Hi Thomas,
Am 18.01.2022 um 13:25 schrieb Thomas Schwinge:
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?
Yes, as far as I understood.
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?
Good question. In contrast to nvptx I observed that __gomp_device_num is
not part of the offload image which we read out in
GOMP_OFFLOAD_load_image ("if (status != HSA_STATUS_SUCCESS)" in
libgomp/plugin/plugin-gcn.c returns false). I validated it with some
additional output in the if-branches.
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?
Actually, I don't see the reason for the different behaviour for nvptx.
I just tested that for nvptx the correct device number is returned by
omp_get_device_num on the device - also if we have more than one device.
Still, should 'static' be removed here, too?
I wouldn't suggest unless it is really necessary? I mean, there we don't
have any issue. Although I aggree with Andrew that we could combine both
icv-device.c files into one common file.
Marcel
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