+  x ^= ((V) v)[u[0]];
+  return x;
+}
+
+int
+main ()
+{
+  unsigned x = foo (0x10, (V) { 1 }, (V) { 0x100, 0x1000, 0x10000 });
+  if (x != 0x11010)
+    __builtin_abort ();
+  return 0;
+}
--- gcc/testsuite/gcc.target/i386/avx512f-pr70421.c.jj  2016-03-29 
09:26:23.380837148 +0200
+++ gcc/testsuite/gcc.target/i386/avx512f-pr70421.c     2016-03-29 
09:27:37.066832846 +0200
@@ -0,0 +1,15 @@
+/* PR target/70421 */
+/* { dg-do run } */
+/* { dg-require-effective-target avx512f } */
+/* { dg-options "-O2 -mavx512f" } */
+
+#include "avx512f-check.h"
+
+#define main() do_main()
+#include "../../gcc.dg/torture/pr70421.c"
+
+static void
+avx512f_test (void)
+{
+  do_main ();
+}

        Jakub