1 files changed, 350 insertions, 155 deletions
diff --git a/contrib/llvm/lib/CodeGen/StackMaps.cpp b/contrib/llvm/lib/CodeGen/StackMaps.cpp
index 40893ea..1473fc1 100644
--- a/contrib/llvm/lib/CodeGen/StackMaps.cpp
+++ b/contrib/llvm/lib/CodeGen/StackMaps.cpp
@@ -7,35 +7,41 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "stackmaps"
-
 #include "llvm/CodeGen/StackMaps.h"
-
 #include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/IR/DataLayout.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCExpr.h"
 #include "llvm/MC/MCObjectFileInfo.h"
 #include "llvm/MC/MCSectionMachO.h"
 #include "llvm/MC/MCStreamer.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetOpcodes.h"
 #include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetOpcodes.h"
 #include "llvm/Target/TargetRegisterInfo.h"
-
 #include <iterator>
 
 using namespace llvm;
 
-PatchPointOpers::PatchPointOpers(const MachineInstr *MI):
-  MI(MI),
-  HasDef(MI->getOperand(0).isReg() && MI->getOperand(0).isDef() &&
-         !MI->getOperand(0).isImplicit()),
-  IsAnyReg(MI->getOperand(getMetaIdx(CCPos)).getImm() == CallingConv::AnyReg) {
+#define DEBUG_TYPE "stackmaps"
+
+static cl::opt<int> StackMapVersion("stackmap-version", cl::init(1),
+  cl::desc("Specify the stackmap encoding version (default = 1)"));
 
+const char *StackMaps::WSMP = "Stack Maps: ";
+
+PatchPointOpers::PatchPointOpers(const MachineInstr *MI)
+  : MI(MI),
+    HasDef(MI->getOperand(0).isReg() && MI->getOperand(0).isDef() &&
+           !MI->getOperand(0).isImplicit()),
+    IsAnyReg(MI->getOperand(getMetaIdx(CCPos)).getImm() == CallingConv::AnyReg)
+{
 #ifndef NDEBUG
-  {
   unsigned CheckStartIdx = 0, e = MI->getNumOperands();
   while (CheckStartIdx < e && MI->getOperand(CheckStartIdx).isReg() &&
          MI->getOperand(CheckStartIdx).isDef() &&
@@ -43,8 +49,7 @@ PatchPointOpers::PatchPointOpers(const MachineInstr *MI):
     ++CheckStartIdx;
 
   assert(getMetaIdx() == CheckStartIdx &&
-         "Unexpected additonal definition in Patchpoint intrinsic.");
-  }
+         "Unexpected additional definition in Patchpoint intrinsic.");
 #endif
 }
 
@@ -65,7 +70,126 @@ unsigned PatchPointOpers::getNextScratchIdx(unsigned StartIdx) const {
   return ScratchIdx;
 }
 
