1 files changed, 0 insertions, 210 deletions
diff --git a/contrib/llvm/lib/CodeGen/OptimizePHIs.cpp b/contrib/llvm/lib/CodeGen/OptimizePHIs.cpp
deleted file mode 100644
index c70b62252139..000000000000
--- a/contrib/llvm/lib/CodeGen/OptimizePHIs.cpp
+++ /dev/null
@@ -1,210 +0,0 @@
-//===- OptimizePHIs.cpp - Optimize machine instruction PHIs ---------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass optimizes machine instruction PHIs to take advantage of
-// opportunities created during DAG legalization.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineOperand.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/TargetRegisterInfo.h"
-#include "llvm/CodeGen/TargetSubtargetInfo.h"
-#include "llvm/Pass.h"
-#include <cassert>
-
-using namespace llvm;
-
-#define DEBUG_TYPE "opt-phis"
-
-STATISTIC(NumPHICycles, "Number of PHI cycles replaced");
-STATISTIC(NumDeadPHICycles, "Number of dead PHI cycles");
-
-namespace {
-
-  class OptimizePHIs : public MachineFunctionPass {
-    MachineRegisterInfo *MRI;
-    const TargetInstrInfo *TII;
-
-  public:
-    static char ID; // Pass identification
-
-    OptimizePHIs() : MachineFunctionPass(ID) {
-      initializeOptimizePHIsPass(*PassRegistry::getPassRegistry());
-    }
-
-    bool runOnMachineFunction(MachineFunction &Fn) override;
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesCFG();
-      MachineFunctionPass::getAnalysisUsage(AU);
-    }
-
-  private:
-    using InstrSet = SmallPtrSet<MachineInstr *, 16>;
-    using InstrSetIterator = SmallPtrSetIterator<MachineInstr *>;
-
-    bool IsSingleValuePHICycle(MachineInstr *MI, unsigned &SingleValReg,
-                               InstrSet &PHIsInCycle);
-    bool IsDeadPHICycle(MachineInstr *MI, InstrSet &PHIsInCycle);
-    bool OptimizeBB(MachineBasicBlock &MBB);
-  };
-
-} // end anonymous namespace
-
-char OptimizePHIs::ID = 0;
-
-char &llvm::OptimizePHIsID = OptimizePHIs::ID;
-
-INITIALIZE_PASS(OptimizePHIs, DEBUG_TYPE,
-                "Optimize machine instruction PHIs", false, false)
-
-bool OptimizePHIs::runOnMachineFunction(MachineFunction &Fn) {
-  if (skipFunction(Fn.getFunction()))
-    return false;
-
-  MRI = &Fn.getRegInfo();
-  TII = Fn.getSubtarget().getInstrInfo();
-
-  // Find dead PHI cycles and PHI cycles that can be replaced by a single
-  // value.  InstCombine does these optimizations, but DAG legalization may
-  // introduce new opportunities, e.g., when i64 values are split up for
-  // 32-bit targets.
-  bool Changed = false;
-  for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I)
-    Changed |= OptimizeBB(*I);
-
-  return Changed;
-}
-
-/// IsSingleValuePHICycle - Check if MI is a PHI where all the source operands
-/// are copies of SingleValReg, possibly via copies through other PHIs. If
-/// SingleValReg is zero on entry, it is set to the register with the single
-/// non-copy value. PHIsInCycle is a set used to keep track of the PHIs that
-/// have been scanned. PHIs may be grouped by cycle, several cycles or chains.
-bool OptimizePHIs::IsSingleValuePHICycle(MachineInstr *MI,
-                                         unsigned &SingleValReg,
-                                         InstrSet &PHIsInCycle) {
-  assert(MI->isPHI() && "IsSingleValuePHICycle expects a PHI instruction");
-  unsigned DstReg = MI->getOperand(0).getReg();
-
-  // See if we already saw this register.
-  if (!PHIsInCycle.insert(MI).second)
-    return true;
-
-  // Don't scan crazily complex things.
-  if (PHIsInCycle.size() == 16)
-    return false;
-
-  // Scan the PHI operands.
