Merge LLVM 7.0.1 release.

With fixes from mortimer@ (thanks!)
Tested by many, especially naddy@ (thanks!)

1 files changed, 195 insertions, 100 deletions

diff --git a/gnu/llvm/lib/Target/X86/X86FrameLowering.cpp b/gnu/llvm/lib/Target/X86/X86FrameLowering.cpp
index 170cd09fb4b..ea076e576ef 100644
--- a/gnu/llvm/lib/Target/X86/X86FrameLowering.cpp
+++ b/gnu/llvm/lib/Target/X86/X86FrameLowering.cpp
@@ -69,7 +69,7 @@ X86FrameLowering::canSimplifyCallFramePseudos(const MachineFunction &MF) const {
 // needsFrameIndexResolution - Do we need to perform FI resolution for
 // this function. Normally, this is required only when the function
 // has any stack objects. However, FI resolution actually has another job,
-// not apparent from the title - it resolves callframesetup/destroy 
+// not apparent from the title - it resolves callframesetup/destroy
 // that were not simplified earlier.
 // So, this is required for x86 functions that have push sequences even
 // when there are no stack objects.
@@ -249,6 +249,7 @@ flagsNeedToBePreservedBeforeTheTerminators(const MachineBasicBlock &MBB) {
 /// stack pointer by a constant value.
 void X86FrameLowering::emitSPUpdate(MachineBasicBlock &MBB,
                                     MachineBasicBlock::iterator &MBBI,
+                                    const DebugLoc &DL,
                                     int64_t NumBytes, bool InEpilogue) const {
   bool isSub = NumBytes < 0;
   uint64_t Offset = isSub ? -NumBytes : NumBytes;
@@ -256,7 +257,6 @@ void X86FrameLowering::emitSPUpdate(MachineBasicBlock &MBB,
       isSub ? MachineInstr::FrameSetup : MachineInstr::FrameDestroy;
 
   uint64_t Chunk = (1LL << 31) - 1;
-  DebugLoc DL = MBB.findDebugLoc(MBBI);
 
   if (Offset > Chunk) {
     // Rather than emit a long series of instructions for large offsets,
@@ -400,28 +400,30 @@ int X86FrameLowering::mergeSPUpdates(MachineBasicBlock &MBB,
     return 0;
 
   MachineBasicBlock::iterator PI = doMergeWithPrevious ? std::prev(MBBI) : MBBI;
-  MachineBasicBlock::iterator NI = doMergeWithPrevious ? nullptr
-                                                       : std::next(MBBI);
+
   PI = skipDebugInstructionsBackward(PI, MBB.begin());
-  if (NI != nullptr)
-    NI = skipDebugInstructionsForward(NI, MBB.end());
+  // It is assumed that ADD/SUB/LEA instruction is succeded by one CFI
+  // instruction, and that there are no DBG_VALUE or other instructions between
+  // ADD/SUB/LEA and its corresponding CFI instruction.
+  /* TODO: Add support for the case where there are multiple CFI instructions
+    below the ADD/SUB/LEA, e.g.:
+    ...
+    add
+    cfi_def_cfa_offset
+    cfi_offset
+    ...
+  */
+  if (doMergeWithPrevious && PI != MBB.begin() && PI->isCFIInstruction())
+    PI = std::prev(PI);
 
   unsigned Opc = PI->getOpcode();
   int Offset = 0;
 