-void StackMaps::recordStackMapOpers(const MachineInstr &MI, uint32_t ID,
+StackMaps::StackMaps(AsmPrinter &AP) : AP(AP) {
+  if (StackMapVersion != 1)
+    llvm_unreachable("Unsupported stackmap version!");
+}
+
+MachineInstr::const_mop_iterator
+StackMaps::parseOperand(MachineInstr::const_mop_iterator MOI,
+                        MachineInstr::const_mop_iterator MOE,
+                        LocationVec &Locs, LiveOutVec &LiveOuts) const {
+  if (MOI->isImm()) {
+    switch (MOI->getImm()) {
+    default: llvm_unreachable("Unrecognized operand type.");
+    case StackMaps::DirectMemRefOp: {
+      unsigned Size = AP.TM.getDataLayout()->getPointerSizeInBits();
+      assert((Size % 8) == 0 && "Need pointer size in bytes.");
+      Size /= 8;
+      unsigned Reg = (++MOI)->getReg();
+      int64_t Imm = (++MOI)->getImm();
+      Locs.push_back(Location(StackMaps::Location::Direct, Size, Reg, Imm));
+      break;
+    }
+    case StackMaps::IndirectMemRefOp: {
+      int64_t Size = (++MOI)->getImm();
+      assert(Size > 0 && "Need a valid size for indirect memory locations.");
+      unsigned Reg = (++MOI)->getReg();
+      int64_t Imm = (++MOI)->getImm();
+      Locs.push_back(Location(StackMaps::Location::Indirect, Size, Reg, Imm));
+      break;
+    }
+    case StackMaps::ConstantOp: {
+      ++MOI;
+      assert(MOI->isImm() && "Expected constant operand.");
+      int64_t Imm = MOI->getImm();
+      Locs.push_back(Location(Location::Constant, sizeof(int64_t), 0, Imm));
+      break;
+    }
+    }
+    return ++MOI;
+  }
+
+  // The physical register number will ultimately be encoded as a DWARF regno.
+  // The stack map also records the size of a spill slot that can hold the
+  // register content. (The runtime can track the actual size of the data type
+  // if it needs to.)
+  if (MOI->isReg()) {
+    // Skip implicit registers (this includes our scratch registers)
+    if (MOI->isImplicit())
+      return ++MOI;
+
+    assert(TargetRegisterInfo::isPhysicalRegister(MOI->getReg()) &&
+           "Virtreg operands should have been rewritten before now.");
+    const TargetRegisterClass *RC =
+      AP.TM.getRegisterInfo()->getMinimalPhysRegClass(MOI->getReg());
+    assert(!MOI->getSubReg() && "Physical subreg still around.");
+    Locs.push_back(
+      Location(Location::Register, RC->getSize(), MOI->getReg(), 0));
+    return ++MOI;
+  }
+
+  if (MOI->isRegLiveOut())
+    LiveOuts = parseRegisterLiveOutMask(MOI->getRegLiveOut());
+
+  return ++MOI;
+}
+
+/// Go up the super-register chain until we hit a valid dwarf register number.
+static unsigned getDwarfRegNum(unsigned Reg, const TargetRegisterInfo *TRI) {
+  int RegNo = TRI->getDwarfRegNum(Reg, false);
+  for (MCSuperRegIterator SR(Reg, TRI); SR.isValid() && RegNo < 0; ++SR)
+    RegNo = TRI->getDwarfRegNum(*SR, false);
+
+  assert(RegNo >= 0 && "Invalid Dwarf register number.");
+  return (unsigned) RegNo;
+}
+
+/// Create a live-out register record for the given register Reg.
+StackMaps::LiveOutReg
+StackMaps::createLiveOutReg(unsigned Reg, const TargetRegisterInfo *TRI) const {
+  unsigned RegNo = getDwarfRegNum(Reg, TRI);
+  unsigned Size = TRI->getMinimalPhysRegClass(Reg)->getSize();
+  return LiveOutReg(Reg, RegNo, Size);
+}
+
+/// Parse the register live-out mask and return a vector of live-out registers
+/// that need to be recorded in the stackmap.
+StackMaps::LiveOutVec
+StackMaps::parseRegisterLiveOutMask(const uint32_t *Mask) const {
+  assert(Mask && "No register mask specified");
+  const TargetRegisterInfo *TRI = AP.TM.getRegisterInfo();
+  LiveOutVec LiveOuts;
+
+  // Create a LiveOutReg for each bit that is set in the register mask.
+  for (unsigned Reg = 0, NumRegs = TRI->getNumRegs(); Reg != NumRegs; ++Reg)
+    if ((Mask[Reg / 32] >> Reg % 32) & 1)
+      LiveOuts.push_back(createLiveOutReg(Reg, TRI));
+
+  // We don't need to keep track of a register if its super-register is already
+  // in the list. Merge entries that refer to the same dwarf register and use
+  // the maximum size that needs to be spilled.
+  std::sort(LiveOuts.begin(), LiveOuts.end());
+  for (LiveOutVec::iterator I = LiveOuts.begin(), E = LiveOuts.end();
+       I != E; ++I) {
+    for (LiveOutVec::iterator II = std::next(I); II != E; ++II) {
+      if (I->RegNo != II->RegNo) {
+        // Skip all the now invalid entries.
+        I = --II;
+        break;
+      }
+      I->Size = std::max(I->Size, II->Size);
+      if (TRI->isSuperRegister(I->Reg, II->Reg))
+        I->Reg = II->Reg;
+      II->MarkInvalid();
+    }
+  }
+  LiveOuts.erase(std::remove_if(LiveOuts.begin(), LiveOuts.end(),
+                                LiveOutReg::IsInvalid), LiveOuts.end());
+  return LiveOuts;
+}
+
+void StackMaps::recordStackMapOpers(const MachineInstr &MI, uint64_t ID,
                                     MachineInstr::const_mop_iterator MOI,
                                     MachineInstr::const_mop_iterator MOE,
                                     bool recordResult) {
@@ -74,71 +198,65 @@ void StackMaps::recordStackMapOpers(const MachineInstr &MI, uint32_t ID,
   MCSymbol *MILabel = OutContext.CreateTempSymbol();
   AP.OutStreamer.EmitLabel(MILabel);
 
