lib/Target/AMDGPU/AMDGPUAnnotateUniformValues.cpp

   1 //===-- AMDGPUAnnotateUniformValues.cpp - ---------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 /// \file
  11 /// This pass adds amdgpu.uniform metadata to IR values so this information
  12 /// can be used during instruction selection.
  13 //
  14 //===----------------------------------------------------------------------===//
  15
  16 #include "AMDGPU.h"
  17 #include "AMDGPUIntrinsicInfo.h"
  18 #include "llvm/Analysis/DivergenceAnalysis.h"
  19 #include "llvm/IR/InstVisitor.h"
  20 #include "llvm/IR/IRBuilder.h"
  21 #include "llvm/Support/Debug.h"
  22 #include "llvm/Support/raw_ostream.h"
  23
  24 #define DEBUG_TYPE "amdgpu-annotate-uniform"
  25
  26 using namespace llvm;
  27
  28 namespace {
  29
  30 class AMDGPUAnnotateUniformValues : public FunctionPass,
  31                        public InstVisitor<AMDGPUAnnotateUniformValues> {
  32   DivergenceAnalysis *DA;
  33
  34 public:
  35   static char ID;
  36   AMDGPUAnnotateUniformValues() :
  37     FunctionPass(ID) { }
  38   bool doInitialization(Module &M) override;
  39   bool runOnFunction(Function &F) override;
  40   const char *getPassName() const override { return "AMDGPU Annotate Uniform Values"; }
  41   void getAnalysisUsage(AnalysisUsage &AU) const override {
  42     AU.addRequired<DivergenceAnalysis>();
  43     AU.setPreservesAll();
  44  }
  45
  46   void visitLoadInst(LoadInst &I);
  47
  48 };
  49
  50 } // End anonymous namespace
  51
  52 INITIALIZE_PASS_BEGIN(AMDGPUAnnotateUniformValues, DEBUG_TYPE,
  53                       "Add AMDGPU uniform metadata", false, false)
  54 INITIALIZE_PASS_DEPENDENCY(DivergenceAnalysis)
  55 INITIALIZE_PASS_END(AMDGPUAnnotateUniformValues, DEBUG_TYPE,
  56                     "Add AMDGPU uniform metadata", false, false)
  57
  58 char AMDGPUAnnotateUniformValues::ID = 0;
  59
  60 void AMDGPUAnnotateUniformValues::visitLoadInst(LoadInst &I) {
  61   Value *Ptr = I.getPointerOperand();
  62   if (!DA->isUniform(Ptr))
  63     return;
  64
  65   if (Instruction *PtrI = dyn_cast<Instruction>(Ptr))
  66     PtrI->setMetadata("amdgpu.uniform", MDNode::get(I.getContext(), {}));
  67
  68 }
  69
  70 bool AMDGPUAnnotateUniformValues::doInitialization(Module &M) {
  71   return false;
  72 }
  73
  74 bool AMDGPUAnnotateUniformValues::runOnFunction(Function &F) {
  75   DA = &getAnalysis<DivergenceAnalysis>();
  76   visit(F);
  77
  78   return true;
  79 }
  80
  81 FunctionPass *
  82 llvm::createAMDGPUAnnotateUniformValues() {
  83   return new AMDGPUAnnotateUniformValues();
  84 }