Change eliminateCallFramePseudoInstr() to return an iterator

This will become necessary in a subsequent change to make this method
merge adjacent stack adjustments, i.e. it might erase the previous
and/or next instruction.

It also greatly simplifies the calls to this function from Prolog-
EpilogInserter. Previously, that had a bunch of logic to resume iteration
after the call; now it just continues with the returned iterator.

Note that this changes the behaviour of PEI a little. Previously,
it attempted to re-visit the new instruction created by
eliminateCallFramePseudoInstr(). That code was added in r36625,
but I can't see any reason for it: the new instructions will obviously
not be pseudo instructions, they will not have FrameIndex operands,
and we have already accounted for the stack adjustment.

Differential Revision: http://reviews.llvm.org/D18627

llvm-svn: 265036

llvm/docs/ReleaseNotes.rst

@@ -52,6 +52,10 @@ Non-comprehensive list of changes in this release
 * The C API function LLVMGetDataLayout is deprecated
   in favor of LLVMGetDataLayoutStr.
 
+* ``TargetFrameLowering::eliminateCallFramePseudoInstr`` now returns an
+  iterator to the next instruction instead of ``void``. Targets that previously
+  did ``MBB.erase(I); return;`` now probably want ``return MBB.erase(I);``.
+
 .. NOTE
    For small 1-3 sentence descriptions, just add an entry at the end of
    this list. If your description won't fit comfortably in one bullet

llvm/include/llvm/Target/TargetFrameLowering.h

@@ -273,14 +273,13 @@ public:
     report_fatal_error("WinEH not implemented for this target");
   }
 
-  /// eliminateCallFramePseudoInstr - This method is called during prolog/epilog
+  /// This method is called during prolog/epilog code insertion to eliminate
-  /// code insertion to eliminate call frame setup and destroy pseudo
+  /// call frame setup and destroy pseudo instructions (but only if the Target
-  /// instructions (but only if the Target is using them).  It is responsible
+  /// is using them).  It is responsible for eliminating these instructions,
-  /// for eliminating these instructions, replacing them with concrete
+  /// replacing them with concrete instructions.  This method need only be
-  /// instructions.  This method need only be implemented if using call frame
+  /// implemented if using call frame setup/destroy pseudo instructions.
-  /// setup/destroy pseudo instructions.
+  /// Returns an iterator pointing to the instruction after the replaced one.
-  ///
+  virtual MachineBasicBlock::iterator
-  virtual void
   eliminateCallFramePseudoInstr(MachineFunction &MF,
                                 MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator MI) const {

llvm/lib/CodeGen/PrologEpilogInserter.cpp

@@ -891,15 +891,7 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
       InsideCallSequence = (I->getOpcode() == FrameSetupOpcode);
       SPAdj += TII.getSPAdjust(I);
 
-      MachineBasicBlock::iterator PrevI = BB->end();
+      I = TFI->eliminateCallFramePseudoInstr(Fn, *BB, I);
-      if (I != BB->begin()) PrevI = std::prev(I);
-      TFI->eliminateCallFramePseudoInstr(Fn, *BB, I);
-
-      // Visit the instructions created by eliminateCallFramePseudoInstr().
-      if (PrevI == BB->end())
-        I = BB->begin();     // The replaced instr was the first in the block.
-      else
-        I = std::next(PrevI);
       continue;
     }
 

llvm/lib/Target/AArch64/AArch64FrameLowering.cpp

@@ -153,7 +153,7 @@ AArch64FrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
   return !MF.getFrameInfo()->hasVarSizedObjects();
 }
 
-void AArch64FrameLowering::eliminateCallFramePseudoInstr(
+MachineBasicBlock::iterator AArch64FrameLowering::eliminateCallFramePseudoInstr(
     MachineFunction &MF, MachineBasicBlock &MBB,
     MachineBasicBlock::iterator I) const {
   const AArch64InstrInfo *TII =
@@ -196,7 +196,7 @@ void AArch64FrameLowering::eliminateCallFramePseudoInstr(
     emitFrameOffset(MBB, I, DL, AArch64::SP, AArch64::SP, -CalleePopAmount,
                     TII);
   }
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 void AArch64FrameLowering::emitCalleeSavedFrameMoves(

llvm/lib/Target/AArch64/AArch64FrameLowering.h

@@ -27,9 +27,9 @@ public:
   void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MBBI) const;
 
