1 files changed, 341 insertions, 58 deletions

diff --git a/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index eb25b6ca268f..20358f7ee6c2 100644
--- a/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -29,14 +29,13 @@
 using namespace llvm;
 
 LegalizerHelper::LegalizerHelper(MachineFunction &MF)
-  : MRI(MF.getRegInfo()) {
+    : MRI(MF.getRegInfo()), LI(*MF.getSubtarget().getLegalizerInfo()) {
   MIRBuilder.setMF(MF);
 }
 
 LegalizerHelper::LegalizeResult
-LegalizerHelper::legalizeInstrStep(MachineInstr &MI,
-                                   const LegalizerInfo &LegalizerInfo) {
-  auto Action = LegalizerInfo.getAction(MI, MRI);
+LegalizerHelper::legalizeInstrStep(MachineInstr &MI) {
+  auto Action = LI.getAction(MI, MRI);
   switch (std::get<0>(Action)) {
   case LegalizerInfo::Legal:
     return AlreadyLegal;
@@ -50,46 +49,32 @@ LegalizerHelper::legalizeInstrStep(MachineInstr &MI,
     return lower(MI, std::get<1>(Action), std::get<2>(Action));
   case LegalizerInfo::FewerElements:
     return fewerElementsVector(MI, std::get<1>(Action), std::get<2>(Action));
+  case LegalizerInfo::Custom:
+    return LI.legalizeCustom(MI, MRI, MIRBuilder) ? Legalized
+                                                  : UnableToLegalize;
   default:
     return UnableToLegalize;
   }
 }
 
-LegalizerHelper::LegalizeResult
-LegalizerHelper::legalizeInstr(MachineInstr &MI,
-                               const LegalizerInfo &LegalizerInfo) {
-  SmallVector<MachineInstr *, 4> WorkList;
-  MIRBuilder.recordInsertions(
-      [&](MachineInstr *MI) { WorkList.push_back(MI); });
-  WorkList.push_back(&MI);
-
-  bool Changed = false;
-  LegalizeResult Res;
-  unsigned Idx = 0;
-  do {
-    Res = legalizeInstrStep(*WorkList[Idx], LegalizerInfo);
-    if (Res == UnableToLegalize) {
-      MIRBuilder.stopRecordingInsertions();
-      return UnableToLegalize;
-    }
-    Changed |= Res == Legalized;
-    ++Idx;
-  } while (Idx < WorkList.size());
-
-  MIRBuilder.stopRecordingInsertions();
-
-  return Changed ? Legalized : AlreadyLegal;
-}
-
 void LegalizerHelper::extractParts(unsigned Reg, LLT Ty, int NumParts,
                                    SmallVectorImpl<unsigned> &VRegs) {
-  unsigned Size = Ty.getSizeInBits();
-  SmallVector<uint64_t, 4> Indexes;
-  for (int i = 0; i < NumParts; ++i) {
+  for (int i = 0; i < NumParts; ++i)
     VRegs.push_back(MRI.createGenericVirtualRegister(Ty));
-    Indexes.push_back(i * Size);
+  MIRBuilder.buildUnmerge(VRegs, Reg);
+}
+
+static RTLIB::Libcall getRTLibDesc(unsigned Opcode, unsigned Size) {
+  switch (Opcode) {
+  case TargetOpcode::G_FADD:
+    assert((Size == 32 || Size == 64) && "Unsupported size");
+    return Size == 64 ? RTLIB::ADD_F64 : RTLIB::ADD_F32;
+  case TargetOpcode::G_FREM:
+    return Size == 64 ? RTLIB::REM_F64 : RTLIB::REM_F32;
+  case TargetOpcode::G_FPOW:
+    return Size == 64 ? RTLIB::POW_F64 : RTLIB::POW_F32;
   }
-  MIRBuilder.buildExtract(VRegs, Indexes, Reg);
+  llvm_unreachable("Unknown libcall function");
 }
 
