[GlobalISel] Restrict G_MERGE_VALUES capability and replace with new opcodes

[aemerson]

Summary

[GlobalISel] Restrict G_MERGE_VALUES capability and replace with new opcodes.

This patch restricts the capability of G_MERGE_VALUES, and uses the new G_BUILD_VECTOR and G_CONCAT_VECTOR opcodes instead in the appropriate places.

The MIRBuilder is modified to generate G_CONCAT when trying to create MERGE_VALUES of vectors.

This patch also includes AArch64 support for selecting G_BUILD_VECTOR of 4xs32 and 2xs64 vectors.

[dsanders]

lib/Target/AArch64/AArch64LegalizerInfo.cpp

320–386

It can be in a follow-up patch but we should simplify this now that we've eliminated a lot of the power these ops had

400–403

This can be in a follow-up patch if you prefer but I don't think these cases should be unsupported. That's really for things that are meaningless or impossible for anyone to legalize. I think we ought to legalize it even if we fewerElements all the way down to scalars.

Ideally, we'd have something along the lines of:

.unsupportedIf([=](const LegalityQuery &Query) {
      // NumOperands doesn't exist right now. We should add it as it's important for variable_ops
      // legalization
      return !Query.Types[0].isVector() || !Query.Types[1].isScalar() ||
             Query.NumOperands != VecTy.getNumElements() + 1;
    })
.legalFor({{v4s32, s32}, {v2s64, s64}})
.clampNumElements(0, s32, v4s32, v4s32)
.clampNumElements(0, s64, v2s64, v2s64)
.maxNumElements(0, 1)
// It's not entirely obvious what we should do with overly large scalars.
// Here I've assumed we keep the SelectionDAG
// semantics of BUILD_VECTOR and allow an implicit truncation
.legalIf([=](const LegalityQuery &Query) {
      return Query.Types[0].getScalarSizeInBits() < Query.Types[1].getSizeInBits();
    })
// At this point we only have to deal with {v4s32, <s32}, {v2s64, <s64}
// I'd suggest adding this one to the library as .minScalarSameAs(1, 0) or similar
.widenScalarIf([=](const LegalityQuery &Query) {
      return Query.Types[0].getScalarSizeInBits() > Query.Types[1].getSizeInBits();
    },
    [=](const LegalityQuery &Query) {
      return std::make_pair(1, Query.Types[0].getElementType());
    } )

404

You don't need to change this unless you also change the unsupportedIf() because that blocks out the incorrect cases but just to mention it:

.legalFor({{v4s32, s32}, {v2s64, s64}})

would be more accurate for this

[aemerson]

lib/Target/AArch64/AArch64LegalizerInfo.cpp

320–386

Sure.

400–403

I'm leaning towards disallowing the implicit truncation for G_BUILD_VECTOR operands. Reason being that I don't think it's that useful, but I'm open to arguments for allowing it. If we disallow that, the rule is redundant as that case will be illegal coming into the legalizer.

Thinking more long term, is there any reason we need to have explicitly unsupported cases? Either they are illegal and should be caught by the verifier/never produced, or in cases where we have targets that have implemented only GISel and thus cannot fall back, there is no way to recover from a legalization failure. It's essentially the same as llvm_unreachable(). I guess it might be useful as way to run the legalizer as a verifier pass to check nothing unexpected happened.

404

Sure.

[aemerson]

Updated AArch64 legalization. I've removed the unsupported case since we're actually making it valid.

[volkan]

test/CodeGen/AArch64/GlobalISel/legalize-nonpowerof2eltsvec.mir

42

This test fails because G_EXTRACT_VECTOR_ELT for v3s64 is not legal. Could you fix that?

[dsanders]

lib/Target/AArch64/AArch64LegalizerInfo.cpp

400–403

Thinking more long term, is there any reason we need to have explicitly unsupported cases? Either they are illegal and should be caught by the
verifier/never produced, or in cases where we have targets that have implemented only GISel and thus cannot fall back, there is no way to recover
from a legalization failure. It's essentially the same as llvm_unreachable(). I guess it might be useful as way to run the legalizer as a verifier pass to
check nothing unexpected happened.

It could be an asserts-only thing. It's easier to debug if we catch a bad input or legalization step the moment it happens.

[volkan]

Hi Amara,

I see a few buildMerge calls in LegalizerHelper. Could you check them to make sure we pick the correct opcode depending on the the destination type?

[volkan]

include/llvm/CodeGen/GlobalISel/LegalizationArtifactCombiner.h

155

Could you handle G_BUILD_VECTOR as well? We are unable to legalize the test below because of the missing combine.

---
name:            test_unmerge
body:             |
  bb.1:
    liveins: $w0
    %0:_(s32) = COPY $w0
    %1:_(<2 x s32>) = G_BUILD_VECTOR %0(s32), %0(s32)
    %2:_(s32), %3:_(s32) = G_UNMERGE_VALUES %1(<2 x s32>)
    $w0 = COPY %2(s32)
...

[qcolombet]

Hi Volkan,

We are unable to legalize the test below because of the missing combine.

This sentence jumped at me. Are you saying we have mandatory combines at this point for legalization to work?
Although that wouldn't surprise me, I would like we have a clear list of what they are (if that's not already the case.)

Cheers,
-Quentin

[volkan]

In D53629#1309860, @qcolombet wrote:

Hi Volkan,

We are unable to legalize the test below because of the missing combine.

This sentence jumped at me. Are you saying we have mandatory combines at this point for legalization to work?
Although that wouldn't surprise me, I would like we have a clear list of what they are (if that's not already the case.)

Cheers,
-Quentin

Hi Quentin,

It's not required for legalization, the target should handle that operation without depending on the artifact combiner.
I meant we should handle G_BUILD_VECTOR to avoid regressions as we are able to legalize the same function with G_MERGE_VALUES.

Volkan

[aemerson]

include/llvm/CodeGen/GlobalISel/LegalizationArtifactCombiner.h

155

Yep, working on this and the other issue.

[qcolombet]

I meant we should handle G_BUILD_VECTOR to avoid regressions as we are able to legalize the same function with G_MERGE_VALUES.

Got it!

[aemerson]

test/CodeGen/AArch64/GlobalISel/legalize-nonpowerof2eltsvec.mir

42

This test doesn't seem to do what it says on the tin. It actually never tested any legalizing, commit r299929 introduced it but as far as I can tell, the G_UNMERGE is deleted due to the legalizercombiner, and G_MERGE here is specified as legal by AArch64 so the legalizer never did anything.

I propose deleting this test as it doesn't seem to achieve anything at the moment.

[volkan]

test/CodeGen/AArch64/GlobalISel/legalize-nonpowerof2eltsvec.mir

42

I added this test to make sure we don't hit the assertion when legalizing non-power-of-2 types. I think it is okay to remove it as there are already tests with non-power-of-2 types.

[aemerson]

Addressed comments, deleted the non power of 2 test.

[aemerson]

Updated to incorporate Volkan's patches to change buildMerge calls to explicitly check for types before choosing the right build method. Also added test for and fixed artifact combiner for G_BUILD_VECTOR.

[volkan]

Thanks Amara, LGTM.

[aemerson]

Thanks, committed in r348788.

include/llvm/CodeGen/GlobalISel/LegalizationArtifactCombiner.h

public:
 
   bool tryCombineMerges(MachineInstr &MI,
                         SmallVectorImpl<MachineInstr *> &DeadInsts) {
 
     if (MI.getOpcode() != TargetOpcode::G_UNMERGE_VALUES)
       return false;
 
     unsigned NumDefs = MI.getNumOperands() - 1;
-    MachineInstr *MergeI = getOpcodeDef(TargetOpcode::G_MERGE_VALUES,
-                                        MI.getOperand(NumDefs).getReg(), MRI);
+
+    unsigned MergingOpcode;
+    if (MRI.getType(MI.getOperand(NumDefs).getReg()).isVector())
+      MergingOpcode = TargetOpcode::G_CONCAT_VECTORS;
+    else
+      MergingOpcode = TargetOpcode::G_MERGE_VALUES;
+
+    MachineInstr *MergeI =
+        getOpcodeDef(MergingOpcode, MI.getOperand(NumDefs).getReg(), MRI);
+
     if (!MergeI)
       return false;
 
     const unsigned NumMergeRegs = MergeI->getNumOperands() - 1;
 
     if (NumMergeRegs < NumDefs) {
       if (NumDefs % NumMergeRegs != 0)
         return false;

lib/CodeGen/GlobalISel/IRTranslator.cpp

bool IRTranslator::translate(const Constant &C, unsigned Reg) {
   } else if (auto GV = dyn_cast<GlobalValue>(&C))
     EntryBuilder.buildGlobalValue(Reg, GV);
   else if (auto CAZ = dyn_cast<ConstantAggregateZero>(&C)) {
     if (!CAZ->getType()->isVectorTy())
       return false;
     // Return the scalar if it is a <1 x Ty> vector.
     if (CAZ->getNumElements() == 1)
       return translate(*CAZ->getElementValue(0u), Reg);
-    std::vector<unsigned> Ops;
+    SmallVector<unsigned, 4> Ops;
     for (unsigned i = 0; i < CAZ->getNumElements(); ++i) {
       Constant &Elt = *CAZ->getElementValue(i);
       Ops.push_back(getOrCreateVReg(Elt));
     }
-    EntryBuilder.buildMerge(Reg, Ops);
+    EntryBuilder.buildBuildVector(Reg, Ops);
   } else if (auto CV = dyn_cast<ConstantDataVector>(&C)) {
     // Return the scalar if it is a <1 x Ty> vector.
     if (CV->getNumElements() == 1)
       return translate(*CV->getElementAsConstant(0), Reg);
-    std::vector<unsigned> Ops;
+    SmallVector<unsigned, 4> Ops;
     for (unsigned i = 0; i < CV->getNumElements(); ++i) {
       Constant &Elt = *CV->getElementAsConstant(i);
       Ops.push_back(getOrCreateVReg(Elt));
     }
-    EntryBuilder.buildMerge(Reg, Ops);
+    EntryBuilder.buildBuildVector(Reg, Ops);
   } else if (auto CE = dyn_cast<ConstantExpr>(&C)) {
     switch(CE->getOpcode()) {
 #define HANDLE_INST(NUM, OPCODE, CLASS)                         \
       case Instruction::OPCODE: return translate##OPCODE(*CE, EntryBuilder);
 #include "llvm/IR/Instruction.def"
     default:
       return false;
     }
   } else if (auto CV = dyn_cast<ConstantVector>(&C)) {
     if (CV->getNumOperands() == 1)
       return translate(*CV->getOperand(0), Reg);
     SmallVector<unsigned, 4> Ops;
     for (unsigned i = 0; i < CV->getNumOperands(); ++i) {
       Ops.push_back(getOrCreateVReg(*CV->getOperand(i)));
     }
-    EntryBuilder.buildMerge(Reg, Ops);
+    EntryBuilder.buildBuildVector(Reg, Ops);
   } else if (auto *BA = dyn_cast<BlockAddress>(&C)) {
     EntryBuilder.buildBlockAddress(Reg, BA);
   } else
     return false;
 
   return true;
 }
 

lib/CodeGen/GlobalISel/Legalizer.cpp

static bool isArtifact(const MachineInstr &MI) {
   default:
     return false;
   case TargetOpcode::G_TRUNC:
   case TargetOpcode::G_ZEXT:
   case TargetOpcode::G_ANYEXT:
   case TargetOpcode::G_SEXT:
   case TargetOpcode::G_MERGE_VALUES:
   case TargetOpcode::G_UNMERGE_VALUES:
+  case TargetOpcode::G_CONCAT_VECTORS:
     return true;
   }
 }
 
 bool Legalizer::runOnMachineFunction(MachineFunction &MF) {
   // If the ISel pipeline failed, do not bother running that pass.
   if (MF.getProperties().hasProperty(
           MachineFunctionProperties::Property::FailedISel))

lib/CodeGen/GlobalISel/MachineIRBuilder.cpp

#ifndef NDEBUG
   assert(Ops.size() * getMRI()->getType(Ops[0]).getSizeInBits() ==
              getMRI()->getType(Res).getSizeInBits() &&
          "input operands do not cover output register");
 #endif
 
   if (Ops.size() == 1)
     return buildCast(Res, Ops[0]);
 
+  // If we're trying to merge vectors, we should use G_CONCAT_VECTORS instead.
+  if (getMRI()->getType(Res).isVector())
+    return buildConcatVectors(Res, Ops);
+
   MachineInstrBuilder MIB = buildInstr(TargetOpcode::G_MERGE_VALUES);
   MIB.addDef(Res);
   for (unsigned i = 0; i < Ops.size(); ++i)
     MIB.addUse(Ops[i]);
   return MIB;
 }
 
 MachineInstrBuilder MachineIRBuilderBase::buildUnmerge(ArrayRef<unsigned> Res,

lib/CodeGen/MachineVerifier.cpp

case TargetOpcode::G_FPTRUNC: {
     case TargetOpcode::G_FPTRUNC:
       if (DstSize >= SrcSize)
         report("Generic truncate has destination type no smaller than source",
                MI);
       break;
     }
     break;
   }
+  case TargetOpcode::G_MERGE_VALUES: {
+    // G_MERGE_VALUES should only be used to merge scalars into a larger scalar,
+    // e.g. s2N = MERGE sN, sN
+    // Merging multiple scalars into a vector is not allowed, should use
+    // G_BUILD_VECTOR for that.
+    LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
+    LLT SrcTy = MRI->getType(MI->getOperand(1).getReg());
+    if (DstTy.isVector() || SrcTy.isVector())
+      report("G_MERGE_VALUES cannot operate on vectors", MI);
+    break;
+  }
+  case TargetOpcode::G_UNMERGE_VALUES: {
+    LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
+    LLT SrcTy = MRI->getType(MI->getOperand(MI->getNumOperands()-1).getReg());
+    // For now G_UNMERGE can split vectors.
+    for (unsigned i = 0; i < MI->getNumOperands()-1; ++i) {
+      if (MRI->getType(MI->getOperand(i).getReg()) != DstTy)
+        report("G_UNMERGE_VALUES destination types do not match", MI);
+    }
+    if (SrcTy.getSizeInBits() !=
+        (DstTy.getSizeInBits() * (MI->getNumOperands() - 1))) {
+      report("G_UNMERGE_VALUES source operand does not cover dest operands",
+             MI);
+    }
+    break;
+  }
   case TargetOpcode::G_BUILD_VECTOR: {
     // Source types must be scalars, dest type a vector. Total size of scalars
     // must match the dest vector size.
     LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
     LLT SrcEltTy = MRI->getType(MI->getOperand(1).getReg());
     if (!DstTy.isVector() || SrcEltTy.isVector())
       report("G_BUILD_VECTOR must produce a vector from scalar operands", MI);
     for (unsigned i = 2; i < MI->getNumOperands(); ++i) {

lib/Target/AArch64/AArch64InstructionSelector.cpp

private:
   bool selectVaStartAAPCS(MachineInstr &I, MachineFunction &MF,
                           MachineRegisterInfo &MRI) const;
   bool selectVaStartDarwin(MachineInstr &I, MachineFunction &MF,
                            MachineRegisterInfo &MRI) const;
 
   bool selectCompareBranch(MachineInstr &I, MachineFunction &MF,
                            MachineRegisterInfo &MRI) const;
 