-  for (unsigned i = 1; i != MI->getNumOperands(); i += 2) {
-    unsigned SrcReg = MI->getOperand(i).getReg();
-    if (SrcReg == DstReg)
-      continue;
-    MachineInstr *SrcMI = MRI->getVRegDef(SrcReg);
-
-    // Skip over register-to-register moves.
-    if (SrcMI && SrcMI->isCopy() &&
-        !SrcMI->getOperand(0).getSubReg() &&
-        !SrcMI->getOperand(1).getSubReg() &&
-        TargetRegisterInfo::isVirtualRegister(SrcMI->getOperand(1).getReg())) {
-      SrcReg = SrcMI->getOperand(1).getReg();
-      SrcMI = MRI->getVRegDef(SrcReg);
-    }
-    if (!SrcMI)
-      return false;
-
-    if (SrcMI->isPHI()) {
-      if (!IsSingleValuePHICycle(SrcMI, SingleValReg, PHIsInCycle))
-        return false;
-    } else {
-      // Fail if there is more than one non-phi/non-move register.
-      if (SingleValReg != 0 && SingleValReg != SrcReg)
-        return false;
-      SingleValReg = SrcReg;
-    }
-  }
-  return true;
-}
-
-/// IsDeadPHICycle - Check if the register defined by a PHI is only used by
-/// other PHIs in a cycle.
-bool OptimizePHIs::IsDeadPHICycle(MachineInstr *MI, InstrSet &PHIsInCycle) {
-  assert(MI->isPHI() && "IsDeadPHICycle expects a PHI instruction");
-  unsigned DstReg = MI->getOperand(0).getReg();
-  assert(TargetRegisterInfo::isVirtualRegister(DstReg) &&
-         "PHI destination is not a virtual register");
-
-  // See if we already saw this register.
-  if (!PHIsInCycle.insert(MI).second)
-    return true;
-
-  // Don't scan crazily complex things.
-  if (PHIsInCycle.size() == 16)
-    return false;
-
-  for (MachineInstr &UseMI : MRI->use_nodbg_instructions(DstReg)) {
-    if (!UseMI.isPHI() || !IsDeadPHICycle(&UseMI, PHIsInCycle))
-      return false;
-  }
-
-  return true;
-}
-
-/// OptimizeBB - Remove dead PHI cycles and PHI cycles that can be replaced by
-/// a single value.
-bool OptimizePHIs::OptimizeBB(MachineBasicBlock &MBB) {
-  bool Changed = false;
-  for (MachineBasicBlock::iterator
-         MII = MBB.begin(), E = MBB.end(); MII != E; ) {
-    MachineInstr *MI = &*MII++;
-    if (!MI->isPHI())
-      break;
-
-    // Check for single-value PHI cycles.
-    unsigned SingleValReg = 0;
-    InstrSet PHIsInCycle;
-    if (IsSingleValuePHICycle(MI, SingleValReg, PHIsInCycle) &&
-        SingleValReg != 0) {
-      unsigned OldReg = MI->getOperand(0).getReg();
-      if (!MRI->constrainRegClass(SingleValReg, MRI->getRegClass(OldReg)))
-        continue;
-
-      MRI->replaceRegWith(OldReg, SingleValReg);
-      MI->eraseFromParent();
-
-      // The kill flags on OldReg and SingleValReg may no longer be correct.
-      MRI->clearKillFlags(SingleValReg);
-
-      ++NumPHICycles;
-      Changed = true;
-      continue;
-    }
-
-    // Check for dead PHI cycles.
-    PHIsInCycle.clear();
-    if (IsDeadPHICycle(MI, PHIsInCycle)) {
-      for (InstrSetIterator PI = PHIsInCycle.begin(), PE = PHIsInCycle.end();
-           PI != PE; ++PI) {
-        MachineInstr *PhiMI = *PI;
-        if (MII == PhiMI)
-          ++MII;
-        PhiMI->eraseFromParent();
-      }
-      ++NumDeadPHICycles;
-      Changed = true;
-    }
-  }
-  return Changed;
-}