 LegalizerHelper::LegalizeResult
@@ -101,17 +86,19 @@ LegalizerHelper::libcall(MachineInstr &MI) {
   switch (MI.getOpcode()) {
   default:
     return UnableToLegalize;
+  case TargetOpcode::G_FADD:
+  case TargetOpcode::G_FPOW:
   case TargetOpcode::G_FREM: {
     auto &Ctx = MIRBuilder.getMF().getFunction()->getContext();
     Type *Ty = Size == 64 ? Type::getDoubleTy(Ctx) : Type::getFloatTy(Ctx);
     auto &CLI = *MIRBuilder.getMF().getSubtarget().getCallLowering();
     auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
-    const char *Name =
-        TLI.getLibcallName(Size == 64 ? RTLIB::REM_F64 : RTLIB::REM_F32);
-
+    auto Libcall = getRTLibDesc(MI.getOpcode(), Size);
+    const char *Name = TLI.getLibcallName(Libcall);
+    MIRBuilder.getMF().getFrameInfo().setHasCalls(true);
     CLI.lowerCall(
-        MIRBuilder, MachineOperand::CreateES(Name),
-        {MI.getOperand(0).getReg(), Ty},
+        MIRBuilder, TLI.getLibcallCallingConv(Libcall),
+        MachineOperand::CreateES(Name), {MI.getOperand(0).getReg(), Ty},
         {{MI.getOperand(1).getReg(), Ty}, {MI.getOperand(2).getReg(), Ty}});
     MI.eraseFromParent();
     return Legalized;
@@ -125,19 +112,18 @@ LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
   // FIXME: Don't know how to handle secondary types yet.
   if (TypeIdx != 0)
     return UnableToLegalize;
+
+  MIRBuilder.setInstr(MI);
+
   switch (MI.getOpcode()) {
   default:
     return UnableToLegalize;
   case TargetOpcode::G_ADD: {
     // Expand in terms of carry-setting/consuming G_ADDE instructions.
-    unsigned NarrowSize = NarrowTy.getSizeInBits();
     int NumParts = MRI.getType(MI.getOperand(0).getReg()).getSizeInBits() /
                    NarrowTy.getSizeInBits();
 
-    MIRBuilder.setInstr(MI);
-
     SmallVector<unsigned, 2> Src1Regs, Src2Regs, DstRegs;
-    SmallVector<uint64_t, 2> Indexes;
     extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, Src1Regs);
     extractParts(MI.getOperand(2).getReg(), NarrowTy, NumParts, Src2Regs);
 
@@ -152,11 +138,138 @@ LegalizerHelper::LegalizeResult LegalizerHelper::narrowScalar(MachineInstr &MI,
                             Src2Regs[i], CarryIn);
 