+  // Helper to generate an equivalent of scalar_to_vector into a new register,
+  // returned via 'Dst'.
+  bool emitScalarToVector(unsigned &Dst, const LLT DstTy,
+                          const TargetRegisterClass *DstRC, unsigned Scalar,
+                          MachineBasicBlock &MBB,
+                          MachineBasicBlock::iterator MBBI,
+                          MachineRegisterInfo &MRI) const;
+  bool selectBuildVector(MachineInstr &I, MachineRegisterInfo &MRI) const;
+
   ComplexRendererFns selectArithImmed(MachineOperand &Root) const;
 
   ComplexRendererFns selectAddrModeUnscaled(MachineOperand &Root,
                                             unsigned Size) const;
 
   ComplexRendererFns selectAddrModeUnscaled8(MachineOperand &Root) const {
     return selectAddrModeUnscaled(Root, 1);
   }
if (TM.getCodeModel() == CodeModel::Large) {
                                         /* Offset */ 0, AArch64II::MO_PAGE)
                        .addBlockAddress(
                            I.getOperand(1).getBlockAddress(), /* Offset */ 0,
                            AArch64II::MO_NC | AArch64II::MO_PAGEOFF);
       I.eraseFromParent();
       return constrainSelectedInstRegOperands(*MovMI, TII, TRI, RBI);
     }
   }
+  case TargetOpcode::G_BUILD_VECTOR:
+    return selectBuildVector(I, MRI);
   }
 
   return false;
 }
 
+bool AArch64InstructionSelector::emitScalarToVector(
+    unsigned &Dst, const LLT DstTy, const TargetRegisterClass *DstRC,
+    unsigned Scalar, MachineBasicBlock &MBB,
+    MachineBasicBlock::iterator MBBI, MachineRegisterInfo &MRI) const {
+  Dst = MRI.createVirtualRegister(DstRC);
+
+  unsigned UndefVec = MRI.createVirtualRegister(DstRC);
+  MachineInstr &UndefMI = *BuildMI(MBB, MBBI, MBBI->getDebugLoc(),
+                                   TII.get(TargetOpcode::IMPLICIT_DEF))
+                               .addDef(UndefVec);
+
+  auto BuildFn = [&](unsigned SubregIndex) {
+    MachineInstr &InsMI = *BuildMI(MBB, MBBI, MBBI->getDebugLoc(),
+                                   TII.get(TargetOpcode::INSERT_SUBREG))
+                               .addDef(Dst)
+                               .addUse(UndefVec)
+                               .addUse(Scalar)
+                               .addImm(SubregIndex);
+    constrainSelectedInstRegOperands(UndefMI, TII, TRI, RBI);
+    return constrainSelectedInstRegOperands(InsMI, TII, TRI, RBI);
+  };
+
+  switch (DstTy.getElementType().getSizeInBits()) {
+  case 32:
+    return BuildFn(AArch64::ssub);
+  case 64:
+    return BuildFn(AArch64::dsub);
+  default:
+    return false;
+  }
+}
+
+bool AArch64InstructionSelector::selectBuildVector(
+    MachineInstr &I, MachineRegisterInfo &MRI) const {
+  assert(I.getOpcode() == TargetOpcode::G_BUILD_VECTOR);
+  // Until we port more of the optimized selections, for now just use a vector
+  // insert sequence.
+  const LLT DstTy = MRI.getType(I.getOperand(0).getReg());
+  const LLT EltTy = MRI.getType(I.getOperand(1).getReg());
+  unsigned EltSize = EltTy.getSizeInBits();
+  if (EltSize < 32 || EltSize > 64)
+    return false; // Don't support all element types yet.
+  const RegisterBank &RB = *RBI.getRegBank(I.getOperand(1).getReg(), MRI, TRI);
+  unsigned Opc;
+  unsigned SubregIdx;
+  if (RB.getID() == AArch64::GPRRegBankID) {
+    if (EltSize == 32) {
+      Opc = AArch64::INSvi32gpr;
+      SubregIdx = AArch64::ssub;
+    } else {
+      Opc = AArch64::INSvi64gpr;
+      SubregIdx = AArch64::dsub;
+    }
+  } else {
+    if (EltSize == 32) {
+      Opc = AArch64::INSvi32lane;
+      SubregIdx = AArch64::ssub;
+    } else {
+      Opc = AArch64::INSvi64lane;
+      SubregIdx = AArch64::dsub;
+    }
+  }
+
+  if (EltSize * DstTy.getNumElements() != 128)
+    return false; // Don't handle unpacked vectors yet.
+
+  unsigned DstVec = 0;
+  const TargetRegisterClass *DstRC = getRegClassForTypeOnBank(
+      DstTy, RBI.getRegBank(AArch64::FPRRegBankID), RBI);
+  emitScalarToVector(DstVec, DstTy, DstRC, I.getOperand(1).getReg(),
+                     *I.getParent(), I.getIterator(), MRI);
+  for (unsigned i = 2, e = DstTy.getSizeInBits() / EltSize + 1; i < e; ++i) {
+    unsigned InsDef;
+    // For the last insert re-use the dst reg of the G_BUILD_VECTOR.
+    if (i + 1 < e)
+      InsDef = MRI.createVirtualRegister(DstRC);
+    else
+      InsDef = I.getOperand(0).getReg();
+    unsigned LaneIdx = i - 1;
+    if (RB.getID() == AArch64::FPRRegBankID) {
+      unsigned ImpDef = MRI.createVirtualRegister(DstRC);
+      MachineInstr &ImpDefMI = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
+                                        TII.get(TargetOpcode::IMPLICIT_DEF))
+                                    .addDef(ImpDef);
+      unsigned InsSubDef = MRI.createVirtualRegister(DstRC);
+      MachineInstr &InsSubMI = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
+                                        TII.get(TargetOpcode::INSERT_SUBREG))
+                                    .addDef(InsSubDef)
+                                    .addUse(ImpDef)
+                                    .addUse(I.getOperand(i).getReg())
+                                    .addImm(SubregIdx);
+      MachineInstr &InsEltMI =
+          *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc))
+               .addDef(InsDef)
+               .addUse(DstVec)
+               .addImm(LaneIdx)
+               .addUse(InsSubDef)
+               .addImm(0);
+      constrainSelectedInstRegOperands(ImpDefMI, TII, TRI, RBI);
+      constrainSelectedInstRegOperands(InsSubMI, TII, TRI, RBI);
+      constrainSelectedInstRegOperands(InsEltMI, TII, TRI, RBI);
+      DstVec = InsDef;
+    } else {
+      MachineInstr &InsMI =
+          *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opc))
+               .addDef(InsDef)
+               .addUse(DstVec)
+               .addImm(LaneIdx)
+               .addUse(I.getOperand(i).getReg());
+      constrainSelectedInstRegOperands(InsMI, TII, TRI, RBI);
+      DstVec = InsDef;
+    }
+  }
+  I.eraseFromParent();
+  return true;
+}
+
 /// SelectArithImmed - Select an immediate value that can be represented as
 /// a 12-bit value shifted left by either 0 or 12.  If so, return true with
 /// Val set to the 12-bit value and Shift set to the shifter operand.
 InstructionSelector::ComplexRendererFns
 AArch64InstructionSelector::selectArithImmed(MachineOperand &Root) const {
   MachineInstr &MI = *Root.getParent();
   MachineBasicBlock &MBB = *MI.getParent();
   MachineFunction &MF = *MBB.getParent();

lib/Target/AArch64/AArch64LegalizerInfo.cpp

AArch64LegalizerInfo::AArch64LegalizerInfo(const AArch64Subtarget &ST) {
   const LLT v8s16 = LLT::vector(8, 16);
   const LLT v4s16 = LLT::vector(4, 16);
   const LLT v2s16 = LLT::vector(2, 16);
   const LLT v2s32 = LLT::vector(2, 32);
   const LLT v4s32 = LLT::vector(4, 32);
   const LLT v2s64 = LLT::vector(2, 64);
 
   getActionDefinitionsBuilder(G_IMPLICIT_DEF)
-      .legalFor({p0, s1, s8, s16, s32, s64})
+      .legalFor({p0, s1, s8, s16, s32, s64, v2s64})
       .clampScalar(0, s1, s64)
       .widenScalarToNextPow2(0, 8);
 
   getActionDefinitionsBuilder(G_PHI)
       .legalFor({p0, s16, s32, s64})
       .clampScalar(0, s16, s64)
       .widenScalarToNextPow2(0);
 
auto notValidElt = [](const LegalityQuery &Query, unsigned TypeIdx) {
       return false;
     };
     auto scalarize =
         [](const LegalityQuery &Query, unsigned TypeIdx) {
           const LLT &Ty = Query.Types[TypeIdx];
           return std::make_pair(TypeIdx, Ty.getElementType());
         };
 
     // FIXME: This rule is horrible, but specifies the same as what we had
     // before with the particularly strange definitions removed (e.g.
     // s8 = G_MERGE_VALUES s32, s32).
     // Part of the complexity comes from these ops being extremely flexible. For
     // example, you can build/decompose vectors with it, concatenate vectors,
     // etc. and in addition to this you can also bitcast with it at the same
     // time. We've been considering breaking it up into multiple ops to make it
     // more manageable throughout the backend.
     getActionDefinitionsBuilder(Op)
         // Break up vectors with weird elements into scalars
         .fewerElementsIf(
             [=](const LegalityQuery &Query) { return notValidElt(Query, 0); },
             [=](const LegalityQuery &Query) { return scalarize(Query, 0); })
         .fewerElementsIf(
             [=](const LegalityQuery &Query) { return notValidElt(Query, 1); },
             [=](const LegalityQuery &Query) { return scalarize(Query, 1); })
         // Clamp the big scalar to s8-s512 and make it either a power of 2, 192,
         // or 384.
         .clampScalar(BigTyIdx, s8, s512)
         .widenScalarIf(
             [=](const LegalityQuery &Query) {
               const LLT &Ty = Query.Types[BigTyIdx];
               return !isPowerOf2_32(Ty.getSizeInBits()) &&
                      Ty.getSizeInBits() % 64 != 0;
             },
             [=](const LegalityQuery &Query) {
               // Pick the next power of 2, or a multiple of 64 over 128.
               // Whichever is smaller.
               const LLT &Ty = Query.Types[BigTyIdx];
               unsigned NewSizeInBits = 1
                                        << Log2_32_Ceil(Ty.getSizeInBits() + 1);
               if (NewSizeInBits >= 256) {
                 unsigned RoundedTo = alignTo<64>(Ty.getSizeInBits() + 1);
                 if (RoundedTo < NewSizeInBits)
                   NewSizeInBits = RoundedTo;
               }
               return std::make_pair(BigTyIdx, LLT::scalar(NewSizeInBits));
             })
         // Clamp the little scalar to s8-s256 and make it a power of 2. It's not
         // worth considering the multiples of 64 since 2*192 and 2*384 are not
         // valid.
         .clampScalar(LitTyIdx, s8, s256)
         .widenScalarToNextPow2(LitTyIdx, /*Min*/ 8)
         // So at this point, we have s8, s16, s32, s64, s128, s192, s256, s384,
         // s512, <X x s8>, <X x s16>, <X x s32>, or <X x s64>.
         // At this point it's simple enough to accept the legal types.
         .legalIf([=](const LegalityQuery &Query) {
           const LLT &BigTy = Query.Types[BigTyIdx];
           const LLT &LitTy = Query.Types[LitTyIdx];
           if (BigTy.isVector() && BigTy.getSizeInBits() < 32)
             return false;
           if (LitTy.isVector() && LitTy.getSizeInBits() < 32)
             return false;
           return BigTy.getSizeInBits() % LitTy.getSizeInBits() == 0;
         })
         // Any vectors left are the wrong size. Scalarize them.
         .fewerElementsIf([](const LegalityQuery &Query) { return true; },
                          [](const LegalityQuery &Query) {
                            return std::make_pair(
                                0, Query.Types[0].getElementType());
                          })
         .fewerElementsIf([](const LegalityQuery &Query) { return true; },
                          [](const LegalityQuery &Query) {
                            return std::make_pair(
                                1, Query.Types[1].getElementType());
                          });
   }
 
   getActionDefinitionsBuilder(G_EXTRACT_VECTOR_ELT)
       .unsupportedIf([=](const LegalityQuery &Query) {
         const LLT &EltTy = Query.Types[1].getElementType();
         return Query.Types[0] != EltTy;
       })
       .minScalar(2, s64)
       .legalIf([=](const LegalityQuery &Query) {
         const LLT &VecTy = Query.Types[1];
         return VecTy == v4s32 || VecTy == v2s64;
       });
 
+  getActionDefinitionsBuilder(G_BUILD_VECTOR)
+      .unsupportedIf([=](const LegalityQuery &Query) {
+        const LLT &VecTy = Query.Types[0];
+        return VecTy.getElementType() != Query.Types[1];
+      })
+      .legalForCartesianProduct({v4s32, v2s64}, {s32, s64});
+
   computeTables();
   verify(*ST.getInstrInfo());
 }
 
 bool AArch64LegalizerInfo::legalizeCustom(MachineInstr &MI,
                                           MachineRegisterInfo &MRI,
                                           MachineIRBuilder &MIRBuilder) const {
   switch (MI.getOpcode()) {

lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp

AMDGPULegalizerInfo::AMDGPULegalizerInfo(const GCNSubtarget &ST,
   getActionDefinitionsBuilder({G_EXTRACT, G_INSERT})
     .legalIf([=](const LegalityQuery &Query) {
         const LLT &Ty0 = Query.Types[0];
         const LLT &Ty1 = Query.Types[1];
         return (Ty0.getSizeInBits() % 32 == 0) &&
                (Ty1.getSizeInBits() % 32 == 0);
       });
 
