1 files changed, 0 insertions, 173 deletions
diff --git a/gnu/llvm/lib/CodeGen/DeadMachineInstructionElim.cpp b/gnu/llvm/lib/CodeGen/DeadMachineInstructionElim.cpp
deleted file mode 100644
index ff44c5660ba..00000000000
--- a/gnu/llvm/lib/CodeGen/DeadMachineInstructionElim.cpp
+++ /dev/null
@@ -1,173 +0,0 @@
-//===- DeadMachineInstructionElim.cpp - Remove dead machine instructions --===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This is an extremely simple MachineInstr-level dead-code-elimination pass.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/CodeGen/TargetSubtargetInfo.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-
-#define DEBUG_TYPE "dead-mi-elimination"
-
-STATISTIC(NumDeletes,          "Number of dead instructions deleted");
-
-namespace {
-  class DeadMachineInstructionElim : public MachineFunctionPass {
-    bool runOnMachineFunction(MachineFunction &MF) override;
-
-    const TargetRegisterInfo *TRI;
-    const MachineRegisterInfo *MRI;
-    const TargetInstrInfo *TII;
-    BitVector LivePhysRegs;
-
-  public:
-    static char ID; // Pass identification, replacement for typeid
-    DeadMachineInstructionElim() : MachineFunctionPass(ID) {
-     initializeDeadMachineInstructionElimPass(*PassRegistry::getPassRegistry());
-    }
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesCFG();
-      MachineFunctionPass::getAnalysisUsage(AU);
-    }
-
-  private:
-    bool isDead(const MachineInstr *MI) const;
-  };
-}
-char DeadMachineInstructionElim::ID = 0;
-char &llvm::DeadMachineInstructionElimID = DeadMachineInstructionElim::ID;
-
-INITIALIZE_PASS(DeadMachineInstructionElim, DEBUG_TYPE,
-                "Remove dead machine instructions", false, false)
-
-bool DeadMachineInstructionElim::isDead(const MachineInstr *MI) const {
-  // Technically speaking inline asm without side effects and no defs can still
-  // be deleted. But there is so much bad inline asm code out there, we should
-  // let them be.
-  if (MI->isInlineAsm())
-    return false;
-
-  // Don't delete frame allocation labels.
-  if (MI->getOpcode() == TargetOpcode::LOCAL_ESCAPE)
-    return false;
-
-  // Don't delete instructions with side effects.
-  bool SawStore = false;
-  if (!MI->isSafeToMove(nullptr, SawStore) && !MI->isPHI())
-    return false;
-
-  // Examine each operand.
-  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
-    const MachineOperand &MO = MI->getOperand(i);
-    if (MO.isReg() && MO.isDef()) {
-      unsigned Reg = MO.getReg();
-      if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
-        // Don't delete live physreg defs, or any reserved register defs.
-        if (LivePhysRegs.test(Reg) || MRI->isReserved(Reg))
-          return false;
-      } else {
-        if (!MRI->use_nodbg_empty(Reg))
-          // This def has a non-debug use. Don't delete the instruction!
-          return false;
-      }
-    }
-  }
-
-  // If there are no defs with uses, the instruction is dead.
-  return true;
-}
-
-bool DeadMachineInstructionElim::runOnMachineFunction(MachineFunction &MF) {
-  if (skipFunction(MF.getFunction()))
-    return false;
-
-  bool AnyChanges = false;
-  MRI = &MF.getRegInfo();
-  TRI = MF.getSubtarget().getRegisterInfo();
-  TII = MF.getSubtarget().getInstrInfo();
-
-  // Loop over all instructions in all blocks, from bottom to top, so that it's
-  // more likely that chains of dependent but ultimately dead instructions will
-  // be cleaned up.
-  for (MachineBasicBlock &MBB : make_range(MF.rbegin(), MF.rend())) {
-    // Start out assuming that reserved registers are live out of this block.
-    LivePhysRegs = MRI->getReservedRegs();
-
-    // Add live-ins from successors to LivePhysRegs. Normally, physregs are not
-    // live across blocks, but some targets (x86) can have flags live out of a
-    // block.
-    for (MachineBasicBlock::succ_iterator S = MBB.succ_begin(),
-           E = MBB.succ_end(); S != E; S++)
-      for (const auto &LI : (*S)->liveins())
-        LivePhysRegs.set(LI.PhysReg);
-
-    // Now scan the instructions and delete dead ones, tracking physreg
-    // liveness as we go.
-    for (MachineBasicBlock::reverse_iterator MII = MBB.rbegin(),
-         MIE = MBB.rend(); MII != MIE; ) {
-      MachineInstr *MI = &*MII++;
-
-      // If the instruction is dead, delete it!
-      if (isDead(MI)) {
-        LLVM_DEBUG(dbgs() << "DeadMachineInstructionElim: DELETING: " << *MI);
-        // It is possible that some DBG_VALUE instructions refer to this
-        // instruction.  They get marked as undef and will be deleted
-        // in the live debug variable analysis.
-        MI->eraseFromParentAndMarkDBGValuesForRemoval();
-        AnyChanges = true;
-        ++NumDeletes;
-        continue;
-      }
-
-      // Record the physreg defs.
-      for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
-        const MachineOperand &MO = MI->getOperand(i);
-        if (MO.isReg() && MO.isDef()) {
-          unsigned Reg = MO.getReg();
-          if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
-            // Check the subreg set, not the alias set, because a def
-            // of a super-register may still be partially live after
-            // this def.
-            for (MCSubRegIterator SR(Reg, TRI,/*IncludeSelf=*/true);
-                 SR.isValid(); ++SR)
-              LivePhysRegs.reset(*SR);
-          }
-        } else if (MO.isRegMask()) {
-          // Register mask of preserved registers. All clobbers are dead.
-          LivePhysRegs.clearBitsNotInMask(MO.getRegMask());
-        }
-      }
-      // Record the physreg uses, after the defs, in case a physreg is
-      // both defined and used in the same instruction.
-      for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
-        const MachineOperand &MO = MI->getOperand(i);
-        if (MO.isReg() && MO.isUse()) {
-          unsigned Reg = MO.getReg();
-          if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
-            for (MCRegAliasIterator AI(Reg, TRI, true); AI.isValid(); ++AI)
-              LivePhysRegs.set(*AI);
-          }
-        }
-      }
-    }
-  }
-
-  LivePhysRegs.clear();
-  return AnyChanges;
-}