-  if (!doMergeWithPrevious && NI != MBB.end() &&
-      NI->getOpcode() == TargetOpcode::CFI_INSTRUCTION) {
-    // Don't merge with the next instruction if it has CFI.
-    return Offset;
-  }
-
   if ((Opc == X86::ADD64ri32 || Opc == X86::ADD64ri8 ||
        Opc == X86::ADD32ri || Opc == X86::ADD32ri8) &&
       PI->getOperand(0).getReg() == StackPtr){
     assert(PI->getOperand(1).getReg() == StackPtr);
-    Offset += PI->getOperand(2).getImm();
-    MBB.erase(PI);
-    if (!doMergeWithPrevious) MBBI = NI;
+    Offset = PI->getOperand(2).getImm();
   } else if ((Opc == X86::LEA32r || Opc == X86::LEA64_32r) &&
              PI->getOperand(0).getReg() == StackPtr &&
              PI->getOperand(1).getReg() == StackPtr &&
@@ -429,17 +431,19 @@ int X86FrameLowering::mergeSPUpdates(MachineBasicBlock &MBB,
              PI->getOperand(3).getReg() == X86::NoRegister &&
              PI->getOperand(5).getReg() == X86::NoRegister) {
     // For LEAs we have: def = lea SP, FI, noreg, Offset, noreg.
-    Offset += PI->getOperand(4).getImm();
-    MBB.erase(PI);
-    if (!doMergeWithPrevious) MBBI = NI;
+    Offset = PI->getOperand(4).getImm();
   } else if ((Opc == X86::SUB64ri32 || Opc == X86::SUB64ri8 ||
               Opc == X86::SUB32ri || Opc == X86::SUB32ri8) &&
              PI->getOperand(0).getReg() == StackPtr) {
     assert(PI->getOperand(1).getReg() == StackPtr);
-    Offset -= PI->getOperand(2).getImm();
-    MBB.erase(PI);
-    if (!doMergeWithPrevious) MBBI = NI;
-  }
+    Offset = -PI->getOperand(2).getImm();
+  } else
+    return 0;
+
+  PI = MBB.erase(PI);
+  if (PI != MBB.end() && PI->isCFIInstruction()) PI = MBB.erase(PI);
+  if (!doMergeWithPrevious)
+    MBBI = skipDebugInstructionsForward(PI, MBB.end());
 
   return Offset;
 }
@@ -604,8 +608,7 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
   int64_t RCXShadowSlot = 0;
   int64_t RDXShadowSlot = 0;
 
-  // If inlining in the prolog, save RCX and RDX.     
-  // Future optimization: don't save or restore if not live in.
+  // If inlining in the prolog, save RCX and RDX.
   if (InProlog) {
     // Compute the offsets. We need to account for things already
     // pushed onto the stack at this point: return address, frame
@@ -613,15 +616,30 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
     X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
     const int64_t CalleeSaveSize = X86FI->getCalleeSavedFrameSize();
     const bool HasFP = hasFP(MF);
-    RCXShadowSlot = 8 + CalleeSaveSize + (HasFP ? 8 : 0);
-    RDXShadowSlot = RCXShadowSlot + 8;
-    // Emit the saves.
-    addRegOffset(BuildMI(&MBB, DL, TII.get(X86::MOV64mr)), X86::RSP, false,
-                 RCXShadowSlot)
-        .addReg(X86::RCX);
-    addRegOffset(BuildMI(&MBB, DL, TII.get(X86::MOV64mr)), X86::RSP, false,
-                 RDXShadowSlot)
-        .addReg(X86::RDX);
+
+    // Check if we need to spill RCX and/or RDX.
+    // Here we assume that no earlier prologue instruction changes RCX and/or
+    // RDX, so checking the block live-ins is enough.
+    const bool IsRCXLiveIn = MBB.isLiveIn(X86::RCX);
+    const bool IsRDXLiveIn = MBB.isLiveIn(X86::RDX);
+    int64_t InitSlot = 8 + CalleeSaveSize + (HasFP ? 8 : 0);
+    // Assign the initial slot to both registers, then change RDX's slot if both
+    // need to be spilled.
+    if (IsRCXLiveIn)
+      RCXShadowSlot = InitSlot;
+    if (IsRDXLiveIn)
+      RDXShadowSlot = InitSlot;
+    if (IsRDXLiveIn && IsRCXLiveIn)
+      RDXShadowSlot += 8;
+    // Emit the saves if needed.
+    if (IsRCXLiveIn)
+      addRegOffset(BuildMI(&MBB, DL, TII.get(X86::MOV64mr)), X86::RSP, false,
+                   RCXShadowSlot)
+          .addReg(X86::RCX);
+    if (IsRDXLiveIn)
+      addRegOffset(BuildMI(&MBB, DL, TII.get(X86::MOV64mr)), X86::RSP, false,
+                   RDXShadowSlot)
+          .addReg(X86::RDX);
   } else {
     // Not in the prolog. Copy RAX to a virtual reg.
     BuildMI(&MBB, DL, TII.get(X86::MOV64rr), SizeReg).addReg(X86::RAX);
@@ -658,6 +676,7 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
   BuildMI(&MBB, DL, TII.get(X86::JAE_1)).addMBB(ContinueMBB);
 
