Imported Upstream version 5.18.0.207

Former-commit-id: 3b152f462918d427ce18620a2cbe4f8b79650449

external/llvm/lib/Target/SystemZ/SystemZExpandPseudo.cpp

@@ -1,153 +0,0 @@
-//==-- SystemZExpandPseudo.cpp - Expand pseudo instructions -------*- C++ -*-=//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file contains a pass that expands pseudo instructions into target
-// instructions to allow proper scheduling and other late optimizations.  This
-// pass should be run after register allocation but before the post-regalloc
-// scheduling pass.
-//
-//===----------------------------------------------------------------------===//
-
-#include "SystemZ.h"
-#include "SystemZInstrInfo.h"
-#include "SystemZSubtarget.h"
-#include "llvm/CodeGen/LivePhysRegs.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-using namespace llvm;
-
-#define SYSTEMZ_EXPAND_PSEUDO_NAME "SystemZ pseudo instruction expansion pass"
-
-namespace llvm {
-  void initializeSystemZExpandPseudoPass(PassRegistry&);
-}
-
-namespace {
-class SystemZExpandPseudo : public MachineFunctionPass {
-public:
-  static char ID;
-  SystemZExpandPseudo() : MachineFunctionPass(ID) {
-    initializeSystemZExpandPseudoPass(*PassRegistry::getPassRegistry());
-  }
-
-  const SystemZInstrInfo *TII;
-
-  bool runOnMachineFunction(MachineFunction &Fn) override;
-
-  StringRef getPassName() const override { return SYSTEMZ_EXPAND_PSEUDO_NAME; }
-
-private:
-  bool expandMBB(MachineBasicBlock &MBB);
-  bool expandMI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
-                MachineBasicBlock::iterator &NextMBBI);
-  bool expandLOCRMux(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
-                     MachineBasicBlock::iterator &NextMBBI);
-};
-char SystemZExpandPseudo::ID = 0;
-}
-
-INITIALIZE_PASS(SystemZExpandPseudo, "systemz-expand-pseudo",
-                SYSTEMZ_EXPAND_PSEUDO_NAME, false, false)
-
-/// \brief Returns an instance of the pseudo instruction expansion pass.
-FunctionPass *llvm::createSystemZExpandPseudoPass(SystemZTargetMachine &TM) {
-  return new SystemZExpandPseudo();
-}
-
-// MI is a load-register-on-condition pseudo instruction that could not be
-// handled as a single hardware instruction.  Replace it by a branch sequence.
-bool SystemZExpandPseudo::expandLOCRMux(MachineBasicBlock &MBB,
-                                        MachineBasicBlock::iterator MBBI,
-                                        MachineBasicBlock::iterator &NextMBBI) {
-  MachineFunction &MF = *MBB.getParent();
-  const BasicBlock *BB = MBB.getBasicBlock();
-  MachineInstr &MI = *MBBI;
-  DebugLoc DL = MI.getDebugLoc();
-  unsigned DestReg = MI.getOperand(0).getReg();
-  unsigned SrcReg = MI.getOperand(2).getReg();
-  unsigned CCValid = MI.getOperand(3).getImm();
-  unsigned CCMask = MI.getOperand(4).getImm();
-
-  LivePhysRegs LiveRegs(TII->getRegisterInfo());
-  LiveRegs.addLiveOuts(MBB);
-  for (auto I = std::prev(MBB.end()); I != MBBI; --I)
-    LiveRegs.stepBackward(*I);
-
-  // Splice MBB at MI, moving the rest of the block into RestMBB.
-  MachineBasicBlock *RestMBB = MF.CreateMachineBasicBlock(BB);
-  MF.insert(std::next(MachineFunction::iterator(MBB)), RestMBB);
-  RestMBB->splice(RestMBB->begin(), &MBB, MI, MBB.end());
-  RestMBB->transferSuccessors(&MBB);
-  for (auto I = LiveRegs.begin(); I != LiveRegs.end(); ++I)
-    RestMBB->addLiveIn(*I);
-
-  // Create a new block MoveMBB to hold the move instruction.
-  MachineBasicBlock *MoveMBB = MF.CreateMachineBasicBlock(BB);
-  MF.insert(std::next(MachineFunction::iterator(MBB)), MoveMBB);
-  MoveMBB->addLiveIn(SrcReg);
-  for (auto I = LiveRegs.begin(); I != LiveRegs.end(); ++I)
-    MoveMBB->addLiveIn(*I);
-
-  // At the end of MBB, create a conditional branch to RestMBB if the
-  // condition is false, otherwise fall through to MoveMBB.
-  BuildMI(&MBB, DL, TII->get(SystemZ::BRC))
-    .addImm(CCValid).addImm(CCMask ^ CCValid).addMBB(RestMBB);
-  MBB.addSuccessor(RestMBB);
-  MBB.addSuccessor(MoveMBB);
-
-  // In MoveMBB, emit an instruction to move SrcReg into DestReg,
-  // then fall through to RestMBB.
-  TII->copyPhysReg(*MoveMBB, MoveMBB->end(), DL, DestReg, SrcReg,
-                   MI.getOperand(2).isKill());
-  MoveMBB->addSuccessor(RestMBB);
-
-  NextMBBI = MBB.end();
-  MI.eraseFromParent();
-  return true;
-}
-
-/// \brief If MBBI references a pseudo instruction that should be expanded here,
-/// do the expansion and return true.  Otherwise return false.
-bool SystemZExpandPseudo::expandMI(MachineBasicBlock &MBB,
-                                   MachineBasicBlock::iterator MBBI,
-                                   MachineBasicBlock::iterator &NextMBBI) {
-  MachineInstr &MI = *MBBI;
-  switch (MI.getOpcode()) {
-  case SystemZ::LOCRMux:
-    return expandLOCRMux(MBB, MBBI, NextMBBI);
-  default:
-    break;
-  }
-  return false;
-}
-
-/// \brief Iterate over the instructions in basic block MBB and expand any
-/// pseudo instructions.  Return true if anything was modified.
-bool SystemZExpandPseudo::expandMBB(MachineBasicBlock &MBB) {
-  bool Modified = false;
-
-  MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
-  while (MBBI != E) {
-    MachineBasicBlock::iterator NMBBI = std::next(MBBI);
-    Modified |= expandMI(MBB, MBBI, NMBBI);
-    MBBI = NMBBI;
-  }
-
-  return Modified;
-}
-
-bool SystemZExpandPseudo::runOnMachineFunction(MachineFunction &MF) {
-  TII = static_cast<const SystemZInstrInfo *>(MF.getSubtarget().getInstrInfo());
-
-  bool Modified = false;
-  for (auto &MBB : MF)
-    Modified |= expandMBB(MBB);
-  return Modified;
-}
-