Re: [PATCH] Fix ix86_fp_cmp_code_to_pcmp_immediate (PR target/71559)

[Uros Bizjak <ubizjak at gmail dot com>]

On Mon, Jun 20, 2016 at 8:31 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> Hi!
>
> As discussed in the PR, this function is missing a lot of comparison codes
> that can validly appear there, and gives wrong values for the others
> except for NE.
> This patch makes those values match what %D3 emits for the AVX vcmp*p{s,d},
> there is some controversy on whether UN{GT,GE,LT,LE,EQ} and/or LTGT should
> raise exceptions or not, but that should be handled later on also together
> with the scalar code (where we never raise exceptions), SSE, AVX and this.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/6.2?
>
> 2016-06-20  Jakub Jelinek  <jakub@redhat.com>
>
>         PR target/71559
>         * config/i386/i386.c (ix86_fp_cmp_code_to_pcmp_immediate): Fix up
>         returned values and add UN*/LTGT/*ORDERED cases with values matching
>         D operand modifier on vcmp for AVX.
>
>         * gcc.target/i386/sse2-pr71559.c: New test.
>         * gcc.target/i386/avx-pr71559.c: New test.
>         * gcc.target/i386/avx512f-pr71559.c: New test.

OK for mainline and release branches after a week or so without
problems in mainline.

(I tried to review usage of all those bits, LGTM, but mistakes can happen...)

Thanks,
Uros.

