Imported Upstream version 5.18.0.207

Former-commit-id: 3b152f462918d427ce18620a2cbe4f8b79650449

external/llvm/lib/CodeGen/GlobalISel/Localizer.cpp

@@ -1,124 +0,0 @@
-//===- Localizer.cpp ---------------------- Localize some instrs -*- C++ -*-==//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-/// \file
-/// This file implements the Localizer class.
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/GlobalISel/Localizer.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Support/Debug.h"
-
-#define DEBUG_TYPE "localizer"
-
-using namespace llvm;
-
-char Localizer::ID = 0;
-INITIALIZE_PASS(Localizer, DEBUG_TYPE,
-                "Move/duplicate certain instructions close to their use", false,
-                false)
-
-Localizer::Localizer() : MachineFunctionPass(ID) {
-  initializeLocalizerPass(*PassRegistry::getPassRegistry());
-}
-
-void Localizer::init(MachineFunction &MF) { MRI = &MF.getRegInfo(); }
-
-bool Localizer::shouldLocalize(const MachineInstr &MI) {
-  switch (MI.getOpcode()) {
-  default:
-    return false;
-  // Constants-like instructions should be close to their users.
-  // We don't want long live-ranges for them.
-  case TargetOpcode::G_CONSTANT:
-  case TargetOpcode::G_FCONSTANT:
-  case TargetOpcode::G_FRAME_INDEX:
-    return true;
-  }
-}
-
-bool Localizer::isLocalUse(MachineOperand &MOUse, const MachineInstr &Def,
-                           MachineBasicBlock *&InsertMBB) {
-  MachineInstr &MIUse = *MOUse.getParent();
-  InsertMBB = MIUse.getParent();
-  if (MIUse.isPHI())
-    InsertMBB = MIUse.getOperand(MIUse.getOperandNo(&MOUse) + 1).getMBB();
-  return InsertMBB == Def.getParent();
-}
-
-bool Localizer::runOnMachineFunction(MachineFunction &MF) {
-  // If the ISel pipeline failed, do not bother running that pass.
-  if (MF.getProperties().hasProperty(
-          MachineFunctionProperties::Property::FailedISel))
-    return false;
-
-  DEBUG(dbgs() << "Localize instructions for: " << MF.getName() << '\n');
-
-  init(MF);
-
-  bool Changed = false;
-  // Keep track of the instructions we localized.
-  // We won't need to process them if we see them later in the CFG.
-  SmallPtrSet<MachineInstr *, 16> LocalizedInstrs;
-  DenseMap<std::pair<MachineBasicBlock *, unsigned>, unsigned> MBBWithLocalDef;
-  // TODO: Do bottom up traversal.
-  for (MachineBasicBlock &MBB : MF) {
-    for (MachineInstr &MI : MBB) {
-      if (LocalizedInstrs.count(&MI) || !shouldLocalize(MI))
-        continue;
-      DEBUG(dbgs() << "Should localize: " << MI);
-      assert(MI.getDesc().getNumDefs() == 1 &&
-             "More than one definition not supported yet");
-      unsigned Reg = MI.getOperand(0).getReg();
-      // Check if all the users of MI are local.
-      // We are going to invalidation the list of use operands, so we
-      // can't use range iterator.
-      for (auto MOIt = MRI->use_begin(Reg), MOItEnd = MRI->use_end();
-           MOIt != MOItEnd;) {
-        MachineOperand &MOUse = *MOIt++;
-        // Check if the use is already local.
-        MachineBasicBlock *InsertMBB;
-        DEBUG(MachineInstr &MIUse = *MOUse.getParent();
-              dbgs() << "Checking use: " << MIUse
-                     << " #Opd: " << MIUse.getOperandNo(&MOUse) << '\n');
-        if (isLocalUse(MOUse, MI, InsertMBB))
-          continue;
-        DEBUG(dbgs() << "Fixing non-local use\n");
-        Changed = true;
-        auto MBBAndReg = std::make_pair(InsertMBB, Reg);
-        auto NewVRegIt = MBBWithLocalDef.find(MBBAndReg);
-        if (NewVRegIt == MBBWithLocalDef.end()) {
-          // Create the localized instruction.
-          MachineInstr *LocalizedMI = MF.CloneMachineInstr(&MI);
-          LocalizedInstrs.insert(LocalizedMI);
-          // Don't try to be smart for the insertion point.
-          // There is no guarantee that the first seen use is the first
-          // use in the block.
-          InsertMBB->insert(InsertMBB->SkipPHIsAndLabels(InsertMBB->begin()),
-                            LocalizedMI);
-
-          // Set a new register for the definition.
-          unsigned NewReg =
-              MRI->createGenericVirtualRegister(MRI->getType(Reg));
-          MRI->setRegClassOrRegBank(NewReg, MRI->getRegClassOrRegBank(Reg));
-          LocalizedMI->getOperand(0).setReg(NewReg);
-          NewVRegIt =
-              MBBWithLocalDef.insert(std::make_pair(MBBAndReg, NewReg)).first;
-          DEBUG(dbgs() << "Inserted: " << *LocalizedMI);
-        }
-        DEBUG(dbgs() << "Update use with: " << printReg(NewVRegIt->second)
-                     << '\n');
-        // Update the user reg.
-        MOUse.setReg(NewVRegIt->second);
-      }
-    }
-  }
-  return Changed;
-}