[fast-isel] Remove SelectInsertValue() as fast-isel wasn't designed to handle

instructions that define aggregate types.

llvm-svn: 146492

llvm/lib/CodeGen/SelectionDAG/FastISel.cpp

@@ -941,106 +941,6 @@ FastISel::SelectExtractValue(const User *U) {
   return true;
 }
 
-bool
-FastISel::SelectInsertValue(const User *U) {
-  return false;
-  const InsertValueInst *IVI = dyn_cast<InsertValueInst>(U);
-  if (!IVI)
-    return false;
-
-  // Only try to handle inserts of legal types.  But also allow i16/i8/i1 because
-  // they're easy.
-  const Value *Val = IVI->getOperand(1);
-  Type *ValTy = Val->getType();
-  EVT ValVT = TLI.getValueType(ValTy, /*AllowUnknown=*/true);
-  if (!ValVT.isSimple())
-    return false;
-  MVT VT = ValVT.getSimpleVT();
-  if (!TLI.isTypeLegal(VT) && VT != MVT::i16 && VT != MVT::i8 && VT != MVT::i1)
-    return false;
-
-  // Get the Val register.
-  unsigned ValReg = getRegForValue(Val);
-  if (ValReg == 0) return false;
-
-  const Value *Agg = IVI->getOperand(0);
-  Type *AggTy = Agg->getType();
-
-  // TODO: Is there a better way to do this?  For each insertvalue we allocate
-  // a new set of virtual registers, which results in a large number of 
-  // loads/stores from/to the stack that copies the aggregate all over the place
-  // and results in lots of spill code.  I believe this is necessary to preserve
-  // SSA form, but maybe there's something we could do to improve this.
-
-  // Get the Aggregate base register.
-  unsigned AggBaseReg;
-  DenseMap<const Value *, unsigned>::iterator I = FuncInfo.ValueMap.find(Agg);
-  if (I != FuncInfo.ValueMap.end())
-    AggBaseReg = I->second;
-  else if (isa<Instruction>(Agg))
-    AggBaseReg = FuncInfo.InitializeRegForValue(Agg);
-  else if (isa<UndefValue>(Agg))
-    // In this case we don't need to allocate a new set of register that will
-    // never be defined.  Just copy Val into the proper result registers.
-    AggBaseReg = 0;
-  else
-    return false; // fast-isel can't handle aggregate constants at the moment
-
-  // Create result register(s).
-  unsigned ResultBaseReg = FuncInfo.CreateRegs(AggTy);
-
-  // Get the actual result register, which is an offset from the base register.
-  unsigned LinearIndex = ComputeLinearIndex(Agg->getType(), IVI->getIndices());
-
-  SmallVector<EVT, 4> AggValueVTs;
-  ComputeValueVTs(TLI, AggTy, AggValueVTs);
-
-  // Copy the beginning value(s) from the original aggregate.
-  unsigned SrcReg;
-  unsigned DestReg;
-  unsigned BaseRegOff = 0;
-  unsigned i = 0;
-  for (; i != LinearIndex; ++i) {
-    unsigned NRE = TLI.getNumRegisters(FuncInfo.Fn->getContext(),
-                                       AggValueVTs[i]);
-    for (unsigned NRI = 0; NRI != NRE; NRI++) {
-      if (AggBaseReg) {
-        SrcReg = AggBaseReg + BaseRegOff + NRI;
-        DestReg = ResultBaseReg + BaseRegOff + NRI;
-        BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
-                DestReg).addReg(SrcReg);
-      }
-    }
-    BaseRegOff += NRE;
-  }
-
-  // FIXME: Handle aggregate inserts.  Haven't seen these in practice, but..
-  // Copy value(s) from the inserted value(s).
-  DestReg = ResultBaseReg + BaseRegOff;
-  BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
-          DestReg).addReg(ValReg);
-  ++BaseRegOff;
-  ++i;
-
-  // Copy remaining value(s) from the original aggregate.
-  if (AggBaseReg) {
-    for (unsigned NumAggValues = AggValueVTs.size(); i != NumAggValues; ++i) {
-      unsigned NRE = TLI.getNumRegisters(FuncInfo.Fn->getContext(),
-                                         AggValueVTs[i]);
-      for (unsigned NRI = 0; NRI != NRE; NRI++) {
-        SrcReg = AggBaseReg + BaseRegOff + NRI;
-        DestReg = ResultBaseReg + BaseRegOff + NRI;
-        BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DL, TII.get(TargetOpcode::COPY),
-                DestReg).addReg(SrcReg);
-        
-      }
-      BaseRegOff += NRE;
-    }
-  }
-  UpdateValueMap(IVI, ResultBaseReg);
-  return true;
-}
-
 bool
 FastISel::SelectOperator(const User *I, unsigned Opcode) {
   switch (Opcode) {
@@ -1148,9 +1048,6 @@ FastISel::SelectOperator(const User *I, unsigned Opcode) {
   case Instruction::ExtractValue:
     return SelectExtractValue(I);
 
-  case Instruction::InsertValue:
-    return SelectInsertValue(I);
-
   case Instruction::PHI:
     llvm_unreachable("FastISel shouldn't visit PHI nodes!");