   // Add code to roundMBB to round the final stack pointer to a page boundary.
+  RoundMBB->addLiveIn(FinalReg);
   BuildMI(RoundMBB, DL, TII.get(X86::AND64ri32), RoundedReg)
       .addReg(FinalReg)
       .addImm(PageMask);
@@ -674,6 +693,7 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
         .addMBB(LoopMBB);
   }
 
+  LoopMBB->addLiveIn(JoinReg);
   addRegOffset(BuildMI(LoopMBB, DL, TII.get(X86::LEA64r), ProbeReg), JoinReg,
                false, -PageSize);
 
@@ -685,6 +705,8 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
       .addImm(0)
       .addReg(0)
       .addImm(0);
+
+  LoopMBB->addLiveIn(RoundedReg);
   BuildMI(LoopMBB, DL, TII.get(X86::CMP64rr))
       .addReg(RoundedReg)
       .addReg(ProbeReg);
@@ -694,16 +716,19 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
 
   // If in prolog, restore RDX and RCX.
   if (InProlog) {
-    addRegOffset(BuildMI(*ContinueMBB, ContinueMBBI, DL, TII.get(X86::MOV64rm),
-                         X86::RCX),
-                 X86::RSP, false, RCXShadowSlot);
-    addRegOffset(BuildMI(*ContinueMBB, ContinueMBBI, DL, TII.get(X86::MOV64rm),
-                         X86::RDX),
-                 X86::RSP, false, RDXShadowSlot);
+    if (RCXShadowSlot) // It means we spilled RCX in the prologue.
+      addRegOffset(BuildMI(*ContinueMBB, ContinueMBBI, DL,
+                           TII.get(X86::MOV64rm), X86::RCX),
+                   X86::RSP, false, RCXShadowSlot);
+    if (RDXShadowSlot) // It means we spilled RDX in the prologue.
+      addRegOffset(BuildMI(*ContinueMBB, ContinueMBBI, DL,
+                           TII.get(X86::MOV64rm), X86::RDX),
+                   X86::RSP, false, RDXShadowSlot);
   }
 
   // Now that the probing is done, add code to continueMBB to update
   // the stack pointer for real.
+  ContinueMBB->addLiveIn(SizeReg);
   BuildMI(*ContinueMBB, ContinueMBBI, DL, TII.get(X86::SUB64rr), X86::RSP)
       .addReg(X86::RSP)
       .addReg(SizeReg);
@@ -731,8 +756,6 @@ void X86FrameLowering::emitStackProbeInline(MachineFunction &MF,
       CMBBI->setFlag(MachineInstr::FrameSetup);
     }
   }
-
-  // Possible TODO: physreg liveness for InProlog case.
 }
 
 void X86FrameLowering::emitStackProbeCall(MachineFunction &MF,
@@ -999,7 +1022,7 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF,
       Fn.arg_size() == 2) {
     StackSize += 8;
     MFI.setStackSize(StackSize);
-    emitSPUpdate(MBB, MBBI, -8, /*InEpilogue=*/false);
+    emitSPUpdate(MBB, MBBI, DL, -8, /*InEpilogue=*/false);
   }
 
