803 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			803 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			C++
		
	
	
	
//===-------------- MIRCanonicalizer.cpp - MIR Canonicalizer --------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// The purpose of this pass is to employ a canonical code transformation so
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// that code compiled with slightly different IR passes can be diffed more
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// effectively than otherwise. This is done by renaming vregs in a given
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// LiveRange in a canonical way. This pass also does a pseudo-scheduling to
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// move defs closer to their use inorder to reduce diffs caused by slightly
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// different schedules.
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//
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// Basic Usage:
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//
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// llc -o - -run-pass mir-canonicalizer example.mir
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//
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// Reorders instructions canonically.
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// Renames virtual register operands canonically.
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// Strips certain MIR artifacts (optionally).
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/ADT/PostOrderIterator.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/CodeGen/MachineInstrBuilder.h"
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#include "llvm/CodeGen/MachineRegisterInfo.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/Support/raw_ostream.h"
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#include <queue>
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using namespace llvm;
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namespace llvm {
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extern char &MIRCanonicalizerID;
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} // namespace llvm
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#define DEBUG_TYPE "mir-canonicalizer"
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static cl::opt<unsigned>
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    CanonicalizeFunctionNumber("canon-nth-function", cl::Hidden, cl::init(~0u),
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                               cl::value_desc("N"),
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                               cl::desc("Function number to canonicalize."));
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static cl::opt<unsigned> CanonicalizeBasicBlockNumber(
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    "canon-nth-basicblock", cl::Hidden, cl::init(~0u), cl::value_desc("N"),
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    cl::desc("BasicBlock number to canonicalize."));
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namespace {
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class MIRCanonicalizer : public MachineFunctionPass {
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public:
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  static char ID;
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  MIRCanonicalizer() : MachineFunctionPass(ID) {}
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  StringRef getPassName() const override {
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    return "Rename register operands in a canonical ordering.";
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  }
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  void getAnalysisUsage(AnalysisUsage &AU) const override {
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    AU.setPreservesCFG();
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    MachineFunctionPass::getAnalysisUsage(AU);
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  }
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  bool runOnMachineFunction(MachineFunction &MF) override;
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};
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} // end anonymous namespace
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enum VRType { RSE_Reg = 0, RSE_FrameIndex, RSE_NewCandidate };
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class TypedVReg {
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  VRType type;
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  unsigned reg;
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public:
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  TypedVReg(unsigned reg) : type(RSE_Reg), reg(reg) {}
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  TypedVReg(VRType type) : type(type), reg(~0U) {
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    assert(type != RSE_Reg && "Expected a non-register type.");
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  }
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  bool isReg() const { return type == RSE_Reg; }
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  bool isFrameIndex() const { return type == RSE_FrameIndex; }
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  bool isCandidate() const { return type == RSE_NewCandidate; }
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  VRType getType() const { return type; }
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  unsigned getReg() const {
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    assert(this->isReg() && "Expected a virtual or physical register.");
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    return reg;
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  }
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};
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char MIRCanonicalizer::ID;
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char &llvm::MIRCanonicalizerID = MIRCanonicalizer::ID;
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INITIALIZE_PASS_BEGIN(MIRCanonicalizer, "mir-canonicalizer",
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                      "Rename Register Operands Canonically", false, false)
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INITIALIZE_PASS_END(MIRCanonicalizer, "mir-canonicalizer",
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                    "Rename Register Operands Canonically", false, false)
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static std::vector<MachineBasicBlock *> GetRPOList(MachineFunction &MF) {
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  ReversePostOrderTraversal<MachineBasicBlock *> RPOT(&*MF.begin());
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  std::vector<MachineBasicBlock *> RPOList;
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  for (auto MBB : RPOT) {
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    RPOList.push_back(MBB);
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  }
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  return RPOList;
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}
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static bool
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rescheduleLexographically(std::vector<MachineInstr *> instructions,
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                          MachineBasicBlock *MBB,
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                          std::function<MachineBasicBlock::iterator()> getPos) {
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  bool Changed = false;
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  using StringInstrPair = std::pair<std::string, MachineInstr *>;
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  std::vector<StringInstrPair> StringInstrMap;
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  for (auto *II : instructions) {
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    std::string S;
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    raw_string_ostream OS(S);
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    II->print(OS);
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    OS.flush();
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    // Trim the assignment, or start from the begining in the case of a store.