       DstRegs.push_back(DstReg);
-      Indexes.push_back(i * NarrowSize);
       CarryIn = CarryOut;
     }
     unsigned DstReg = MI.getOperand(0).getReg();
-    MIRBuilder.buildSequence(DstReg, DstRegs, Indexes);
+    MIRBuilder.buildMerge(DstReg, DstRegs);
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_INSERT: {
+    if (TypeIdx != 0)
+      return UnableToLegalize;
+
+    int64_t NarrowSize = NarrowTy.getSizeInBits();
+    int NumParts =
+        MRI.getType(MI.getOperand(0).getReg()).getSizeInBits() / NarrowSize;
+
+    SmallVector<unsigned, 2> SrcRegs, DstRegs;
+    SmallVector<uint64_t, 2> Indexes;
+    extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, SrcRegs);
+
+    unsigned OpReg = MI.getOperand(2).getReg();
+    int64_t OpStart = MI.getOperand(3).getImm();
+    int64_t OpSize = MRI.getType(OpReg).getSizeInBits();
+    for (int i = 0; i < NumParts; ++i) {
+      unsigned DstStart = i * NarrowSize;
+
+      if (DstStart + NarrowSize <= OpStart || DstStart >= OpStart + OpSize) {
+        // No part of the insert affects this subregister, forward the original.
+        DstRegs.push_back(SrcRegs[i]);
+        continue;
+      } else if (DstStart == OpStart && NarrowTy == MRI.getType(OpReg)) {
+        // The entire subregister is defined by this insert, forward the new
+        // value.
+        DstRegs.push_back(OpReg);
+        continue;
+      }
+
+      // OpSegStart is where this destination segment would start in OpReg if it
+      // extended infinitely in both directions.
+      int64_t ExtractOffset, InsertOffset, SegSize;
+      if (OpStart < DstStart) {
+        InsertOffset = 0;
+        ExtractOffset = DstStart - OpStart;
+        SegSize = std::min(NarrowSize, OpStart + OpSize - DstStart);
+      } else {
+        InsertOffset = OpStart - DstStart;
+        ExtractOffset = 0;
+        SegSize =
+            std::min(NarrowSize - InsertOffset, OpStart + OpSize - DstStart);
+      }
+
+      unsigned SegReg = OpReg;
+      if (ExtractOffset != 0 || SegSize != OpSize) {
+        // A genuine extract is needed.
+        SegReg = MRI.createGenericVirtualRegister(LLT::scalar(SegSize));
+        MIRBuilder.buildExtract(SegReg, OpReg, ExtractOffset);
+      }
+
+      unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
+      MIRBuilder.buildInsert(DstReg, SrcRegs[i], SegReg, InsertOffset);
+      DstRegs.push_back(DstReg);
+    }
+
+    assert(DstRegs.size() == (unsigned)NumParts && "not all parts covered");
+    MIRBuilder.buildMerge(MI.getOperand(0).getReg(), DstRegs);
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_LOAD: {
+    unsigned NarrowSize = NarrowTy.getSizeInBits();
+    int NumParts =
+        MRI.getType(MI.getOperand(0).getReg()).getSizeInBits() / NarrowSize;
+    LLT NarrowPtrTy = LLT::pointer(
+        MRI.getType(MI.getOperand(1).getReg()).getAddressSpace(), NarrowSize);
+
+    SmallVector<unsigned, 2> DstRegs;
+    for (int i = 0; i < NumParts; ++i) {
+      unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
+      unsigned SrcReg = MRI.createGenericVirtualRegister(NarrowPtrTy);
+      unsigned Offset = MRI.createGenericVirtualRegister(LLT::scalar(64));
+
+      MIRBuilder.buildConstant(Offset, i * NarrowSize / 8);
