diff --git a/include/llvm/ExecutionEngine/ExecutionEngine.h b/include/llvm/ExecutionEngine/ExecutionEngine.h
index a730260..5102344 100644
--- a/include/llvm/ExecutionEngine/ExecutionEngine.h
+++ b/include/llvm/ExecutionEngine/ExecutionEngine.h
@@ -550,6 +550,7 @@ public:
   /// is called and is successful, the created engine takes ownership of the
   /// memory manager. This option defaults to NULL.
   EngineBuilder &setMCJITMemoryManager(std::unique_ptr<RTDyldMemoryManager> mcjmm);
+  EngineBuilder &setMCJITMemoryManager(std::shared_ptr<RTDyldMemoryManager> mcjmm);
 
   EngineBuilder&
   setMemoryManager(std::unique_ptr<MCJITMemoryManager> MM);
diff --git a/include/llvm/MC/MCInst.h b/include/llvm/MC/MCInst.h
index 4688b5f..e3124bf 100644
--- a/include/llvm/MC/MCInst.h
+++ b/include/llvm/MC/MCInst.h
@@ -27,6 +27,7 @@ class MCAsmInfo;
 class MCInstPrinter;
 class MCExpr;
 class MCInst;
+class DebugLoc;
 
 /// \brief Instances of this class represent operands of the MCInst class.
 /// This is a simple discriminated union.
@@ -151,9 +152,10 @@ class MCInst {
   unsigned Opcode;
   SMLoc Loc;
   SmallVector<MCOperand, 8> Operands;
+  const DebugLoc *DbgLoc;
 
 public:
-  MCInst() : Opcode(0) {}
+  MCInst() : Opcode(0), DbgLoc(nullptr) {}
 
   void setOpcode(unsigned Op) { Opcode = Op; }
   unsigned getOpcode() const { return Opcode; }
@@ -161,6 +163,9 @@ public:
   void setLoc(SMLoc loc) { Loc = loc; }
   SMLoc getLoc() const { return Loc; }
 
+  void setDebugLoc(const DebugLoc *Loc) { DbgLoc = Loc; }
+  const DebugLoc *getDebugLoc() const { return DbgLoc; }
+
   const MCOperand &getOperand(unsigned i) const { return Operands[i]; }
   MCOperand &getOperand(unsigned i) { return Operands[i]; }
   unsigned getNumOperands() const { return Operands.size(); }
diff --git a/include/llvm/MC/MCInstrInfo.h b/include/llvm/MC/MCInstrInfo.h
index 70c8658..69a6427 100644
--- a/include/llvm/MC/MCInstrInfo.h
+++ b/include/llvm/MC/MCInstrInfo.h
@@ -26,6 +26,7 @@ class MCInstrInfo {
   const unsigned *InstrNameIndices; // Array for name indices in InstrNameData
   const char *InstrNameData;        // Instruction name string pool
   unsigned NumOpcodes;              // Number of entries in the desc array
+  unsigned long HQEMUExitAddr;
 
 public:
   /// \brief Initialize MCInstrInfo, called by TableGen auto-generated routines.
@@ -52,6 +53,9 @@ public:
     assert(Opcode < NumOpcodes && "Invalid opcode!");
     return &InstrNameData[InstrNameIndices[Opcode]];
   }
+
+  void setHQEMUExitAddr(unsigned long Addr) { HQEMUExitAddr = Addr; }
+  unsigned long getHQEMUExitAddr() const { return HQEMUExitAddr; }
 };
 
 } // End llvm namespace
diff --git a/lib/ExecutionEngine/ExecutionEngine.cpp b/lib/ExecutionEngine/ExecutionEngine.cpp
index 41c8da4..ffca9ea 100644
--- a/lib/ExecutionEngine/ExecutionEngine.cpp
+++ b/lib/ExecutionEngine/ExecutionEngine.cpp
@@ -497,6 +497,13 @@ EngineBuilder &EngineBuilder::setMCJITMemoryManager(
   return *this;
 }
 
+EngineBuilder &EngineBuilder::setMCJITMemoryManager(
+                                   std::shared_ptr<RTDyldMemoryManager> mcjmm) {
+  MemMgr = mcjmm;
+  Resolver = mcjmm;
+  return *this;
+}
+
 EngineBuilder&
 EngineBuilder::setMemoryManager(std::unique_ptr<MCJITMemoryManager> MM) {
   MemMgr = std::shared_ptr<MCJITMemoryManager>(std::move(MM));
diff --git a/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index dfab6ec..8a9752f 100644
--- a/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -23,6 +23,7 @@
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/MCSymbol.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/IR/DebugLoc.h"
 
 using namespace llvm;
 
@@ -164,6 +165,9 @@ public:
                         const MCInst &MI, const MCInstrDesc &Desc,
                         const MCSubtargetInfo &STI,
                         raw_ostream &OS) const;
+
+  bool EmitHQEMUInstruction(const MCInst &MI, raw_ostream &OS,
+                            SmallVectorImpl<MCFixup> &Fixups) const;
 };
 
 } // end anonymous namespace
@@ -1158,6 +1162,52 @@ void X86MCCodeEmitter::EmitOpcodePrefix(uint64_t TSFlags, unsigned &CurByte,
   }
 }
 