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    const size_t i = S.find("=");
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    StringInstrMap.push_back({(i == std::string::npos) ? S : S.substr(i), II});
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  }
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  llvm::sort(StringInstrMap,
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             [](const StringInstrPair &a, const StringInstrPair &b) -> bool {
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               return (a.first < b.first);
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             });
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  for (auto &II : StringInstrMap) {
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    LLVM_DEBUG({
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      dbgs() << "Splicing ";
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      II.second->dump();
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      dbgs() << " right before: ";
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      getPos()->dump();
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    });
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    Changed = true;
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    MBB->splice(getPos(), MBB, II.second);
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  }
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  return Changed;
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}
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static bool rescheduleCanonically(unsigned &PseudoIdempotentInstCount,
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                                  MachineBasicBlock *MBB) {
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  bool Changed = false;
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  // Calculates the distance of MI from the begining of its parent BB.
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  auto getInstrIdx = [](const MachineInstr &MI) {
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    unsigned i = 0;
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    for (auto &CurMI : *MI.getParent()) {
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      if (&CurMI == &MI)
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        return i;
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      i++;
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    }
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    return ~0U;
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  };
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  // Pre-Populate vector of instructions to reschedule so that we don't
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  // clobber the iterator.
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  std::vector<MachineInstr *> Instructions;
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  for (auto &MI : *MBB) {
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    Instructions.push_back(&MI);
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  }
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  std::map<MachineInstr *, std::vector<MachineInstr *>> MultiUsers;
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  std::vector<MachineInstr *> PseudoIdempotentInstructions;
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  std::vector<unsigned> PhysRegDefs;
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  for (auto *II : Instructions) {
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    for (unsigned i = 1; i < II->getNumOperands(); i++) {
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      MachineOperand &MO = II->getOperand(i);
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      if (!MO.isReg())
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        continue;
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      if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
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        continue;
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      if (!MO.isDef())
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        continue;
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      PhysRegDefs.push_back(MO.getReg());
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    }
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  }
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  for (auto *II : Instructions) {
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    if (II->getNumOperands() == 0)
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      continue;
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    if (II->mayLoadOrStore())
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      continue;
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    MachineOperand &MO = II->getOperand(0);
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    if (!MO.isReg() || !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
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      continue;
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    if (!MO.isDef())
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      continue;
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    bool IsPseudoIdempotent = true;
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    for (unsigned i = 1; i < II->getNumOperands(); i++) {
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      if (II->getOperand(i).isImm()) {
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        continue;
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      }
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      if (II->getOperand(i).isReg()) {
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        if (!TargetRegisterInfo::isVirtualRegister(II->getOperand(i).getReg()))
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          if (llvm::find(PhysRegDefs, II->getOperand(i).getReg()) ==
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              PhysRegDefs.end()) {
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            continue;
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          }
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      }
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      IsPseudoIdempotent = false;
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      break;
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    }
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    if (IsPseudoIdempotent) {
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      PseudoIdempotentInstructions.push_back(II);
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      continue;
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    }
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    LLVM_DEBUG(dbgs() << "Operand " << 0 << " of "; II->dump(); MO.dump(););
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    MachineInstr *Def = II;
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    unsigned Distance = ~0U;
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    MachineInstr *UseToBringDefCloserTo = nullptr;
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    MachineRegisterInfo *MRI = &MBB->getParent()->getRegInfo();
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    for (auto &UO : MRI->use_nodbg_operands(MO.getReg())) {
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      MachineInstr *UseInst = UO.getParent();
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      const unsigned DefLoc = getInstrIdx(*Def);
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      const unsigned UseLoc = getInstrIdx(*UseInst);
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      const unsigned Delta = (UseLoc - DefLoc);
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      if (UseInst->getParent() != Def->getParent())
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        continue;
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      if (DefLoc >= UseLoc)
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        continue;
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      if (Delta < Distance) {
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        Distance = Delta;
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        UseToBringDefCloserTo = UseInst;
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      }
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    }
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    const auto BBE = MBB->instr_end();
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    MachineBasicBlock::iterator DefI = BBE;
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    MachineBasicBlock::iterator UseI = BBE;
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    for (auto BBI = MBB->instr_begin(); BBI != BBE; ++BBI) {
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      if (DefI != BBE && UseI != BBE)
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        break;
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      if (&*BBI == Def) {
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        DefI = BBI;
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        continue;
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      }
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      if (&*BBI == UseToBringDefCloserTo) {
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        UseI = BBI;
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        continue;
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      }
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    }
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    if (DefI == BBE || UseI == BBE)
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      continue;
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    LLVM_DEBUG({
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      dbgs() << "Splicing ";
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      DefI->dump();
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      dbgs() << " right before: ";
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      UseI->dump();
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    });
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    MultiUsers[UseToBringDefCloserTo].push_back(Def);
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    Changed = true;
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    MBB->splice(UseI, MBB, DefI);
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  }
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  // Sort the defs for users of multiple defs lexographically.