-  void eliminateCallFramePseudoInstr(MachineFunction &MF,
+  MachineBasicBlock::iterator
-                                  MachineBasicBlock &MBB,
+  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                                  MachineBasicBlock::iterator I) const override;
+                                MachineBasicBlock::iterator I) const override;
 
   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
   /// the function.

llvm/lib/Target/ARM/ARMFrameLowering.cpp

@@ -1726,10 +1726,9 @@ void ARMFrameLowering::determineCalleeSaves(MachineFunction &MF,
   }
 }
 
-
+MachineBasicBlock::iterator ARMFrameLowering::eliminateCallFramePseudoInstr(
-void ARMFrameLowering::
+    MachineFunction &MF, MachineBasicBlock &MBB,
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+    MachineBasicBlock::iterator I) const {
-                              MachineBasicBlock::iterator I) const {
   const ARMBaseInstrInfo &TII =
       *static_cast<const ARMBaseInstrInfo *>(MF.getSubtarget().getInstrInfo());
   if (!hasReservedCallFrame(MF)) {
@@ -1769,7 +1768,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
       }
     }
   }
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 /// Get the minimum constant for ARM that is greater than or equal to the

llvm/lib/Target/ARM/ARMFrameLowering.h

@@ -74,7 +74,7 @@ public:
                    bool(*Func)(unsigned, bool),
                    unsigned NumAlignedDPRCS2Regs) const;
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF,
                                 MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator MI) const override;

llvm/lib/Target/ARM/Thumb1FrameLowering.cpp

@@ -49,7 +49,7 @@ emitSPUpdate(MachineBasicBlock &MBB,
 }
 
 
-void Thumb1FrameLowering::
+MachineBasicBlock::iterator Thumb1FrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
   const Thumb1InstrInfo &TII =
@@ -80,7 +80,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
       }
     }
   }
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 void Thumb1FrameLowering::emitPrologue(MachineFunction &MF,

llvm/lib/Target/ARM/Thumb1FrameLowering.h

@@ -41,7 +41,7 @@ public:
 
   bool hasReservedCallFrame(const MachineFunction &MF) const override;
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF,
                                 MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator MI) const override;

llvm/lib/Target/BPF/BPFFrameLowering.h

@@ -31,10 +31,10 @@ public:
   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
                             RegScavenger *RS) const override;
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator MI) const override {
-    MBB.erase(MI);
+    return MBB.erase(MI);
   }
 };
 }

llvm/lib/Target/Hexagon/HexagonFrameLowering.cpp

@@ -1060,15 +1060,15 @@ bool HexagonFrameLowering::insertCSRRestoresInBlock(MachineBasicBlock &MBB,
   return true;
 }
 
-
+MachineBasicBlock::iterator HexagonFrameLowering::eliminateCallFramePseudoInstr(
-void HexagonFrameLowering::eliminateCallFramePseudoInstr(MachineFunction &MF,
+    MachineFunction &MF, MachineBasicBlock &MBB,
-      MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const {
+    MachineBasicBlock::iterator I) const {
   MachineInstr &MI = *I;
   unsigned Opc = MI.getOpcode();
   (void)Opc; // Silence compiler warning.
   assert((Opc == Hexagon::ADJCALLSTACKDOWN || Opc == Hexagon::ADJCALLSTACKUP) &&
          "Cannot handle this call frame pseudo instruction");
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 

llvm/lib/Target/Hexagon/HexagonFrameLowering.h

@@ -42,8 +42,9 @@ public:
     return true;
   }
 
-  void eliminateCallFramePseudoInstr(MachineFunction &MF,
+  MachineBasicBlock::iterator
-      MachineBasicBlock &MBB, MachineBasicBlock::iterator I) const override;
+  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                                MachineBasicBlock::iterator I) const override;
   void processFunctionBeforeFrameFinalized(MachineFunction &MF,
       RegScavenger *RS = nullptr) const override;
   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,

llvm/lib/Target/Lanai/LanaiFrameLowering.cpp

@@ -139,11 +139,11 @@ void LanaiFrameLowering::emitPrologue(MachineFunction &MF,
     replaceAdjDynAllocPseudo(MF);
 }
 
-void LanaiFrameLowering::eliminateCallFramePseudoInstr(
+MachineBasicBlock::iterator LanaiFrameLowering::eliminateCallFramePseudoInstr(
     MachineFunction &MF, MachineBasicBlock &MBB,
     MachineBasicBlock::iterator I) const {
   // Discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 // The function epilogue should not depend on the current stack pointer!