-  LocationVec CallsiteLocs;
+  LocationVec Locations;
+  LiveOutVec LiveOuts;
 
   if (recordResult) {
-    std::pair<Location, MachineInstr::const_mop_iterator> ParseResult =
-      OpParser(MI.operands_begin(), llvm::next(MI.operands_begin()), AP.TM);
-
-    Location &Loc = ParseResult.first;
-    assert(Loc.LocType == Location::Register &&
-           "Stackmap return location must be a register.");
-    CallsiteLocs.push_back(Loc);
+    assert(PatchPointOpers(&MI).hasDef() && "Stackmap has no return value.");
+    parseOperand(MI.operands_begin(), std::next(MI.operands_begin()),
+                 Locations, LiveOuts);
   }
 
+  // Parse operands.
   while (MOI != MOE) {
-    std::pair<Location, MachineInstr::const_mop_iterator> ParseResult =
-      OpParser(MOI, MOE, AP.TM);
-
-    Location &Loc = ParseResult.first;
+    MOI = parseOperand(MOI, MOE, Locations, LiveOuts);
+  }
 
-    // Move large constants into the constant pool.
-    if (Loc.LocType == Location::Constant && (Loc.Offset & ~0xFFFFFFFFULL)) {
-      Loc.LocType = Location::ConstantIndex;
-      Loc.Offset = ConstPool.getConstantIndex(Loc.Offset);
+  // Move large constants into the constant pool.
+  for (LocationVec::iterator I = Locations.begin(), E = Locations.end();
+       I != E; ++I) {
+    // Constants are encoded as sign-extended integers.
+    // -1 is directly encoded as .long 0xFFFFFFFF with no constant pool.
+    if (I->LocType == Location::Constant &&
+        ((I->Offset + (int64_t(1)<<31)) >> 32) != 0) {
+      I->LocType = Location::ConstantIndex;
+      auto Result = ConstPool.insert(std::make_pair(I->Offset, I->Offset));
+      I->Offset = Result.first - ConstPool.begin();
     }
-
-    CallsiteLocs.push_back(Loc);
-    MOI = ParseResult.second;
   }
 
+  // Create an expression to calculate the offset of the callsite from function
+  // entry.
   const MCExpr *CSOffsetExpr = MCBinaryExpr::CreateSub(
     MCSymbolRefExpr::Create(MILabel, OutContext),
     MCSymbolRefExpr::Create(AP.CurrentFnSym, OutContext),
     OutContext);
 
-  CSInfos.push_back(CallsiteInfo(CSOffsetExpr, ID, CallsiteLocs));
-}
+  CSInfos.push_back(CallsiteInfo(CSOffsetExpr, ID, Locations, LiveOuts));
 
-static MachineInstr::const_mop_iterator
-getStackMapEndMOP(MachineInstr::const_mop_iterator MOI,
-                  MachineInstr::const_mop_iterator MOE) {
-  for (; MOI != MOE; ++MOI)
-    if (MOI->isRegMask() || (MOI->isReg() && MOI->isImplicit()))
-      break;
-
-  return MOI;
+  // Record the stack size of the current function.
+  const MachineFrameInfo *MFI = AP.MF->getFrameInfo();
+  FnStackSize[AP.CurrentFnSym] =
+    MFI->hasVarSizedObjects() ? UINT64_MAX : MFI->getStackSize();
 }
 
 void StackMaps::recordStackMap(const MachineInstr &MI) {
-  assert(MI.getOpcode() == TargetOpcode::STACKMAP && "exected stackmap");
+  assert(MI.getOpcode() == TargetOpcode::STACKMAP && "expected stackmap");
 