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  for (const auto &E : MultiUsers) {
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    auto UseI =
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        std::find_if(MBB->instr_begin(), MBB->instr_end(),
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                     [&](MachineInstr &MI) -> bool { return &MI == E.first; });
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    if (UseI == MBB->instr_end())
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      continue;
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    LLVM_DEBUG(
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        dbgs() << "Rescheduling Multi-Use Instructions Lexographically.";);
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    Changed |= rescheduleLexographically(
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        E.second, MBB, [&]() -> MachineBasicBlock::iterator { return UseI; });
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  }
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  PseudoIdempotentInstCount = PseudoIdempotentInstructions.size();
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  LLVM_DEBUG(
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      dbgs() << "Rescheduling Idempotent Instructions Lexographically.";);
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  Changed |= rescheduleLexographically(
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      PseudoIdempotentInstructions, MBB,
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      [&]() -> MachineBasicBlock::iterator { return MBB->begin(); });
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  return Changed;
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}
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static bool propagateLocalCopies(MachineBasicBlock *MBB) {
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  bool Changed = false;
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  MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
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  std::vector<MachineInstr *> Copies;
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  for (MachineInstr &MI : MBB->instrs()) {
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    if (MI.isCopy())
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      Copies.push_back(&MI);
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  }
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  for (MachineInstr *MI : Copies) {
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    if (!MI->getOperand(0).isReg())
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      continue;
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    if (!MI->getOperand(1).isReg())
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      continue;
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    const unsigned Dst = MI->getOperand(0).getReg();
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    const unsigned Src = MI->getOperand(1).getReg();
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    if (!TargetRegisterInfo::isVirtualRegister(Dst))
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      continue;
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    if (!TargetRegisterInfo::isVirtualRegister(Src))
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      continue;
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    if (MRI.getRegClass(Dst) != MRI.getRegClass(Src))
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      continue;
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    for (auto UI = MRI.use_begin(Dst); UI != MRI.use_end(); ++UI) {
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      MachineOperand *MO = &*UI;
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      MO->setReg(Src);
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      Changed = true;
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    }
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    MI->eraseFromParent();
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  }
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  return Changed;
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}
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/// Here we find our candidates. What makes an interesting candidate?
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/// An candidate for a canonicalization tree root is normally any kind of
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/// instruction that causes side effects such as a store to memory or a copy to
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/// a physical register or a return instruction. We use these as an expression
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/// tree root that we walk inorder to build a canonical walk which should result
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/// in canoncal vreg renaming.
