Andrew: Does the GCN change look okay to you?
This patch permits to use GCN devices with 'omp requires unified_address' which
in principle works already, except that the requirement handling did disable it.
(It also updates libgomp.texi for this change and likewise for an older
likewise nvptx change.)
I will later add a testcase → https://gcc.gnu.org/PR109837
However, the patch was tested with the respective sollve_vv testcase with an
additional
fix applied on top → https://github.com/SOLLVE/sollve_vv/pull/737
(I do note that with the USM patches for OG12/OG13, unified_address is accepted,
cf. OG13 https://gcc.gnu.org/g:3ddf3565faee70e8c910d90ab0c80e71813a0ba1 ,
but USM itself goes much beyond what we need here.)
Tobias
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libgomp: plugin-gcn - support 'unified_address'
Effectively, for GCN (as for nvptx) there is a common address space between
host and device, whether being accessible or not. Thus, this commit
permits to use 'omp requires unified_address' with GCN devices.
(nvptx accepts this requirement since r13-3460-g131d18e928a3ea.)
libgomp/
* plugin/plugin-gcn.c (GOMP_OFFLOAD_get_num_devices): Regard
unified_address requirement as supported.
* libgomp.texi (OpenMP 5.0, AMD Radeon, nvptx): Remove
'unified_address' from the not-supported requirements.
libgomp/libgomp.texi | 9 ++++-----
libgomp/plugin/plugin-gcn.c | 4 +++-
2 files changed, 7 insertions(+), 6 deletions(-)
diff --git a/libgomp/libgomp.texi b/libgomp/libgomp.texi
index 76c56a73969..a3d370a0fb3 100644
--- a/libgomp/libgomp.texi
+++ b/libgomp/libgomp.texi
@@ -192,8 +192,7 @@ The OpenMP 4.5 specification is fully supported.
env variable @tab Y @tab
@item Nested-parallel changes to @emph{max-active-levels-var} ICV @tab Y @tab
@item @code{requires} directive @tab P
- @tab complete but no non-host devices provides @code{unified_address} or
- @code{unified_shared_memory}
+ @tab complete but no non-host devices provides @code{unified_shared_memory}
@item @code{teams} construct outside an enclosing target region @tab Y @tab
@item Non-rectangular loop nests @tab P @tab Full support for C/C++, partial for Fortran
@item @code{!=} as relational-op in canonical loop form for C/C++ @tab Y @tab
@@ -4460,7 +4459,7 @@ The implementation remark:
@code{device(ancestor:1)}) are processed serially per @code{target} region
such that the next reverse offload region is only executed after the previous
one returned.
-@item OpenMP code that has a requires directive with @code{unified_address} or
+@item OpenMP code that has a @code{requires} directive with
@code{unified_shared_memory} will remove any GCN device from the list of
available devices (``host fallback'').
@item The available stack size can be changed using the @code{GCN_STACK_SIZE}
@@ -4522,8 +4521,8 @@ The implementation remark:
Per device, reverse offload regions are processed serially such that
the next reverse offload region is only executed after the previous
one returned.
-@item OpenMP code that has a requires directive with @code{unified_address}
- or @code{unified_shared_memory} will remove any nvptx device from the
+@item OpenMP code that has a @code{requires} directive with
+ @code{unified_shared_memory} will remove any nvptx device from the
list of available devices (``host fallback'').
@end itemize
diff --git a/libgomp/plugin/plugin-gcn.c b/libgomp/plugin/plugin-gcn.c
index 2181bf0235f..ef22d48da79 100644
--- a/libgomp/plugin/plugin-gcn.c
+++ b/libgomp/plugin/plugin-gcn.c
@@ -3231,7 +3231,9 @@ GOMP_OFFLOAD_get_num_devices (unsigned int omp_requires_mask)
/* Return -1 if no omp_requires_mask cannot be fulfilled but
devices were present. */
if (hsa_context.agent_count > 0
- && (omp_requires_mask & ~GOMP_REQUIRES_REVERSE_OFFLOAD) != 0)
+ && ((omp_requires_mask
+ & ~(GOMP_REQUIRES_UNIFIED_ADDRESS
+ | GOMP_REQUIRES_REVERSE_OFFLOAD)) != 0))
return -1;
return hsa_context.agent_count;
}
