[PATCH, rs6000] Disable gimple fold for float or double vec_minmax when fast-math is not set

HAO CHEN GUI guihaoc@linux.ibm.com
Wed Aug 25 08:17:20 GMT 2021


Hi Kewen,

   Thanks for your advice.

On 25/8/2021 下午 3:50, Kewen.Lin wrote:
> Hi Haochen,
>
> on 2021/8/25 下午3:06, HAO CHEN GUI via Gcc-patches wrote:
>> Hi,
>>
>>      I refined the patch according to Bill's advice. I pasted the ChangeLog and diff file here. If it doesn't work, please let me know. Thanks.
>>
>> 2021-08-25 Haochen Gui <guihaoc@linux.ibm.com>
>>
>> gcc/
> IIUC, this patch is for PR93127, one line for PR is missing here.
The patch does comes from the PR, but it doesn't work as the PR 
requires. So I am not sure if I should add the PR number.
>
>>      * config/rs6000/rs6000-call.c (rs6000_gimple_fold_builtin):
>>      Modify the VSX_BUILTIN_XVMINDP, ALTIVEC_BUILTIN_VMINFP,
>>      VSX_BUILTIN_XVMAXDP, ALTIVEC_BUILTIN_VMAXFP expansions.
>>
>> gcc/testsuite/
> Same, need a PR line.
>
>>      * gcc.target/powerpc/vec-minmax-1.c: New test.
>>      * gcc.target/powerpc/vec-minmax-2.c: Likewise.
>>
> Maybe it's better to use pr93127-{1,2}.c for case names?
>
> ...
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/powerpc/vec-minmax-1.c
>> @@ -0,0 +1,53 @@
>> +/* { dg-do compile { target { powerpc64le-*-* } } } */
> I guess this "powerpc64le" isn't intentional?  The test case
> has the macro to distinguish endianess, I assume we want this
> to be compiled on BE?  If so, we just put the line below instead?
It should be tested on BE as well. I will replace it with 'powerpc*-*-* 
&& lp64'.
>
> /* { dg-do compile } */
>
> And it needs extra testing on BE as well.  :)
>
> Thanks for fixing this!
>
> BR,
> Kewen
>
>> +/* { dg-require-effective-target powerpc_p9vector_ok } */
>> +/* { dg-options "-O2 -mdejagnu-cpu=power9" } */
>> +/* { dg-final { scan-assembler-times {\mxvmaxdp\M} 1 } } */
>> +/* { dg-final { scan-assembler-times {\mxvmaxsp\M} 1 } } */
>> +/* { dg-final { scan-assembler-times {\mxvmindp\M} 1 } } */
>> +/* { dg-final { scan-assembler-times {\mxvminsp\M} 1 } } */
>> +
>> +/* This test verifies that float or double vec_min/max are bound to
>> +   xv[min|max][d|s]p instructions when fast-math is not set.  */
>> +
>> +
>> +#include <altivec.h>
>> +
>> +#ifdef _BIG_ENDIAN
>> +   const int PREF_D = 0;
>> +#else
>> +   const int PREF_D = 1;
>> +#endif
>> +
>> +double vmaxd (double a, double b)
>> +{
>> +  vector double va = vec_promote (a, PREF_D);
>> +  vector double vb = vec_promote (b, PREF_D);
>> +  return vec_extract (vec_max (va, vb), PREF_D);
>> +}
>> +
>> +double vmind (double a, double b)
>> +{
>> +  vector double va = vec_promote (a, PREF_D);
>> +  vector double vb = vec_promote (b, PREF_D);
>> +  return vec_extract (vec_min (va, vb), PREF_D);
>> +}
>> +
>> +#ifdef _BIG_ENDIAN
>> +   const int PREF_F = 0;
>> +#else
>> +   const int PREF_F = 3;
>> +#endif
>> +
>> +float vmaxf (float a, float b)
>> +{
>> +  vector float va = vec_promote (a, PREF_F);
>> +  vector float vb = vec_promote (b, PREF_F);
>> +  return vec_extract (vec_max (va, vb), PREF_F);
>> +}
>> +
>> +float vminf (float a, float b)
>> +{
>> +  vector float va = vec_promote (a, PREF_F);
>> +  vector float vb = vec_promote (b, PREF_F);
>> +  return vec_extract (vec_min (va, vb), PREF_F);
>> +}
>> diff --git a/gcc/testsuite/gcc.target/powerpc/vec-minmax-2.c b/gcc/testsuite/gcc.target/powerpc/vec-minmax-2.c
>> new file mode 100644
>> index 00000000000..d318b933181
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.target/powerpc/vec-minmax-2.c
>> @@ -0,0 +1,51 @@
>> +/* { dg-do compile { target { powerpc64le-*-* } } } */
>> +/* { dg-require-effective-target powerpc_p9vector_ok } */
>> +/* { dg-options "-O2 -mdejagnu-cpu=power9 -ffast-math" } */
>> +/* { dg-final { scan-assembler-times {\mxsmaxcdp\M} 2 } } */
>> +/* { dg-final { scan-assembler-times {\mxsmincdp\M} 2 } } */
>> +
>> +/* This test verifies that float or double vec_min/max can be converted
>> +   to scalar comparison when fast-math is set.  */
>> +
>> +
>> +#include <altivec.h>
>> +
>> +#ifdef _BIG_ENDIAN
>> +   const int PREF_D = 0;
>> +#else
>> +   const int PREF_D = 1;
>> +#endif
>> +
>> +double vmaxd (double a, double b)
>> +{
>> +  vector double va = vec_promote (a, PREF_D);
>> +  vector double vb = vec_promote (b, PREF_D);
>> +  return vec_extract (vec_max (va, vb), PREF_D);
>> +}
>> +
>> +double vmind (double a, double b)
>> +{
>> +  vector double va = vec_promote (a, PREF_D);
>> +  vector double vb = vec_promote (b, PREF_D);
>> +  return vec_extract (vec_min (va, vb), PREF_D);
>> +}
>> +
>> +#ifdef _BIG_ENDIAN
>> +   const int PREF_F = 0;
>> +#else
>> +   const int PREF_F = 3;
>> +#endif
>> +
>> +float vmaxf (float a, float b)
>> +{
>> +  vector float va = vec_promote (a, PREF_F);
>> +  vector float vb = vec_promote (b, PREF_F);
>> +  return vec_extract (vec_max (va, vb), PREF_F);
>> +}
>> +
>> +float vminf (float a, float b)
>> +{
>> +  vector float va = vec_promote (a, PREF_F);
>> +  vector float vb = vec_promote (b, PREF_F);
>> +  return vec_extract (vec_min (va, vb), PREF_F);
>> +}
>>


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