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static std::vector<MachineInstr *> populateCandidates(MachineBasicBlock *MBB) {
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  std::vector<MachineInstr *> Candidates;
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  MachineRegisterInfo &MRI = MBB->getParent()->getRegInfo();
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  for (auto II = MBB->begin(), IE = MBB->end(); II != IE; ++II) {
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    MachineInstr *MI = &*II;
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    bool DoesMISideEffect = false;
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    if (MI->getNumOperands() > 0 && MI->getOperand(0).isReg()) {
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      const unsigned Dst = MI->getOperand(0).getReg();
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      DoesMISideEffect |= !TargetRegisterInfo::isVirtualRegister(Dst);
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      for (auto UI = MRI.use_begin(Dst); UI != MRI.use_end(); ++UI) {
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        if (DoesMISideEffect)
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          break;
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        DoesMISideEffect |= (UI->getParent()->getParent() != MI->getParent());
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      }
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    }
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    if (!MI->mayStore() && !MI->isBranch() && !DoesMISideEffect)
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      continue;
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    LLVM_DEBUG(dbgs() << "Found Candidate:  "; MI->dump(););
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    Candidates.push_back(MI);
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  }
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  return Candidates;
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}
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static void doCandidateWalk(std::vector<TypedVReg> &VRegs,
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                            std::queue<TypedVReg> &RegQueue,
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                            std::vector<MachineInstr *> &VisitedMIs,
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                            const MachineBasicBlock *MBB) {
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  const MachineFunction &MF = *MBB->getParent();
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  const MachineRegisterInfo &MRI = MF.getRegInfo();
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  while (!RegQueue.empty()) {
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    auto TReg = RegQueue.front();
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    RegQueue.pop();
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    if (TReg.isFrameIndex()) {
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      LLVM_DEBUG(dbgs() << "Popping frame index.\n";);
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      VRegs.push_back(TypedVReg(RSE_FrameIndex));
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      continue;
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    }
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    assert(TReg.isReg() && "Expected vreg or physreg.");
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    unsigned Reg = TReg.getReg();
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    if (TargetRegisterInfo::isVirtualRegister(Reg)) {
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      LLVM_DEBUG({
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        dbgs() << "Popping vreg ";
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        MRI.def_begin(Reg)->dump();
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        dbgs() << "\n";
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      });
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      if (!llvm::any_of(VRegs, [&](const TypedVReg &TR) {
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            return TR.isReg() && TR.getReg() == Reg;
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          })) {
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        VRegs.push_back(TypedVReg(Reg));
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      }