llvm/lib/Target/Lanai/LanaiFrameLowering.h

@@ -42,7 +42,7 @@ public:
   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator I) const override;
 

llvm/lib/Target/MSP430/MSP430FrameLowering.cpp

@@ -224,9 +224,9 @@ MSP430FrameLowering::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
   return true;
 }
 
-void MSP430FrameLowering::
+MachineBasicBlock::iterator MSP430FrameLowering::eliminateCallFramePseudoInstr(
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+    MachineFunction &MF, MachineBasicBlock &MBB,
-                              MachineBasicBlock::iterator I) const {
+    MachineBasicBlock::iterator I) const {
   const MSP430InstrInfo &TII =
       *static_cast<const MSP430InstrInfo *>(MF.getSubtarget().getInstrInfo());
   unsigned StackAlign = getStackAlignment();
@@ -283,7 +283,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     }
   }
 
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 void

llvm/lib/Target/MSP430/MSP430FrameLowering.h

@@ -30,9 +30,9 @@ public:
   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
 
-  void eliminateCallFramePseudoInstr(MachineFunction &MF,
+  MachineBasicBlock::iterator
-                                  MachineBasicBlock &MBB,
+  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                                  MachineBasicBlock::iterator I) const override;
+                                MachineBasicBlock::iterator I) const override;
 
   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
                                  MachineBasicBlock::iterator MI,

llvm/lib/Target/Mips/MipsFrameLowering.cpp

@@ -143,7 +143,7 @@ uint64_t MipsFrameLowering::estimateStackSize(const MachineFunction &MF) const {
 }
 
 // Eliminate ADJCALLSTACKDOWN, ADJCALLSTACKUP pseudo instructions
-void MipsFrameLowering::
+MachineBasicBlock::iterator MipsFrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
   unsigned SP = STI.getABI().IsN64() ? Mips::SP_64 : Mips::SP;
@@ -156,5 +156,5 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     STI.getInstrInfo()->adjustStackPtr(SP, Amount, MBB, I);
   }
 
-  MBB.erase(I);
+  return MBB.erase(I);
 }

llvm/lib/Target/Mips/MipsFrameLowering.h

@@ -36,7 +36,7 @@ public:
 
   bool isFPCloseToIncomingSP() const override { return false; }
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF,
                                 MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator I) const override;

llvm/lib/Target/NVPTX/NVPTXFrameLowering.cpp

@@ -70,10 +70,10 @@ void NVPTXFrameLowering::emitEpilogue(MachineFunction &MF,
 
 // This function eliminates ADJCALLSTACKDOWN,
 // ADJCALLSTACKUP pseudo instructions
-void NVPTXFrameLowering::eliminateCallFramePseudoInstr(
+MachineBasicBlock::iterator NVPTXFrameLowering::eliminateCallFramePseudoInstr(
     MachineFunction &MF, MachineBasicBlock &MBB,
     MachineBasicBlock::iterator I) const {
   // Simply discard ADJCALLSTACKDOWN,
   // ADJCALLSTACKUP instructions.
-  MBB.erase(I);
+  return MBB.erase(I);
 }

llvm/lib/Target/NVPTX/NVPTXFrameLowering.h

@@ -26,7 +26,7 @@ public:
   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator I) const override;
 };

llvm/lib/Target/PowerPC/PPCFrameLowering.cpp

@@ -1770,7 +1770,7 @@ restoreCRs(bool isPPC64, bool is31,
                .addReg(MoveReg, getKillRegState(true)));
 }
 
-void PPCFrameLowering::
+MachineBasicBlock::iterator PPCFrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
   const TargetInstrInfo &TII = *Subtarget.getInstrInfo();
@@ -1807,7 +1807,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     }
   }
   // Simply discard ADJCALLSTACKDOWN, ADJCALLSTACKUP instructions.
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 bool

llvm/lib/Target/PowerPC/PPCFrameLowering.h

@@ -93,9 +93,9 @@ public:
                                  const std::vector<CalleeSavedInfo> &CSI,
                                  const TargetRegisterInfo *TRI) const override;
 