+  getActionDefinitionsBuilder(G_BUILD_VECTOR)
+      .legalIf([=](const LegalityQuery &Query) {
+        const LLT &VecTy = Query.Types[0];
+        const LLT &ScalarTy = Query.Types[1];
+        return VecTy.getSizeInBits() % 32 == 0 &&
+               ScalarTy.getSizeInBits() % 32 == 0 &&
+               VecTy.getSizeInBits() <= 512;
+      });
   // Merge/Unmerge
   for (unsigned Op : {G_MERGE_VALUES, G_UNMERGE_VALUES}) {
     unsigned BigTyIdx = Op == G_MERGE_VALUES ? 0 : 1;
     unsigned LitTyIdx = Op == G_MERGE_VALUES ? 1 : 0;
 
     getActionDefinitionsBuilder(Op)
       .legalIf([=](const LegalityQuery &Query) {
           const LLT &BigTy = Query.Types[BigTyIdx];

lib/Target/X86/X86InstructionSelector.cpp

case TargetOpcode::G_ICMP:
     return selectCmp(I, MRI, MF);
   case TargetOpcode::G_FCMP:
     return selectFCmp(I, MRI, MF);
   case TargetOpcode::G_UADDE:
     return selectUadde(I, MRI, MF);
   case TargetOpcode::G_UNMERGE_VALUES:
     return selectUnmergeValues(I, MRI, MF, CoverageInfo);
   case TargetOpcode::G_MERGE_VALUES:
+  case TargetOpcode::G_CONCAT_VECTORS:
     return selectMergeValues(I, MRI, MF, CoverageInfo);
   case TargetOpcode::G_EXTRACT:
     return selectExtract(I, MRI, MF);
   case TargetOpcode::G_INSERT:
     return selectInsert(I, MRI, MF);
   case TargetOpcode::G_BRCOND:
     return selectCondBranch(I, MRI, MF);
   case TargetOpcode::G_IMPLICIT_DEF:
bool X86InstructionSelector::selectUnmergeValues(
 
   I.eraseFromParent();
   return true;
 }
 
 bool X86InstructionSelector::selectMergeValues(
     MachineInstr &I, MachineRegisterInfo &MRI, MachineFunction &MF,
     CodeGenCoverage &CoverageInfo) const {
-  assert((I.getOpcode() == TargetOpcode::G_MERGE_VALUES) &&
+  assert((I.getOpcode() == TargetOpcode::G_MERGE_VALUES ||
+          I.getOpcode() == TargetOpcode::G_CONCAT_VECTORS) &&
          "unexpected instruction");
 
   // Split to inserts.
   unsigned DstReg = I.getOperand(0).getReg();
   unsigned SrcReg0 = I.getOperand(1).getReg();
 
   const LLT DstTy = MRI.getType(DstReg);
   const LLT SrcTy = MRI.getType(SrcReg0);

lib/Target/X86/X86LegalizerInfo.cpp

for (unsigned MemOp : {G_LOAD, G_STORE})
     for (auto Ty : {v4s32, v2s64})
       setAction({MemOp, Ty}, Legal);
 
   // Constants
   setAction({TargetOpcode::G_FCONSTANT, s32}, Legal);
 
   // Merge/Unmerge
   for (const auto &Ty : {v4s32, v2s64}) {
-    setAction({G_MERGE_VALUES, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, 1, Ty}, Legal);
   }
   setAction({G_MERGE_VALUES, 1, s64}, Legal);
   setAction({G_UNMERGE_VALUES, s64}, Legal);
 }
 
 void X86LegalizerInfo::setLegalizerInfoSSE2() {
   if (!Subtarget.hasSSE2())
void X86LegalizerInfo::setLegalizerInfoSSE2() {
   setAction({G_FPTRUNC, 1, s64}, Legal);
 
   // Constants
   setAction({TargetOpcode::G_FCONSTANT, s64}, Legal);
 
   // Merge/Unmerge
   for (const auto &Ty :
        {v16s8, v32s8, v8s16, v16s16, v4s32, v8s32, v2s64, v4s64}) {
-    setAction({G_MERGE_VALUES, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, 1, Ty}, Legal);
   }
   for (const auto &Ty : {v16s8, v8s16, v4s32, v2s64}) {
-    setAction({G_MERGE_VALUES, 1, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, 1, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, Ty}, Legal);
   }
 }
 
 void X86LegalizerInfo::setLegalizerInfoSSE41() {
   if (!Subtarget.hasSSE41())
     return;
 
void X86LegalizerInfo::setLegalizerInfoAVX() {
   }
   for (auto Ty : {v16s8, v8s16, v4s32, v2s64}) {
     setAction({G_INSERT, 1, Ty}, Legal);
     setAction({G_EXTRACT, Ty}, Legal);
   }
   // Merge/Unmerge
   for (const auto &Ty :
        {v32s8, v64s8, v16s16, v32s16, v8s32, v16s32, v4s64, v8s64}) {
-    setAction({G_MERGE_VALUES, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, 1, Ty}, Legal);
   }
   for (const auto &Ty :
        {v16s8, v32s8, v8s16, v16s16, v4s32, v8s32, v2s64, v4s64}) {
-    setAction({G_MERGE_VALUES, 1, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, 1, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, Ty}, Legal);
   }
 }
 
 void X86LegalizerInfo::setLegalizerInfoAVX2() {
   if (!Subtarget.hasAVX2())
     return;
 
for (unsigned BinOp : {G_ADD, G_SUB})
     for (auto Ty : {v32s8, v16s16, v8s32, v4s64})
       setAction({BinOp, Ty}, Legal);
 
   for (auto Ty : {v16s16, v8s32})
     setAction({G_MUL, Ty}, Legal);
 
   // Merge/Unmerge
   for (const auto &Ty : {v64s8, v32s16, v16s32, v8s64}) {
-    setAction({G_MERGE_VALUES, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, 1, Ty}, Legal);
   }
   for (const auto &Ty : {v32s8, v16s16, v8s32, v4s64}) {
-    setAction({G_MERGE_VALUES, 1, Ty}, Legal);
+    setAction({G_CONCAT_VECTORS, 1, Ty}, Legal);
     setAction({G_UNMERGE_VALUES, Ty}, Legal);
   }
 }
 
 void X86LegalizerInfo::setLegalizerInfoAVX512() {
   if (!Subtarget.hasAVX512())
     return;
 

test/CodeGen/AArch64/GlobalISel/arm64-irtranslator.ll

; CHECK: $w0 = COPY [[ELT]](s32)
   %vec = insertelement <1 x i32> undef, i32 %elt, i32 0
   %res = extractelement <1 x i32> %vec, i32 0
   ret i32 %res
 }
 
 define <2 x i32> @test_constantaggzerovector_v2i32() {
 ; CHECK-LABEL: name: test_constantaggzerovector_v2i32
 ; CHECK: [[ZERO:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
-; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[ZERO]](s32), [[ZERO]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[ZERO]](s32), [[ZERO]](s32)
 ; CHECK: $d0 = COPY [[VEC]](<2 x s32>)
   ret <2 x i32> zeroinitializer
 }
 
 define <2 x float> @test_constantaggzerovector_v2f32() {
 ; CHECK-LABEL: name: test_constantaggzerovector_v2f32
 ; CHECK: [[ZERO:%[0-9]+]]:_(s32) = G_FCONSTANT float 0.000000e+00
-; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[ZERO]](s32), [[ZERO]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[ZERO]](s32), [[ZERO]](s32)
 ; CHECK: $d0 = COPY [[VEC]](<2 x s32>)
   ret <2 x float> zeroinitializer
 }
 
 define i32 @test_constantaggzerovector_v3i32() {
 ; CHECK-LABEL: name: test_constantaggzerovector_v3i32
 ; CHECK: [[ZERO:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
-; CHECK: [[VEC:%[0-9]+]]:_(<3 x s32>) = G_MERGE_VALUES [[ZERO]](s32), [[ZERO]](s32), [[ZERO]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<3 x s32>) = G_BUILD_VECTOR [[ZERO]](s32), [[ZERO]](s32), [[ZERO]](s32)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<3 x s32>)
   %elt = extractelement <3 x i32> zeroinitializer, i32 1
   ret i32 %elt
 }
 
 define <2 x i32> @test_constantdatavector_v2i32() {
 ; CHECK-LABEL: name: test_constantdatavector_v2i32
 ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
-; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C2]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C2]](s32)
 ; CHECK: $d0 = COPY [[VEC]](<2 x s32>)
   ret <2 x i32> <i32 1, i32 2>
 }
 
 define i32 @test_constantdatavector_v3i32() {
 ; CHECK-LABEL: name: test_constantdatavector_v3i32
 ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
 ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
-; CHECK: [[VEC:%[0-9]+]]:_(<3 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C2]](s32), [[C3]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<3 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C2]](s32), [[C3]](s32)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<3 x s32>)
   %elt = extractelement <3 x i32> <i32 1, i32 2, i32 3>, i32 1
   ret i32 %elt
 }
 
 define <4 x i32> @test_constantdatavector_v4i32() {
 ; CHECK-LABEL: name: test_constantdatavector_v4i32
 ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
 ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
 ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
-; CHECK: [[VEC:%[0-9]+]]:_(<4 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C2]](s32), [[C3]](s32), [[C4]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C2]](s32), [[C3]](s32), [[C4]](s32)
 ; CHECK: $q0 = COPY [[VEC]](<4 x s32>)
   ret <4 x i32> <i32 1, i32 2, i32 3, i32 4>
 }
 
 define <2 x double> @test_constantdatavector_v2f64() {
 ; CHECK-LABEL: name: test_constantdatavector_v2f64
 ; CHECK: [[FC1:%[0-9]+]]:_(s64) = G_FCONSTANT double 1.000000e+00
 ; CHECK: [[FC2:%[0-9]+]]:_(s64) = G_FCONSTANT double 2.000000e+00
-; CHECK: [[VEC:%[0-9]+]]:_(<2 x s64>) = G_MERGE_VALUES [[FC1]](s64), [[FC2]](s64)
+; CHECK: [[VEC:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[FC1]](s64), [[FC2]](s64)
 ; CHECK: $q0 = COPY [[VEC]](<2 x s64>)
   ret <2 x double> <double 1.0, double 2.0>
 }
 
 define i32 @test_constantaggzerovector_v1s32(i32 %arg){
 ; CHECK-LABEL: name: test_constantaggzerovector_v1s32
 ; CHECK: [[ARG:%[0-9]+]]:_(s32) = COPY $w0
 ; CHECK: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
; CHECK: BL @different_call_conv_target, csr_aarch64_aapcs, implicit-def $lr, implicit $sp, implicit $s8, implicit-def $s0
   ret float %res
 }
 
 define <2 x i32> @test_shufflevector_s32_v2s32(i32 %arg) {
 ; CHECK-LABEL: name: test_shufflevector_s32_v2s32
 ; CHECK: [[ARG:%[0-9]+]]:_(s32) = COPY $w0
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C0]](s32), [[C0]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C0]](s32), [[C0]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_SHUFFLE_VECTOR [[ARG]](s32), [[UNDEF]], [[MASK]](<2 x s32>)
 ; CHECK: $d0 = COPY [[VEC]](<2 x s32>)
   %vec = insertelement <1 x i32> undef, i32 %arg, i32 0
   %res = shufflevector <1 x i32> %vec, <1 x i32> undef, <2 x i32> zeroinitializer
   ret <2 x i32> %res
 }
 
 define i32 @test_shufflevector_v2s32_s32(<2 x i32> %arg) {

 }
 
 define <2 x i32> @test_shufflevector_v2s32_v2s32(<2 x i32> %arg) {
 ; CHECK-LABEL: name: test_shufflevector_v2s32_v2s32
 ; CHECK: [[ARG:%[0-9]+]]:_(<2 x s32>) = COPY $d0
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(<2 x s32>) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C0]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C0]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_SHUFFLE_VECTOR [[ARG]](<2 x s32>), [[UNDEF]], [[MASK]](<2 x s32>)
 ; CHECK: $d0 = COPY [[VEC]](<2 x s32>)
   %res = shufflevector <2 x i32> %arg, <2 x i32> undef, <2 x i32> <i32 1, i32 0>
   ret <2 x i32> %res
 }
 
 define i32 @test_shufflevector_v2s32_v3s32(<2 x i32> %arg) {
 ; CHECK-LABEL: name: test_shufflevector_v2s32_v3s32
 ; CHECK: [[ARG:%[0-9]+]]:_(<2 x s32>) = COPY $d0
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(<2 x s32>) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<3 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C0]](s32), [[C1]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<3 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C0]](s32), [[C1]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<3 x s32>) = G_SHUFFLE_VECTOR [[ARG]](<2 x s32>), [[UNDEF]], [[MASK]](<3 x s32>)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<3 x s32>)
   %vec = shufflevector <2 x i32> %arg, <2 x i32> undef, <3 x i32> <i32 1, i32 0, i32 1>
   %res = extractelement <3 x i32> %vec, i32 0
   ret i32 %res
 }
 
 define <4 x i32> @test_shufflevector_v2s32_v4s32(<2 x i32> %arg1, <2 x i32> %arg2) {
 ; CHECK-LABEL: name: test_shufflevector_v2s32_v4s32
 ; CHECK: [[ARG1:%[0-9]+]]:_(<2 x s32>) = COPY $d0
 ; CHECK: [[ARG2:%[0-9]+]]:_(<2 x s32>) = COPY $d1
 ; CHECK: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
 ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
 ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
-; CHECK: [[MASK:%[0-9]+]]:_(<4 x s32>) = G_MERGE_VALUES [[C0]](s32), [[C1]](s32), [[C2]](s32), [[C3]](s32)
+; CHECK: [[MASK:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[C0]](s32), [[C1]](s32), [[C2]](s32), [[C3]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<4 x s32>) = G_SHUFFLE_VECTOR [[ARG1]](<2 x s32>), [[ARG2]], [[MASK]](<4 x s32>)
 ; CHECK: $q0 = COPY [[VEC]](<4 x s32>)
   %res = shufflevector <2 x i32> %arg1, <2 x i32> %arg2, <4 x i32> <i32 0, i32 1, i32 2, i32 3>
   ret <4 x i32> %res
 }
 
 define <2 x i32> @test_shufflevector_v4s32_v2s32(<4 x i32> %arg) {
 ; CHECK-LABEL: name: test_shufflevector_v4s32_v2s32
 ; CHECK: [[ARG:%[0-9]+]]:_(<4 x s32>) = COPY $q0
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(<4 x s32>) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK-DAG: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C3]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C3]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_SHUFFLE_VECTOR [[ARG]](<4 x s32>), [[UNDEF]], [[MASK]](<2 x s32>)
 ; CHECK: $d0 = COPY [[VEC]](<2 x s32>)
   %res = shufflevector <4 x i32> %arg, <4 x i32> undef, <2 x i32> <i32 1, i32 3>
   ret <2 x i32> %res
 }
 
 
 define <16 x i8> @test_shufflevector_v8s8_v16s8(<8 x i8> %arg1, <8 x i8> %arg2) {

 ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
 ; CHECK: [[C12:%[0-9]+]]:_(s32) = G_CONSTANT i32 12
 ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 5
 ; CHECK: [[C13:%[0-9]+]]:_(s32) = G_CONSTANT i32 13
 ; CHECK: [[C6:%[0-9]+]]:_(s32) = G_CONSTANT i32 6
 ; CHECK: [[C14:%[0-9]+]]:_(s32) = G_CONSTANT i32 14
 ; CHECK: [[C7:%[0-9]+]]:_(s32) = G_CONSTANT i32 7
 ; CHECK: [[C15:%[0-9]+]]:_(s32) = G_CONSTANT i32 15
-; CHECK: [[MASK:%[0-9]+]]:_(<16 x s32>) = G_MERGE_VALUES [[C0]](s32), [[C8]](s32), [[C1]](s32), [[C9]](s32), [[C2]](s32), [[C10]](s32), [[C3]](s32), [[C11]](s32), [[C4]](s32), [[C12]](s32), [[C5]](s32), [[C13]](s32), [[C6]](s32), [[C14]](s32), [[C7]](s32), [[C15]](s32)
+; CHECK: [[MASK:%[0-9]+]]:_(<16 x s32>) = G_BUILD_VECTOR [[C0]](s32), [[C8]](s32), [[C1]](s32), [[C9]](s32), [[C2]](s32), [[C10]](s32), [[C3]](s32), [[C11]](s32), [[C4]](s32), [[C12]](s32), [[C5]](s32), [[C13]](s32), [[C6]](s32), [[C14]](s32), [[C7]](s32), [[C15]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<16 x s8>) = G_SHUFFLE_VECTOR [[ARG1]](<8 x s8>), [[ARG2]], [[MASK]](<16 x s32>)
 ; CHECK: $q0 = COPY [[VEC]](<16 x s8>)
   %res = shufflevector <8 x i8> %arg1, <8 x i8> %arg2, <16 x i32> <i32 0, i32 8, i32 1, i32 9, i32 2, i32 10, i32 3, i32 11, i32 4, i32 12, i32 5, i32 13, i32 6, i32 14, i32 7, i32 15>
   ret <16 x i8> %res
 }
 
 ; CHECK-LABEL: test_constant_vector
 ; CHECK: [[UNDEF:%[0-9]+]]:_(s16) = G_IMPLICIT_DEF
 ; CHECK: [[F:%[0-9]+]]:_(s16) = G_FCONSTANT half 0xH3C00
-; CHECK: [[M:%[0-9]+]]:_(<4 x s16>) = G_MERGE_VALUES [[UNDEF]](s16), [[UNDEF]](s16), [[UNDEF]](s16), [[F]](s16)
+; CHECK: [[M:%[0-9]+]]:_(<4 x s16>) = G_BUILD_VECTOR [[UNDEF]](s16), [[UNDEF]](s16), [[UNDEF]](s16), [[F]](s16)
 ; CHECK: $d0 = COPY [[M]](<4 x s16>)
 define <4 x half> @test_constant_vector() {
   ret <4 x half> <half undef, half undef, half undef, half 0xH3C00>
 }
 
 define i32 @test_target_mem_intrinsic(i32* %addr) {
 ; CHECK-LABEL: name: test_target_mem_intrinsic
 ; CHECK: [[ADDR:%[0-9]+]]:_(p0) = COPY $x0

test/CodeGen/AArch64/GlobalISel/legalize-add.mir

bb.0.entry:
     ; CHECK: [[ADD:%[0-9]+]]:_(<2 x s64>) = G_ADD [[COPY]], [[COPY2]]
     ; CHECK: [[ADD1:%[0-9]+]]:_(<2 x s64>) = G_ADD [[COPY1]], [[COPY3]]
     ; CHECK: $q0 = COPY [[ADD]](<2 x s64>)
     ; CHECK: $q1 = COPY [[ADD1]](<2 x s64>)
     %0:_(<2 x s64>) = COPY $q0
     %1:_(<2 x s64>) = COPY $q1
     %2:_(<2 x s64>) = COPY $q2
     %3:_(<2 x s64>) = COPY $q3
-    %4:_(<4 x s64>) = G_MERGE_VALUES %0, %1
-    %5:_(<4 x s64>) = G_MERGE_VALUES %2, %3
+    %4:_(<4 x s64>) = G_CONCAT_VECTORS %0, %1
+    %5:_(<4 x s64>) = G_CONCAT_VECTORS %2, %3
     %6:_(<4 x s64>) = G_ADD %4, %5
     %7:_(<2 x s64>), %8:_(<2 x s64>) = G_UNMERGE_VALUES %6
     $q0 = COPY %7
     $q1 = COPY %8
 ...
 ---
 name:            test_vector_add_nonpow2
 registers:
bb.0.entry:
     ; CHECK: $q0 = COPY [[RES_LO]]
     ; CHECK: $q1 = COPY [[RES_MI]]
     ; CHECK: $q2 = COPY [[RES_HI]]
 
     %0(<2 x s64>) = COPY $q0
     %1(<2 x s64>) = COPY $q1
     %2(<2 x s64>) = COPY $q2
     %3(<2 x s64>) = COPY $q3
-    %4(<6 x s64>) = G_MERGE_VALUES %0, %1, %2
-    %5(<6 x s64>) = G_MERGE_VALUES %1, %2, %3
+    %4(<6 x s64>) = G_CONCAT_VECTORS %0, %1, %2
+    %5(<6 x s64>) = G_CONCAT_VECTORS %1, %2, %3
     %6(<6 x s64>) = G_ADD %4, %5
     %7(<2 x s64>), %8(<2 x s64>), %9(<2 x s64>) = G_UNMERGE_VALUES %6
     $q0 = COPY %7
     $q1 = COPY %8
     $q2 = COPY %9
 ...

test/CodeGen/AArch64/GlobalISel/legalize-build-vector.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=aarch64-linux-gnu -O0 -run-pass=legalizer %s -o - | FileCheck %s
+
+---
+name:            legal_v4s32
+body: |
+  bb.0:
+    liveins: $w0, $w1, $w2, $w3
+    ; CHECK-LABEL: name: legal_v4s32
+    ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $w0
+    ; CHECK: [[COPY1:%[0-9]+]]:_(s32) = COPY $w1
+    ; CHECK: [[COPY2:%[0-9]+]]:_(s32) = COPY $w2
+    ; CHECK: [[COPY3:%[0-9]+]]:_(s32) = COPY $w3
+    ; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[COPY]](s32), [[COPY1]](s32), [[COPY2]](s32), [[COPY3]](s32)
+    ; CHECK: $q0 = COPY [[BUILD_VECTOR]](<4 x s32>)
+    ; CHECK: RET_ReallyLR
+    %0:_(s32) = COPY $w0
+    %1:_(s32) = COPY $w1
+    %2:_(s32) = COPY $w2
+    %3:_(s32) = COPY $w3
+    %4:_(<4 x s32>) = G_BUILD_VECTOR %0(s32), %1(s32), %2(s32), %3(s32)
+    $q0 = COPY %4(<4 x s32>)
+    RET_ReallyLR
+...
+---
+name:            legal_v2s64
+body: |
+  bb.0:
+    liveins: $x0, $x1
+    ; CHECK-LABEL: name: legal_v2s64
+    ; CHECK: [[COPY:%[0-9]+]]:_(s64) = COPY $x0
+    ; CHECK: [[COPY1:%[0-9]+]]:_(s64) = COPY $x1
+    ; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[COPY]](s64), [[COPY1]](s64)
+    ; CHECK: $q0 = COPY [[BUILD_VECTOR]](<2 x s64>)
+    ; CHECK: RET_ReallyLR
+    %0:_(s64) = COPY $x0
+    %1:_(s64) = COPY $x1
+    %2:_(<2 x s64>) = G_BUILD_VECTOR %0(s64), %1(s64)
+    $q0 = COPY %2(<2 x s64>)
+    RET_ReallyLR
+...

test/CodeGen/AArch64/GlobalISel/legalize-extract-vector-elt.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=aarch64-linux-gnu -O0 -run-pass=legalizer %s -o - | FileCheck %s
+
+---
+name:            test_eve_1
+body: |
+  bb.0:
+    liveins: $q0
+    ; CHECK-LABEL: name: test_eve_1
+    ; CHECK: [[COPY:%[0-9]+]]:_(<2 x s64>) = COPY $q0
+    ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
+    ; CHECK: [[SEXT:%[0-9]+]]:_(s64) = G_SEXT [[C]](s32)
+    ; CHECK: [[EVEC:%[0-9]+]]:_(s64) = G_EXTRACT_VECTOR_ELT [[COPY]](<2 x s64>), [[SEXT]](s64)
+    ; CHECK: $x0 = COPY [[EVEC]](s64)
+    ; CHECK: RET_ReallyLR
+    %0:_(<2 x s64>) = COPY $q0
+    %1:_(s32) = G_CONSTANT i32 1
+    %2:_(s64) = G_EXTRACT_VECTOR_ELT %0(<2 x s64>), %1(s32)
+    $x0 = COPY %2(s64)
+    RET_ReallyLR
+...

test/CodeGen/AArch64/GlobalISel/legalize-nonpowerof2eltsvec.mir

 name:            test_legalize_merge_v3s64
 registers:
   - { id: 0, class: _ }
   - { id: 1, class: _ }
   - { id: 2, class: _ }
   - { id: 3, class: _ }
   - { id: 4, class: _ }
   - { id: 5, class: _ }
+  - { id: 6, class: _ }
+  - { id: 7, class: _ }
 body: |
   bb.0:
     liveins: $w0
     ; CHECK-LABEL: name: test_legalize_merge_v3s64
     ; CHECK: [[COPY:%[0-9]+]]:_(s64) = COPY $x0
-    ; CHECK: [[MV:%[0-9]+]]:_(<3 x s64>) = G_MERGE_VALUES [[COPY]](s64), [[COPY]](s64), [[COPY]](s64)
-    ; CHECK: $x0 = COPY [[COPY]](s64)
-    ; CHECK: $noreg = PATCHABLE_RET [[MV]](<3 x s64>)
+    ; CHECK: [[BUILD_VECTOR:%[0-9]+]]:_(<3 x s64>) = G_BUILD_VECTOR [[COPY]](s64), [[COPY]](s64), [[COPY]](s64)
+    ; CHECK: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
+    ; CHECK: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
+    ; CHECK: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 2
+    ; CHECK: [[EVEC:%[0-9]+]]:_(s64) = G_EXTRACT_VECTOR_ELT [[BUILD_VECTOR]](<3 x s64>), [[C]](s64)
+    ; CHECK: [[EVEC1:%[0-9]+]]:_(s64) = G_EXTRACT_VECTOR_ELT [[BUILD_VECTOR]](<3 x s64>), [[C1]](s64)
+    ; CHECK: $x0 = COPY [[EVEC1]](s64)
+    ; CHECK: $noreg = PATCHABLE_RET [[BUILD_VECTOR]](<3 x s64>)
     %0(s64) = COPY $x0
-    %1(<3 x s64>) = G_MERGE_VALUES %0(s64), %0(s64), %0(s64)
-    %2(s64), %3(s64), %4(s64) = G_UNMERGE_VALUES %1(<3 x s64>)
-    $x0 = COPY %3(s64)
+    %1(<3 x s64>) = G_BUILD_VECTOR %0(s64), %0(s64), %0(s64)
+    %2(s64) = G_CONSTANT i64 0
+    %3(s64) = G_CONSTANT i64 1
+    %4(s64) = G_CONSTANT i64 2
+    %5(s64) = G_EXTRACT_VECTOR_ELT %1(<3 x s64>), %2(s64)
+    %6(s64) = G_EXTRACT_VECTOR_ELT %1(<3 x s64>), %3(s64)
+    %7(s64) = G_EXTRACT_VECTOR_ELT %1(<3 x s64>), %4(s64)
+    $x0 = COPY %6(s64)
     $noreg = PATCHABLE_RET %1(<3 x s64>)
 ...