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    } else {
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      LLVM_DEBUG(dbgs() << "Popping physreg.\n";);
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      VRegs.push_back(TypedVReg(Reg));
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      continue;
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    }
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    for (auto RI = MRI.def_begin(Reg), RE = MRI.def_end(); RI != RE; ++RI) {
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      MachineInstr *Def = RI->getParent();
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      if (Def->getParent() != MBB)
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        continue;
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      if (llvm::any_of(VisitedMIs,
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                       [&](const MachineInstr *VMI) { return Def == VMI; })) {
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        break;
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      }
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      LLVM_DEBUG({
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        dbgs() << "\n========================\n";
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        dbgs() << "Visited MI: ";
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        Def->dump();
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        dbgs() << "BB Name: " << Def->getParent()->getName() << "\n";
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        dbgs() << "\n========================\n";
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      });
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      VisitedMIs.push_back(Def);
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      for (unsigned I = 1, E = Def->getNumOperands(); I != E; ++I) {
 | 
						|
 | 
						|
        MachineOperand &MO = Def->getOperand(I);
 | 
						|
        if (MO.isFI()) {
 | 
						|
          LLVM_DEBUG(dbgs() << "Pushing frame index.\n";);
 | 
						|
          RegQueue.push(TypedVReg(RSE_FrameIndex));
 | 
						|
        }
 | 
						|
 | 
						|
        if (!MO.isReg())
 | 
						|
          continue;
 | 
						|
        RegQueue.push(TypedVReg(MO.getReg()));
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
}
 | 
						|
 | 
						|
namespace {
 | 
						|
class NamedVRegCursor {
 | 
						|
  MachineRegisterInfo &MRI;
 | 
						|
  unsigned virtualVRegNumber;
 | 
						|
 | 
						|
public:
 | 
						|
  NamedVRegCursor(MachineRegisterInfo &MRI) : MRI(MRI) {
 | 
						|
    unsigned VRegGapIndex = 0;
 | 
						|
    const unsigned VR_GAP = (++VRegGapIndex * 1000);
 | 
						|
 | 
						|
    unsigned I = MRI.createIncompleteVirtualRegister();
 | 
						|
    const unsigned E = (((I + VR_GAP) / VR_GAP) + 1) * VR_GAP;
 | 
						|
 | 
						|
    virtualVRegNumber = E;
 | 
						|
  }
 | 
						|
 | 
						|
  void SkipVRegs() {
 | 
						|
    unsigned VRegGapIndex = 1;
 | 
						|
    const unsigned VR_GAP = (++VRegGapIndex * 1000);
 | 
						|
 | 
						|
    unsigned I = virtualVRegNumber;
 | 
						|
    const unsigned E = (((I + VR_GAP) / VR_GAP) + 1) * VR_GAP;
 | 
						|
 | 
						|
    virtualVRegNumber = E;
 | 
						|
  }
 | 
						|
 | 
						|
  unsigned getVirtualVReg() const { return virtualVRegNumber; }
 | 
						|
 | 
						|
  unsigned incrementVirtualVReg(unsigned incr = 1) {
 | 
						|
    virtualVRegNumber += incr;
 | 
						|
    return virtualVRegNumber;
 | 
						|
  }
 | 
						|
 | 
						|
  unsigned createVirtualRegister(const TargetRegisterClass *RC) {
 | 
						|
    std::string S;
 | 
						|
    raw_string_ostream OS(S);
 | 
						|
    OS << "namedVReg" << (virtualVRegNumber & ~0x80000000);
 | 
						|
    OS.flush();
 | 
						|
    virtualVRegNumber++;
 | 
						|
 | 
						|
    return MRI.createVirtualRegister(RC, OS.str());
 | 
						|
  }
 | 
						|
};
 | 
						|
} // namespace
 | 
						|
 | 
						|
static std::map<unsigned, unsigned>
 | 
						|
GetVRegRenameMap(const std::vector<TypedVReg> &VRegs,
 | 
						|
                 const std::vector<unsigned> &renamedInOtherBB,
 | 
						|
                 MachineRegisterInfo &MRI, NamedVRegCursor &NVC) {
 | 
						|
  std::map<unsigned, unsigned> VRegRenameMap;
 | 
						|
  bool FirstCandidate = true;
 | 
						|
 | 
						|
  for (auto &vreg : VRegs) {
 | 
						|
    if (vreg.isFrameIndex()) {
 | 
						|
      // We skip one vreg for any frame index because there is a good chance