   // If this is x86-64 and the Red Zone is not disabled, if we are a leaf
@@ -1214,30 +1237,34 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF,
     bool isEAXAlive = isEAXLiveIn(MBB);
 
     if (isEAXAlive) {
-      // Sanity check that EAX is not livein for this function.
-      // It should not be, so throw an assert.
-      assert(!Is64Bit && "EAX is livein in x64 case!");
-
-      // Save EAX
-      BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
-        .addReg(X86::EAX, RegState::Kill)
-        .setMIFlag(MachineInstr::FrameSetup);
+      if (Is64Bit) {
+        // Save RAX
+        BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH64r))
+          .addReg(X86::RAX, RegState::Kill)
+          .setMIFlag(MachineInstr::FrameSetup);
+      } else {
+        // Save EAX
+        BuildMI(MBB, MBBI, DL, TII.get(X86::PUSH32r))
+          .addReg(X86::EAX, RegState::Kill)
+          .setMIFlag(MachineInstr::FrameSetup);
+      }
     }
 
     if (Is64Bit) {
       // Handle the 64-bit Windows ABI case where we need to call __chkstk.
       // Function prologue is responsible for adjusting the stack pointer.
-      if (isUInt<32>(NumBytes)) {
+      int Alloc = isEAXAlive ? NumBytes - 8 : NumBytes;
+      if (isUInt<32>(Alloc)) {
         BuildMI(MBB, MBBI, DL, TII.get(X86::MOV32ri), X86::EAX)
-            .addImm(NumBytes)
+            .addImm(Alloc)
             .setMIFlag(MachineInstr::FrameSetup);
-      } else if (isInt<32>(NumBytes)) {
+      } else if (isInt<32>(Alloc)) {
         BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri32), X86::RAX)
-            .addImm(NumBytes)
+            .addImm(Alloc)
             .setMIFlag(MachineInstr::FrameSetup);
       } else {
         BuildMI(MBB, MBBI, DL, TII.get(X86::MOV64ri), X86::RAX)
-            .addImm(NumBytes)
+            .addImm(Alloc)
             .setMIFlag(MachineInstr::FrameSetup);
       }
     } else {
@@ -1252,15 +1279,19 @@ void X86FrameLowering::emitPrologue(MachineFunction &MF,
     emitStackProbe(MF, MBB, MBBI, DL, true);
 
     if (isEAXAlive) {
-      // Restore EAX
-      MachineInstr *MI =
-          addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm), X86::EAX),
-                       StackPtr, false, NumBytes - 4);
+      // Restore RAX/EAX
+      MachineInstr *MI;
+      if (Is64Bit)
+        MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV64rm), X86::RAX),
+                          StackPtr, false, NumBytes - 8);
+      else
+        MI = addRegOffset(BuildMI(MF, DL, TII.get(X86::MOV32rm), X86::EAX),
+                          StackPtr, false, NumBytes - 4);
       MI->setFlag(MachineInstr::FrameSetup);
       MBB.insert(MBBI, MI);
     }
   } else if (NumBytes) {
-    emitSPUpdate(MBB, MBBI, -(int64_t)NumBytes, /*InEpilogue=*/false);
+    emitSPUpdate(MBB, MBBI, DL, -(int64_t)NumBytes, /*InEpilogue=*/false);
   }
 
   if (NeedsWinCFI && NumBytes) {
@@ -1566,6 +1597,11 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   bool HasFP = hasFP(MF);
   uint64_t NumBytes = 0;
 