> --- gcc/config/i386/i386.c.jj   2016-06-20 10:36:29.489994876 +0200
> +++ gcc/config/i386/i386.c      2016-06-20 12:07:37.311006144 +0200
> @@ -23622,17 +23622,33 @@ ix86_fp_cmp_code_to_pcmp_immediate (enum
>    switch (code)
>      {
>      case EQ:
> -      return 0x08;
> +      return 0x00;
>      case NE:
>        return 0x04;
>      case GT:
> -      return 0x16;
> +      return 0x0e;
>      case LE:
> -      return 0x1a;
> +      return 0x02;
>      case GE:
> -      return 0x15;
> +      return 0x0d;
>      case LT:
> -      return 0x19;
> +      return 0x01;
> +    case UNLE:
> +      return 0x0a;
> +    case UNLT:
> +      return 0x09;
> +    case UNGE:
> +      return 0x05;
> +    case UNGT:
> +      return 0x06;
> +    case UNEQ:
> +      return 0x18;
> +    case LTGT:
> +      return 0x0c;
> +    case ORDERED:
> +      return 0x07;
> +    case UNORDERED:
> +      return 0x03;
>      default:
>        gcc_unreachable ();
>      }
> --- gcc/testsuite/gcc.target/i386/sse2-pr71559.c.jj     2016-06-20 12:10:27.621795187 +0200
> +++ gcc/testsuite/gcc.target/i386/sse2-pr71559.c        2016-06-20 12:14:44.821457893 +0200
> @@ -0,0 +1,73 @@
> +/* PR target/71559 */
> +/* { dg-do run { target sse2 } } */
> +/* { dg-options "-O2 -ftree-vectorize -msse2" } */
> +
> +#ifndef PR71559_TEST
> +#include "sse2-check.h"
> +#define PR71559_TEST sse2_test
> +#endif
> +
> +#define N 16
> +float a[N] = { 5.0f, -3.0f, 1.0f, __builtin_nanf (""), 9.0f, 7.0f, -3.0f, -9.0f,
> +               -3.0f, -5.0f, -9.0f, __builtin_nanf (""), 0.5f, -0.5f, 0.0f, 0.0f };
> +float b[N] = { -5.0f, 3.0f, 1.0f, 7.0f, 8.0f, 8.0f, -3.0f, __builtin_nanf (""),
> +               -4.0f, -4.0f, -9.0f, __builtin_nanf (""), 0.0f, 0.0f, 0.0f, __builtin_nanf ("") };
> +int c[N], d[N];
> +
> +#define FN(name, op) \
> +void                                   \
> +name (void)                            \
> +{                                      \
> +  int i;                               \
> +  for (i = 0; i < N; i++)              \
> +    c[i] = (op || d[i] > 37) ? 5 : 32; \
> +}
> +FN (eq, a[i] == b[i])
> +FN (ne, a[i] != b[i])
> +FN (gt, a[i] > b[i])
> +FN (ge, a[i] >= b[i])
> +FN (lt, a[i] < b[i])
> +FN (le, a[i] <= b[i])
> +FN (unle, !__builtin_isgreater (a[i], b[i]))
> +FN (unlt, !__builtin_isgreaterequal (a[i], b[i]))
> +FN (unge, !__builtin_isless (a[i], b[i]))
> +FN (ungt, !__builtin_islessequal (a[i], b[i]))
> +FN (uneq, !__builtin_islessgreater (a[i], b[i]))
> +FN (ordered, !__builtin_isunordered (a[i], b[i]))
> +FN (unordered, __builtin_isunordered (a[i], b[i]))
> +
> +#define TEST(name, GT, LT, EQ, UO) \
> +  name ();                             \
> +  for (i = 0; i < N; i++)              \
> +    {                                  \
> +      int v;                           \
> +      switch (i % 4)                   \
> +       {                               \
> +       case 0: v = GT ? 5 : 32; break; \
> +       case 1: v = LT ? 5 : 32; break; \
> +       case 2: v = EQ ? 5 : 32; break; \
> +       case 3: v = UO ? 5 : 32; break; \
> +       }                               \
> +      if (c[i] != v)                   \
> +       __builtin_abort ();             \
> +    }
> +
> +void
> +PR71559_TEST (void)
> +{
> +  int i;
> +  asm volatile ("" : : "g" (a), "g" (b), "g" (c), "g" (d) : "memory");
> +  TEST (eq, 0, 0, 1, 0)
> +  TEST (ne, 1, 1, 0, 1)
> +  TEST (gt, 1, 0, 0, 0)
> +  TEST (ge, 1, 0, 1, 0)
> +  TEST (lt, 0, 1, 0, 0)
> +  TEST (le, 0, 1, 1, 0)
> +  TEST (unle, 0, 1, 1, 1)
> +  TEST (unlt, 0, 1, 0, 1)
> +  TEST (unge, 1, 0, 1, 1)
> +  TEST (ungt, 1, 0, 0, 1)
> +  TEST (uneq, 0, 0, 1, 1)
> +  TEST (ordered, 1, 1, 1, 0)
> +  TEST (unordered, 0, 0, 0, 1)
> +}
> --- gcc/testsuite/gcc.target/i386/avx-pr71559.c.jj      2016-06-20 12:10:44.028582301 +0200
> +++ gcc/testsuite/gcc.target/i386/avx-pr71559.c 2016-06-20 12:14:32.627616114 +0200
> @@ -0,0 +1,8 @@
> +/* PR target/71559 */
> +/* { dg-do run { target avx } } */
> +/* { dg-options "-O2 -ftree-vectorize -mavx" } */
> +
> +#include "avx-check.h"
> +#define PR71559_TEST avx_test
> +
> +#include "sse2-pr71559.c"
> --- gcc/testsuite/gcc.target/i386/avx512f-pr71559.c.jj  2016-06-20 12:11:32.812949299 +0200
> +++ gcc/testsuite/gcc.target/i386/avx512f-pr71559.c     2016-06-20 12:14:51.070376810 +0200
> @@ -0,0 +1,8 @@
> +/* PR target/71559 */
> +/* { dg-do run { target avx512f } } */
> +/* { dg-options "-O2 -ftree-vectorize -mavx512f" } */
> +
> +#include "avx512f-check.h"
> +#define PR71559_TEST avx512f_test
> +
> +#include "sse2-pr71559.c"
>
>         Jakub