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diff --git a/llvm/lib/Target/Mips/MipsHazardSchedule.cpp b/llvm/lib/Target/Mips/MipsHazardSchedule.cpp
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+++ b/llvm/lib/Target/Mips/MipsHazardSchedule.cpp
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+//===-- MipsHazardSchedule.cpp - Workaround pipeline hazards---------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This pass is used to workaround certain pipeline hazards. For now, this covers
+/// compact branch hazards. In future this pass can be extended to other pipeline
+/// hazards, such as various MIPS1 hazards, processor errata that require
+/// instruction reorganization, etc.
+///
+/// This pass has to run after the delay slot filler as that pass can introduce
+/// pipeline hazards, hence the existing hazard recognizer is not suitable.
+///
+/// Hazards handled: forbidden slots for MIPSR6.
+///
+/// A forbidden slot hazard occurs when a compact branch instruction is executed
+/// and the adjacent instruction in memory is a control transfer instruction such
+/// as a branch or jump, ERET, ERETNC, DERET, WAIT and PAUSE.
+///
+/// For example:
+///
+/// 0x8004	bnec	a1,v0,<P+0x18>
+/// 0x8008	beqc	a1,a2,<P+0x54>
+///
+/// In such cases, the processor is required to signal a Reserved Instruction
+/// exception.
+///
+/// Here, if the instruction at 0x8004 is executed, the processor will raise an
+/// exception as there is a control transfer instruction at 0x8008.
+///
+/// There are two sources of forbidden slot hazards:
+///
+/// A) A previous pass has created a compact branch directly.
+/// B) Transforming a delay slot branch into compact branch. This case can be
+///    difficult to process as lookahead for hazards is insufficent, as
+///    backwards delay slot fillling can also produce hazards in previously
+///    processed instuctions.
+///
+//===----------------------------------------------------------------------===//
+
+#include "Mips.h"
+#include "MipsInstrInfo.h"
+#include "MipsSEInstrInfo.h"
+#include "MipsTargetMachine.h"
+#include "llvm/IR/Function.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "mips-hazard-schedule"
+
+STATISTIC(NumInsertedNops, "Number of nops inserted");
+
+namespace {
+
+typedef MachineBasicBlock::iterator Iter;
+typedef MachineBasicBlock::reverse_iterator ReverseIter;
+
+class MipsHazardSchedule : public MachineFunctionPass {
+
+public:
+  MipsHazardSchedule(TargetMachine &tm) : MachineFunctionPass(ID), TM(tm) {}
+
+  const char *getPassName() const override { return "Mips Hazard Schedule"; }
+
+  bool runOnMachineFunction(MachineFunction &F) override;
+
+private:
+  static char ID;
+  const TargetMachine &TM;
+};
+
+char MipsHazardSchedule::ID = 0;
+} // end of anonymous namespace
+
+/// Returns a pass that clears pipeline hazards.
+FunctionPass *llvm::createMipsHazardSchedule(MipsTargetMachine &tm) {
+  return new MipsHazardSchedule(tm);
+}
+
+bool MipsHazardSchedule::runOnMachineFunction(MachineFunction &MF) {
+
+  const MipsSubtarget *STI =
+      &static_cast<const MipsSubtarget &>(MF.getSubtarget());
+
+  // Forbidden slot hazards are only defined for MIPSR6.
+  if (!STI->hasMips32r6() || STI->inMicroMipsMode())
+    return false;
+
+  bool Changed = false;
+  const MipsInstrInfo *TII = STI->getInstrInfo();
+
+  for (MachineFunction::iterator FI = MF.begin(); FI != MF.end(); ++FI) {
+    for (Iter I = FI->begin(); I != FI->end(); ++I) {
+
+      // Forbidden slot hazard handling. Use lookahead over state.
+      if (!TII->HasForbiddenSlot(*I))
+        continue;
+
+      bool InsertNop = false;
+      // Next instruction in the basic block.
+      if (std::next(I) != FI->end() &&
+          !TII->SafeInForbiddenSlot(*std::next(I))) {
+        InsertNop = true;
+      } else {
+        // Next instruction in the physical successor basic block.
+        for (auto *Succ : FI->successors()) {
+          if (FI->isLayoutSuccessor(Succ) &&
+              Succ->getFirstNonDebugInstr() != Succ->end() &&
+              !TII->SafeInForbiddenSlot(*Succ->getFirstNonDebugInstr())) {
+            InsertNop = true;
+            break;
+          }
+        }
+      }
+
+      if (InsertNop) {
+        Changed = true;
+        MIBundleBuilder(I)
+            .append(BuildMI(MF, I->getDebugLoc(), TII->get(Mips::NOP)));
+        NumInsertedNops++;
+      }
+    }
+  }
+  return Changed;
+}