test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir

 #
 # DEBUG-NEXT: G_INSERT (opcode {{[0-9]+}}): 2 type indices
 # DEBUG:      .. type index coverage check SKIPPED: user-defined predicate detected
 #
 # DEBUG-NEXT: G_MERGE_VALUES (opcode {{[0-9]+}}): 2 type indices
 # DEBUG:      .. type index coverage check SKIPPED: user-defined predicate detected
 #
 # DEBUG-NEXT: G_BUILD_VECTOR (opcode 52): 2 type indices
-# DEBUG:      .. type index coverage check SKIPPED: no rules defined
+# DEBUG:      .. the first uncovered type index: 2, OK
 #
 # DEBUG-NEXT: G_CONCAT_VECTORS (opcode 53): 2 type indices
 # DEBUG:      .. type index coverage check SKIPPED: no rules defined
 #
 # DEBUG-NEXT: G_PTRTOINT (opcode {{[0-9]+}}): 2 type indices
 # DEBUG:      .. the first uncovered type index: 2, OK
 #
 # DEBUG-NEXT: G_INTTOPTR (opcode {{[0-9]+}}): 2 type indices

test/CodeGen/AArch64/GlobalISel/select-build-vector.mir

+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -mtriple=aarch64-- -run-pass=instruction-select -verify-machineinstrs %s -o - | FileCheck %s
+--- |
+  target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
+  target triple = "aarch64"
+
+  define <4 x float> @test_f32(float %a, float %b, float %c, float %d) {
+    ret <4 x float> undef
+  }
+
+  define <2 x double> @test_f64(double %a, double %b) {
+    ret <2 x double> undef
+  }
+
+  define <4 x i32> @test_i32(i32 %a, i32 %b, i32 %c, i32 %d) {
+    ret <4 x i32> undef
+  }
+
+  define <2 x i64> @test_i64(i64 %a, i64 %b) {
+    ret <2 x i64> undef
+  }
+
+...
+---
+name:            test_f32
+alignment:       2
+exposesReturnsTwice: false
+legalized:       true
+regBankSelected: true
+selected:        false
+failedISel:      false
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: fpr, preferred-register: '' }
+  - { id: 1, class: fpr, preferred-register: '' }
+  - { id: 2, class: fpr, preferred-register: '' }
+  - { id: 3, class: fpr, preferred-register: '' }
+  - { id: 4, class: fpr, preferred-register: '' }
+  - { id: 5, class: _, preferred-register: '' }
+  - { id: 6, class: _, preferred-register: '' }
+  - { id: 7, class: _, preferred-register: '' }
+  - { id: 8, class: _, preferred-register: '' }
+  - { id: 9, class: _, preferred-register: '' }
+  - { id: 10, class: _, preferred-register: '' }
+  - { id: 11, class: _, preferred-register: '' }
+  - { id: 12, class: _, preferred-register: '' }
+  - { id: 13, class: gpr, preferred-register: '' }
+  - { id: 14, class: gpr, preferred-register: '' }
+  - { id: 15, class: gpr, preferred-register: '' }
+  - { id: 16, class: gpr, preferred-register: '' }
+liveins:
+frameInfo:
+  isFrameAddressTaken: false
+  isReturnAddressTaken: false
+  hasStackMap:     false
+  hasPatchPoint:   false
+  stackSize:       0
+  offsetAdjustment: 0
+  maxAlignment:    0
+  adjustsStack:    false
+  hasCalls:        false
+  stackProtector:  ''
+  maxCallFrameSize: 0
+  hasOpaqueSPAdjustment: false
+  hasVAStart:      false
+  hasMustTailInVarArgFunc: false
+  localFrameSize:  0
+  savePoint:       ''
+  restorePoint:    ''
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $s0, $s1, $s2, $s3
+
+    ; CHECK-LABEL: name: test_f32
+    ; CHECK: liveins: $s0, $s1, $s2, $s3
+    ; CHECK: [[COPY:%[0-9]+]]:fpr32 = COPY $s0
+    ; CHECK: [[COPY1:%[0-9]+]]:fpr32 = COPY $s1
+    ; CHECK: [[COPY2:%[0-9]+]]:fpr32 = COPY $s2
+    ; CHECK: [[COPY3:%[0-9]+]]:fpr32 = COPY $s3
+    ; CHECK: [[DEF:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF]], [[COPY]], %subreg.ssub
+    ; CHECK: [[DEF1:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG1:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF1]], [[COPY1]], %subreg.ssub
+    ; CHECK: [[INSvi32lane:%[0-9]+]]:fpr128 = INSvi32lane [[INSERT_SUBREG]], 1, [[INSERT_SUBREG1]], 0
+    ; CHECK: [[DEF2:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG2:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF2]], [[COPY2]], %subreg.ssub
+    ; CHECK: [[INSvi32lane1:%[0-9]+]]:fpr128 = INSvi32lane [[INSvi32lane]], 2, [[INSERT_SUBREG2]], 0
+    ; CHECK: [[DEF3:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG3:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF3]], [[COPY3]], %subreg.ssub
+    ; CHECK: [[INSvi32lane2:%[0-9]+]]:fpr128 = INSvi32lane [[INSvi32lane1]], 3, [[INSERT_SUBREG3]], 0
+    ; CHECK: $q0 = COPY [[INSvi32lane2]]
+    ; CHECK: RET_ReallyLR implicit $q0
+    %0:fpr(s32) = COPY $s0
+    %1:fpr(s32) = COPY $s1
+    %2:fpr(s32) = COPY $s2
+    %3:fpr(s32) = COPY $s3
+    %4:fpr(<4 x s32>) = G_BUILD_VECTOR %0(s32), %1(s32), %2(s32), %3(s32)
+    $q0 = COPY %4(<4 x s32>)
+    RET_ReallyLR implicit $q0
+
+...
+---
+name:            test_f64
+alignment:       2
+exposesReturnsTwice: false
+legalized:       true
+regBankSelected: true
+selected:        false
+failedISel:      false
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: fpr, preferred-register: '' }
+  - { id: 1, class: fpr, preferred-register: '' }
+  - { id: 2, class: fpr, preferred-register: '' }
+  - { id: 3, class: fpr, preferred-register: '' }
+  - { id: 4, class: fpr, preferred-register: '' }
+  - { id: 5, class: _, preferred-register: '' }
+  - { id: 6, class: _, preferred-register: '' }
+  - { id: 7, class: _, preferred-register: '' }
+  - { id: 8, class: _, preferred-register: '' }
+  - { id: 9, class: gpr, preferred-register: '' }
+  - { id: 10, class: gpr, preferred-register: '' }
+liveins:
+frameInfo:
+  isFrameAddressTaken: false
+  isReturnAddressTaken: false
+  hasStackMap:     false
+  hasPatchPoint:   false
+  stackSize:       0
+  offsetAdjustment: 0
+  maxAlignment:    0
+  adjustsStack:    false
+  hasCalls:        false
+  stackProtector:  ''
+  maxCallFrameSize: 0
+  hasOpaqueSPAdjustment: false
+  hasVAStart:      false
+  hasMustTailInVarArgFunc: false
+  localFrameSize:  0
+  savePoint:       ''
+  restorePoint:    ''
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $d0, $d1, $d2, $d3
+
+    ; CHECK-LABEL: name: test_f64
+    ; CHECK: liveins: $d0, $d1, $d2, $d3
+    ; CHECK: [[COPY:%[0-9]+]]:fpr64 = COPY $d0
+    ; CHECK: [[COPY1:%[0-9]+]]:fpr64 = COPY $d1
+    ; CHECK: [[DEF:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF]], [[COPY]], %subreg.dsub
+    ; CHECK: [[DEF1:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG1:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF1]], [[COPY1]], %subreg.dsub
+    ; CHECK: [[INSvi64lane:%[0-9]+]]:fpr128 = INSvi64lane [[INSERT_SUBREG]], 1, [[INSERT_SUBREG1]], 0
+    ; CHECK: $q0 = COPY [[INSvi64lane]]
+    ; CHECK: RET_ReallyLR implicit $q0
+    %0:fpr(s64) = COPY $d0
+    %1:fpr(s64) = COPY $d1
+    %4:fpr(<2 x s64>) = G_BUILD_VECTOR %0(s64), %1(s64)
+    $q0 = COPY %4(<2 x s64>)
+    RET_ReallyLR implicit $q0
+
+...
+---
+name:            test_i32
+alignment:       2
+exposesReturnsTwice: false
+legalized:       true
+regBankSelected: true
+selected:        false
+failedISel:      false
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gpr, preferred-register: '' }
+  - { id: 1, class: gpr, preferred-register: '' }
+  - { id: 2, class: gpr, preferred-register: '' }
+  - { id: 3, class: gpr, preferred-register: '' }
+  - { id: 4, class: fpr, preferred-register: '' }
+  - { id: 5, class: _, preferred-register: '' }
+  - { id: 6, class: _, preferred-register: '' }
+  - { id: 7, class: _, preferred-register: '' }
+  - { id: 8, class: _, preferred-register: '' }
+  - { id: 9, class: _, preferred-register: '' }
+  - { id: 10, class: _, preferred-register: '' }
+  - { id: 11, class: _, preferred-register: '' }
+  - { id: 12, class: _, preferred-register: '' }
+liveins:
+frameInfo:
+  isFrameAddressTaken: false
+  isReturnAddressTaken: false
+  hasStackMap:     false
+  hasPatchPoint:   false
+  stackSize:       0
+  offsetAdjustment: 0
+  maxAlignment:    0
+  adjustsStack:    false
+  hasCalls:        false
+  stackProtector:  ''
+  maxCallFrameSize: 0
+  hasOpaqueSPAdjustment: false
+  hasVAStart:      false
+  hasMustTailInVarArgFunc: false
+  localFrameSize:  0
+  savePoint:       ''
+  restorePoint:    ''
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $w0, $w1, $w2, $w3
+
+    ; CHECK-LABEL: name: test_i32
+    ; CHECK: liveins: $w0, $w1, $w2, $w3
+    ; CHECK: [[COPY:%[0-9]+]]:gpr32all = COPY $w0
+    ; CHECK: [[COPY1:%[0-9]+]]:gpr32 = COPY $w1
+    ; CHECK: [[COPY2:%[0-9]+]]:gpr32 = COPY $w2
+    ; CHECK: [[COPY3:%[0-9]+]]:gpr32 = COPY $w3
+    ; CHECK: [[DEF:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF]], [[COPY]], %subreg.ssub
+    ; CHECK: [[INSvi32gpr:%[0-9]+]]:fpr128 = INSvi32gpr [[INSERT_SUBREG]], 1, [[COPY1]]
+    ; CHECK: [[INSvi32gpr1:%[0-9]+]]:fpr128 = INSvi32gpr [[INSvi32gpr]], 2, [[COPY2]]
+    ; CHECK: [[INSvi32gpr2:%[0-9]+]]:fpr128 = INSvi32gpr [[INSvi32gpr1]], 3, [[COPY3]]
+    ; CHECK: $q0 = COPY [[INSvi32gpr2]]
+    ; CHECK: RET_ReallyLR implicit $q0
+    %0:gpr(s32) = COPY $w0
+    %1:gpr(s32) = COPY $w1
+    %2:gpr(s32) = COPY $w2
+    %3:gpr(s32) = COPY $w3
+    %4:fpr(<4 x s32>) = G_BUILD_VECTOR %0(s32), %1(s32), %2(s32), %3(s32)
+    $q0 = COPY %4(<4 x s32>)
+    RET_ReallyLR implicit $q0
+
+...
+---
+name:            test_i64
+alignment:       2
+exposesReturnsTwice: false
+legalized:       true
+regBankSelected: true
+selected:        false
+failedISel:      false
+tracksRegLiveness: true
+registers:
+  - { id: 0, class: gpr, preferred-register: '' }
+  - { id: 1, class: gpr, preferred-register: '' }
+  - { id: 2, class: gpr, preferred-register: '' }
+  - { id: 3, class: gpr, preferred-register: '' }
+  - { id: 4, class: fpr, preferred-register: '' }
+  - { id: 5, class: _, preferred-register: '' }
+  - { id: 6, class: _, preferred-register: '' }
+  - { id: 7, class: _, preferred-register: '' }
+  - { id: 8, class: _, preferred-register: '' }
+liveins:
+frameInfo:
+  isFrameAddressTaken: false
+  isReturnAddressTaken: false
+  hasStackMap:     false
+  hasPatchPoint:   false
+  stackSize:       0
+  offsetAdjustment: 0
+  maxAlignment:    0
+  adjustsStack:    false
+  hasCalls:        false
+  stackProtector:  ''
+  maxCallFrameSize: 0
+  hasOpaqueSPAdjustment: false
+  hasVAStart:      false
+  hasMustTailInVarArgFunc: false
+  localFrameSize:  0
+  savePoint:       ''
+  restorePoint:    ''
+fixedStack:
+stack:
+constants:
+body:             |
+  bb.0 (%ir-block.0):
+    liveins: $x0, $x1, $x2, $x3
+
+    ; CHECK-LABEL: name: test_i64
+    ; CHECK: liveins: $x0, $x1, $x2, $x3
+    ; CHECK: [[COPY:%[0-9]+]]:gpr64all = COPY $x0
+    ; CHECK: [[COPY1:%[0-9]+]]:gpr64 = COPY $x1
+    ; CHECK: [[DEF:%[0-9]+]]:fpr128 = IMPLICIT_DEF
+    ; CHECK: [[INSERT_SUBREG:%[0-9]+]]:fpr128 = INSERT_SUBREG [[DEF]], [[COPY]], %subreg.dsub
+    ; CHECK: [[INSvi64gpr:%[0-9]+]]:fpr128 = INSvi64gpr [[INSERT_SUBREG]], 1, [[COPY1]]
+    ; CHECK: $q0 = COPY [[INSvi64gpr]]
+    ; CHECK: RET_ReallyLR implicit $q0
+    %0:gpr(s64) = COPY $x0
+    %1:gpr(s64) = COPY $x1
+    %4:fpr(<2 x s64>) = G_BUILD_VECTOR %0(s64), %1(s64)
+    $q0 = COPY %4(<2 x s64>)
+    RET_ReallyLR implicit $q0
+
+...

test/CodeGen/AMDGPU/GlobalISel/legalize-extract-vector-elt.mir

 ---
 name: extract_vector_elt_0_v5i32
 
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: extract_vector_elt_0_v5i32
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[MV:%[0-9]+]]:_(<5 x s32>) = G_MERGE_VALUES [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<5 x s32>) = G_BUILD_VECTOR [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[EVEC:%[0-9]+]]:_(s32) = G_EXTRACT_VECTOR_ELT [[MV]](<5 x s32>), [[C]](s32)
     ; CHECK: $vgpr0 = COPY [[EVEC]](s32)
     %0:_(s32) = COPY $vgpr0
-    %1:_(<5 x s32>) = G_MERGE_VALUES %0, %0, %0, %0, %0
+    %1:_(<5 x s32>) = G_BUILD_VECTOR %0, %0, %0, %0, %0
     %2:_(s32) = G_CONSTANT i32 0
     %3:_(s32) = G_EXTRACT_VECTOR_ELT %1, %2
     $vgpr0 = COPY %3
 ...
 
 ---
 name: extract_vector_elt_0_v6i32
 
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: extract_vector_elt_0_v6i32
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[MV:%[0-9]+]]:_(<6 x s32>) = G_MERGE_VALUES [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<6 x s32>) = G_BUILD_VECTOR [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[EVEC:%[0-9]+]]:_(s32) = G_EXTRACT_VECTOR_ELT [[MV]](<6 x s32>), [[C]](s32)
     ; CHECK: $vgpr0 = COPY [[EVEC]](s32)
     %0:_(s32) = COPY $vgpr0
-    %1:_(<6 x s32>) = G_MERGE_VALUES %0, %0, %0, %0, %0, %0
+    %1:_(<6 x s32>) = G_BUILD_VECTOR %0, %0, %0, %0, %0, %0
     %2:_(s32) = G_CONSTANT i32 0
     %3:_(s32) = G_EXTRACT_VECTOR_ELT %1, %2
     $vgpr0 = COPY %3
 ...
 
