Revert "[TargetInstrInfo] enable foldMemoryOperand for InlineAsm (#70743)"

This reverts commit 99ee2db.

It's causing ICEs in the ARM tests. See the comment here:

99ee2db

Author: bwendling

llvm/include/llvm/CodeGen/TargetInstrInfo.h

@@ -2188,16 +2188,6 @@ class TargetInstrInfo : public MCInstrInfo {
   // Get the call frame size just before MI.
   unsigned getCallFrameSizeAt(MachineInstr &MI) const;
 
-  /// Fills in the necessary MachineOperands to refer to a frame index.
-  /// The best way to understand this is to print `asm(""::"m"(x));` after
-  /// finalize-isel. Example:
-  /// INLINEASM ... 262190 /* mem:m */, %stack.0.x.addr, 1, $noreg, 0, $noreg
-  /// we would add placeholders for:                     ^  ^       ^  ^
-  virtual void
-  getFrameIndexOperands(SmallVectorImpl<MachineOperand> &Ops) const {
-    llvm_unreachable("unknown number of operands necessary");
-  }
-
 private:
   mutable std::unique_ptr<MIRFormatter> Formatter;
   unsigned CallFrameSetupOpcode, CallFrameDestroyOpcode;

llvm/lib/CodeGen/TargetInstrInfo.cpp

@@ -565,64 +565,6 @@ static MachineInstr *foldPatchpoint(MachineFunction &MF, MachineInstr &MI,
   return NewMI;
 }
 
-static void foldInlineAsmMemOperand(MachineInstr *MI, unsigned OpNo, int FI,
-                                    const TargetInstrInfo &TII) {
-  MachineOperand &MO = MI->getOperand(OpNo);
-  const VirtRegInfo &RI = AnalyzeVirtRegInBundle(*MI, MO.getReg());
-
-  // If the machine operand is tied, untie it first.
-  if (MO.isTied()) {
-    unsigned TiedTo = MI->findTiedOperandIdx(OpNo);
-    MI->untieRegOperand(OpNo);
-    // Intentional recursion!
-    foldInlineAsmMemOperand(MI, TiedTo, FI, TII);
-  }
-
-  // Change the operand from a register to a frame index.
-  MO.ChangeToFrameIndex(FI, MO.getTargetFlags());
-
-  SmallVector<MachineOperand, 4> NewOps;
-  TII.getFrameIndexOperands(NewOps);
-  assert(!NewOps.empty() && "getFrameIndexOperands didn't create any operands");
-  MI->insert(MI->operands_begin() + OpNo + 1, NewOps);
-
-  // Change the previous operand to a MemKind InlineAsm::Flag. The second param
-  // is the per-target number of operands that represent the memory operand
-  // excluding this one (MD). This includes MO.
-  InlineAsm::Flag F(InlineAsm::Kind::Mem, NewOps.size() + 1);
-  F.setMemConstraint(InlineAsm::ConstraintCode::m);
-  MachineOperand &MD = MI->getOperand(OpNo - 1);
-  MD.setImm(F);
-
-  // Update mayload/maystore metadata.
-  MachineOperand &ExtraMO = MI->getOperand(InlineAsm::MIOp_ExtraInfo);
-  if (RI.Reads)
-    ExtraMO.setImm(ExtraMO.getImm() | InlineAsm::Extra_MayLoad);
-  if (RI.Writes)
-    ExtraMO.setImm(ExtraMO.getImm() | InlineAsm::Extra_MayStore);
-}
-
-// Returns nullptr if not possible to fold.
-static MachineInstr *foldInlineAsmMemOperand(MachineInstr &MI,
-                                             ArrayRef<unsigned> Ops, int FI,
-                                             const TargetInstrInfo &TII) {
-  assert(MI.isInlineAsm() && "wrong opcode");
-  if (Ops.size() > 1)
-    return nullptr;
-  unsigned Op = Ops[0];
-  assert(Op && "should never be first operand");
-  assert(MI.getOperand(Op).isReg() && "shouldn't be folding non-reg operands");
-
-  if (!MI.mayFoldInlineAsmRegOp(Op))
-    return nullptr;
-
-  MachineInstr &NewMI = TII.duplicate(*MI.getParent(), MI.getIterator(), MI);
-
-  foldInlineAsmMemOperand(&NewMI, Op, FI, TII);
-
-  return &NewMI;
-}
-
 MachineInstr *TargetInstrInfo::foldMemoryOperand(MachineInstr &MI,
                                                  ArrayRef<unsigned> Ops, int FI,
                                                  LiveIntervals *LIS,
@@ -670,8 +612,6 @@ MachineInstr *TargetInstrInfo::foldMemoryOperand(MachineInstr &MI,
     NewMI = foldPatchpoint(MF, MI, Ops, FI, *this);
     if (NewMI)
       MBB->insert(MI, NewMI);
-  } else if (MI.isInlineAsm()) {
-    NewMI = foldInlineAsmMemOperand(MI, Ops, FI, *this);
   } else {
     // Ask the target to do the actual folding.
     NewMI = foldMemoryOperandImpl(MF, MI, Ops, MI, FI, LIS, VRM);
@@ -743,8 +683,6 @@ MachineInstr *TargetInstrInfo::foldMemoryOperand(MachineInstr &MI,
     NewMI = foldPatchpoint(MF, MI, Ops, FrameIndex, *this);
     if (NewMI)
       NewMI = &*MBB.insert(MI, NewMI);
-  } else if (MI.isInlineAsm() && isLoadFromStackSlot(LoadMI, FrameIndex)) {
-    NewMI = foldInlineAsmMemOperand(MI, Ops, FrameIndex, *this);
   } else {
     // Ask the target to do the actual folding.
     NewMI = foldMemoryOperandImpl(MF, MI, Ops, MI, LoadMI, LIS);