+  bool NeedsDwarfCFI =
+      (!MF.getTarget().getTargetTriple().isOSDarwin() &&
+       !MF.getTarget().getTargetTriple().isOSWindows()) &&
+      (MF.getMMI().hasDebugInfo() || MF.getFunction().needsUnwindTableEntry());
+
   if (IsFunclet) {
     assert(HasFP && "EH funclets without FP not yet implemented");
     NumBytes = getWinEHFuncletFrameSize(MF);
@@ -1588,6 +1624,13 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
     BuildMI(MBB, MBBI, DL, TII.get(Is64Bit ? X86::POP64r : X86::POP32r),
             MachineFramePtr)
         .setMIFlag(MachineInstr::FrameDestroy);
+    if (NeedsDwarfCFI) {
+      unsigned DwarfStackPtr =
+          TRI->getDwarfRegNum(Is64Bit ? X86::RSP : X86::ESP, true);
+      BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createDefCfa(
+                                  nullptr, DwarfStackPtr, -SlotSize));
+      --MBBI;
+    }
   }
 
   MachineBasicBlock::iterator FirstCSPop = MBBI;
@@ -1650,7 +1693,12 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
     }
   } else if (NumBytes) {
     // Adjust stack pointer back: ESP += numbytes.
-    emitSPUpdate(MBB, MBBI, NumBytes, /*InEpilogue=*/true);
+    emitSPUpdate(MBB, MBBI, DL, NumBytes, /*InEpilogue=*/true);
+    if (!hasFP(MF) && NeedsDwarfCFI) {
+      // Define the current CFA rule to use the provided offset.
+      BuildCFI(MBB, MBBI, DL, MCCFIInstruction::createDefCfaOffset(
+                                  nullptr, -CSSize - SlotSize));
+    }
     --MBBI;
   }
 
@@ -1663,6 +1711,23 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
   if (NeedsWin64CFI && MF.hasWinCFI())
     BuildMI(MBB, MBBI, DL, TII.get(X86::SEH_Epilogue));
 
+  if (!hasFP(MF) && NeedsDwarfCFI) {
+    MBBI = FirstCSPop;
+    int64_t Offset = -CSSize - SlotSize;
+    // Mark callee-saved pop instruction.
+    // Define the current CFA rule to use the provided offset.
+    while (MBBI != MBB.end()) {
+      MachineBasicBlock::iterator PI = MBBI;
+      unsigned Opc = PI->getOpcode();
+      ++MBBI;
+      if (Opc == X86::POP32r || Opc == X86::POP64r) {
+        Offset += SlotSize;
+        BuildCFI(MBB, MBBI, DL,
+                 MCCFIInstruction::createDefCfaOffset(nullptr, Offset));
+      }
+    }
+  }
+
   if (Terminator == MBB.end() || !isTailCallOpcode(Terminator->getOpcode())) {
     // Add the return addr area delta back since we are not tail calling.
     int Offset = -1 * X86FI->getTCReturnAddrDelta();
@@ -1670,7 +1735,7 @@ void X86FrameLowering::emitEpilogue(MachineFunction &MF,
     if (Offset) {
       // Check for possible merge with preceding ADD instruction.
       Offset += mergeSPUpdates(MBB, Terminator, true);
-      emitSPUpdate(MBB, Terminator, Offset, /*InEpilogue=*/true);
+      emitSPUpdate(MBB, Terminator, DL, Offset, /*InEpilogue=*/true);
     }
   }
 }
@@ -1861,6 +1926,32 @@ bool X86FrameLowering::assignCalleeSavedSpillSlots(
   unsigned CalleeSavedFrameSize = 0;
   int SpillSlotOffset = getOffsetOfLocalArea() + X86FI->getTCReturnAddrDelta();
 
