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diff --git a/llvm/lib/CodeGen/AntiDepBreaker.h b/llvm/lib/CodeGen/AntiDepBreaker.h
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-//===- llvm/CodeGen/AntiDepBreaker.h - Anti-Dependence Breaking -*- C++ -*-===//
-//
-// 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 file implements the AntiDepBreaker class, which implements
-// anti-dependence breaking heuristics for post-register-allocation scheduling.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIB_CODEGEN_ANTIDEPBREAKER_H
-#define LLVM_LIB_CODEGEN_ANTIDEPBREAKER_H
-
-#include "llvm/ADT/iterator_range.h"
-#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineOperand.h"
-#include "llvm/CodeGen/ScheduleDAG.h"
-#include "llvm/Support/Compiler.h"
-#include <cassert>
-#include <utility>
-#include <vector>
-
-namespace llvm {
-
-/// This class works in conjunction with the post-RA scheduler to rename
-/// registers to break register anti-dependencies (WAR hazards).
-class LLVM_LIBRARY_VISIBILITY AntiDepBreaker {
-public:
- using DbgValueVector =
- std::vector<std::pair<MachineInstr *, MachineInstr *>>;
-
- virtual ~AntiDepBreaker();
-
- /// Initialize anti-dep breaking for a new basic block.
- virtual void StartBlock(MachineBasicBlock *BB) = 0;
-
- /// Identifiy anti-dependencies within a basic-block region and break them by
- /// renaming registers. Return the number of anti-dependencies broken.
- virtual unsigned BreakAntiDependencies(const std::vector<SUnit> &SUnits,
- MachineBasicBlock::iterator Begin,
- MachineBasicBlock::iterator End,
- unsigned InsertPosIndex,
- DbgValueVector &DbgValues) = 0;
-
- /// Update liveness information to account for the current
- /// instruction, which will not be scheduled.
- virtual void Observe(MachineInstr &MI, unsigned Count,
- unsigned InsertPosIndex) = 0;
-
- /// Finish anti-dep breaking for a basic block.
- virtual void FinishBlock() = 0;
-
- /// Update DBG_VALUE if dependency breaker is updating
- /// other machine instruction to use NewReg.
- void UpdateDbgValue(MachineInstr &MI, unsigned OldReg, unsigned NewReg) {
- assert(MI.isDebugValue() && "MI is not DBG_VALUE!");
- if (MI.getOperand(0).isReg() && MI.getOperand(0).getReg() == OldReg)
- MI.getOperand(0).setReg(NewReg);
- }
-
- /// Update all DBG_VALUE instructions that may be affected by the dependency
- /// breaker's update of ParentMI to use NewReg.
- void UpdateDbgValues(const DbgValueVector &DbgValues, MachineInstr *ParentMI,
- unsigned OldReg, unsigned NewReg) {
- // The following code is dependent on the order in which the DbgValues are
- // constructed in ScheduleDAGInstrs::buildSchedGraph.
- MachineInstr *PrevDbgMI = nullptr;
- for (const auto &DV : make_range(DbgValues.crbegin(), DbgValues.crend())) {
- MachineInstr *PrevMI = DV.second;
- if ((PrevMI == ParentMI) || (PrevMI == PrevDbgMI)) {
- MachineInstr *DbgMI = DV.first;
- UpdateDbgValue(*DbgMI, OldReg, NewReg);
- PrevDbgMI = DbgMI;
- } else if (PrevDbgMI) {
- break; // If no match and already found a DBG_VALUE, we're done.
- }
- }
- }
-};
-
-} // end namespace llvm
-
-#endif // LLVM_LIB_CODEGEN_ANTIDEPBREAKER_H