[1/3] libgomp: Prepare for reverse offload fn lookup
Commit Message
Technically, this patch is stand alone, but conceptually it based on the
submitted but not reviewed patch:
"[Patch] OpenMP: Support reverse offload (middle end part)"
https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598662.html
With that patch, for reverse offloads ('omp target device(ancestor:1)'),
calls like the following are added:
GOMP_target_ext (-2 /* initial device */, omp_fn.1
where 'omp_fn.1' on nonhost devices a stub function just required for
looking up the host function pointer via the offload_funcs table.
The attached patch prepare for reverse-offload device->host
function-address lookup by requesting (if needed) the on-device address.
OK for mainline?
Tobias
-----------------
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Comments
On Thu, Aug 25, 2022 at 04:54:51PM +0200, Tobias Burnus wrote:
> Technically, this patch is stand alone, but conceptually it based on the
> submitted but not reviewed patch:
> "[Patch] OpenMP: Support reverse offload (middle end part)"
> https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598662.html
>
> With that patch, for reverse offloads ('omp target device(ancestor:1)'),
> calls like the following are added:
> GOMP_target_ext (-2 /* initial device */, omp_fn.1
> where 'omp_fn.1' on nonhost devices a stub function just required for
> looking up the host function pointer via the offload_funcs table.
>
> The attached patch prepare for reverse-offload device->host
> function-address lookup by requesting (if needed) the on-device address.
>
> OK for mainline?
>
> Tobias
>
>
> -----------------
> Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955
> libgomp: Prepare for reverse offload fn lookup
>
> Prepare for reverse-offloading function-pointer lookup by passing
> a rev_fn_table argument to GOMP_OFFLOAD_load_image.
>
> The argument will be NULL, unless GOMP_REQUIRES_REVERSE_OFFLOAD is
> requested and devices not supported it, are filtered out.
> (Up to and including this commit, no non-host device claims such
> support and the caller currently always passes NULL.)
>
> libgomp/ChangeLog:
>
> * libgomp-plugin.h (GOMP_OFFLOAD_load_image): Add
> 'uint64_t **rev_fn_table' argument.
> * oacc-host.c (host_load_image): Likewise.
> * plugin/plugin-gcn.c (GOMP_OFFLOAD_load_image): Likewise;
> currently unused.
> * plugin/plugin-nvptx.c (GOMP_OFFLOAD_load_image): Likewise.
> * target.c (gomp_load_image_to_device): Update call but pass
> NULL for now.
>
> liboffloadmic/ChangeLog:
>
> * plugin/libgomp-plugin-intelmic.cpp (GOMP_OFFLOAD_load_image):
> Add (unused) uint64_t **rev_fn_table argument.
Ok, thanks.
Jakub
libgomp: Prepare for reverse offload fn lookup
Prepare for reverse-offloading function-pointer lookup by passing
a rev_fn_table argument to GOMP_OFFLOAD_load_image.
The argument will be NULL, unless GOMP_REQUIRES_REVERSE_OFFLOAD is
requested and devices not supported it, are filtered out.
(Up to and including this commit, no non-host device claims such
support and the caller currently always passes NULL.)
libgomp/ChangeLog:
* libgomp-plugin.h (GOMP_OFFLOAD_load_image): Add
'uint64_t **rev_fn_table' argument.
* oacc-host.c (host_load_image): Likewise.
* plugin/plugin-gcn.c (GOMP_OFFLOAD_load_image): Likewise;
currently unused.
* plugin/plugin-nvptx.c (GOMP_OFFLOAD_load_image): Likewise.
* target.c (gomp_load_image_to_device): Update call but pass
NULL for now.
liboffloadmic/ChangeLog:
* plugin/libgomp-plugin-intelmic.cpp (GOMP_OFFLOAD_load_image):
Add (unused) uint64_t **rev_fn_table argument.
libgomp/libgomp-plugin.h | 2 +-
libgomp/oacc-host.c | 3 ++-
libgomp/plugin/plugin-gcn.c | 7 +++++--
libgomp/plugin/plugin-nvptx.c | 7 +++++--
libgomp/target.c | 2 +-
liboffloadmic/plugin/libgomp-plugin-intelmic.cpp | 3 ++-
6 files changed, 16 insertions(+), 8 deletions(-)
@@ -130,7 +130,7 @@ extern bool GOMP_OFFLOAD_init_device (int);
extern bool GOMP_OFFLOAD_fini_device (int);
extern unsigned GOMP_OFFLOAD_version (void);
extern int GOMP_OFFLOAD_load_image (int, unsigned, const void *,
- struct addr_pair **);
+ struct addr_pair **, uint64_t **);
extern bool GOMP_OFFLOAD_unload_image (int, unsigned, const void *);
extern void *GOMP_OFFLOAD_alloc (int, size_t);
extern bool GOMP_OFFLOAD_free (int, void *);
@@ -81,7 +81,8 @@ static int
host_load_image (int n __attribute__ ((unused)),
unsigned v __attribute__ ((unused)),
const void *t __attribute__ ((unused)),
- struct addr_pair **r __attribute__ ((unused)))
+ struct addr_pair **r __attribute__ ((unused)),
+ uint64_t **f __attribute__ ((unused)))
{
return 0;
}
@@ -3346,11 +3346,14 @@ GOMP_OFFLOAD_init_device (int n)
/* Load GCN object-code module described by struct gcn_image_desc in
TARGET_DATA and return references to kernel descriptors in TARGET_TABLE.
- If there are any constructors then run them. */
+ If there are any constructors then run them. If not NULL, REV_FN_TABLE will
+ contain the on-device addresses of the functions for reverse offload. To be
+ freed by the caller. */
int
GOMP_OFFLOAD_load_image (int ord, unsigned version, const void *target_data,
- struct addr_pair **target_table)
+ struct addr_pair **target_table,
+ uint64_t **rev_fn_table __attribute__((unused)))
{
if (GOMP_VERSION_DEV (version) != GOMP_VERSION_GCN)
{
@@ -1266,11 +1266,14 @@ nvptx_set_clocktick (CUmodule module, struct ptx_device *dev)
}
/* Load the (partial) program described by TARGET_DATA to device
- number ORD. Allocate and return TARGET_TABLE. */
+ number ORD. Allocate and return TARGET_TABLE. If not NULL, REV_FN_TABLE
+ will contain the on-device addresses of the functions for reverse offload.
+ To be freed by the caller. */
int
GOMP_OFFLOAD_load_image (int ord, unsigned version, const void *target_data,
- struct addr_pair **target_table)
+ struct addr_pair **target_table,
+ uint64_t **rev_fn_table __attribute__((unused)))
{
CUmodule module;
const char *const *var_names;
@@ -2137,7 +2137,7 @@ gomp_load_image_to_device (struct gomp_device_descr *devicep, unsigned version,
num_target_entries
= devicep->load_image_func (devicep->target_id, version,
- target_data, &target_table);
+ target_data, &target_table, NULL);
if (num_target_entries != num_funcs + num_vars
/* Others (device_num) are included as trailing entries in pair list. */
@@ -349,7 +349,8 @@ GOMP_OFFLOAD_version (void)
extern "C" int
GOMP_OFFLOAD_load_image (int device, const unsigned version,
- const void *target_image, addr_pair **result)
+ const void *target_image, addr_pair **result,
+ uint64_t ** /* rev_fn_table */)
{
TRACE ("(device = %d, target_image = %p)", device, target_image);