+  int64_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
+
+  if (TailCallReturnAddrDelta < 0) {
+    // create RETURNADDR area
+    //   arg
+    //   arg
+    //   RETADDR
+    //   { ...
+    //     RETADDR area
+    //     ...
+    //   }
+    //   [EBP]
+    MFI.CreateFixedObject(-TailCallReturnAddrDelta,
+                           TailCallReturnAddrDelta - SlotSize, true);
+  }
+
+  // Spill the BasePtr if it's used.
+  if (this->TRI->hasBasePointer(MF)) {
+    // Allocate a spill slot for EBP if we have a base pointer and EH funclets.
+    if (MF.hasEHFunclets()) {
+      int FI = MFI.CreateSpillStackObject(SlotSize, SlotSize);
+      X86FI->setHasSEHFramePtrSave(true);
+      X86FI->setSEHFramePtrSaveIndex(FI);
+    }
+  }
+
   if (hasFP(MF)) {
     // emitPrologue always spills frame register the first thing.
     SpillSlotOffset -= SlotSize;
@@ -1900,7 +1991,12 @@ bool X86FrameLowering::assignCalleeSavedSpillSlots(
     if (X86::GR64RegClass.contains(Reg) || X86::GR32RegClass.contains(Reg))
       continue;
 
-    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+    // If this is k-register make sure we lookup via the largest legal type.
+    MVT VT = MVT::Other;
+    if (X86::VK16RegClass.contains(Reg))
+      VT = STI.hasBWI() ? MVT::v64i1 : MVT::v16i1;
+
+    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg, VT);
     unsigned Size = TRI->getSpillSize(*RC);
     unsigned Align = TRI->getSpillAlignment(*RC);
     // ensure alignment
@@ -1967,9 +2063,15 @@ bool X86FrameLowering::spillCalleeSavedRegisters(
     unsigned Reg = CSI[i-1].getReg();
     if (X86::GR64RegClass.contains(Reg) || X86::GR32RegClass.contains(Reg))
       continue;
+
+    // If this is k-register make sure we lookup via the largest legal type.
+    MVT VT = MVT::Other;
+    if (X86::VK16RegClass.contains(Reg))
+      VT = STI.hasBWI() ? MVT::v64i1 : MVT::v16i1;
+
     // Add the callee-saved register as live-in. It's killed at the spill.
     MBB.addLiveIn(Reg);
-    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg, VT);
 
     TII.storeRegToStackSlot(MBB, MI, Reg, true, CSI[i - 1].getFrameIdx(), RC,
                             TRI);
@@ -2043,7 +2145,12 @@ bool X86FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
         X86::GR32RegClass.contains(Reg))
       continue;
 
-    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg);
+    // If this is k-register make sure we lookup via the largest legal type.
+    MVT VT = MVT::Other;
+    if (X86::VK16RegClass.contains(Reg))
+      VT = STI.hasBWI() ? MVT::v64i1 : MVT::v16i1;
+
+    const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg, VT);
     TII.loadRegFromStackSlot(MBB, MI, Reg, CSI[i].getFrameIdx(), RC, TRI);
   }
 
@@ -2066,35 +2173,12 @@ void X86FrameLowering::determineCalleeSaves(MachineFunction &MF,
                                             RegScavenger *RS) const {
   TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS);
 
-  MachineFrameInfo &MFI = MF.getFrameInfo();
-
-  X86MachineFunctionInfo *X86FI = MF.getInfo<X86MachineFunctionInfo>();
-  int64_t TailCallReturnAddrDelta = X86FI->getTCReturnAddrDelta();
-
-  if (TailCallReturnAddrDelta < 0) {
-    // create RETURNADDR area
-    //   arg
-    //   arg
-    //   RETADDR
-    //   { ...
-    //     RETADDR area
-    //     ...
-    //   }
-    //   [EBP]
-    MFI.CreateFixedObject(-TailCallReturnAddrDelta,
-                           TailCallReturnAddrDelta - SlotSize, true);
-  }
-
   // Spill the BasePtr if it's used.
-  if (TRI->hasBasePointer(MF)) {
-    SavedRegs.set(TRI->getBaseRegister());
-
-    // Allocate a spill slot for EBP if we have a base pointer and EH funclets.
-    if (MF.hasEHFunclets()) {
-      int FI = MFI.CreateSpillStackObject(SlotSize, SlotSize);
-      X86FI->setHasSEHFramePtrSave(true);
-      X86FI->setSEHFramePtrSaveIndex(FI);
-    }
+  if (TRI->hasBasePointer(MF)){
+    unsigned BasePtr = TRI->getBaseRegister();
+    if (STI.isTarget64BitILP32())
+      BasePtr = getX86SubSuperRegister(BasePtr, 64);
+    SavedRegs.set(BasePtr);
   }
 }
 
