Commit a90a6502 authored by Austin Kerbow's avatar Austin Kerbow
Browse files

[DA][TTI][AMDGPU] Add option to select GPUDA with TTI 

Summary: Enable the new diveregence analysis by default for AMDGPU.

Reviewers: rampitec, nhaehnle, arsenm

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73049
parent 98e55477

llvm/include/llvm/Analysis/LegacyDivergenceAnalysis.h

+2 −1
Original line number Diff line number Diff line
@@ -54,7 +54,8 @@ public: 


private:

  // Whether analysis should be performed by GPUDivergenceAnalysis.

  bool shouldUseGPUDivergenceAnalysis(const Function &F) const;

  bool shouldUseGPUDivergenceAnalysis(const Function &F,

                                      const TargetTransformInfo &TTI) const;



  // (optional) handle to new DivergenceAnalysis

  std::unique_ptr<GPUDivergenceAnalysis> gpuDA;

llvm/include/llvm/Analysis/TargetTransformInfo.h

+6 −0
Original line number Diff line number Diff line
@@ -342,6 +342,10 @@ public: 
  /// branches.

  bool hasBranchDivergence() const;



  /// Return true if the target prefers to use GPU divergence analysis to

  /// replace the legacy version.

  bool useGPUDivergenceAnalysis() const;



  /// Returns whether V is a source of divergence.

  ///

  /// This function provides the target-dependent information for
@@ -1198,6 +1202,7 @@ public: 
  virtual int

  getUserCost(const User *U, ArrayRef<const Value *> Operands) = 0;

  virtual bool hasBranchDivergence() = 0;

  virtual bool useGPUDivergenceAnalysis() = 0;

  virtual bool isSourceOfDivergence(const Value *V) = 0;

  virtual bool isAlwaysUniform(const Value *V) = 0;

  virtual unsigned getFlatAddressSpace() = 0;
@@ -1452,6 +1457,7 @@ public: 
    return Impl.getUserCost(U, Operands);

  }

  bool hasBranchDivergence() override { return Impl.hasBranchDivergence(); }

  bool useGPUDivergenceAnalysis() override { return Impl.useGPUDivergenceAnalysis(); }

  bool isSourceOfDivergence(const Value *V) override {

    return Impl.isSourceOfDivergence(V);

  }

llvm/include/llvm/Analysis/TargetTransformInfoImpl.h

+2 −0
Original line number Diff line number Diff line
@@ -152,6 +152,8 @@ public: 


  bool hasBranchDivergence() { return false; }



  bool useGPUDivergenceAnalysis() { return false; }



  bool isSourceOfDivergence(const Value *V) { return false; }



  bool isAlwaysUniform(const Value *V) { return false; }

llvm/include/llvm/CodeGen/BasicTTIImpl.h

+2 −0
Original line number Diff line number Diff line
@@ -207,6 +207,8 @@ public: 


  bool hasBranchDivergence() { return false; }



  bool useGPUDivergenceAnalysis() { return false; }



  bool isSourceOfDivergence(const Value *V) { return false; }



  bool isAlwaysUniform(const Value *V) { return false; }

llvm/lib/Analysis/LegacyDivergenceAnalysis.cpp

+4 −5
Original line number Diff line number Diff line
@@ -301,14 +301,13 @@ FunctionPass *llvm::createLegacyDivergenceAnalysisPass() { 
void LegacyDivergenceAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {

  AU.addRequired<DominatorTreeWrapperPass>();

  AU.addRequired<PostDominatorTreeWrapperPass>();

  if (UseGPUDA)

  AU.addRequired<LoopInfoWrapperPass>();

  AU.setPreservesAll();

}



bool LegacyDivergenceAnalysis::shouldUseGPUDivergenceAnalysis(

    const Function &F) const {

  if (!UseGPUDA)

    const Function &F, const TargetTransformInfo &TTI) const {

  if (!(UseGPUDA || TTI.useGPUDivergenceAnalysis()))

    return false;



  // GPUDivergenceAnalysis requires a reducible CFG.
@@ -337,7 +336,7 @@ bool LegacyDivergenceAnalysis::runOnFunction(Function &F) { 
  auto &DT = getAnalysis<DominatorTreeWrapperPass>().getDomTree();

  auto &PDT = getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree();



  if (shouldUseGPUDivergenceAnalysis(F)) {

  if (shouldUseGPUDivergenceAnalysis(F, TTI)) {

    // run the new GPU divergence analysis

    auto &LI = getAnalysis<LoopInfoWrapperPass>().getLoopInfo();

    gpuDA = std::make_unique<GPUDivergenceAnalysis>(F, DT, PDT, LI, TTI);