 | 
						|
      // (especially when comparing SelectionDAG to GlobalISel generated MIR)
 | 
						|
      // that in the other file we are just getting an incoming vreg that comes
 | 
						|
      // from a copy from a frame index. So it's safe to skip by one.
 | 
						|
      unsigned LastRenameReg = NVC.incrementVirtualVReg();
 | 
						|
      (void)LastRenameReg;
 | 
						|
      LLVM_DEBUG(dbgs() << "Skipping rename for FI " << LastRenameReg << "\n";);
 | 
						|
      continue;
 | 
						|
    } else if (vreg.isCandidate()) {
 | 
						|
 | 
						|
      // After the first candidate, for every subsequent candidate, we skip mod
 | 
						|
      // 10 registers so that the candidates are more likely to start at the
 | 
						|
      // same vreg number making it more likely that the canonical walk from the
 | 
						|
      // candidate insruction. We don't need to skip from the first candidate of
 | 
						|
      // the BasicBlock because we already skip ahead several vregs for each BB.
 | 
						|
      unsigned LastRenameReg = NVC.getVirtualVReg();
 | 
						|
      if (FirstCandidate)
 | 
						|
        NVC.incrementVirtualVReg(LastRenameReg % 10);
 | 
						|
      FirstCandidate = false;
 | 
						|
      continue;
 | 
						|
    } else if (!TargetRegisterInfo::isVirtualRegister(vreg.getReg())) {
 | 
						|
      unsigned LastRenameReg = NVC.incrementVirtualVReg();
 | 
						|
      (void)LastRenameReg;
 | 
						|
      LLVM_DEBUG({
 | 
						|
        dbgs() << "Skipping rename for Phys Reg " << LastRenameReg << "\n";
 | 
						|
      });
 | 
						|
      continue;
 | 
						|
    }
 | 
						|
 | 
						|
    auto Reg = vreg.getReg();
 | 
						|
    if (llvm::find(renamedInOtherBB, Reg) != renamedInOtherBB.end()) {
 | 
						|
      LLVM_DEBUG(dbgs() << "Vreg " << Reg
 | 
						|
                        << " already renamed in other BB.\n";);
 | 
						|
      continue;
 | 
						|
    }
 | 
						|
 | 
						|
    auto Rename = NVC.createVirtualRegister(MRI.getRegClass(Reg));
 | 
						|
 | 
						|
    if (VRegRenameMap.find(Reg) == VRegRenameMap.end()) {
 | 
						|
      LLVM_DEBUG(dbgs() << "Mapping vreg ";);
 | 
						|
      if (MRI.reg_begin(Reg) != MRI.reg_end()) {
 | 
						|
        LLVM_DEBUG(auto foo = &*MRI.reg_begin(Reg); foo->dump(););
 | 
						|
      } else {
 | 
						|
        LLVM_DEBUG(dbgs() << Reg;);
 | 
						|
      }
 | 
						|
      LLVM_DEBUG(dbgs() << " to ";);
 | 
						|
      if (MRI.reg_begin(Rename) != MRI.reg_end()) {
 | 
						|
        LLVM_DEBUG(auto foo = &*MRI.reg_begin(Rename); foo->dump(););
 | 
						|
      } else {
 | 
						|
        LLVM_DEBUG(dbgs() << Rename;);
 | 
						|
      }
 | 
						|
      LLVM_DEBUG(dbgs() << "\n";);
 | 
						|
 | 
						|
      VRegRenameMap.insert(std::pair<unsigned, unsigned>(Reg, Rename));
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  return VRegRenameMap;
 | 
						|
}
 | 
						|
 | 
						|
static bool doVRegRenaming(std::vector<unsigned> &RenamedInOtherBB,
 | 
						|
                           const std::map<unsigned, unsigned> &VRegRenameMap,
 | 
						|
                           MachineRegisterInfo &MRI) {
 | 
						|
  bool Changed = false;
 | 
						|
  for (auto I = VRegRenameMap.begin(), E = VRegRenameMap.end(); I != E; ++I) {
 | 
						|
 | 
						|
    auto VReg = I->first;
 | 
						|
    auto Rename = I->second;
 | 
						|
 | 
						|
    RenamedInOtherBB.push_back(Rename);
 | 
						|
 | 
						|
    std::vector<MachineOperand *> RenameMOs;
 | 
						|
    for (auto &MO : MRI.reg_operands(VReg)) {
 | 
						|
      RenameMOs.push_back(&MO);
 | 
						|
    }
 | 
						|
 | 
						|
    for (auto *MO : RenameMOs) {
 | 
						|
      Changed = true;
 | 
						|
      MO->setReg(Rename);
 | 
						|
 | 
						|
      if (!MO->isDef())
 | 
						|
        MO->setIsKill(false);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  return Changed;
 | 
						|
}
 | 
						|
 | 
						|
static bool doDefKillClear(MachineBasicBlock *MBB) {
 | 
						|
  bool Changed = false;
 | 
						|
 | 
						|
  for (auto &MI : *MBB) {
 | 
						|
    for (auto &MO : MI.operands()) {
 | 
						|
      if (!MO.isReg())
 | 
						|
        continue;
 | 
						|
      if (!MO.isDef() && MO.isKill()) {
 | 
						|
        Changed = true;
 | 
						|
        MO.setIsKill(false);
 | 
						|
      }
 | 
						|
 | 
						|
      if (MO.isDef() && MO.isDead()) {
 | 
						|
        Changed = true;
 | 
						|
        MO.setIsDead(false);
 | 
						|
      }