 ---
 name: extract_vector_elt_0_v7i32
 
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: extract_vector_elt_0_v7i32
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[MV:%[0-9]+]]:_(<7 x s32>) = G_MERGE_VALUES [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<7 x s32>) = G_BUILD_VECTOR [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[EVEC:%[0-9]+]]:_(s32) = G_EXTRACT_VECTOR_ELT [[MV]](<7 x s32>), [[C]](s32)
     ; CHECK: $vgpr0 = COPY [[EVEC]](s32)
     %0:_(s32) = COPY $vgpr0
-    %1:_(<7 x s32>) = G_MERGE_VALUES %0, %0, %0, %0, %0, %0, %0
+    %1:_(<7 x s32>) = G_BUILD_VECTOR %0, %0, %0, %0, %0, %0, %0
     %2:_(s32) = G_CONSTANT i32 0
     %3:_(s32) = G_EXTRACT_VECTOR_ELT %1, %2
     $vgpr0 = COPY %3
 ...
 
 ---
 name: extract_vector_elt_0_v8i32
 
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: extract_vector_elt_0_v8i32
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<8 x s32>) = G_BUILD_VECTOR [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[EVEC:%[0-9]+]]:_(s32) = G_EXTRACT_VECTOR_ELT [[MV]](<8 x s32>), [[C]](s32)
     ; CHECK: $vgpr0 = COPY [[EVEC]](s32)
     %0:_(s32) = COPY $vgpr0
-    %1:_(<8 x s32>) = G_MERGE_VALUES %0, %0, %0, %0, %0, %0, %0, %0
+    %1:_(<8 x s32>) = G_BUILD_VECTOR %0, %0, %0, %0, %0, %0, %0, %0
     %2:_(s32) = G_CONSTANT i32 0
     %3:_(s32) = G_EXTRACT_VECTOR_ELT %1, %2
     $vgpr0 = COPY %3
 ...
 
 ---
 name: extract_vector_elt_0_v16i32
 
 body: |
   bb.0:
     liveins: $vgpr0
     ; CHECK-LABEL: name: extract_vector_elt_0_v16i32
     ; CHECK: [[COPY:%[0-9]+]]:_(s32) = COPY $vgpr0
-    ; CHECK: [[MV:%[0-9]+]]:_(<16 x s32>) = G_MERGE_VALUES [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<16 x s32>) = G_BUILD_VECTOR [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32), [[COPY]](s32)
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[EVEC:%[0-9]+]]:_(s32) = G_EXTRACT_VECTOR_ELT [[MV]](<16 x s32>), [[C]](s32)
     ; CHECK: $vgpr0 = COPY [[EVEC]](s32)
     %0:_(s32) = COPY $vgpr0
-    %1:_(<16 x s32>) = G_MERGE_VALUES %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0
+    %1:_(<16 x s32>) = G_BUILD_VECTOR %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0, %0
     %2:_(s32) = G_CONSTANT i32 0
     %3:_(s32) = G_EXTRACT_VECTOR_ELT %1, %2
     $vgpr0 = COPY %3
 ...
 
 ---
 name: extract_vector_elt_var_v2i32
 

test/CodeGen/AMDGPU/GlobalISel/legalize-merge-values-build-vector.mir

 
 ---
 name: test_merge_s32_s32_v2s32
 body: |
   bb.0:
     ; CHECK-LABEL: name: test_merge_s32_s32_v2s32
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
-    ; CHECK: [[MV:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C]](s32), [[C1]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C]](s32), [[C1]](s32)
     ; CHECK: $vgpr0_vgpr1 = COPY [[MV]](<2 x s32>)
     %0:_(s32) = G_CONSTANT i32 0
     %1:_(s32) = G_CONSTANT i32 1
-    %2:_(<2 x s32>) = G_MERGE_VALUES %0:_(s32), %1:_(s32)
+    %2:_(<2 x s32>) = G_BUILD_VECTOR %0:_(s32), %1:_(s32)
     $vgpr0_vgpr1 = COPY %2(<2 x s32>)
 ...
 
 ---
 name: test_merge_s32_s32_s32_v3s32
 body: |
   bb.0:
     ; CHECK-LABEL: name: test_merge_s32_s32_s32_v3s32
     ; CHECK: [[C:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
     ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
     ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
-    ; CHECK: [[MV:%[0-9]+]]:_(<3 x s32>) = G_MERGE_VALUES [[C]](s32), [[C1]](s32), [[C2]](s32)
+    ; CHECK: [[MV:%[0-9]+]]:_(<3 x s32>) = G_BUILD_VECTOR [[C]](s32), [[C1]](s32), [[C2]](s32)
     ; CHECK: $vgpr0_vgpr1_vgpr2 = COPY [[MV]](<3 x s32>)
     %0:_(s32) = G_CONSTANT i32 0
     %1:_(s32) = G_CONSTANT i32 1
     %2:_(s32) = G_CONSTANT i32 2
-    %3:_(<3 x s32>) = G_MERGE_VALUES %0:_(s32), %1:_(s32), %2:_(s32)
+    %3:_(<3 x s32>) = G_BUILD_VECTOR %0:_(s32), %1:_(s32), %2:_(s32)
     $vgpr0_vgpr1_vgpr2 = COPY %3(<3 x s32>)
 ...
 
 ---
 name: test_merge_s64_s64_s128
 body: |
   bb.0:
     ; CHECK-LABEL: name: test_merge_s64_s64_s128
     ; CHECK: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
     ; CHECK: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
-    ; CHECK: [[MV:%[0-9]+]]:_(<2 x s64>) = G_MERGE_VALUES [[C]](s64), [[C1]](s64)
+    ; CHECK: [[MV:%[0-9]+]]:_(<2 x s64>) = G_BUILD_VECTOR [[C]](s64), [[C1]](s64)
     ; CHECK: $vgpr0_vgpr1_vgpr2_vgpr3 = COPY [[MV]](<2 x s64>)
     %0:_(s64) = G_CONSTANT i64 0
     %1:_(s64) = G_CONSTANT i64 1
-    %2:_(<2 x s64>) = G_MERGE_VALUES %0(s64), %1(s64)
+    %2:_(<2 x s64>) = G_BUILD_VECTOR %0(s64), %1(s64)
     $vgpr0_vgpr1_vgpr2_vgpr3 = COPY %2(<2 x s64>)
 ...
 
 ---
 name: test_merge_s64_s64_s64_s64_v4s64
 body: |
   bb.0:
     ; CHECK-LABEL: name: test_merge_s64_s64_s64_s64_v4s64
     ; CHECK: [[C:%[0-9]+]]:_(s64) = G_CONSTANT i64 0
     ; CHECK: [[C1:%[0-9]+]]:_(s64) = G_CONSTANT i64 1
     ; CHECK: [[C2:%[0-9]+]]:_(s64) = G_CONSTANT i64 2
     ; CHECK: [[C3:%[0-9]+]]:_(s64) = G_CONSTANT i64 3
-    ; CHECK: [[MV:%[0-9]+]]:_(<4 x s64>) = G_MERGE_VALUES [[C]](s64), [[C1]](s64), [[C2]](s64), [[C3]](s64)
+    ; CHECK: [[MV:%[0-9]+]]:_(<4 x s64>) = G_BUILD_VECTOR [[C]](s64), [[C1]](s64), [[C2]](s64), [[C3]](s64)
     ; CHECK: $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7 = COPY [[MV]](<4 x s64>)
     %0:_(s64) = G_CONSTANT i64 0
     %1:_(s64) = G_CONSTANT i64 1
     %2:_(s64) = G_CONSTANT i64 2
     %3:_(s64) = G_CONSTANT i64 3
-    %4:_(<4 x s64>) = G_MERGE_VALUES %0(s64), %1(s64), %2(s64), %3(s64)
+    %4:_(<4 x s64>) = G_BUILD_VECTOR %0(s64), %1(s64), %2(s64), %3(s64)
     $vgpr0_vgpr1_vgpr2_vgpr3_vgpr4_vgpr5_vgpr6_vgpr7 = COPY %4(<4 x s64>)
 ...
 
 # FIXME: Should be split up
 # ---
 # name: test_merge_17_x_i32
 # body: |
 #   bb.0:

 
 #     %12:_(s32) = G_CONSTANT i32 12
 #     %13:_(s32) = G_CONSTANT i32 13
 #     %14:_(s32) = G_CONSTANT i32 14
 #     %15:_(s32) = G_CONSTANT i32 15
 
 #     %16:_(s32) = G_CONSTANT i32 16
 
-#     %17:_(<17 x s32>) = G_MERGE_VALUES %0:_(s32), %1:_(s32), %2:_(s32), %3:_(s32), %4:_(s32), %5:_(s32), %6:_(s32), %7:_(s32), %8:_(s32), %9:_(s32), %10:_(s32), %11:_(s32), %12:_(s32), %13:_(s32), %14:_(s32), %15:_(s32), %16:_(s32)
+#     %17:_(<17 x s32>) = G_BUILD_VECTOR %0:_(s32), %1:_(s32), %2:_(s32), %3:_(s32), %4:_(s32), %5:_(s32), %6:_(s32), %7:_(s32), %8:_(s32), %9:_(s32), %10:_(s32), %11:_(s32), %12:_(s32), %13:_(s32), %14:_(s32), %15:_(s32), %16:_(s32)
 #     S_ENDPGM implicit %17(<17 x s32>)
 # ...

test/CodeGen/AMDGPU/GlobalISel/legalize-unmerge-values.mir

bb.0:
     ; CHECK: $vgpr0 = COPY [[UV]](s32)
     ; CHECK: $vgpr2 = COPY [[UV1]](s32)
     %0:_(s64) = G_CONSTANT i64 0
     %1:_(s32), %2:_(s32) = G_UNMERGE_VALUES %0:_(s64)
     $vgpr0 = COPY %1(s32)
     $vgpr2 = COPY %2(s32)
 ...
 
----
-name: test_unmerge_v2s32_s32
-body: |
-  bb.0:
-    liveins: $vgpr0_vgpr1
-    ; CHECK-LABEL: name: test_unmerge_v2s32_s32
-    ; CHECK: [[COPY:%[0-9]+]]:_(<2 x s32>) = COPY $vgpr0_vgpr1
-    ; CHECK: [[UV:%[0-9]+]]:_(s32), [[UV1:%[0-9]+]]:_(s32) = G_UNMERGE_VALUES [[COPY]](<2 x s32>)
-    ; CHECK: $vgpr0 = COPY [[UV]](s32)
-    ; CHECK: $vgpr2 = COPY [[UV1]](s32)
-    %0:_(<2 x s32>) = COPY $vgpr0_vgpr1
-    %1:_(s32), %2:_(s32) = G_UNMERGE_VALUES %0:_(<2 x s32>)
-    $vgpr0 = COPY %1(s32)
-    $vgpr2 = COPY %2(s32)
-...

test/CodeGen/ARM/GlobalISel/arm-irtranslator.ll

entry:
   ret double %v
 }
 
 define i32 @test_shufflevector_s32_v2s32(i32 %arg) {
 ; CHECK-LABEL: name: test_shufflevector_s32_v2s32
 ; CHECK: [[ARG:%[0-9]+]]:_(s32) = COPY $r0
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(s32) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C0]](s32), [[C0]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C0]](s32), [[C0]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_SHUFFLE_VECTOR [[ARG]](s32), [[UNDEF]], [[MASK]](<2 x s32>)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<2 x s32>)
   %vec = insertelement <1 x i32> undef, i32 %arg, i32 0
   %shuffle = shufflevector <1 x i32> %vec, <1 x i32> undef, <2 x i32> zeroinitializer
   %res = extractelement <2 x i32> %shuffle, i32 0
   ret i32 %res
 }
 
 define i32 @test_shufflevector_v2s32_v3s32(i32 %arg1, i32 %arg2) {
 ; CHECK-LABEL: name: test_shufflevector_v2s32_v3s32
 ; CHECK: [[ARG1:%[0-9]+]]:_(s32) = COPY $r0
 ; CHECK: [[ARG2:%[0-9]+]]:_(s32) = COPY $r1
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(<2 x s32>) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
 ; CHECK-DAG: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<3 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C0]](s32), [[C1]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<3 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C0]](s32), [[C1]](s32)
 ; CHECK-DAG: [[V1:%[0-9]+]]:_(<2 x s32>) = G_INSERT_VECTOR_ELT [[UNDEF]], [[ARG1]](s32), [[C0]](s32)
 ; CHECK-DAG: [[V2:%[0-9]+]]:_(<2 x s32>) = G_INSERT_VECTOR_ELT [[V1]], [[ARG2]](s32), [[C1]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<3 x s32>) = G_SHUFFLE_VECTOR [[V2]](<2 x s32>), [[UNDEF]], [[MASK]](<3 x s32>)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<3 x s32>)
   %v1 = insertelement <2 x i32> undef, i32 %arg1, i32 0
   %v2 = insertelement <2 x i32> %v1, i32 %arg2, i32 1
   %shuffle = shufflevector <2 x i32> %v2, <2 x i32> undef, <3 x i32> <i32 1, i32 0, i32 1>
   %res = extractelement <3 x i32> %shuffle, i32 0
   ret i32 %res
 }
 
 
 define i32 @test_shufflevector_v2s32_v4s32(i32 %arg1, i32 %arg2) {
 ; CHECK-LABEL: name: test_shufflevector_v2s32_v4s32
 ; CHECK: [[ARG1:%[0-9]+]]:_(s32) = COPY $r0
 ; CHECK: [[ARG2:%[0-9]+]]:_(s32) = COPY $r1
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(<2 x s32>) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
 ; CHECK-DAG: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<4 x s32>) = G_MERGE_VALUES [[C0]](s32), [[C0]](s32), [[C0]](s32), [[C0]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<4 x s32>) = G_BUILD_VECTOR [[C0]](s32), [[C0]](s32), [[C0]](s32), [[C0]](s32)
 ; CHECK-DAG: [[V1:%[0-9]+]]:_(<2 x s32>) = G_INSERT_VECTOR_ELT [[UNDEF]], [[ARG1]](s32), [[C0]](s32)
 ; CHECK-DAG: [[V2:%[0-9]+]]:_(<2 x s32>) = G_INSERT_VECTOR_ELT [[V1]], [[ARG2]](s32), [[C1]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<4 x s32>) = G_SHUFFLE_VECTOR [[V2]](<2 x s32>), [[UNDEF]], [[MASK]](<4 x s32>)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<4 x s32>)
   %v1 = insertelement <2 x i32> undef, i32 %arg1, i32 0
   %v2 = insertelement <2 x i32> %v1, i32 %arg2, i32 1
   %shuffle = shufflevector <2 x i32> %v2, <2 x i32> undef, <4 x i32> zeroinitializer
   %res = extractelement <4 x i32> %shuffle, i32 0
   ret i32 %res
 }
 