   int64_t ID = MI.getOperand(0).getImm();
-  assert((int32_t)ID == ID && "Stack maps hold 32-bit IDs");
-  recordStackMapOpers(MI, ID, llvm::next(MI.operands_begin(), 2),
-                      getStackMapEndMOP(MI.operands_begin(),
-                                        MI.operands_end()));
+  recordStackMapOpers(MI, ID, std::next(MI.operands_begin(), 2),
+                      MI.operands_end());
 }
 
 void StackMaps::recordPatchPoint(const MachineInstr &MI) {
-  assert(MI.getOpcode() == TargetOpcode::PATCHPOINT && "exected stackmap");
+  assert(MI.getOpcode() == TargetOpcode::PATCHPOINT && "expected patchpoint");
 
   PatchPointOpers opers(&MI);
   int64_t ID = opers.getMetaOper(PatchPointOpers::IDPos).getImm();
-  assert((int32_t)ID == ID && "Stack maps hold 32-bit IDs");
+
   MachineInstr::const_mop_iterator MOI =
-    llvm::next(MI.operands_begin(), opers.getStackMapStartIdx());
-  recordStackMapOpers(MI, ID, MOI, getStackMapEndMOP(MOI, MI.operands_end()),
+    std::next(MI.operands_begin(), opers.getStackMapStartIdx());
+  recordStackMapOpers(MI, ID, MOI, MI.operands_end(),
                       opers.isAnyReg() && opers.hasDef());
 
 #ifndef NDEBUG
@@ -153,14 +271,66 @@ void StackMaps::recordPatchPoint(const MachineInstr &MI) {
 #endif
 }
 
