[PATCH] xfail and improve some failing libgomp tests

[Tom de Vries]

On 10/22/20 3:19 PM, Jakub Jelinek wrote:
> On Tue, Oct 06, 2020 at 05:45:31PM +0200, Tom de Vries wrote:
>> I've updated the patch accordingly.
>>
>> FWIW, I now run into an ICE which looks like PR96680:
> 
> With the patch I've posted today to fix up declare variant LTO handling,
> Tobias reported the patch still doesn't work, and there are two
> reasons for that.
> One is that when the base function is marked implicitly as declare target,
> we don't mark also implicitly the variants.  I'll need to ask on omp-lang
> about details for that, but generally the compiler should do it some way.
> The other one is that the way base_delay is written, it will always
> call the usleep function, which is undesirable for nvptx.  While the
> compiler will replace all direct calls to base_delay to nvptx_delay,
> the base_delay definition which calls usleep stays.
> 
> The following should work instead (I've tested it without offloading and
> Tobias with offloading):
> 

I've tested this patch in combination with:
- "[PATCH] lto: LTO cgraph support for late declare variant resolution"
  https://gcc.gnu.org/pipermail/gcc-patches/2020-October/556793.html
- "[omp, simt] Handle alternative IV"
  https://gcc.gnu.org/pipermail/gcc-patches/2020-October/555352.html
on top of commit c26d7df1031 "OpenMP: Fortran - support omp flush's
memorder clauses".

The only FAILs I see are for PR97532 (
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97532 ), 10 in total.

So, LGTM.

Thanks,
- Tom

> 2020-10-22  Jakub Jelinek  <jakub@redhat.com>
> 	    Tom de Vries  <tdevries@suse.de>
> 
> 	PR testsuite/81690
> 	* testsuite/libgomp.c/usleep.h: New file.
> 	* testsuite/libgomp.c/target-32.c: Include usleep.h.
> 	(main): Use tgt_usleep instead of usleep.
> 	* testsuite/libgomp.c/thread-limit-2.c: Include usleep.h.
> 	(main): Use tgt_usleep instead of usleep.
> 
> --- gcc/libgomp/testsuite/libgomp.c/usleep.h.jj	2020-10-22 14:45:14.034196695 +0200
> +++ gcc/libgomp/testsuite/libgomp.c/usleep.h	2020-10-22 14:48:05.186719495 +0200
> @@ -0,0 +1,24 @@
> +#include <unistd.h>
> +
> +int
> +nvptx_usleep (useconds_t d)
> +{
> +  /* This function serves as a replacement for usleep in
> +     this test case.  It does not even attempt to be functionally
> +     equivalent  - we just want some sort of delay. */
> +  int i;
> +  int N = d * 2000;
> +  for (i = 0; i < N; i++)
> +    asm volatile ("" : : : "memory");
> +  return 0;
> +}
> +
> +#pragma omp declare variant (nvptx_usleep) match(construct={target},device={arch(nvptx)})
> +#pragma omp declare variant (usleep) match(user={condition(1)})
> +int
> +tgt_usleep (useconds_t d)
> +{
> +  return 0;
> +}
> +
> +#pragma omp declare target to (nvptx_usleep, tgt_usleep)
> --- gcc/libgomp/testsuite/libgomp.c/target-32.c.jj	2020-01-12 11:54:39.037373820 +0100
> +++ gcc/libgomp/testsuite/libgomp.c/target-32.c	2020-10-22 14:46:23.211195456 +0200
> @@ -1,5 +1,6 @@
>  #include <stdlib.h>
>  #include <unistd.h>
> +#include "usleep.h"
>  
>  int main ()
>  {
> @@ -18,28 +19,28 @@ int main ()
>  
>      #pragma omp target nowait map(alloc: b) depend(in: d[2]) depend(out: d[3])
>      {
> -      usleep (1000);
> +      tgt_usleep (1000);
>        #pragma omp atomic update
>        b |= 4;
>      }
>  
>      #pragma omp target nowait map(alloc: b) depend(in: d[2]) depend(out: d[4])
>      {
> -      usleep (5000);
> +      tgt_usleep (5000);
>        #pragma omp atomic update
>        b |= 1;
>      }
>  
>      #pragma omp target nowait map(alloc: c) depend(in: d[3], d[4]) depend(out: d[5])
>      {
> -      usleep (5000);
> +      tgt_usleep (5000);
>        #pragma omp atomic update
>        c |= 8;
>      }
>  
>      #pragma omp target nowait map(alloc: c) depend(in: d[3], d[4]) depend(out: d[6])
>      {
> -      usleep (1000);
> +      tgt_usleep (1000);
>        #pragma omp atomic update
>        c |= 2;
>      }
> --- gcc/libgomp/testsuite/libgomp.c/thread-limit-2.c.jj	2020-01-12 11:54:39.037373820 +0100
> +++ gcc/libgomp/testsuite/libgomp.c/thread-limit-2.c	2020-10-22 14:57:31.957516284 +0200
> @@ -4,6 +4,7 @@
>  #include <stdlib.h>
>  #include <unistd.h>
>  #include <omp.h>
> +#include "usleep.h"
>  
>  int
>  main ()
> @@ -48,7 +49,7 @@ main ()
>  	  v = ++cnt;
>  	  if (v > 6)
>  	    abort ();
> -	  usleep (10000);
> +	  tgt_usleep (10000);
>  	  #pragma omp atomic
>  	  --cnt;
>  	}
> 
> 
> 	Jakub
>