llvm/lib/Target/AMDGPU/AMDGPUResourceUsageAnalysis.h

   1 //===- AMDGPUResourceUsageAnalysis.h ---- analysis of resources -*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 /// \file
  10 /// \brief Analyzes how many registers and other resources are used by
  11 /// functions.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_LIB_TARGET_AMDGPU_AMDGPURESOURCEUSAGEANALYSIS_H
  16 #define LLVM_LIB_TARGET_AMDGPU_AMDGPURESOURCEUSAGEANALYSIS_H
  17
  18 #include "llvm/Analysis/CallGraphSCCPass.h"
  19 #include "llvm/CodeGen/MachineModuleInfo.h"
  20 #include "llvm/IR/ValueMap.h"
  21
  22 namespace llvm {
  23
  24 class GCNSubtarget;
  25 class MachineFunction;
  26 class TargetMachine;
  27
  28 struct AMDGPUResourceUsageAnalysis : public CallGraphSCCPass {
  29   static char ID;
  30
  31 public:
  32   // Track resource usage for callee functions.
  33   struct SIFunctionResourceInfo {
  34     // Track the number of explicitly used VGPRs. Special registers reserved at
  35     // the end are tracked separately.
  36     int32_t NumVGPR = 0;
  37     int32_t NumAGPR = 0;
  38     int32_t NumExplicitSGPR = 0;
  39     uint64_t PrivateSegmentSize = 0;
  40     bool UsesVCC = false;
  41     bool UsesFlatScratch = false;
  42     bool HasDynamicallySizedStack = false;
  43     bool HasRecursion = false;
  44     bool HasIndirectCall = false;
  45
  46     int32_t getTotalNumSGPRs(const GCNSubtarget &ST) const;
  47     int32_t getTotalNumVGPRs(const GCNSubtarget &ST) const;
  48   };
  49
  50   AMDGPUResourceUsageAnalysis() : CallGraphSCCPass(ID) {}
  51
  52   bool runOnSCC(CallGraphSCC &SCC) override;
  53
  54   bool doInitialization(CallGraph &CG) override {
  55     CallGraphResourceInfo.clear();
  56     return CallGraphSCCPass::doInitialization(CG);
  57   }
  58
  59   void getAnalysisUsage(AnalysisUsage &AU) const override {
  60     AU.addRequired<MachineModuleInfoWrapperPass>();
  61     AU.setPreservesAll();
  62   }
  63
  64   const SIFunctionResourceInfo &getResourceInfo(const Function *F) const {
  65     auto Info = CallGraphResourceInfo.find(F);
  66     assert(Info != CallGraphResourceInfo.end() &&
  67            "Failed to find resource info for function");
  68     return Info->getSecond();
  69   }
  70
  71 private:
  72   SIFunctionResourceInfo analyzeResourceUsage(const MachineFunction &MF,
  73                                               const TargetMachine &TM) const;
  74   void propagateIndirectCallRegisterUsage();
  75
  76   DenseMap<const Function *, SIFunctionResourceInfo> CallGraphResourceInfo;
  77 };
  78 } // namespace llvm
  79 #endif // LLVM_LIB_TARGET_AMDGPU_AMDGPURESOURCEUSAGEANALYSIS_H