-/// serializeToStackMapSection conceptually populates the following fields:
+/// Emit the stackmap header.
 ///
-/// uint32 : Reserved (header)
+/// Header {
+///   uint8  : Stack Map Version (currently 1)
+///   uint8  : Reserved (expected to be 0)
+///   uint16 : Reserved (expected to be 0)
+/// }
+/// uint32 : NumFunctions
 /// uint32 : NumConstants
-/// int64  : Constants[NumConstants]
 /// uint32 : NumRecords
+void StackMaps::emitStackmapHeader(MCStreamer &OS) {
+  // Header.
+  OS.EmitIntValue(StackMapVersion, 1); // Version.
+  OS.EmitIntValue(0, 1); // Reserved.
+  OS.EmitIntValue(0, 2); // Reserved.
+
+  // Num functions.
+  DEBUG(dbgs() << WSMP << "#functions = " << FnStackSize.size() << '\n');
+  OS.EmitIntValue(FnStackSize.size(), 4);
+  // Num constants.
+  DEBUG(dbgs() << WSMP << "#constants = " << ConstPool.size() << '\n');
+  OS.EmitIntValue(ConstPool.size(), 4);
+  // Num callsites.
+  DEBUG(dbgs() << WSMP << "#callsites = " << CSInfos.size() << '\n');
+  OS.EmitIntValue(CSInfos.size(), 4);
+}
+
+/// Emit the function frame record for each function.
+///
+/// StkSizeRecord[NumFunctions] {
+///   uint64 : Function Address
+///   uint64 : Stack Size
+/// }
+void StackMaps::emitFunctionFrameRecords(MCStreamer &OS) {
+  // Function Frame records.
+  DEBUG(dbgs() << WSMP << "functions:\n");
+  for (auto const &FR : FnStackSize) {
+    DEBUG(dbgs() << WSMP << "function addr: " << FR.first
+                         << " frame size: " << FR.second);
+    OS.EmitSymbolValue(FR.first, 8);
+    OS.EmitIntValue(FR.second, 8);
+  }
+}
+
+/// Emit the constant pool.
+///
+/// int64  : Constants[NumConstants]
+void StackMaps::emitConstantPoolEntries(MCStreamer &OS) {
+  // Constant pool entries.
+  DEBUG(dbgs() << WSMP << "constants:\n");
+  for (auto ConstEntry : ConstPool) {
+    DEBUG(dbgs() << WSMP << ConstEntry.second << '\n');
+    OS.EmitIntValue(ConstEntry.second, 8);
+  }
+}
+
+/// Emit the callsite info for each callsite.
+///
 /// StkMapRecord[NumRecords] {
-///   uint32 : PatchPoint ID
+///   uint64 : PatchPoint ID
 ///   uint32 : Instruction Offset
 ///   uint16 : Reserved (record flags)
 ///   uint16 : NumLocations
@@ -170,6 +340,14 @@ void StackMaps::recordPatchPoint(const MachineInstr &MI) {
 ///     uint16 : Dwarf RegNum
 ///     int32  : Offset
 ///   }
+///   uint16 : Padding
+///   uint16 : NumLiveOuts
+///   LiveOuts[NumLiveOuts] {
+///     uint16 : Dwarf RegNum
+///     uint8  : Reserved
+///     uint8  : Size in Bytes
+///   }
+///   uint32 : Padding (only if required to align to 8 byte)
 /// }
 ///
 /// Location Encoding, Type, Value:
@@ -178,137 +356,154 @@ void StackMaps::recordPatchPoint(const MachineInstr &MI) {
 ///   0x3, Indirect, [Reg + Offset]      (spilled value)
 ///   0x4, Constant, Offset              (small constant)
 ///   0x5, ConstIndex, Constants[Offset] (large constant)
-///
-void StackMaps::serializeToStackMapSection() {
-  // Bail out if there's no stack map data.
-  if (CSInfos.empty())
-    return;
-
-  MCContext &OutContext = AP.OutStreamer.getContext();
-  const TargetRegisterInfo *TRI = AP.TM.getRegisterInfo();
-
-  // Create the section.
-  const MCSection *StackMapSection =
-    OutContext.getObjectFileInfo()->getStackMapSection();
-  AP.OutStreamer.SwitchSection(StackMapSection);
-
-  // Emit a dummy symbol to force section inclusion.
-  AP.OutStreamer.EmitLabel(
-    OutContext.GetOrCreateSymbol(Twine("__LLVM_StackMaps")));
-
-  // Serialize data.
-  const char *WSMP = "Stack Maps: ";
-  (void)WSMP;
-  const MCRegisterInfo &MCRI = *OutContext.getRegisterInfo();
-
-  DEBUG(dbgs() << "********** Stack Map Output **********\n");
-
-  // Header.
-  AP.OutStreamer.EmitIntValue(0, 4);
-
-  // Num constants.
-  AP.OutStreamer.EmitIntValue(ConstPool.getNumConstants(), 4);
-
-  // Constant pool entries.
-  for (unsigned i = 0; i < ConstPool.getNumConstants(); ++i)
-    AP.OutStreamer.EmitIntValue(ConstPool.getConstant(i), 8);
-
-  DEBUG(dbgs() << WSMP << "#callsites = " << CSInfos.size() << "\n");
-  AP.OutStreamer.EmitIntValue(CSInfos.size(), 4);
+void StackMaps::emitCallsiteEntries(MCStreamer &OS,
+                                    const TargetRegisterInfo *TRI) {
+  // Callsite entries.
+  DEBUG(dbgs() << WSMP << "callsites:\n");
+  for (const auto &CSI : CSInfos) {
+    const LocationVec &CSLocs = CSI.Locations;
+    const LiveOutVec &LiveOuts = CSI.LiveOuts;
 
-  for (CallsiteInfoList::const_iterator CSII = CSInfos.begin(),
-                                        CSIE = CSInfos.end();
-       CSII != CSIE; ++CSII) {
-
-    unsigned CallsiteID = CSII->ID;
-    const LocationVec &CSLocs = CSII->Locations;
-
-    DEBUG(dbgs() << WSMP << "callsite " << CallsiteID << "\n");
+    DEBUG(dbgs() << WSMP << "callsite " << CSI.ID << "\n");
 