-  void eliminateCallFramePseudoInstr(MachineFunction &MF,
+  MachineBasicBlock::iterator
-                                  MachineBasicBlock &MBB,
+  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                                  MachineBasicBlock::iterator I) const override;
+                                MachineBasicBlock::iterator I) const override;
 
   bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator MI,

llvm/lib/Target/Sparc/SparcFrameLowering.cpp

@@ -183,7 +183,7 @@ void SparcFrameLowering::emitPrologue(MachineFunction &MF,
   }
 }
 
-void SparcFrameLowering::
+MachineBasicBlock::iterator SparcFrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
   if (!hasReservedCallFrame(MF)) {
@@ -195,7 +195,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     if (Size)
       emitSPAdjustment(MF, MBB, I, Size, SP::ADDrr, SP::ADDri);
   }
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 

llvm/lib/Target/Sparc/SparcFrameLowering.h

@@ -29,7 +29,7 @@ public:
   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
 
-  void
+  MachineBasicBlock::iterator
   eliminateCallFramePseudoInstr(MachineFunction &MF,
                                 MachineBasicBlock &MBB,
                                 MachineBasicBlock::iterator I) const override;

llvm/lib/Target/SystemZ/SystemZFrameLowering.cpp

@@ -511,7 +511,7 @@ SystemZFrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
   return true;
 }
 
-void SystemZFrameLowering::
+MachineBasicBlock::iterator SystemZFrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF,
                               MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator MI) const {
@@ -520,7 +520,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF,
   case SystemZ::ADJCALLSTACKUP:
     assert(hasReservedCallFrame(MF) &&
            "ADJSTACKDOWN and ADJSTACKUP should be no-ops");
-    MBB.erase(MI);
+    return MBB.erase(MI);
     break;
 
   default:

llvm/lib/Target/SystemZ/SystemZFrameLowering.h

@@ -46,10 +46,9 @@ public:
   int getFrameIndexReference(const MachineFunction &MF, int FI,
                              unsigned &FrameReg) const override;
   bool hasReservedCallFrame(const MachineFunction &MF) const override;
-  void eliminateCallFramePseudoInstr(MachineFunction &MF,
+  MachineBasicBlock::iterator
-                                     MachineBasicBlock &MBB,
+  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                                     MachineBasicBlock::iterator MI) const
+                                MachineBasicBlock::iterator MI) const override;
-    override;
 
   // Return the number of bytes in the callee-allocated part of the frame.
   uint64_t getAllocatedStackSize(const MachineFunction &MF) const;

llvm/lib/Target/WebAssembly/WebAssemblyFrameLowering.cpp

@@ -100,7 +100,8 @@ static void writeSPToMemory(unsigned SrcReg, MachineFunction &MF,
   MF.getInfo<WebAssemblyFunctionInfo>()->stackifyVReg(SPAddr);
 }
 
-void WebAssemblyFrameLowering::eliminateCallFramePseudoInstr(
+MachineBasicBlock::iterator
+WebAssemblyFrameLowering::eliminateCallFramePseudoInstr(
     MachineFunction &MF, MachineBasicBlock &MBB,
     MachineBasicBlock::iterator I) const {
   assert(!I->getOperand(0).getImm() && hasFP(MF) &&
@@ -111,7 +112,7 @@ void WebAssemblyFrameLowering::eliminateCallFramePseudoInstr(
     DebugLoc DL = I->getDebugLoc();
     writeSPToMemory(WebAssembly::SP32, MF, MBB, I, I, DL);
   }
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 void WebAssemblyFrameLowering::emitPrologue(MachineFunction &MF,

llvm/lib/Target/WebAssembly/WebAssemblyFrameLowering.h

@@ -34,7 +34,7 @@ class WebAssemblyFrameLowering final : public TargetFrameLowering {
                             /*TransientStackAlignment=*/16,
                             /*StackRealignable=*/true) {}
 