+      MIRBuilder.buildGEP(SrcReg, MI.getOperand(1).getReg(), Offset);
+      // TODO: This is conservatively correct, but we probably want to split the
+      // memory operands in the future.
+      MIRBuilder.buildLoad(DstReg, SrcReg, **MI.memoperands_begin());
+
+      DstRegs.push_back(DstReg);
+    }
+    unsigned DstReg = MI.getOperand(0).getReg();
+    MIRBuilder.buildMerge(DstReg, DstRegs);
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_STORE: {
+    unsigned NarrowSize = NarrowTy.getSizeInBits();
+    int NumParts =
+        MRI.getType(MI.getOperand(0).getReg()).getSizeInBits() / NarrowSize;
+    LLT NarrowPtrTy = LLT::pointer(
+        MRI.getType(MI.getOperand(1).getReg()).getAddressSpace(), NarrowSize);
+
+    SmallVector<unsigned, 2> SrcRegs;
+    extractParts(MI.getOperand(0).getReg(), NarrowTy, NumParts, SrcRegs);
+
+    for (int i = 0; i < NumParts; ++i) {
+      unsigned DstReg = MRI.createGenericVirtualRegister(NarrowPtrTy);
+      unsigned Offset = MRI.createGenericVirtualRegister(LLT::scalar(64));
+      MIRBuilder.buildConstant(Offset, i * NarrowSize / 8);
+      MIRBuilder.buildGEP(DstReg, MI.getOperand(1).getReg(), Offset);
+      // TODO: This is conservatively correct, but we probably want to split the
+      // memory operands in the future.
+      MIRBuilder.buildStore(SrcRegs[i], DstReg, **MI.memoperands_begin());
+    }
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_CONSTANT: {
+    unsigned NarrowSize = NarrowTy.getSizeInBits();
+    int NumParts =
+        MRI.getType(MI.getOperand(0).getReg()).getSizeInBits() / NarrowSize;
+    const APInt &Cst = MI.getOperand(1).getCImm()->getValue();
+    LLVMContext &Ctx = MIRBuilder.getMF().getFunction()->getContext();
+
+    SmallVector<unsigned, 2> DstRegs;
+    for (int i = 0; i < NumParts; ++i) {
+      unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
+      ConstantInt *CI =
+          ConstantInt::get(Ctx, Cst.lshr(NarrowSize * i).trunc(NarrowSize));
+      MIRBuilder.buildConstant(DstReg, *CI);
+      DstRegs.push_back(DstReg);
+    }
+    unsigned DstReg = MI.getOperand(0).getReg();
+    MIRBuilder.buildMerge(DstReg, DstRegs);
     MI.eraseFromParent();
     return Legalized;
   }
@@ -175,7 +288,8 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_MUL:
   case TargetOpcode::G_OR:
   case TargetOpcode::G_XOR:
-  case TargetOpcode::G_SUB: {
+  case TargetOpcode::G_SUB:
+  case TargetOpcode::G_SHL: {
     // Perform operation at larger width (any extension is fine here, high bits
     // don't affect the result) and then truncate the result back to the
     // original type.
@@ -195,10 +309,13 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
   }
   case TargetOpcode::G_SDIV:
-  case TargetOpcode::G_UDIV: {
-    unsigned ExtOp = MI.getOpcode() == TargetOpcode::G_SDIV
-                          ? TargetOpcode::G_SEXT
-                          : TargetOpcode::G_ZEXT;
+  case TargetOpcode::G_UDIV:
+  case TargetOpcode::G_ASHR:
+  case TargetOpcode::G_LSHR: {
+    unsigned ExtOp = MI.getOpcode() == TargetOpcode::G_SDIV ||
+                             MI.getOpcode() == TargetOpcode::G_ASHR
+                         ? TargetOpcode::G_SEXT
+                         : TargetOpcode::G_ZEXT;
 
