[OG12] amdgcn: Support AMD-specific 'isa' and 'arch' traits in OpenMP context selectors

Message ID e929111e-d5f2-8ed3-c3ec-f1280615d8fc@codesourcery.com
State Unresolved
Headers
Series [OG12] amdgcn: Support AMD-specific 'isa' and 'arch' traits in OpenMP context selectors |

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Commit Message

Paul-Antoine Arras Nov. 30, 2022, 3:32 p.m. UTC
  Hi all,

This patch adds or fixes support for various AMD 'isa' and 'arch' trait 
selectors, so as to be consistent with LLVM. It also adds test cases 
checking all supported AMD ISAs are properly recognised when used in a 
'metadirective' construct.

This patch is closely related to 
https://gcc.gnu.org/r13-4403-g1fd508744eccda but cannot be committed to 
mainline because metadirectives and dynamic context selectors have not 
landed there yet.

Can this be committed to OG12?

Thanks,
From 88522107dd39ba3ff8465cf688fe4438fa3b77b4 Mon Sep 17 00:00:00 2001
From: Paul-Antoine Arras <pa@codesourcery.com>
Date: Wed, 30 Nov 2022 14:52:55 +0100
Subject: [PATCH] amdgcn: Support AMD-specific 'isa' and 'arch' traits in
 OpenMP context selectors

Add or fix libgomp support for 'amdgcn' as arch, and 'gfx908' and 'gfx90a' as isa traits.
Add test case for all supported 'isa' values used as context selectors in a metadirective construct..

libgomp/ChangeLog:

	* config/gcn/selector.c (GOMP_evaluate_current_device): Recognise 'amdgcn' as arch, and 'gfx908' and
	'gfx90a' as isa traits.
	* testsuite/libgomp.c-c++-common/metadirective-6.c: New test.
---
 libgomp/config/gcn/selector.c                 | 15 ++++--
 .../libgomp.c-c++-common/metadirective-6.c    | 48 +++++++++++++++++++
 2 files changed, 60 insertions(+), 3 deletions(-)
 create mode 100644 libgomp/testsuite/libgomp.c-c++-common/metadirective-6.c
  

Comments

Kwok Cheung Yeung Nov. 30, 2022, 6:50 p.m. UTC | #1
Hello PA,

> --- libgomp/config/gcn/selector.c
> +++ libgomp/config/gcn/selector.c
> @@ -36,7 +36,7 @@ GOMP_evaluate_current_device (const char *kind, const char *arch,
>    if (kind && strcmp (kind, "gpu") != 0)
>      return false;
>  
> -  if (arch && strcmp (arch, "gcn") != 0)
> +  if (arch && (strcmp (arch, "gcn") != 0 || strcmp (arch, "amdgcn") != 0))
>      return false;

The logic here looks wrong to me - surely it should return false if arch 
is not 'gcn' AND it is not 'amdgcn'?

> @@ -48,8 +48,17 @@ GOMP_evaluate_current_device (const char *kind, const char *arch,
>  #endif
>  
>  #ifdef __GCN5__
> -  if (strcmp (isa, "gfx900") == 0 || strcmp (isa, "gfx906") != 0
> -      || strcmp (isa, "gfx908") == 0)
> +  if (strcmp (isa, "gfx900") == 0 || strcmp (isa, "gfx906") != 0)
> +    return true;
> +#endif
> +
> +#ifdef __CDNA1__
> +  if (strcmp (isa, "gfx908") == 0)
> +    return true;
> +#endif
> +
> +#ifdef __CDNA2__
> +  if (strcmp (isa, "gfx90a") == 0)
>      return true;
>  #endif

Okay for gfx908 and gfx90a, but is there any way of distinguishing 
between 'gfx900' and 'gfx906' ISAs? I don't think these are mutually 
compatible.

