diff options
Diffstat (limited to 'llvm/lib/Target/AMDGPU')
| -rw-r--r-- | llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp index 540ca5f399f..ff5558bf4db 100644 --- a/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp +++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp @@ -186,6 +186,13 @@ bool AMDGPUTTIImpl::isSourceOfDivergence(const Value *V) const { if (const LoadInst *Load = dyn_cast<LoadInst>(V)) return Load->getPointerAddressSpace() == AMDGPUAS::PRIVATE_ADDRESS; + // Atomics are divergent because they are executed sequentially: when an + // atomic operation refers to the same address in each thread, then each + // thread after the first sees the value written by the previous thread as + // original value. + if (isa<AtomicRMWInst>(V) || isa<AtomicCmpXchgInst>(V)) + return true; + if (const IntrinsicInst *Intrinsic = dyn_cast<IntrinsicInst>(V)) { const TargetMachine &TM = getTLI()->getTargetMachine(); return isIntrinsicSourceOfDivergence(TM.getIntrinsicInfo(), Intrinsic); |