     // Verify stack map entry. It's better to communicate a problem to the
     // runtime than crash in case of in-process compilation. Currently, we do
     // simple overflow checks, but we may eventually communicate other
     // compilation errors this way.
-    if (CSLocs.size() > UINT16_MAX) {
-      AP.OutStreamer.EmitIntValue(UINT32_MAX, 4); // Invalid ID.
-      AP.OutStreamer.EmitValue(CSII->CSOffsetExpr, 4);
-      AP.OutStreamer.EmitIntValue(0, 2); // Reserved.
-      AP.OutStreamer.EmitIntValue(0, 2); // 0 locations.
+    if (CSLocs.size() > UINT16_MAX || LiveOuts.size() > UINT16_MAX) {
+      OS.EmitIntValue(UINT64_MAX, 8); // Invalid ID.
+      OS.EmitValue(CSI.CSOffsetExpr, 4);
+      OS.EmitIntValue(0, 2); // Reserved.
+      OS.EmitIntValue(0, 2); // 0 locations.
+      OS.EmitIntValue(0, 2); // padding.
+      OS.EmitIntValue(0, 2); // 0 live-out registers.
+      OS.EmitIntValue(0, 4); // padding.
       continue;
     }
 
-    AP.OutStreamer.EmitIntValue(CallsiteID, 4);
-    AP.OutStreamer.EmitValue(CSII->CSOffsetExpr, 4);
+    OS.EmitIntValue(CSI.ID, 8);
+    OS.EmitValue(CSI.CSOffsetExpr, 4);
 
     // Reserved for flags.
-    AP.OutStreamer.EmitIntValue(0, 2);
+    OS.EmitIntValue(0, 2);
 
     DEBUG(dbgs() << WSMP << "  has " << CSLocs.size() << " locations\n");
 
-    AP.OutStreamer.EmitIntValue(CSLocs.size(), 2);
-
-    unsigned operIdx = 0;
-    for (LocationVec::const_iterator LocI = CSLocs.begin(), LocE = CSLocs.end();
-         LocI != LocE; ++LocI, ++operIdx) {
-      const Location &Loc = *LocI;
-      DEBUG(
-        dbgs() << WSMP << "  Loc " << operIdx << ": ";
-        switch (Loc.LocType) {
-        case Location::Unprocessed:
-          dbgs() << "<Unprocessed operand>";
-          break;
-        case Location::Register:
-          dbgs() << "Register " << MCRI.getName(Loc.Reg);
-          break;
-        case Location::Direct:
-          dbgs() << "Direct " << MCRI.getName(Loc.Reg);
-          if (Loc.Offset)
-            dbgs() << " + " << Loc.Offset;
-          break;
-        case Location::Indirect:
-          dbgs() << "Indirect " << MCRI.getName(Loc.Reg)
-                 << " + " << Loc.Offset;
-          break;
-        case Location::Constant:
-          dbgs() << "Constant " << Loc.Offset;
-          break;
-        case Location::ConstantIndex:
-          dbgs() << "Constant Index " << Loc.Offset;
-          break;
-        }
-        dbgs() << "\n";
-      );
+    OS.EmitIntValue(CSLocs.size(), 2);
 