 define i32 @test_shufflevector_v4s32_v2s32(i32 %arg1, i32 %arg2, i32 %arg3, i32 %arg4) {
 ; CHECK-LABEL: name: test_shufflevector_v4s32_v2s32
 ; CHECK: [[ARG1:%[0-9]+]]:_(s32) = COPY $r0
 ; CHECK: [[ARG2:%[0-9]+]]:_(s32) = COPY $r1
 ; CHECK: [[ARG3:%[0-9]+]]:_(s32) = COPY $r2
 ; CHECK: [[ARG4:%[0-9]+]]:_(s32) = COPY $r3
 ; CHECK-DAG: [[UNDEF:%[0-9]+]]:_(<4 x s32>) = G_IMPLICIT_DEF
 ; CHECK-DAG: [[C0:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
 ; CHECK-DAG: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK-DAG: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
 ; CHECK-DAG: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
-; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C3]](s32)
+; CHECK-DAG: [[MASK:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C3]](s32)
 ; CHECK-DAG: [[V1:%[0-9]+]]:_(<4 x s32>) = G_INSERT_VECTOR_ELT [[UNDEF]], [[ARG1]](s32), [[C0]](s32)
 ; CHECK-DAG: [[V2:%[0-9]+]]:_(<4 x s32>) = G_INSERT_VECTOR_ELT [[V1]], [[ARG2]](s32), [[C1]](s32)
 ; CHECK-DAG: [[V3:%[0-9]+]]:_(<4 x s32>) = G_INSERT_VECTOR_ELT [[V2]], [[ARG3]](s32), [[C2]](s32)
 ; CHECK-DAG: [[V4:%[0-9]+]]:_(<4 x s32>) = G_INSERT_VECTOR_ELT [[V3]], [[ARG4]](s32), [[C3]](s32)
 ; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_SHUFFLE_VECTOR [[V4]](<4 x s32>), [[UNDEF]], [[MASK]](<2 x s32>)
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<2 x s32>)
   %v1 = insertelement <4 x i32> undef, i32 %arg1, i32 0
   %v2 = insertelement <4 x i32> %v1, i32 %arg2, i32 1
   %v3 = insertelement <4 x i32> %v2, i32 %arg3, i32 2
   %v4 = insertelement <4 x i32> %v3, i32 %arg4, i32 3
   %shuffle = shufflevector <4 x i32> %v4, <4 x i32> undef, <2 x i32> <i32 1, i32 3>
   %res = extractelement <2 x i32> %shuffle, i32 0
   ret i32 %res
 }
 
 %struct.v2s32 = type { <2 x i32> }
 
 define i32 @test_constantstruct_v2s32() {
 ; CHECK-LABEL: name: test_constantstruct_v2s32
 ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
-; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C2]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C2]](s32)
 ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<2 x s32>), [[C3]]
   %vec = extractvalue %struct.v2s32 {<2 x i32><i32 1, i32 2>}, 0
   %elt = extractelement <2 x i32> %vec, i32 0
   ret i32 %elt
 }
 
 %struct.v2s32.s32.s32 = type { <2 x i32>, i32, i32 }
 
 define i32 @test_constantstruct_v2s32_s32_s32() {
 ; CHECK-LABEL: name: test_constantstruct_v2s32_s32_s32
 ; CHECK: [[C1:%[0-9]+]]:_(s32) = G_CONSTANT i32 1
 ; CHECK: [[C2:%[0-9]+]]:_(s32) = G_CONSTANT i32 2
-; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_MERGE_VALUES [[C1]](s32), [[C2]](s32)
+; CHECK: [[VEC:%[0-9]+]]:_(<2 x s32>) = G_BUILD_VECTOR [[C1]](s32), [[C2]](s32)
 ; CHECK: [[C3:%[0-9]+]]:_(s32) = G_CONSTANT i32 3
 ; CHECK: [[C4:%[0-9]+]]:_(s32) = G_CONSTANT i32 4
 ; CHECK: [[C5:%[0-9]+]]:_(s32) = G_CONSTANT i32 0
 ; CHECK: G_EXTRACT_VECTOR_ELT [[VEC]](<2 x s32>), [[C5]](s32)
   %vec = extractvalue %struct.v2s32.s32.s32 {<2 x i32><i32 1, i32 2>, i32 3, i32 4}, 0
   %elt = extractelement <2 x i32> %vec, i32 0
   ret i32 %elt
 }

test/CodeGen/X86/GlobalISel/irtranslator-callingconv.ll

 }
 
 define <8 x i32> @test_v8i32_args(<8 x i32> %arg1) {
   ; X32-LABEL: name: test_v8i32_args
   ; X32: bb.1 (%ir-block.0):
   ; X32:   liveins: $xmm0, $xmm1
   ; X32:   [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $xmm0
   ; X32:   [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $xmm1
-  ; X32:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
+  ; X32:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
   ; X32:   [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[MV]](<8 x s32>)
   ; X32:   $xmm0 = COPY [[UV]](<4 x s32>)
   ; X32:   $xmm1 = COPY [[UV1]](<4 x s32>)
   ; X32:   RET 0, implicit $xmm0, implicit $xmm1
   ; X64-LABEL: name: test_v8i32_args
   ; X64: bb.1 (%ir-block.0):
   ; X64:   liveins: $xmm0, $xmm1
   ; X64:   [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $xmm0
   ; X64:   [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $xmm1
-  ; X64:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
+  ; X64:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
   ; X64:   [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[MV]](<8 x s32>)
   ; X64:   $xmm0 = COPY [[UV]](<4 x s32>)
   ; X64:   $xmm1 = COPY [[UV1]](<4 x s32>)
   ; X64:   RET 0, implicit $xmm0, implicit $xmm1
   ret <8 x i32> %arg1
 }
 
 define void @test_void_return() {
define <8 x i32> @test_split_return_callee(<8 x i32> %arg1, <8 x i32> %arg2) {
   ; X32-LABEL: name: test_split_return_callee
   ; X32: bb.1 (%ir-block.0):
   ; X32:   liveins: $xmm0, $xmm1, $xmm2
   ; X32:   [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $xmm0
   ; X32:   [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $xmm1
   ; X32:   [[COPY2:%[0-9]+]]:_(<4 x s32>) = COPY $xmm2
   ; X32:   [[FRAME_INDEX:%[0-9]+]]:_(p0) = G_FRAME_INDEX %fixed-stack.0
   ; X32:   [[LOAD:%[0-9]+]]:_(<4 x s32>) = G_LOAD [[FRAME_INDEX]](p0) :: (invariant load 16 from %fixed-stack.0, align 0)
-  ; X32:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
-  ; X32:   [[MV1:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY2]](<4 x s32>), [[LOAD]](<4 x s32>)
+  ; X32:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
+  ; X32:   [[MV1:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY2]](<4 x s32>), [[LOAD]](<4 x s32>)
   ; X32:   ADJCALLSTACKDOWN32 0, 0, 0, implicit-def $esp, implicit-def $eflags, implicit-def $ssp, implicit $esp, implicit $ssp
   ; X32:   [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[MV1]](<8 x s32>)
   ; X32:   $xmm0 = COPY [[UV]](<4 x s32>)
   ; X32:   $xmm1 = COPY [[UV1]](<4 x s32>)
   ; X32:   CALLpcrel32 @split_return_callee, csr_32, implicit $esp, implicit $ssp, implicit $xmm0, implicit $xmm1, implicit-def $xmm0, implicit-def $xmm1
   ; X32:   [[COPY3:%[0-9]+]]:_(<4 x s32>) = COPY $xmm0
   ; X32:   [[COPY4:%[0-9]+]]:_(<4 x s32>) = COPY $xmm1
-  ; X32:   [[MV2:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY3]](<4 x s32>), [[COPY4]](<4 x s32>)
+  ; X32:   [[MV2:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY3]](<4 x s32>), [[COPY4]](<4 x s32>)
   ; X32:   ADJCALLSTACKUP32 0, 0, implicit-def $esp, implicit-def $eflags, implicit-def $ssp, implicit $esp, implicit $ssp
   ; X32:   [[ADD:%[0-9]+]]:_(<8 x s32>) = G_ADD [[MV]], [[MV2]]
   ; X32:   [[UV2:%[0-9]+]]:_(<4 x s32>), [[UV3:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[ADD]](<8 x s32>)
   ; X32:   $xmm0 = COPY [[UV2]](<4 x s32>)
   ; X32:   $xmm1 = COPY [[UV3]](<4 x s32>)
   ; X32:   RET 0, implicit $xmm0, implicit $xmm1
   ; X64-LABEL: name: test_split_return_callee
   ; X64: bb.1 (%ir-block.0):
   ; X64:   liveins: $xmm0, $xmm1, $xmm2, $xmm3
   ; X64:   [[COPY:%[0-9]+]]:_(<4 x s32>) = COPY $xmm0
   ; X64:   [[COPY1:%[0-9]+]]:_(<4 x s32>) = COPY $xmm1
   ; X64:   [[COPY2:%[0-9]+]]:_(<4 x s32>) = COPY $xmm2
   ; X64:   [[COPY3:%[0-9]+]]:_(<4 x s32>) = COPY $xmm3
-  ; X64:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
-  ; X64:   [[MV1:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY2]](<4 x s32>), [[COPY3]](<4 x s32>)
+  ; X64:   [[MV:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY]](<4 x s32>), [[COPY1]](<4 x s32>)
+  ; X64:   [[MV1:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY2]](<4 x s32>), [[COPY3]](<4 x s32>)
   ; X64:   ADJCALLSTACKDOWN64 0, 0, 0, implicit-def $rsp, implicit-def $eflags, implicit-def $ssp, implicit $rsp, implicit $ssp
   ; X64:   [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[MV1]](<8 x s32>)
   ; X64:   $xmm0 = COPY [[UV]](<4 x s32>)
   ; X64:   $xmm1 = COPY [[UV1]](<4 x s32>)
   ; X64:   CALL64pcrel32 @split_return_callee, csr_64, implicit $rsp, implicit $ssp, implicit $xmm0, implicit $xmm1, implicit-def $xmm0, implicit-def $xmm1
   ; X64:   [[COPY4:%[0-9]+]]:_(<4 x s32>) = COPY $xmm0
   ; X64:   [[COPY5:%[0-9]+]]:_(<4 x s32>) = COPY $xmm1
-  ; X64:   [[MV2:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[COPY4]](<4 x s32>), [[COPY5]](<4 x s32>)
+  ; X64:   [[MV2:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[COPY4]](<4 x s32>), [[COPY5]](<4 x s32>)
   ; X64:   ADJCALLSTACKUP64 0, 0, implicit-def $rsp, implicit-def $eflags, implicit-def $ssp, implicit $rsp, implicit $ssp
   ; X64:   [[ADD:%[0-9]+]]:_(<8 x s32>) = G_ADD [[MV]], [[MV2]]
   ; X64:   [[UV2:%[0-9]+]]:_(<4 x s32>), [[UV3:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[ADD]](<8 x s32>)
   ; X64:   $xmm0 = COPY [[UV2]](<4 x s32>)
   ; X64:   $xmm1 = COPY [[UV3]](<4 x s32>)
   ; X64:   RET 0, implicit $xmm0, implicit $xmm1
   %call = call <8 x i32> @split_return_callee(<8 x i32> %arg2)
   %r = add <8 x i32> %arg1, %call

test/CodeGen/X86/GlobalISel/legalize-add-v256.mir

bb.1 (%ir-block.0):
     ; SSE2: [[UV:%[0-9]+]]:_(<16 x s8>), [[UV1:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[DEF]](<32 x s8>)
     ; SSE2: [[UV2:%[0-9]+]]:_(<16 x s8>), [[UV3:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[DEF1]](<32 x s8>)
     ; AVX1: [[UV:%[0-9]+]]:_(<16 x s8>), [[UV1:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[DEF]](<32 x s8>)
     ; AVX1: [[UV2:%[0-9]+]]:_(<16 x s8>), [[UV3:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[DEF1]](<32 x s8>)
     ; SSE2: [[ADD:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV]], [[UV2]]
     ; SSE2: [[ADD1:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV1]], [[UV3]]
     ; AVX1: [[ADD:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV]], [[UV2]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV1]], [[UV3]]
-    ; SSE2: [[MV:%[0-9]+]]:_(<32 x s8>) = G_MERGE_VALUES [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>)
-    ; AVX1: [[MV:%[0-9]+]]:_(<32 x s8>) = G_MERGE_VALUES [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>)
+    ; SSE2: [[MV:%[0-9]+]]:_(<32 x s8>) = G_CONCAT_VECTORS [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<32 x s8>) = G_CONCAT_VECTORS [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>)
     ; SSE2: $ymm0 = COPY [[MV]](<32 x s8>)
     ; AVX1: $ymm0 = COPY [[MV]](<32 x s8>)
     ; AVX2: [[ADD:%[0-9]+]]:_(<32 x s8>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX2: $ymm0 = COPY [[ADD]](<32 x s8>)
     ; ALL: RET 0
     %0(<32 x s8>) = IMPLICIT_DEF
     %1(<32 x s8>) = IMPLICIT_DEF
     %2(<32 x s8>) = G_ADD %0, %1
bb.1 (%ir-block.0):
 
     ; ALL-LABEL: name: test_add_v16i16
     ; ALL: [[DEF:%[0-9]+]]:_(<16 x s16>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<16 x s16>) = IMPLICIT_DEF
     ; SSE2: [[UV:%[0-9]+]]:_(<8 x s16>), [[UV1:%[0-9]+]]:_(<8 x s16>) = G_UNMERGE_VALUES [[DEF]](<16 x s16>)
     ; SSE2: [[UV2:%[0-9]+]]:_(<8 x s16>), [[UV3:%[0-9]+]]:_(<8 x s16>) = G_UNMERGE_VALUES [[DEF1]](<16 x s16>)
     ; SSE2: [[ADD:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV]], [[UV2]]
     ; SSE2: [[ADD1:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV1]], [[UV3]]
-    ; SSE2: [[MV:%[0-9]+]]:_(<16 x s16>) = G_MERGE_VALUES [[ADD]](<8 x s16>), [[ADD1]](<8 x s16>)
+    ; SSE2: [[MV:%[0-9]+]]:_(<16 x s16>) = G_CONCAT_VECTORS [[ADD]](<8 x s16>), [[ADD1]](<8 x s16>)
     ; AVX1: [[UV:%[0-9]+]]:_(<8 x s16>), [[UV1:%[0-9]+]]:_(<8 x s16>) = G_UNMERGE_VALUES [[DEF]](<16 x s16>)
     ; AVX1: [[UV2:%[0-9]+]]:_(<8 x s16>), [[UV3:%[0-9]+]]:_(<8 x s16>) = G_UNMERGE_VALUES [[DEF1]](<16 x s16>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV]], [[UV2]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV1]], [[UV3]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<16 x s16>) = G_MERGE_VALUES [[ADD]](<8 x s16>), [[ADD1]](<8 x s16>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<16 x s16>) = G_CONCAT_VECTORS [[ADD]](<8 x s16>), [[ADD1]](<8 x s16>)
     ; SSE2: $ymm0 = COPY [[MV]](<16 x s16>)
     ; AVX1: $ymm0 = COPY [[MV]](<16 x s16>)
     ; AVX2: [[ADD:%[0-9]+]]:_(<16 x s16>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX2: $ymm0 = COPY [[ADD]](<16 x s16>)
     ; ALL: RET 0
     %0(<16 x s16>) = IMPLICIT_DEF
     %1(<16 x s16>) = IMPLICIT_DEF
     %2(<16 x s16>) = G_ADD %0, %1
bb.1 (%ir-block.0):
 
