diff options
Diffstat (limited to 'llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp')
| -rw-r--r-- | llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp index d2a02143e4e7..5762f1906a16 100644 --- a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp +++ b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp @@ -1026,6 +1026,51 @@ public: return N; } + /// Strip "amdgpu-no-lds-kernel-id" from any functions where we may have + /// introduced its use. If AMDGPUAttributor ran prior to the pass, we inferred + /// the lack of llvm.amdgcn.lds.kernel.id calls. + void removeNoLdsKernelIdFromReachable(CallGraph &CG, Function *KernelRoot) { + KernelRoot->removeFnAttr("amdgpu-no-lds-kernel-id"); + + SmallVector<Function *> Tmp({CG[KernelRoot]->getFunction()}); + if (!Tmp.back()) + return; + + SmallPtrSet<Function *, 8> Visited; + bool SeenUnknownCall = false; + + do { + Function *F = Tmp.pop_back_val(); + + for (auto &N : *CG[F]) { + if (!N.second) + continue; + + Function *Callee = N.second->getFunction(); + if (!Callee) { + if (!SeenUnknownCall) { + SeenUnknownCall = true; + + // If we see any indirect calls, assume nothing about potential + // targets. + // TODO: This could be refined to possible LDS global users. + for (auto &N : *CG.getExternalCallingNode()) { + Function *PotentialCallee = N.second->getFunction(); + if (!isKernelLDS(PotentialCallee)) + PotentialCallee->removeFnAttr("amdgpu-no-lds-kernel-id"); + } + + continue; + } + } + + Callee->removeFnAttr("amdgpu-no-lds-kernel-id"); + if (Visited.insert(Callee).second) + Tmp.push_back(Callee); + } + } while (!Tmp.empty()); + } + DenseMap<Function *, GlobalVariable *> lowerDynamicLDSVariables( Module &M, LDSUsesInfoTy &LDSUsesInfo, DenseSet<Function *> const &KernelsThatIndirectlyAllocateDynamicLDS, @@ -1175,6 +1220,13 @@ public: M, TableLookupVariablesOrdered, OrderedKernels, KernelToReplacement); replaceUsesInInstructionsWithTableLookup(M, TableLookupVariablesOrdered, LookupTable); + + // Strip amdgpu-no-lds-kernel-id from all functions reachable from the + // kernel. We may have inferred this wasn't used prior to the pass. + // + // TODO: We could filter out subgraphs that do not access LDS globals. + for (Function *F : KernelsThatAllocateTableLDS) + removeNoLdsKernelIdFromReachable(CG, F); } DenseMap<Function *, GlobalVariable *> KernelToCreatedDynamicLDS = |