A splay-tree was previously used to lookup equivalent target addresses
for a given host address on offload targets. However, as splay-trees can
modify their structure on lookup, they are not suitable for concurrent
access from separate teams/threads without some form of locking. This
patch changes the lookup data structure to a hashtab instead, which does
not have these issues.
The call to build_indirect_map to initialize the data structure is now
called from just the first thread of the first team to avoid redundant
calls to this function.
2024-03-22 Kwok Cheung Yeung <kcyeung@baylibre.com>
libgomp/
* config/accel/target-indirect.c: Include string.h and hashtab.h.
Remove include of splay-tree.h. Update comments.
(splay_tree_prefix, splay_tree_c): Delete.
(struct indirect_map_t): New.
(hash_entry_type, htab_alloc, htab_free, htab_hash, htab_eq): New.
(GOMP_INDIRECT_ADD_MAP): Remove volatile qualifier.
(USE_SPLAY_TREE_LOOKUP): Rename to...
(USE_HASHTAB_LOOKUP): ..this.
(indirect_map, indirect_array): Delete.
(indirect_htab): New.
(build_indirect_map): Remove locking. Build indirect map using
hashtab.
(GOMP_target_map_indirect_ptr): Use indirect_htab to lookup target
address.
(GOMP_target_map_indirect_ptr): Remove volatile qualifier.
* config/gcn/team.c (gomp_gcn_enter_kernel): Call build_indirect_map
from first thread of first team only.
* config/nvptx/team.c (gomp_nvptx_main): Likewise.
* testsuite/libgomp.c-c++-common/declare-target-indirect-2.c (main):
Add missing break statements.
* testsuite/libgomp.fortran/declare-target-indirect-2.f90: Remove
xfail.
637e76b90e