-  void eliminateCallFramePseudoInstr(
+  MachineBasicBlock::iterator eliminateCallFramePseudoInstr(
       MachineFunction &MF, MachineBasicBlock &MBB,
       MachineBasicBlock::iterator I) const override;
 

llvm/lib/Target/WebAssembly/WebAssemblyPEI.cpp

@@ -877,16 +877,7 @@ void WasmPEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn,
         I->getOpcode() == FrameDestroyOpcode) {
       InsideCallSequence = (I->getOpcode() == FrameSetupOpcode);
       SPAdj += TII.getSPAdjust(I);
-
+      I = TFI->eliminateCallFramePseudoInstr(Fn, *BB, I);
-      MachineBasicBlock::iterator PrevI = BB->end();
-      if (I != BB->begin()) PrevI = std::prev(I);
-      TFI->eliminateCallFramePseudoInstr(Fn, *BB, I);
-
-      // Visit the instructions created by eliminateCallFramePseudoInstr().
-      if (PrevI == BB->end())
-        I = BB->begin();     // The replaced instr was the first in the block.
-      else
-        I = std::next(PrevI);
       continue;
     }
 

llvm/lib/Target/X86/X86FrameLowering.cpp

@@ -2477,7 +2477,7 @@ bool X86FrameLowering::adjustStackWithPops(MachineBasicBlock &MBB,
   return true;
 }
 
-void X86FrameLowering::
+MachineBasicBlock::iterator X86FrameLowering::
 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                               MachineBasicBlock::iterator I) const {
   bool reserveCallFrame = hasReservedCallFrame(MF);
@@ -2521,7 +2521,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                MCCFIInstruction::createGnuArgsSize(nullptr, Amount));
 
     if (Amount == 0)
-      return;
+      return I;
 
     // Factor out the amount that gets handled inside the sequence
     // (Pushes of argument for frame setup, callee pops for frame destroy)
@@ -2561,7 +2561,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
       }
     }
 
-    return;
+    return I;
   }
 
   if (isDestroy && InternalAmt) {
@@ -2571,11 +2571,14 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     // We are not tracking the stack pointer adjustment by the callee, so make
     // sure we restore the stack pointer immediately after the call, there may
     // be spill code inserted between the CALL and ADJCALLSTACKUP instructions.
+    MachineBasicBlock::iterator CI = I;
     MachineBasicBlock::iterator B = MBB.begin();
-    while (I != B && !std::prev(I)->isCall())
+    while (CI != B && !std::prev(I)->isCall())
       --I;
-    BuildStackAdjustment(MBB, I, DL, -InternalAmt, /*InEpilogue=*/false);
+    BuildStackAdjustment(MBB, CI, DL, -InternalAmt, /*InEpilogue=*/false);
   }
+
+  return I;
 }
 
 bool X86FrameLowering::canUseAsEpilogue(const MachineBasicBlock &MBB) const {

llvm/lib/Target/X86/X86FrameLowering.h

@@ -103,9 +103,9 @@ public:
   int getFrameIndexReferenceFromSP(const MachineFunction &MF, int FI,
                                    unsigned &FrameReg) const override;
 
-  void eliminateCallFramePseudoInstr(MachineFunction &MF,
+  MachineBasicBlock::iterator
-                                 MachineBasicBlock &MBB,
+  eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
-                                 MachineBasicBlock::iterator MI) const override;
+                                MachineBasicBlock::iterator MI) const override;
 
   unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
 

llvm/lib/Target/XCore/XCoreFrameLowering.cpp

@@ -482,9 +482,9 @@ restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
 
 // This function eliminates ADJCALLSTACKDOWN,
 // ADJCALLSTACKUP pseudo instructions
-void XCoreFrameLowering::
+MachineBasicBlock::iterator XCoreFrameLowering::eliminateCallFramePseudoInstr(
-eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+    MachineFunction &MF, MachineBasicBlock &MBB,
-                              MachineBasicBlock::iterator I) const {
+    MachineBasicBlock::iterator I) const {
   const XCoreInstrInfo &TII = *MF.getSubtarget<XCoreSubtarget>().getInstrInfo();
   if (!hasReservedCallFrame(MF)) {
     // Turn the adjcallstackdown instruction into 'extsp <amt>' and the
@@ -528,7 +528,7 @@ eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
     }
   }
 
-  MBB.erase(I);
+  return MBB.erase(I);
 }
 
 void XCoreFrameLowering::determineCalleeSaves(MachineFunction &MF,

llvm/lib/Target/XCore/XCoreFrameLowering.h

@@ -41,8 +41,8 @@ namespace llvm {
                                   const std::vector<CalleeSavedInfo> &CSI,
                                   const TargetRegisterInfo *TRI) const override;
 
-    void eliminateCallFramePseudoInstr(MachineFunction &MF,
+    MachineBasicBlock::iterator
-                                  MachineBasicBlock &MBB,
+    eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
                                   MachineBasicBlock::iterator I) const override;
 
     bool hasFP(const MachineFunction &MF) const override;