Hi!
Maybe I'm just totally confused -- as so often ;-) -- but things seem
strange here:
On 2022-01-12T10:43:05+0100, Marcel Vollweiler <mar...@codesourcery.com> wrote:
> Currently omp_get_device_num does not work on gcn targets with more than
> one offload device. The reason is that GOMP_DEVICE_NUM_VAR
I understand the 'GOMP_DEVICE_NUM_VAR' "macro indirection" is so that we
define the actual symbol name ('__gomp_device_num') in one place
('libgomp/libgomp-plugin.h'), and then use it (via macro expansion) in
several places, right?
> is static in
> icv-device.c and thus "__gomp_device_num" is not visible in the offload
> image.
That behavior seems correct -- but undesired indeed?
> This patch removes "static" such that "__gomp_device_num" is now part of
> the offload image and can now be found in GOMP_OFFLOAD_load_image in the
> plugin.
That seems correct?
Or, is there a reason to have it 'static', say, so that several such
local variables can co-exist, instead of just one global one?
> This is not an issue for nvptx. There, "__gomp_device_num" is in the
> offload image even with "static".
That's unexpected then, and should be looked into?
Still, should 'static' be removed here, too?
Grüße
Thomas
> The patch was tested on x86_64-linux with amdgcn offloading with no
> regressions.
> libgomp, OpenMP: Fix issue for omp_get_device_num on gcn targets.
>
> Currently omp_get_device_num does not work on gcn targets with more than one
> offload device. The reason is that GOMP_DEVICE_NUM_VAR is static in
> icv-device.c and thus "__gomp_device_num" is not visible in the offload image.
>
> This patch removes "static" such that "__gomp_device_num" is now part of the
> offload image and can now be found in GOMP_OFFLOAD_load_image in the plugin.
>
> This is not an issue for nvptx. There, "__gomp_device_num" is in the offload
> image even with "static".
>
> libgomp/ChangeLog:
>
> * config/gcn/icv-device.c: Make GOMP_DEVICE_NUM_VAR public (remove
> "static") to make the device num available in the offload image.
>
> diff --git a/libgomp/config/gcn/icv-device.c b/libgomp/config/gcn/icv-device.c
> index fcfa0f3..f70b7e6 100644
> --- a/libgomp/config/gcn/icv-device.c
> +++ b/libgomp/config/gcn/icv-device.c
> @@ -60,7 +60,7 @@ omp_is_initial_device (void)
>
> /* This is set to the device number of current GPU during device
> initialization,
> when the offload image containing this libgomp portion is loaded. */
> -static volatile int GOMP_DEVICE_NUM_VAR;
> +volatile int GOMP_DEVICE_NUM_VAR;
>
> int
> omp_get_device_num (void)
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