As -foffload={options,targets,targets=options} is very convoluted,
it has been split into -foffload=targets (supporting the old syntax
for backward compatibilty) and -foffload-options={options,target=options}.
Only the new syntax is documented.
Additionally, -foffload=default is supported, which can reset the
devices after -foffload=disable / -foffload=targets to the default,
if needed.
gcc/ChangeLog:
PR other/67300
* common.opt (-foffload=): Update description.
(-foffload-options=): New.
* doc/invoke.texi (C Language Options): Document
-foffload and -foffload-options.
* gcc.c (check_offload_target_name): New, split off from
handle_foffload_option.
(check_foffload_target_names): New.
(handle_foffload_option): Handle -foffload=default.
(driver_handle_option): Update for -foffload-options.
* lto-opts.c (lto_write_options): Use -foffload-options
instead of -foffload.
* lto-wrapper.c (merge_and_complain, append_offload_options):
Likewise.
* opts.c (common_handle_option): Likewise.
libgomp/ChangeLog:
PR other/67300
* testsuite/libgomp.c-c++-common/reduction-16.c: Replace
-foffload=nvptx-none= by -foffload-options=nvptx-none= to
avoid disabling other offload targets.
* testsuite/libgomp.c-c++-common/reduction-5.c: Likewise.
* testsuite/libgomp.c-c++-common/reduction-6.c: Likewise.
* testsuite/libgomp.c/target-44.c: Likewise.
libatomic isn't built for amdgcn but reduction-16.c adds it
via -foffload=-latomic when offloading for nvptx is enabled.
The following avoids linker errors when offloading to amdgcn is enabled
as well.
2021-04-21 Richard Biener <rguenther@suse.de>
libgomp/
* testsuite/libgomp.c-c++-common/reduction-16.c: Use -latomic
only on nvptx-none.
As reported here
( https://gcc.gnu.org/pipermail/gcc-patches/2020-September/553070.html ),
when running test-case libgomp.c-c++-common/reduction-16.c for powerpc host
with nvptx accelerator, we run into:
...
unresolved symbol __sync_val_compare_and_swap_16
...
I can reproduce the problem on x86_64 with a trigger patch that:
- initializes ix86_isa_flags2 to TARGET_ISA2_CX16
- enables define_expand "atomic_load<mode>" in gcc/config/i386/sync.md
for TImode
The problem is that omp-expand.c generates atomic builtin calls based on
checks whether those are supported on the host, which forces the target to
support these, even though those checks fail for the accelerator target.
Fix this by:
- adding a __sync_val_compare_and_swap_16 in libgomp for nvptx,
which falls back onto libatomic's __atomic_compare_and_swap_16
- adding -foffload=-latomic in the test-case
Tested libgomp on x86_64-linux with nvptx accelerator.
Tested libgomp with trigger patch on x86_64-linux with nvptx accelerator.
libgomp/ChangeLog:
* config/nvptx/atomic.c: New file. Add
__sync_val_compare_and_swap_16.
* testsuite/libgomp.c-c++-common/reduction-16.c: Add -latomic for
target offload_target_nvptx.
This adds support for __sync_val_compare_and_swap and
__sync_bool_compare_and_swap for 1-byte and 2-byte long
values, which are not natively supported on nvptx.
Build and reg-tested on nvptx.
Build and reg-tested libgomp on x86_64 with nvptx accelerator.
2020-07-16 Kwok Cheung Yeung <kcy@codesourcery.com>
libgcc/
* config/nvptx/atomic.c: New.
* config/nvptx/t-nvptx (LIB2ADD): Add atomic.c.
gcc/testsuite/
* gcc.target/nvptx/ia64-sync-5.c: New.
libgomp/
* testsuite/libgomp.c-c++-common/reduction-16.c: New.
