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| author | Shilei Tian <tianshilei1992@gmail.com> | 2021-10-16 12:58:11 -0400 |
|---|---|---|
| committer | Shilei Tian <tianshilei1992@gmail.com> | 2021-10-16 12:58:29 -0400 |
| commit | 2c941fa2f9b9a93b42bdddc810a817b02a937b55 (patch) | |
| tree | a44b85ac189df92734b183405cf6c746d827a30d /clang/lib/CodeGen | |
| parent | 85b87179f4820592894d2d1da699794edf9ad6b6 (diff) | |
| download | llvm-2c941fa2f9b9a93b42bdddc810a817b02a937b55.zip llvm-2c941fa2f9b9a93b42bdddc810a817b02a937b55.tar.gz llvm-2c941fa2f9b9a93b42bdddc810a817b02a937b55.tar.bz2 | |
[OpenMP][deviceRTLs] Fix wrong return value of `__kmpc_is_spmd_exec_mode`
D110279 introduced a bug to the device runtime. In `__kmpc_parallel_51`, we detect
whether we are already in parallel region by `__kmpc_parallel_level() > __kmpc_is_spmd_exec_mode()`.
It is based on the assumption that:
- In SPMD mode, parallel level is initialized to 1.
- In generic mode, parallel level is initialized to 0.
- `__kmpc_is_spmd_exec_mode` returns `1` for SPMD mode, 0 otherwise.
Because the return value type of `__kmpc_is_spmd_exec_mode` is `int8_t`, there
was an implicit cast from `bool` to `int8_t`. We can make sure it is either 0 or
1 since C++14. In D110279, the return value is the result of an `and` operation,
which is 2 in SPMD mode. This breaks the assumption in `__kmpc_parallel_51`.
Reviewed By: carlo.bertolli, dpalermo
Differential Revision: https://reviews.llvm.org/D111905
Diffstat (limited to 'clang/lib/CodeGen')
0 files changed, 0 insertions, 0 deletions