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  return Changed;
 | 
						|
}
 | 
						|
 | 
						|
static bool runOnBasicBlock(MachineBasicBlock *MBB,
 | 
						|
                            std::vector<StringRef> &bbNames,
 | 
						|
                            std::vector<unsigned> &renamedInOtherBB,
 | 
						|
                            unsigned &basicBlockNum, unsigned &VRegGapIndex,
 | 
						|
                            NamedVRegCursor &NVC) {
 | 
						|
 | 
						|
  if (CanonicalizeBasicBlockNumber != ~0U) {
 | 
						|
    if (CanonicalizeBasicBlockNumber != basicBlockNum++)
 | 
						|
      return false;
 | 
						|
    LLVM_DEBUG(dbgs() << "\n Canonicalizing BasicBlock " << MBB->getName()
 | 
						|
                      << "\n";);
 | 
						|
  }
 | 
						|
 | 
						|
  if (llvm::find(bbNames, MBB->getName()) != bbNames.end()) {
 | 
						|
    LLVM_DEBUG({
 | 
						|
      dbgs() << "Found potentially duplicate BasicBlocks: " << MBB->getName()
 | 
						|
             << "\n";
 | 
						|
    });
 | 
						|
    return false;
 | 
						|
  }
 | 
						|
 | 
						|
  LLVM_DEBUG({
 | 
						|
    dbgs() << "\n\n  NEW BASIC BLOCK: " << MBB->getName() << "  \n\n";
 | 
						|
    dbgs() << "\n\n================================================\n\n";
 | 
						|
  });
 | 
						|
 | 
						|
  bool Changed = false;
 | 
						|
  MachineFunction &MF = *MBB->getParent();
 | 
						|
  MachineRegisterInfo &MRI = MF.getRegInfo();
 | 
						|
 | 
						|
  bbNames.push_back(MBB->getName());
 | 
						|
  LLVM_DEBUG(dbgs() << "\n\n NEW BASIC BLOCK: " << MBB->getName() << "\n\n";);
 | 
						|
 | 
						|
  LLVM_DEBUG(dbgs() << "MBB Before Canonical Copy Propagation:\n";
 | 
						|
             MBB->dump(););
 | 
						|
  Changed |= propagateLocalCopies(MBB);
 | 
						|
  LLVM_DEBUG(dbgs() << "MBB After Canonical Copy Propagation:\n"; MBB->dump(););
 | 
						|
 | 
						|
  LLVM_DEBUG(dbgs() << "MBB Before Scheduling:\n"; MBB->dump(););
 | 
						|
  unsigned IdempotentInstCount = 0;
 | 
						|
  Changed |= rescheduleCanonically(IdempotentInstCount, MBB);
 | 
						|
  LLVM_DEBUG(dbgs() << "MBB After Scheduling:\n"; MBB->dump(););
 | 
						|
 | 
						|
  std::vector<MachineInstr *> Candidates = populateCandidates(MBB);
 | 
						|
  std::vector<MachineInstr *> VisitedMIs;
 | 
						|
  llvm::copy(Candidates, std::back_inserter(VisitedMIs));
 | 
						|
 | 
						|
  std::vector<TypedVReg> VRegs;
 | 
						|
  for (auto candidate : Candidates) {
 | 
						|
    VRegs.push_back(TypedVReg(RSE_NewCandidate));
 | 
						|
 | 
						|
    std::queue<TypedVReg> RegQueue;
 | 
						|
 | 
						|
    // Here we walk the vreg operands of a non-root node along our walk.
 | 
						|
    // The root nodes are the original candidates (stores normally).
 | 
						|
    // These are normally not the root nodes (except for the case of copies to
 | 
						|
    // physical registers).
 | 
						|
    for (unsigned i = 1; i < candidate->getNumOperands(); i++) {
 | 
						|
      if (candidate->mayStore() || candidate->isBranch())
 | 
						|
        break;
 | 
						|
 | 
						|
      MachineOperand &MO = candidate->getOperand(i);
 | 
						|
      if (!(MO.isReg() && TargetRegisterInfo::isVirtualRegister(MO.getReg())))
 | 
						|
        continue;
 | 
						|
 | 
						|
      LLVM_DEBUG(dbgs() << "Enqueue register"; MO.dump(); dbgs() << "\n";);
 | 
						|
      RegQueue.push(TypedVReg(MO.getReg()));
 | 
						|
    }
 | 
						|
 | 
						|
    // Here we walk the root candidates. We start from the 0th operand because
 | 
						|
    // the root is normally a store to a vreg.
 | 
						|
    for (unsigned i = 0; i < candidate->getNumOperands(); i++) {
 | 
						|
 | 
						|
      if (!candidate->mayStore() && !candidate->isBranch())
 | 
						|
        break;
 | 
						|
 | 
						|
      MachineOperand &MO = candidate->getOperand(i);
 | 
						|
 | 
						|
      // TODO: Do we want to only add vregs here?
 | 
						|
      if (!MO.isReg() && !MO.isFI())
 | 
						|
        continue;
 | 
						|
 | 
						|
      LLVM_DEBUG(dbgs() << "Enqueue Reg/FI"; MO.dump(); dbgs() << "\n";);
 | 
						|
 | 
						|
      RegQueue.push(MO.isReg() ? TypedVReg(MO.getReg())
 | 
						|
                               : TypedVReg(RSE_FrameIndex));
 | 
						|
    }
 | 
						|
 | 
						|
    doCandidateWalk(VRegs, RegQueue, VisitedMIs, MBB);
 | 
						|
  }
 | 
						|
 | 
						|
  // If we have populated no vregs to rename then bail.
 | 
						|
  // The rest of this function does the vreg remaping.
