https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97444
Bug ID: 97444
Summary: [nvptx] stack atomics
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: vries at gcc dot gnu.org
Target Milestone: ---
There's currently a bunch of tests failing:
...
FAIL: gcc.dg/atomic/c11-atomic-exec-6.c -O0 execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-6.c -O1 execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-6.c -O2 execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-6.c -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-6.c -O3 -g execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-6.c -Os execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-7.c -O0 execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-7.c -O1 execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-7.c -O2 execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-7.c -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-7.c -O3 -g execution test
FAIL: gcc.dg/atomic/c11-atomic-exec-7.c -Os execution test
FAIL: gcc.dg/atomic/stdatomic-op-5.c -O0 execution test
FAIL: gcc.dg/atomic/stdatomic-op-5.c -O1 execution test
FAIL: gcc.dg/atomic/stdatomic-op-5.c -O2 execution test
FAIL: gcc.dg/atomic/stdatomic-op-5.c -O3 -g execution test
FAIL: gcc.dg/atomic/stdatomic-op-5.c -Os execution test
...
due to using atomics with stack memory.
The nvptx atomic ops do not support using stack memory.
I've been marking test-cases with atomic builtins using stack with
dg-require-effective-target sync_int_long_stack, which is ok because they're
just builtins.
But it's another thing when atomics are part of the language like in the
examples above.
In principle, it should possible to generate a run-time test using isspacep,
and switch between using an atomic op or a non-atomic fallback (that is either
an atom.add.u32, or an add.u32, because it's effectively atomic in .local
memory).
OTOH, we want a mode of operation where we generate atomics as currently,
without the runtime test to have smaller and faster code.
So, perhaps, a switch -mstack-atomics.