+    unsigned OperIdx = 0;
+    for (const auto &Loc : CSLocs) {
       unsigned RegNo = 0;
       int Offset = Loc.Offset;
       if(Loc.Reg) {
-        RegNo = MCRI.getDwarfRegNum(Loc.Reg, false);
-        for (MCSuperRegIterator SR(Loc.Reg, TRI);
-             SR.isValid() && (int)RegNo < 0; ++SR) {
-          RegNo = TRI->getDwarfRegNum(*SR, false);
-        }
+        RegNo = getDwarfRegNum(Loc.Reg, TRI);
+
         // If this is a register location, put the subregister byte offset in
         // the location offset.
         if (Loc.LocType == Location::Register) {
           assert(!Loc.Offset && "Register location should have zero offset");
-          unsigned LLVMRegNo = MCRI.getLLVMRegNum(RegNo, false);
-          unsigned SubRegIdx = MCRI.getSubRegIndex(LLVMRegNo, Loc.Reg);
+          unsigned LLVMRegNo = TRI->getLLVMRegNum(RegNo, false);
+          unsigned SubRegIdx = TRI->getSubRegIndex(LLVMRegNo, Loc.Reg);
           if (SubRegIdx)
-            Offset = MCRI.getSubRegIdxOffset(SubRegIdx);
+            Offset = TRI->getSubRegIdxOffset(SubRegIdx);
         }
       }
       else {
         assert(Loc.LocType != Location::Register &&
                "Missing location register");
       }
-      AP.OutStreamer.EmitIntValue(Loc.LocType, 1);
-      AP.OutStreamer.EmitIntValue(Loc.Size, 1);
-      AP.OutStreamer.EmitIntValue(RegNo, 2);
-      AP.OutStreamer.EmitIntValue(Offset, 4);
+
+      DEBUG(dbgs() << WSMP << "  Loc " << OperIdx << ": ";
+            switch (Loc.LocType) {
+            case Location::Unprocessed:
+              dbgs() << "<Unprocessed operand>";
+              break;
+            case Location::Register:
+              dbgs() << "Register " << TRI->getName(Loc.Reg);
+              break;
+            case Location::Direct:
+              dbgs() << "Direct " << TRI->getName(Loc.Reg);
+              if (Loc.Offset)
+              dbgs() << " + " << Loc.Offset;
+              break;
+            case Location::Indirect:
+              dbgs() << "Indirect " << TRI->getName(Loc.Reg)
+              << " + " << Loc.Offset;
+              break;
+            case Location::Constant:
+              dbgs() << "Constant " << Loc.Offset;
+              break;
+            case Location::ConstantIndex:
+              dbgs() << "Constant Index " << Loc.Offset;
+              break;
+              }
+            dbgs() << "     [encoding: .byte " << Loc.LocType
+            << ", .byte " << Loc.Size
+            << ", .short " << RegNo
+            << ", .int " << Offset << "]\n";
+            );
+
+      OS.EmitIntValue(Loc.LocType, 1);
+      OS.EmitIntValue(Loc.Size, 1);
+      OS.EmitIntValue(RegNo, 2);
+      OS.EmitIntValue(Offset, 4);
+      OperIdx++;
+    }
+
+    DEBUG(dbgs() << WSMP << "  has " << LiveOuts.size()
+                         << " live-out registers\n");
+
+    // Num live-out registers and padding to align to 4 byte.
+    OS.EmitIntValue(0, 2);
+    OS.EmitIntValue(LiveOuts.size(), 2);
+
+    OperIdx = 0;
+    for (const auto &LO : LiveOuts) {
+      DEBUG(dbgs() << WSMP << "  LO " << OperIdx << ": "
+                           << TRI->getName(LO.Reg)
+                           << "     [encoding: .short " << LO.RegNo
+                           << ", .byte 0, .byte " << LO.Size << "]\n");
+      OS.EmitIntValue(LO.RegNo, 2);
+      OS.EmitIntValue(0, 1);
+      OS.EmitIntValue(LO.Size, 1);
     }
+    // Emit alignment to 8 byte.
+    OS.EmitValueToAlignment(8);
   }
+}
 
-  AP.OutStreamer.AddBlankLine();
+/// Serialize the stackmap data.
+void StackMaps::serializeToStackMapSection() {
+  (void) WSMP;
+  // Bail out if there's no stack map data.
+  assert((!CSInfos.empty() || (CSInfos.empty() && ConstPool.empty())) &&
+         "Expected empty constant pool too!");
+  assert((!CSInfos.empty() || (CSInfos.empty() && FnStackSize.empty())) &&
+         "Expected empty function record too!");
+  if (CSInfos.empty())
+    return;
+
+  MCContext &OutContext = AP.OutStreamer.getContext();
+  MCStreamer &OS = AP.OutStreamer;
+  const TargetRegisterInfo *TRI = AP.TM.getRegisterInfo();
+
+  // Create the section.
+  const MCSection *StackMapSection =
+    OutContext.getObjectFileInfo()->getStackMapSection();
+  OS.SwitchSection(StackMapSection);
+
+  // Emit a dummy symbol to force section inclusion.
+  OS.EmitLabel(OutContext.GetOrCreateSymbol(Twine("__LLVM_StackMaps")));
+
+  // Serialize data.
+  DEBUG(dbgs() << "********** Stack Map Output **********\n");
+  emitStackmapHeader(OS);
+  emitFunctionFrameRecords(OS);
+  emitConstantPoolEntries(OS);
+  emitCallsiteEntries(OS, TRI);
+  OS.AddBlankLine();
 
+  // Clean up.
   CSInfos.clear();
+  ConstPool.clear();
 }