Re: [PATCH] Fix architecture support in OMP_OFFLOAD_init_device for gcn

[Andrew Stubbs <ams@baylibre.com>]

On 26/01/2024 11:42, Richard Biener wrote:
> The following makes the existing architecture support check work
> instead of being optimized away (enum vs. -1).  This avoids
> later asserts when we assume such devices are never actually
> used.
> 
> Tested as previously, now the error is
> 
> libgomp: GCN fatal error: Unknown GCN agent architecture
> Runtime message: HSA_STATUS_ERROR: A generic error has occurred.
> 
> now will figure why we try to initialize that device.
> 
> OK?

OK.

> 
> libgomp/
> 	* plugin/plugin-gcn.c
> 	(EF_AMDGPU_MACH::EF_AMDGPU_MACH_UNSUPPORTED): Add.
> 	(isa_code): Return that instead of -1.
> 	(GOMP_OFFLOAD_init_device): Adjust.
> ---
>   libgomp/plugin/plugin-gcn.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/libgomp/plugin/plugin-gcn.c b/libgomp/plugin/plugin-gcn.c
> index db28781dedb..588358bbbf9 100644
> --- a/libgomp/plugin/plugin-gcn.c
> +++ b/libgomp/plugin/plugin-gcn.c
> @@ -384,6 +384,7 @@ struct gcn_image_desc
>      See https://llvm.org/docs/AMDGPUUsage.html#amdgpu-ef-amdgpu-mach-table */
>   
>   typedef enum {
> +  EF_AMDGPU_MACH_UNSUPPORTED = -1,
>     EF_AMDGPU_MACH_AMDGCN_GFX803 = 0x02a,
>     EF_AMDGPU_MACH_AMDGCN_GFX900 = 0x02c,
>     EF_AMDGPU_MACH_AMDGCN_GFX906 = 0x02f,
> @@ -1727,7 +1728,7 @@ isa_code(const char *isa) {
>     if (!strncmp (isa, gcn_gfx1100_s, gcn_isa_name_len))
>       return EF_AMDGPU_MACH_AMDGCN_GFX1100;
>   
> -  return -1;
> +  return EF_AMDGPU_MACH_UNSUPPORTED;
>   }
>   
>   /* CDNA2 devices have twice as many VGPRs compared to older devices.  */
> @@ -3374,7 +3375,7 @@ GOMP_OFFLOAD_init_device (int n)
>       return hsa_error ("Error querying the name of the agent", status);
>   
>     agent->device_isa = isa_code (agent->name);
> -  if (agent->device_isa < 0)
> +  if (agent->device_isa == EF_AMDGPU_MACH_UNSUPPORTED)
>       return hsa_error ("Unknown GCN agent architecture", HSA_STATUS_ERROR);
>   
>     status = hsa_fns.hsa_agent_get_info_fn (agent->id, HSA_AGENT_INFO_VENDOR_NAME,