     unsigned LHSExt = MRI.createGenericVirtualRegister(WideTy);
     MIRBuilder.buildInstr(ExtOp).addDef(LHSExt).addUse(
@@ -218,6 +335,85 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     MI.eraseFromParent();
     return Legalized;
   }
+  case TargetOpcode::G_SELECT: {
+    if (TypeIdx != 0)
+      return UnableToLegalize;
+
+    // Perform operation at larger width (any extension is fine here, high bits
+    // don't affect the result) and then truncate the result back to the
+    // original type.
+    unsigned Src1Ext = MRI.createGenericVirtualRegister(WideTy);
+    unsigned Src2Ext = MRI.createGenericVirtualRegister(WideTy);
+    MIRBuilder.buildAnyExt(Src1Ext, MI.getOperand(2).getReg());
+    MIRBuilder.buildAnyExt(Src2Ext, MI.getOperand(3).getReg());
+
+    unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
+    MIRBuilder.buildInstr(TargetOpcode::G_SELECT)
+        .addDef(DstExt)
+        .addReg(MI.getOperand(1).getReg())
+        .addUse(Src1Ext)
+        .addUse(Src2Ext);
+
+    MIRBuilder.buildTrunc(MI.getOperand(0).getReg(), DstExt);
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_FPTOSI:
+  case TargetOpcode::G_FPTOUI: {
+    if (TypeIdx != 0)
+      return UnableToLegalize;
+
+    unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
+    MIRBuilder.buildInstr(MI.getOpcode())
+        .addDef(DstExt)
+        .addUse(MI.getOperand(1).getReg());
+
+    MIRBuilder.buildTrunc(MI.getOperand(0).getReg(), DstExt);
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_SITOFP:
+  case TargetOpcode::G_UITOFP: {
+    if (TypeIdx != 1)
+      return UnableToLegalize;
+
+    unsigned Src = MI.getOperand(1).getReg();
+    unsigned SrcExt = MRI.createGenericVirtualRegister(WideTy);
+
+    if (MI.getOpcode() == TargetOpcode::G_SITOFP) {
+      MIRBuilder.buildSExt(SrcExt, Src);
+    } else {
+      assert(MI.getOpcode() == TargetOpcode::G_UITOFP && "Unexpected conv op");
+      MIRBuilder.buildZExt(SrcExt, Src);
+    }
+
+    MIRBuilder.buildInstr(MI.getOpcode())
+        .addDef(MI.getOperand(0).getReg())
+        .addUse(SrcExt);
+
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_INSERT: {
+    if (TypeIdx != 0)
+      return UnableToLegalize;
+
+    unsigned Src = MI.getOperand(1).getReg();
+    unsigned SrcExt = MRI.createGenericVirtualRegister(WideTy);
+    MIRBuilder.buildAnyExt(SrcExt, Src);
+
+    unsigned DstExt = MRI.createGenericVirtualRegister(WideTy);
+    auto MIB = MIRBuilder.buildInsert(DstExt, SrcExt, MI.getOperand(2).getReg(),
+                                      MI.getOperand(3).getImm());
+    for (unsigned OpNum = 4; OpNum < MI.getNumOperands(); OpNum += 2) {
+      MIB.addReg(MI.getOperand(OpNum).getReg());
+      MIB.addImm(MI.getOperand(OpNum + 1).getImm());
+    }
+
+    MIRBuilder.buildTrunc(MI.getOperand(0).getReg(), DstExt);
+    MI.eraseFromParent();
+    return Legalized;
+  }
   case TargetOpcode::G_LOAD: {
     assert(alignTo(MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(), 8) ==
                WideTy.getSizeInBits() &&
@@ -231,12 +427,24 @@ LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
     return Legalized;
   }
   case TargetOpcode::G_STORE: {
-    assert(alignTo(MRI.getType(MI.getOperand(0).getReg()).getSizeInBits(), 8) ==
-               WideTy.getSizeInBits() &&
-           "illegal to increase number of bytes modified by a store");
+    if (MRI.getType(MI.getOperand(0).getReg()) != LLT::scalar(1) ||
+        WideTy != LLT::scalar(8))
+      return UnableToLegalize;
+
+    auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
+    auto Content = TLI.getBooleanContents(false, false);
+
+    unsigned ExtOp = TargetOpcode::G_ANYEXT;
+    if (Content == TargetLoweringBase::ZeroOrOneBooleanContent)
+      ExtOp = TargetOpcode::G_ZEXT;
+    else if (Content == TargetLoweringBase::ZeroOrNegativeOneBooleanContent)
+      ExtOp = TargetOpcode::G_SEXT;
+    else
+      ExtOp = TargetOpcode::G_ANYEXT;
 