@@ -2177,8 +2261,10 @@ void X86FrameLowering::adjustForSegmentedStacks(
   // prologue.
   StackSize = MFI.getStackSize();
 
-  // Do not generate a prologue for functions with a stack of size zero
-  if (StackSize == 0)
+  // Do not generate a prologue for leaf functions with a stack of size zero.
+  // For non-leaf functions we have to allow for the possibility that the
+  // call is to a non-split function, as in PR37807.
+  if (StackSize == 0 && !MFI.hasTailCall())
     return;
 
   MachineBasicBlock *allocMBB = MF.CreateMachineBasicBlock();
@@ -2628,7 +2714,7 @@ bool X86FrameLowering::adjustStackWithPops(MachineBasicBlock &MBB,
     Regs[FoundRegs++] = Regs[0];
 
   for (int i = 0; i < NumPops; ++i)
-    BuildMI(MBB, MBBI, DL, 
+    BuildMI(MBB, MBBI, DL,
             TII.get(STI.is64Bit() ? X86::POP64r : X86::POP32r), Regs[i]);
 
   return true;
@@ -2693,7 +2779,6 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
 
     // Add Amount to SP to destroy a frame, or subtract to setup.
     int64_t StackAdjustment = isDestroy ? Amount : -Amount;
-    int64_t CfaAdjustment = -StackAdjustment;
 
     if (StackAdjustment) {
       // Merge with any previous or following adjustment instruction. Note: the
@@ -2718,6 +2803,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
       // offset to be correct at each call site, while for debugging we want
       // it to be more precise.
 
+      int64_t CfaAdjustment = -StackAdjustment;
       // TODO: When not using precise CFA, we also need to adjust for the
       // InternalAmt here.
       if (CfaAdjustment) {
@@ -2848,6 +2934,15 @@ MachineBasicBlock::iterator X86FrameLowering::restoreWin32EHStackPointers(
   return MBBI;
 }
 
+int X86FrameLowering::getInitialCFAOffset(const MachineFunction &MF) const {
+  return TRI->getSlotSize();
+}
+
+unsigned X86FrameLowering::getInitialCFARegister(const MachineFunction &MF)
+    const {
+  return TRI->getDwarfRegNum(StackPtr, true);
+}
+
 namespace {
 // Struct used by orderFrameObjects to help sort the stack objects.
 struct X86FrameSortingObject {
@@ -2909,7 +3004,7 @@ struct X86FrameSortingComparator {
     // in general. Something to keep in mind, though.
     if (DensityAScaled == DensityBScaled)
       return A.ObjectAlignment < B.ObjectAlignment;
-    
+
     return DensityAScaled < DensityBScaled;
   }
 };
@@ -2945,14 +3040,14 @@ void X86FrameLowering::orderFrameObjects(
     if (ObjectSize == 0)
       // Variable size. Just use 4.
       SortingObjects[Obj].ObjectSize = 4;
-    else      
+    else
       SortingObjects[Obj].ObjectSize = ObjectSize;
   }
 
   // Count the number of uses for each object.
   for (auto &MBB : MF) {
     for (auto &MI : MBB) {
-      if (MI.isDebugValue())
+      if (MI.isDebugInstr())
         continue;
       for (const MachineOperand &MO : MI.operands()) {
         // Check to see if it's a local stack symbol.