From 42204c94ba9fcb0b4b1335e648ce140a3eef8a9d Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Sun, 19 Nov 2023 01:00:46 -0800
Subject: [PATCH] Revert "[TargetInstrInfo] enable foldMemoryOperand for
 InlineAsm (#70743)"

This reverts commit 99ee2db198d86f685bcb07a1495a7115ffc31d7e.

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

https://github.com/llvm/llvm-project/commit/99ee2db198d86f685bcb07a1495a7115ffc31d7e
---
 llvm/include/llvm/CodeGen/TargetInstrInfo.h | 10 ----
 llvm/lib/CodeGen/TargetInstrInfo.cpp        | 62 ---------------------
 2 files changed, 72 deletions(-)

diff --git a/llvm/include/llvm/CodeGen/TargetInstrInfo.h b/llvm/include/llvm/CodeGen/TargetInstrInfo.h
index de065849eaa6eb..fe130d282ded15 100644
--- a/llvm/include/llvm/CodeGen/TargetInstrInfo.h
+++ b/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;
diff --git a/llvm/lib/CodeGen/TargetInstrInfo.cpp b/llvm/lib/CodeGen/TargetInstrInfo.cpp
index 5ede36505b5b00..3013a768bc4d56 100644
--- a/llvm/lib/CodeGen/TargetInstrInfo.cpp
+++ b/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);