Thanks

Kwok
  
Paul-Antoine Arras Dec. 1, 2022, 11:10 a.m. UTC | #2
Hi Kwok,

On 30/11/2022 19:50, Kwok Cheung Yeung wrote:
> Hello PA,
> 
>> --- libgomp/config/gcn/selector.c
>> +++ libgomp/config/gcn/selector.c
>> @@ -36,7 +36,7 @@ GOMP_evaluate_current_device (const char *kind, 
>> const char *arch,
>>    if (kind && strcmp (kind, "gpu") != 0)
>>      return false;
>>
>> -  if (arch && strcmp (arch, "gcn") != 0)
>> +  if (arch && (strcmp (arch, "gcn") != 0 || strcmp (arch, "amdgcn") 
>> != 0))
>>      return false;
> 
> The logic here looks wrong to me - surely it should return false if arch 
> is not 'gcn' AND it is not 'amdgcn'?

Sure. Fixed in revised patch.

>> @@ -48,8 +48,17 @@ GOMP_evaluate_current_device (const char *kind, 
>> const char *arch,
>>  #endif
>>
>>  #ifdef __GCN5__
>> -  if (strcmp (isa, "gfx900") == 0 || strcmp (isa, "gfx906") != 0
>> -      || strcmp (isa, "gfx908") == 0)
>> +  if (strcmp (isa, "gfx900") == 0 || strcmp (isa, "gfx906") != 0)
>> +    return true;
>> +#endif
>> +
>> +#ifdef __CDNA1__
>> +  if (strcmp (isa, "gfx908") == 0)
>> +    return true;
>> +#endif
>> +
>> +#ifdef __CDNA2__
>> +  if (strcmp (isa, "gfx90a") == 0)
>>      return true;
>>  #endif
> 
> Okay for gfx908 and gfx90a, but is there any way of distinguishing 
> between 'gfx900' and 'gfx906' ISAs? I don't think these are mutually 
> compatible.
>

Since I did not find any existing builtin to check the exact ISA, I 
added all of them for consistency. Let me know if that looks good to you.

Thanks,
  
Andrew Stubbs Dec. 1, 2022, 12:45 p.m. UTC | #3
On 01/12/2022 11:10, Paul-Antoine Arras wrote:
> +      if (TARGET_FIJI)                                                         \
> +	builtin_define ("__FIJI__");                                           \
> +      else if (TARGET_VEGA10)                                                  \
> +	builtin_define ("__VEGA10__");                                         \
> +      else if (TARGET_VEGA20)                                                  \
> +	builtin_define ("__VEGA20__");                                         \
> +      else if (TARGET_GFX908)                                                  \
> +	builtin_define ("__GFX908__");                                         \
> +      else if (TARGET_GFX90a)                                                  \
> +	builtin_define ("__GFX90a__");                                         \
> +  } while (0)
>  

I don't think it makes sense to say __VEGA10__ when the user asked for 
-march=gfx900.

This whole naming thing is a bit of a mess already, so I think we'd do 
better to either keep the same names throughout or match what LLVM does 
(since it got to these first).

Please use "__gfx900__" etc. (lower case).

I'm half tempted to do a global search and replace on the internal 
names, but since they're not externally visible that would probably just 
be making merge conflicts for the sake of it.

Thanks

Andrew

P.S. If you want to split the patch into the GCN bits and the bits that 
depend on metadirectives then we can apply the first part to mainline 
right away.
  
Paul-Antoine Arras Dec. 1, 2022, 3:48 p.m. UTC | #4
On 01/12/2022 13:45, Andrew Stubbs wrote:
> P.S. If you want to split the patch into the GCN bits and the bits that 
> depend on metadirectives then we can apply the first part to mainline 
> right away.

So this is the OG12-specific part (including metadirective and dynamic 
context selectors) of the previous patch.

Once https://gcc.gnu.org/r13-4446-ge41b243302e996 is backported, is it 
OK for OG12?

Thanks,
  
Kwok Cheung Yeung Dec. 2, 2022, 4:51 p.m. UTC | #5
> So this is the OG12-specific part (including metadirective and dynamic 
> context selectors) of the previous patch.
> 
> Once https://gcc.gnu.org/r13-4446-ge41b243302e996 is backported, is it 
> OK for OG12?

Looks good to me, thanks!

