llvm/lib/CodeGen/RegAllocPriorityAdvisor.cpp

   1 //===- RegAllocPriorityAdvisor.cpp - live ranges priority advisor ---------===//
   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 // Implementation of the default priority advisor and of the Analysis pass.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "RegAllocPriorityAdvisor.h"
  14 #include "RegAllocGreedy.h"
  15 #include "llvm/CodeGen/MachineFunction.h"
  16 #include "llvm/CodeGen/VirtRegMap.h"
  17 #include "llvm/IR/Module.h"
  18 #include "llvm/InitializePasses.h"
  19 #include "llvm/Pass.h"
  20
  21 using namespace llvm;
  22
  23 static cl::opt<RegAllocPriorityAdvisorAnalysis::AdvisorMode> Mode(
  24     "regalloc-enable-priority-advisor", cl::Hidden,
  25     cl::init(RegAllocPriorityAdvisorAnalysis::AdvisorMode::Default),
  26     cl::desc("Enable regalloc advisor mode"),
  27     cl::values(
  28         clEnumValN(RegAllocPriorityAdvisorAnalysis::AdvisorMode::Default,
  29                    "default", "Default"),
  30         clEnumValN(RegAllocPriorityAdvisorAnalysis::AdvisorMode::Release,
  31                    "release", "precompiled"),
  32         clEnumValN(RegAllocPriorityAdvisorAnalysis::AdvisorMode::Development,
  33                    "development", "for training")));
  34
  35 char RegAllocPriorityAdvisorAnalysis::ID = 0;
  36 INITIALIZE_PASS(RegAllocPriorityAdvisorAnalysis, "regalloc-priority",
  37                 "Regalloc priority policy", false, true)
  38
  39 namespace {
  40 class DefaultPriorityAdvisorAnalysis final
  41     : public RegAllocPriorityAdvisorAnalysis {
  42 public:
  43   DefaultPriorityAdvisorAnalysis(bool NotAsRequested)
  44       : RegAllocPriorityAdvisorAnalysis(AdvisorMode::Default),
  45         NotAsRequested(NotAsRequested) {}
  46
  47   // support for isa<> and dyn_cast.
  48   static bool classof(const RegAllocPriorityAdvisorAnalysis *R) {
  49     return R->getAdvisorMode() == AdvisorMode::Default;
  50   }
  51
  52 private:
  53   void getAnalysisUsage(AnalysisUsage &AU) const override {
  54     AU.addRequired<SlotIndexes>();
  55     RegAllocPriorityAdvisorAnalysis::getAnalysisUsage(AU);
  56   }
  57   std::unique_ptr<RegAllocPriorityAdvisor>
  58   getAdvisor(const MachineFunction &MF, const RAGreedy &RA) override {
  59     return std::make_unique<DefaultPriorityAdvisor>(
  60         MF, RA, &getAnalysis<SlotIndexes>());
  61   }
  62   bool doInitialization(Module &M) override {
  63     if (NotAsRequested)
  64       M.getContext().emitError("Requested regalloc priority advisor analysis "
  65                                "could be created. Using default");
  66     return RegAllocPriorityAdvisorAnalysis::doInitialization(M);
  67   }
  68   const bool NotAsRequested;
  69 };
  70 } // namespace
  71
  72 template <> Pass *llvm::callDefaultCtor<RegAllocPriorityAdvisorAnalysis>() {
  73   Pass *Ret = nullptr;
  74   switch (Mode) {
  75   case RegAllocPriorityAdvisorAnalysis::AdvisorMode::Default:
  76     Ret = new DefaultPriorityAdvisorAnalysis(/*NotAsRequested*/ false);
  77     break;
  78   case RegAllocPriorityAdvisorAnalysis::AdvisorMode::Development:
  79 #if defined(LLVM_HAVE_TFLITE)
  80     Ret = createDevelopmentModePriorityAdvisor();
  81 #endif
  82     break;
  83   case RegAllocPriorityAdvisorAnalysis::AdvisorMode::Release:
  84     Ret = createReleaseModePriorityAdvisor();
  85     break;
  86   }
  87   if (Ret)
  88     return Ret;
  89   return new DefaultPriorityAdvisorAnalysis(/*NotAsRequested*/ true);
  90 }
  91
  92 StringRef RegAllocPriorityAdvisorAnalysis::getPassName() const {
  93   switch (getAdvisorMode()) {
  94   case AdvisorMode::Default:
  95     return "Default Regalloc Priority Advisor";
  96   case AdvisorMode::Release:
  97     return "Release mode Regalloc Priority Advisor";
  98   case AdvisorMode::Development:
  99     return "Development mode Regalloc Priority Advisor";
 100   }
 101   llvm_unreachable("Unknown advisor kind");
 102 }
 103
 104 RegAllocPriorityAdvisor::RegAllocPriorityAdvisor(const MachineFunction &MF,
 105                                                  const RAGreedy &RA,
 106                                                  SlotIndexes *const Indexes)
 107     : RA(RA), LIS(RA.getLiveIntervals()), VRM(RA.getVirtRegMap()),
 108       MRI(&VRM->getRegInfo()), TRI(MF.getSubtarget().getRegisterInfo()),
 109       RegClassInfo(RA.getRegClassInfo()), Indexes(Indexes),
 110       RegClassPriorityTrumpsGlobalness(
 111           RA.getRegClassPriorityTrumpsGlobalness()),
 112       ReverseLocalAssignment(RA.getReverseLocalAssignment()) {}