 | 
						|
  if (VRegs.size() == 0)
 | 
						|
    return Changed;
 | 
						|
 | 
						|
  auto VRegRenameMap = GetVRegRenameMap(VRegs, renamedInOtherBB, MRI, NVC);
 | 
						|
  Changed |= doVRegRenaming(renamedInOtherBB, VRegRenameMap, MRI);
 | 
						|
 | 
						|
  // Here we renumber the def vregs for the idempotent instructions from the top
 | 
						|
  // of the MachineBasicBlock so that they are named in the order that we sorted
 | 
						|
  // them alphabetically. Eventually we wont need SkipVRegs because we will use
 | 
						|
  // named vregs instead.
 | 
						|
  NVC.SkipVRegs();
 | 
						|
 | 
						|
  auto MII = MBB->begin();
 | 
						|
  for (unsigned i = 0; i < IdempotentInstCount && MII != MBB->end(); ++i) {
 | 
						|
    MachineInstr &MI = *MII++;
 | 
						|
    Changed = true;
 | 
						|
    unsigned vRegToRename = MI.getOperand(0).getReg();
 | 
						|
    auto Rename = NVC.createVirtualRegister(MRI.getRegClass(vRegToRename));
 | 
						|
 | 
						|
    std::vector<MachineOperand *> RenameMOs;
 | 
						|
    for (auto &MO : MRI.reg_operands(vRegToRename)) {
 | 
						|
      RenameMOs.push_back(&MO);
 | 
						|
    }
 | 
						|
 | 
						|
    for (auto *MO : RenameMOs) {
 | 
						|
      MO->setReg(Rename);
 | 
						|
    }
 | 
						|
  }
 | 
						|
 | 
						|
  Changed |= doDefKillClear(MBB);
 | 
						|
 | 
						|
  LLVM_DEBUG(dbgs() << "Updated MachineBasicBlock:\n"; MBB->dump();
 | 
						|
             dbgs() << "\n";);
 | 
						|
  LLVM_DEBUG(
 | 
						|
      dbgs() << "\n\n================================================\n\n");
 | 
						|
  return Changed;
 | 
						|
}
 | 
						|
 | 
						|
bool MIRCanonicalizer::runOnMachineFunction(MachineFunction &MF) {
 | 
						|
 | 
						|
  static unsigned functionNum = 0;
 | 
						|
  if (CanonicalizeFunctionNumber != ~0U) {
 | 
						|
    if (CanonicalizeFunctionNumber != functionNum++)
 | 
						|
      return false;
 | 
						|
    LLVM_DEBUG(dbgs() << "\n Canonicalizing Function " << MF.getName()
 | 
						|
                      << "\n";);
 | 
						|
  }
 | 
						|
 | 
						|
  // we need a valid vreg to create a vreg type for skipping all those
 | 
						|
  // stray vreg numbers so reach alignment/canonical vreg values.
 | 
						|
  std::vector<MachineBasicBlock *> RPOList = GetRPOList(MF);
 | 
						|
 | 
						|
  LLVM_DEBUG(
 | 
						|
      dbgs() << "\n\n  NEW MACHINE FUNCTION: " << MF.getName() << "  \n\n";
 | 
						|
      dbgs() << "\n\n================================================\n\n";
 | 
						|
      dbgs() << "Total Basic Blocks: " << RPOList.size() << "\n";
 | 
						|
      for (auto MBB
 | 
						|
           : RPOList) { dbgs() << MBB->getName() << "\n"; } dbgs()
 | 
						|
      << "\n\n================================================\n\n";);
 | 
						|
 | 
						|
  std::vector<StringRef> BBNames;
 | 
						|
  std::vector<unsigned> RenamedInOtherBB;
 | 
						|
 | 
						|
  unsigned GapIdx = 0;
 | 
						|
  unsigned BBNum = 0;
 | 
						|
 | 
						|
  bool Changed = false;
 | 
						|
 | 
						|
  MachineRegisterInfo &MRI = MF.getRegInfo();
 | 
						|
  NamedVRegCursor NVC(MRI);
 | 
						|
  for (auto MBB : RPOList)
 | 
						|
    Changed |=
 | 
						|
        runOnBasicBlock(MBB, BBNames, RenamedInOtherBB, BBNum, GapIdx, NVC);
 | 
						|
 | 
						|
  return Changed;
 | 
						|
}
 |