Kwok
  

Patch

diff --git libgomp/config/gcn/selector.c libgomp/config/gcn/selector.c
index 60793fc05d3..c948497c538 100644
--- libgomp/config/gcn/selector.c
+++ libgomp/config/gcn/selector.c
@@ -36,7 +36,7 @@  GOMP_evaluate_current_device (const char *kind, const char *arch,
   if (kind && strcmp (kind, "gpu") != 0)
     return false;
 
-  if (arch && strcmp (arch, "gcn") != 0)
+  if (arch && (strcmp (arch, "gcn") != 0 || strcmp (arch, "amdgcn") != 0))
     return false;
 
   if (!isa)
@@ -48,8 +48,17 @@  GOMP_evaluate_current_device (const char *kind, const char *arch,
 #endif
 
 #ifdef __GCN5__
-  if (strcmp (isa, "gfx900") == 0 || strcmp (isa, "gfx906") != 0
-      || strcmp (isa, "gfx908") == 0)
+  if (strcmp (isa, "gfx900") == 0 || strcmp (isa, "gfx906") != 0)
+    return true;
+#endif
+
+#ifdef __CDNA1__
+  if (strcmp (isa, "gfx908") == 0)
+    return true;
+#endif
+
+#ifdef __CDNA2__
+  if (strcmp (isa, "gfx90a") == 0)
     return true;
 #endif
 
diff --git libgomp/testsuite/libgomp.c-c++-common/metadirective-6.c libgomp/testsuite/libgomp.c-c++-common/metadirective-6.c
new file mode 100644
index 00000000000..6d169001db1
--- /dev/null
+++ libgomp/testsuite/libgomp.c-c++-common/metadirective-6.c
@@ -0,0 +1,48 @@ 
+/* { dg-do link { target { offload_target_amdgcn } } } */
+/* { dg-additional-options "-foffload=-fdump-tree-omp_expand_metadirective" } */
+
+#define N 100
+
+void f (int x[], int y[], int z[])
+{
+  int i;
+
+  #pragma omp target map(to: x, y) map(from: z)
+    #pragma omp metadirective \
+      when (device={isa("gfx803")}: teams num_teams(512)) \
+      when (device={isa("gfx900")}: teams num_teams(256)) \
+      when (device={isa("gfx906")}: teams num_teams(128)) \
+      when (device={isa("gfx908")}: teams num_teams(64)) \
+      when (device={isa("gfx90a")}: teams num_teams(32)) \
+      default (teams num_teams(4))
+	for (i = 0; i < N; i++)
+	  z[i] = x[i] * y[i];
+}
+
+int main (void)
+{
+  int x[N], y[N], z[N];
+  int i;
+
+  for (i = 0; i < N; i++)
+    {
+      x[i] = i;
+      y[i] = -i;
+    }
+
+  f (x, y, z);
+
+  for (i = 0; i < N; i++)
+    if (z[i] != x[i] * y[i])
+      return 1;
+
+  return 0;
+}
+
+/* The metadirective should be resolved after Gimplification.  */
+
+/* { dg-final { scan-offload-tree-dump "__builtin_GOMP_teams4 \\(512, 512" "omp_expand_metadirective" { target { any-opts "-foffload=-march=fiji" } } } } */
+/* { dg-final { scan-offload-tree-dump "__builtin_GOMP_teams4 \\(256, 256" "omp_expand_metadirective" { target { any-opts "-foffload=-march=gfx900" } } } } */
+/* { dg-final { scan-offload-tree-dump "__builtin_GOMP_teams4 \\(128, 128" "omp_expand_metadirective" { target { any-opts "-foffload=-march=gfx906" } } } } */
+/* { dg-final { scan-offload-tree-dump "__builtin_GOMP_teams4 \\(64, 64" "omp_expand_metadirective" { target { any-opts "-foffload=-march=gfx908" } } } } */
+/* { dg-final { scan-offload-tree-dump "__builtin_GOMP_teams4 \\(32, 32" "omp_expand_metadirective" { target { any-opts "-foffload=-march=gfx90a" } } } } */