+bool X86MCCodeEmitter::
+EmitHQEMUInstruction(const MCInst &MI, raw_ostream &OS,
+                     SmallVectorImpl<MCFixup> &Fixups) const {
+  /* NOTE: the following flags must be synchronized with those in file
+   *       llvm-opc.h of the HQEMU source tree. */
+  enum {
+    PATCH_HQEMU = 0x4182U,
+    PATCH_DUMMY,
+    PATCH_EXIT_TB,
+    PATCH_DIRECT_JUMP,
+    PATCH_TRACE_BLOCK_CHAINING,
+    PATCH_QMMU
+  };
+
+  unsigned Opcode = MI.getOpcode();
+  switch (Opcode) {
+  case X86::TRAP:
+  case X86::RETQ:
+    break;
+  default: return false;
+  }
+
+  unsigned CurByte = 0;
+  const DebugLoc *Loc = MI.getDebugLoc();
+  if (!Loc)
+    return false;
+
+  unsigned PatchType = Loc->getLine();
+  if (PatchType < PATCH_HQEMU || PatchType > PATCH_QMMU)
+    return false;
+
+  if (Opcode == X86::TRAP) {
+    for (unsigned i = 0; i != 8; ++i)
+      EmitByte(0x90, CurByte, OS);
+    return true;
+  }
+  if (Opcode == X86::RETQ) {
+    uintptr_t ExitAddr = MCII.getHQEMUExitAddr();
+    EmitByte(0xE9, CurByte, OS);
+    EmitImmediate(MCOperand::createImm(ExitAddr), MI.getLoc(), 4, FK_PCRel_4,
+                  CurByte, OS, Fixups);
+    return true;
+  }
+  return false;
+}
+
 void X86MCCodeEmitter::
 encodeInstruction(const MCInst &MI, raw_ostream &OS,
                   SmallVectorImpl<MCFixup> &Fixups,
@@ -1166,6 +1216,9 @@ encodeInstruction(const MCInst &MI, raw_ostream &OS,
   const MCInstrDesc &Desc = MCII.get(Opcode);
   uint64_t TSFlags = Desc.TSFlags;
 
+  if (EmitHQEMUInstruction(MI, OS, Fixups))
+    return;
+
   // Pseudo instructions don't get encoded.
   if ((TSFlags & X86II::FormMask) == X86II::Pseudo)
     return;
diff --git a/lib/Target/X86/X86MCInstLower.cpp b/lib/Target/X86/X86MCInstLower.cpp
index e1ca558..c3acaec 100644
--- a/lib/Target/X86/X86MCInstLower.cpp
+++ b/lib/Target/X86/X86MCInstLower.cpp
@@ -437,6 +437,9 @@ X86MCInstLower::LowerMachineOperand(const MachineInstr *MI,
 void X86MCInstLower::Lower(const MachineInstr *MI, MCInst &OutMI) const {
   OutMI.setOpcode(MI->getOpcode());
 
+  if (MI->getDebugLoc())
+    OutMI.setDebugLoc(&MI->getDebugLoc());
+
   for (const MachineOperand &MO : MI->operands())
     if (auto MaybeMCOp = LowerMachineOperand(MI, MO))
       OutMI.addOperand(MaybeMCOp.getValue());
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp
index 274b566..dbb4fec 100644
--- a/lib/Target/X86/X86RegisterInfo.cpp
+++ b/lib/Target/X86/X86RegisterInfo.cpp
@@ -473,6 +473,19 @@ BitVector X86RegisterInfo::getReservedRegs(const MachineFunction &MF) const {
     }
   }
 
+  // Reserve registers for HQEMU.
+  if (MF.getFunction()->hasFnAttribute("hqemu")) {
+    if (!Is64Bit) {
+      Reserved.set(X86::EBP);
+      Reserved.set(X86::BP);
+      Reserved.set(X86::BPL);
+    } else {
+      Reserved.set(X86::R14);
+      Reserved.set(X86::R14B);
+      Reserved.set(X86::R14D);
+      Reserved.set(X86::R14W);
+    }
+  }
   return Reserved;
 }
 
diff --git a/lib/Transforms/Utils/Local.cpp b/lib/Transforms/Utils/Local.cpp
index abc9b65..39241c2 100644
--- a/lib/Transforms/Utils/Local.cpp
+++ b/lib/Transforms/Utils/Local.cpp
@@ -1302,7 +1302,8 @@ static bool markAliveBlocks(Function &F,
         }
 
       if (CallInst *CI = dyn_cast<CallInst>(BBI)) {
-        if (CI->doesNotReturn()) {
+        // HQEMU: do not delete instructions after llvm.trap.
+        if (!F.hasFnAttribute("hqemu") && CI->doesNotReturn()) {
           // If we found a call to a no-return function, insert an unreachable
           // instruction after it.  Make sure there isn't *already* one there
           // though.
diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index e484b69..6ac6033 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1120,6 +1120,9 @@ static bool HoistThenElseCodeToIf(BranchInst *BI,
 
   bool Changed = false;
   do {
+    if (BIParent->getParent()->hasFnAttribute("hqemu"))
+      if (isa<IntrinsicInst>(I1) || I1->hasMetadata())
+        return Changed;
     // If we are hoisting the terminator instruction, don't move one (making a
     // broken BB), instead clone it, and remove BI.
     if (isa<TerminatorInst>(I1))
@@ -4898,6 +4901,9 @@ bool SimplifyCFGOpt::SimplifyIndirectBr(IndirectBrInst *IBI) {
   BasicBlock *BB = IBI->getParent();
   bool Changed = false;
 
+  if (BB->getParent()->hasFnAttribute("hqemu"))
+    return false;
+
   // Eliminate redundant destinations.
   SmallPtrSet<Value *, 8> Succs;
   for (unsigned i = 0, e = IBI->getNumDestinations(); i != e; ++i) {