[PATCH] Improve _fmadd__mask3

[Jakub Jelinek]

Hi!

As the testcase can show, we should be using v constraint and generate
better code that way.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2016-05-04  Jakub Jelinek  <ja...@redhat.com>

        * config/i386/sse.md (<avx512>_fmadd_<mode>_mask3<round_name>): Use
        v constraint instead of x.

        * gcc.target/i386/avx512f-vfmadd-1.c: New test.

--- gcc/config/i386/sse.md.jj   2016-05-04 14:36:08.000000000 +0200
+++ gcc/config/i386/sse.md      2016-05-04 15:16:44.180894303 +0200
@@ -3327,10 +3327,10 @@ (define_insn "<avx512>_fmadd_<mode>_mask
    (set_attr "mode" "<MODE>")])
 
 (define_insn "<avx512>_fmadd_<mode>_mask3<round_name>"
-  [(set (match_operand:VF_AVX512VL 0 "register_operand" "=x")
+  [(set (match_operand:VF_AVX512VL 0 "register_operand" "=v")
        (vec_merge:VF_AVX512VL
          (fma:VF_AVX512VL
-           (match_operand:VF_AVX512VL 1 "register_operand" "x")
+           (match_operand:VF_AVX512VL 1 "register_operand" "v")
            (match_operand:VF_AVX512VL 2 "nonimmediate_operand" 
"<round_constraint>")
            (match_operand:VF_AVX512VL 3 "register_operand" "0"))
          (match_dup 3)
--- gcc/testsuite/gcc.target/i386/avx512f-vfmadd-1.c.jj 2016-05-04 
15:35:54.919506742 +0200
+++ gcc/testsuite/gcc.target/i386/avx512f-vfmadd-1.c    2016-05-04 
15:36:08.648326113 +0200
@@ -0,0 +1,24 @@
+/* { dg-do assemble { target { avx512f && { ! ia32 } } } } */
+/* { dg-options "-O2 -mavx512f" } */
+
+#include <x86intrin.h>
+
+void
+f1 (__m512d x, __m512d y, __m512d z, __mmask8 m)
+{
+  register __m512d a __asm ("xmm16"), b __asm ("xmm17"), c __asm ("xmm18");
+  a = x; b = y; c = z;
+  asm volatile ("" : "+v" (a), "+v" (b), "+v" (c));
+  a = _mm512_mask3_fmadd_round_pd (c, b, a, m, _MM_FROUND_TO_NEG_INF | 
_MM_FROUND_NO_EXC);
+  asm volatile ("" : "+v" (a));
+}
+
+void
+f2 (__m512 x, __m512 y, __m512 z, __mmask8 m)
+{
+  register __m512 a __asm ("xmm16"), b __asm ("xmm17"), c __asm ("xmm18");
+  a = x; b = y; c = z;
+  asm volatile ("" : "+v" (a), "+v" (b), "+v" (c));
+  a = _mm512_mask3_fmadd_round_ps (c, b, a, m, _MM_FROUND_TO_NEG_INF | 
_MM_FROUND_NO_EXC);
+  asm volatile ("" : "+v" (a));
+}

        Jakub