     unsigned SrcExt = MRI.createGenericVirtualRegister(WideTy);
-    MIRBuilder.buildAnyExt(SrcExt, MI.getOperand(0).getReg());
+    MIRBuilder.buildInstr(ExtOp).addDef(SrcExt).addUse(
+        MI.getOperand(0).getReg());
     MIRBuilder.buildStore(SrcExt, MI.getOperand(1).getReg(),
                           **MI.memoperands_begin());
     MI.eraseFromParent();
@@ -315,6 +523,83 @@ LegalizerHelper::lower(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
     MI.eraseFromParent();
     return Legalized;
   }
+  case TargetOpcode::G_SMULO:
+  case TargetOpcode::G_UMULO: {
+    // Generate G_UMULH/G_SMULH to check for overflow and a normal G_MUL for the
+    // result.
+    unsigned Res = MI.getOperand(0).getReg();
+    unsigned Overflow = MI.getOperand(1).getReg();
+    unsigned LHS = MI.getOperand(2).getReg();
+    unsigned RHS = MI.getOperand(3).getReg();
+
+    MIRBuilder.buildMul(Res, LHS, RHS);
+
+    unsigned Opcode = MI.getOpcode() == TargetOpcode::G_SMULO
+                          ? TargetOpcode::G_SMULH
+                          : TargetOpcode::G_UMULH;
+
+    unsigned HiPart = MRI.createGenericVirtualRegister(Ty);
+    MIRBuilder.buildInstr(Opcode)
+      .addDef(HiPart)
+      .addUse(LHS)
+      .addUse(RHS);
+
+    unsigned Zero = MRI.createGenericVirtualRegister(Ty);
+    MIRBuilder.buildConstant(Zero, 0);
+    MIRBuilder.buildICmp(CmpInst::ICMP_NE, Overflow, HiPart, Zero);
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_FNEG: {
+    // TODO: Handle vector types once we are able to
+    // represent them.
+    if (Ty.isVector())
+      return UnableToLegalize;
+    unsigned Res = MI.getOperand(0).getReg();
+    Type *ZeroTy;
+    LLVMContext &Ctx = MIRBuilder.getMF().getFunction()->getContext();
+    switch (Ty.getSizeInBits()) {
+    case 16:
+      ZeroTy = Type::getHalfTy(Ctx);
+      break;
+    case 32:
+      ZeroTy = Type::getFloatTy(Ctx);
+      break;
+    case 64:
+      ZeroTy = Type::getDoubleTy(Ctx);
+      break;
+    default:
+      llvm_unreachable("unexpected floating-point type");
+    }
+    ConstantFP &ZeroForNegation =
+        *cast<ConstantFP>(ConstantFP::getZeroValueForNegation(ZeroTy));
+    unsigned Zero = MRI.createGenericVirtualRegister(Ty);
+    MIRBuilder.buildFConstant(Zero, ZeroForNegation);
+    MIRBuilder.buildInstr(TargetOpcode::G_FSUB)
+        .addDef(Res)
+        .addUse(Zero)
+        .addUse(MI.getOperand(1).getReg());
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  case TargetOpcode::G_FSUB: {
+    // Lower (G_FSUB LHS, RHS) to (G_FADD LHS, (G_FNEG RHS)).
+    // First, check if G_FNEG is marked as Lower. If so, we may
+    // end up with an infinite loop as G_FSUB is used to legalize G_FNEG.
+    if (LI.getAction({G_FNEG, Ty}).first == LegalizerInfo::Lower)
+      return UnableToLegalize;
+    unsigned Res = MI.getOperand(0).getReg();
+    unsigned LHS = MI.getOperand(1).getReg();
+    unsigned RHS = MI.getOperand(2).getReg();
+    unsigned Neg = MRI.createGenericVirtualRegister(Ty);
+    MIRBuilder.buildInstr(TargetOpcode::G_FNEG).addDef(Neg).addUse(RHS);
+    MIRBuilder.buildInstr(TargetOpcode::G_FADD)
+        .addDef(Res)
+        .addUse(LHS)
+        .addUse(Neg);
+    MI.eraseFromParent();
+    return Legalized;
+  }
   }
 }
 
@@ -335,7 +620,6 @@ LegalizerHelper::fewerElementsVector(MachineInstr &MI, unsigned TypeIdx,
     MIRBuilder.setInstr(MI);
 
     SmallVector<unsigned, 2> Src1Regs, Src2Regs, DstRegs;
-    SmallVector<uint64_t, 2> Indexes;
     extractParts(MI.getOperand(1).getReg(), NarrowTy, NumParts, Src1Regs);
     extractParts(MI.getOperand(2).getReg(), NarrowTy, NumParts, Src2Regs);
 
@@ -343,10 +627,9 @@ LegalizerHelper::fewerElementsVector(MachineInstr &MI, unsigned TypeIdx,
       unsigned DstReg = MRI.createGenericVirtualRegister(NarrowTy);
       MIRBuilder.buildAdd(DstReg, Src1Regs[i], Src2Regs[i]);
       DstRegs.push_back(DstReg);
-      Indexes.push_back(i * NarrowSize);
     }
 
-    MIRBuilder.buildSequence(DstReg, DstRegs, Indexes);
+    MIRBuilder.buildMerge(DstReg, DstRegs);
     MI.eraseFromParent();
     return Legalized;
   }