     ; ALL-LABEL: name: test_add_v8i32
     ; ALL: [[DEF:%[0-9]+]]:_(<8 x s32>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<8 x s32>) = IMPLICIT_DEF
     ; SSE2: [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[DEF]](<8 x s32>)
     ; SSE2: [[UV2:%[0-9]+]]:_(<4 x s32>), [[UV3:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[DEF1]](<8 x s32>)
     ; SSE2: [[ADD:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV]], [[UV2]]
     ; SSE2: [[ADD1:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV1]], [[UV3]]
-    ; SSE2: [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[ADD]](<4 x s32>), [[ADD1]](<4 x s32>)
+    ; SSE2: [[MV:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[ADD]](<4 x s32>), [[ADD1]](<4 x s32>)
     ; SSE2: $ymm0 = COPY [[MV]](<8 x s32>)
     ; AVX1: [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[DEF]](<8 x s32>)
     ; AVX1: [[UV2:%[0-9]+]]:_(<4 x s32>), [[UV3:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[DEF1]](<8 x s32>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV]], [[UV2]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV1]], [[UV3]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<8 x s32>) = G_MERGE_VALUES [[ADD]](<4 x s32>), [[ADD1]](<4 x s32>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<8 x s32>) = G_CONCAT_VECTORS [[ADD]](<4 x s32>), [[ADD1]](<4 x s32>)
     ; AVX1: $ymm0 = COPY [[MV]](<8 x s32>)
     ; AVX2: [[ADD:%[0-9]+]]:_(<8 x s32>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX2: $ymm0 = COPY [[ADD]](<8 x s32>)
     ; ALL: RET 0
     %0(<8 x s32>) = IMPLICIT_DEF
     %1(<8 x s32>) = IMPLICIT_DEF
     %2(<8 x s32>) = G_ADD %0, %1
     $ymm0 = COPY %2
bb.1 (%ir-block.0):
 
     ; ALL-LABEL: name: test_add_v4i64
     ; ALL: [[DEF:%[0-9]+]]:_(<4 x s64>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<4 x s64>) = IMPLICIT_DEF
     ; SSE2: [[UV:%[0-9]+]]:_(<2 x s64>), [[UV1:%[0-9]+]]:_(<2 x s64>) = G_UNMERGE_VALUES [[DEF]](<4 x s64>)
     ; SSE2: [[UV2:%[0-9]+]]:_(<2 x s64>), [[UV3:%[0-9]+]]:_(<2 x s64>) = G_UNMERGE_VALUES [[DEF1]](<4 x s64>)
     ; SSE2: [[ADD:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV]], [[UV2]]
     ; SSE2: [[ADD1:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV1]], [[UV3]]
-    ; SSE2: [[MV:%[0-9]+]]:_(<4 x s64>) = G_MERGE_VALUES [[ADD]](<2 x s64>), [[ADD1]](<2 x s64>)
+    ; SSE2: [[MV:%[0-9]+]]:_(<4 x s64>) = G_CONCAT_VECTORS [[ADD]](<2 x s64>), [[ADD1]](<2 x s64>)
     ; AVX1: [[UV:%[0-9]+]]:_(<2 x s64>), [[UV1:%[0-9]+]]:_(<2 x s64>) = G_UNMERGE_VALUES [[DEF]](<4 x s64>)
     ; AVX1: [[UV2:%[0-9]+]]:_(<2 x s64>), [[UV3:%[0-9]+]]:_(<2 x s64>) = G_UNMERGE_VALUES [[DEF1]](<4 x s64>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV]], [[UV2]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV1]], [[UV3]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<4 x s64>) = G_MERGE_VALUES [[ADD]](<2 x s64>), [[ADD1]](<2 x s64>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<4 x s64>) = G_CONCAT_VECTORS [[ADD]](<2 x s64>), [[ADD1]](<2 x s64>)
     ; SSE2: $ymm0 = COPY [[MV]](<4 x s64>)
     ; AVX1: $ymm0 = COPY [[MV]](<4 x s64>)
     ; AVX2: [[ADD:%[0-9]+]]:_(<4 x s64>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX2: $ymm0 = COPY [[ADD]](<4 x s64>)
     ; ALL: RET 0
     %0(<4 x s64>) = IMPLICIT_DEF
     %1(<4 x s64>) = IMPLICIT_DEF
     %2(<4 x s64>) = G_ADD %0, %1
     $ymm0 = COPY %2
     RET 0
 
 ...

test/CodeGen/X86/GlobalISel/legalize-add-v512.mir

bb.1 (%ir-block.0):
     ; ALL: [[DEF:%[0-9]+]]:_(<64 x s8>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<64 x s8>) = IMPLICIT_DEF
     ; AVX1: [[UV:%[0-9]+]]:_(<16 x s8>), [[UV1:%[0-9]+]]:_(<16 x s8>), [[UV2:%[0-9]+]]:_(<16 x s8>), [[UV3:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[DEF]](<64 x s8>)
     ; AVX1: [[UV4:%[0-9]+]]:_(<16 x s8>), [[UV5:%[0-9]+]]:_(<16 x s8>), [[UV6:%[0-9]+]]:_(<16 x s8>), [[UV7:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[DEF1]](<64 x s8>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV]], [[UV4]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV1]], [[UV5]]
     ; AVX1: [[ADD2:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV2]], [[UV6]]
     ; AVX1: [[ADD3:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV3]], [[UV7]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<64 x s8>) = G_MERGE_VALUES [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>), [[ADD2]](<16 x s8>), [[ADD3]](<16 x s8>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<64 x s8>) = G_CONCAT_VECTORS [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>), [[ADD2]](<16 x s8>), [[ADD3]](<16 x s8>)
     ; AVX1: $zmm0 = COPY [[MV]](<64 x s8>)
     ; AVX512F: [[UV:%[0-9]+]]:_(<32 x s8>), [[UV1:%[0-9]+]]:_(<32 x s8>) = G_UNMERGE_VALUES [[DEF]](<64 x s8>)
     ; AVX512F: [[UV2:%[0-9]+]]:_(<32 x s8>), [[UV3:%[0-9]+]]:_(<32 x s8>) = G_UNMERGE_VALUES [[DEF1]](<64 x s8>)
     ; AVX512F: [[ADD:%[0-9]+]]:_(<32 x s8>) = G_ADD [[UV]], [[UV2]]
     ; AVX512F: [[ADD1:%[0-9]+]]:_(<32 x s8>) = G_ADD [[UV1]], [[UV3]]
-    ; AVX512F: [[MV:%[0-9]+]]:_(<64 x s8>) = G_MERGE_VALUES [[ADD]](<32 x s8>), [[ADD1]](<32 x s8>)
+    ; AVX512F: [[MV:%[0-9]+]]:_(<64 x s8>) = G_CONCAT_VECTORS [[ADD]](<32 x s8>), [[ADD1]](<32 x s8>)
     ; AVX512F: $zmm0 = COPY [[MV]](<64 x s8>)
     ; AVX512BW: [[ADD:%[0-9]+]]:_(<64 x s8>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX512BW: $zmm0 = COPY [[ADD]](<64 x s8>)
     ; ALL: RET 0
     %0(<64 x s8>) = IMPLICIT_DEF
     %1(<64 x s8>) = IMPLICIT_DEF
     %2(<64 x s8>) = G_ADD %0, %1
     $zmm0 = COPY %2
bb.1 (%ir-block.0):
     ; ALL: [[DEF:%[0-9]+]]:_(<32 x s16>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<32 x s16>) = IMPLICIT_DEF
     ; AVX1: [[UV:%[0-9]+]]:_(<8 x s16>), [[UV1:%[0-9]+]]:_(<8 x s16>), [[UV2:%[0-9]+]]:_(<8 x s16>), [[UV3:%[0-9]+]]:_(<8 x s16>) = G_UNMERGE_VALUES [[DEF]](<32 x s16>)
     ; AVX1: [[UV4:%[0-9]+]]:_(<8 x s16>), [[UV5:%[0-9]+]]:_(<8 x s16>), [[UV6:%[0-9]+]]:_(<8 x s16>), [[UV7:%[0-9]+]]:_(<8 x s16>) = G_UNMERGE_VALUES [[DEF1]](<32 x s16>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV]], [[UV4]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV1]], [[UV5]]
     ; AVX1: [[ADD2:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV2]], [[UV6]]
     ; AVX1: [[ADD3:%[0-9]+]]:_(<8 x s16>) = G_ADD [[UV3]], [[UV7]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<32 x s16>) = G_MERGE_VALUES [[ADD]](<8 x s16>), [[ADD1]](<8 x s16>), [[ADD2]](<8 x s16>), [[ADD3]](<8 x s16>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<32 x s16>) = G_CONCAT_VECTORS [[ADD]](<8 x s16>), [[ADD1]](<8 x s16>), [[ADD2]](<8 x s16>), [[ADD3]](<8 x s16>)
     ; AVX1: $zmm0 = COPY [[MV]](<32 x s16>)
     ; AVX512F: [[UV:%[0-9]+]]:_(<16 x s16>), [[UV1:%[0-9]+]]:_(<16 x s16>) = G_UNMERGE_VALUES [[DEF]](<32 x s16>)
     ; AVX512F: [[UV2:%[0-9]+]]:_(<16 x s16>), [[UV3:%[0-9]+]]:_(<16 x s16>) = G_UNMERGE_VALUES [[DEF1]](<32 x s16>)
     ; AVX512F: [[ADD:%[0-9]+]]:_(<16 x s16>) = G_ADD [[UV]], [[UV2]]
     ; AVX512F: [[ADD1:%[0-9]+]]:_(<16 x s16>) = G_ADD [[UV1]], [[UV3]]
-    ; AVX512F: [[MV:%[0-9]+]]:_(<32 x s16>) = G_MERGE_VALUES [[ADD]](<16 x s16>), [[ADD1]](<16 x s16>)
+    ; AVX512F: [[MV:%[0-9]+]]:_(<32 x s16>) = G_CONCAT_VECTORS [[ADD]](<16 x s16>), [[ADD1]](<16 x s16>)
     ; AVX512F: $zmm0 = COPY [[MV]](<32 x s16>)
     ; AVX512BW: [[ADD:%[0-9]+]]:_(<32 x s16>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX512BW: $zmm0 = COPY [[ADD]](<32 x s16>)
     ; ALL: RET 0
     %0(<32 x s16>) = IMPLICIT_DEF
     %1(<32 x s16>) = IMPLICIT_DEF
     %2(<32 x s16>) = G_ADD %0, %1
     $zmm0 = COPY %2
bb.1 (%ir-block.0):
     ; ALL: [[DEF:%[0-9]+]]:_(<16 x s32>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<16 x s32>) = IMPLICIT_DEF
     ; AVX1: [[UV:%[0-9]+]]:_(<4 x s32>), [[UV1:%[0-9]+]]:_(<4 x s32>), [[UV2:%[0-9]+]]:_(<4 x s32>), [[UV3:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[DEF]](<16 x s32>)
     ; AVX1: [[UV4:%[0-9]+]]:_(<4 x s32>), [[UV5:%[0-9]+]]:_(<4 x s32>), [[UV6:%[0-9]+]]:_(<4 x s32>), [[UV7:%[0-9]+]]:_(<4 x s32>) = G_UNMERGE_VALUES [[DEF1]](<16 x s32>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV]], [[UV4]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV1]], [[UV5]]
     ; AVX1: [[ADD2:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV2]], [[UV6]]
     ; AVX1: [[ADD3:%[0-9]+]]:_(<4 x s32>) = G_ADD [[UV3]], [[UV7]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<16 x s32>) = G_MERGE_VALUES [[ADD]](<4 x s32>), [[ADD1]](<4 x s32>), [[ADD2]](<4 x s32>), [[ADD3]](<4 x s32>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<16 x s32>) = G_CONCAT_VECTORS [[ADD]](<4 x s32>), [[ADD1]](<4 x s32>), [[ADD2]](<4 x s32>), [[ADD3]](<4 x s32>)
     ; AVX1: $zmm0 = COPY [[MV]](<16 x s32>)
     ; AVX512F: [[ADD:%[0-9]+]]:_(<16 x s32>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX512F: $zmm0 = COPY [[ADD]](<16 x s32>)
     ; AVX512BW: [[ADD:%[0-9]+]]:_(<16 x s32>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX512BW: $zmm0 = COPY [[ADD]](<16 x s32>)
     ; ALL: RET 0
     %0(<16 x s32>) = IMPLICIT_DEF
     %1(<16 x s32>) = IMPLICIT_DEF
bb.1 (%ir-block.0):
     ; ALL: [[DEF:%[0-9]+]]:_(<8 x s64>) = IMPLICIT_DEF
     ; ALL: [[DEF1:%[0-9]+]]:_(<8 x s64>) = IMPLICIT_DEF
     ; AVX1: [[UV:%[0-9]+]]:_(<2 x s64>), [[UV1:%[0-9]+]]:_(<2 x s64>), [[UV2:%[0-9]+]]:_(<2 x s64>), [[UV3:%[0-9]+]]:_(<2 x s64>) = G_UNMERGE_VALUES [[DEF]](<8 x s64>)
     ; AVX1: [[UV4:%[0-9]+]]:_(<2 x s64>), [[UV5:%[0-9]+]]:_(<2 x s64>), [[UV6:%[0-9]+]]:_(<2 x s64>), [[UV7:%[0-9]+]]:_(<2 x s64>) = G_UNMERGE_VALUES [[DEF1]](<8 x s64>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV]], [[UV4]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV1]], [[UV5]]
     ; AVX1: [[ADD2:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV2]], [[UV6]]
     ; AVX1: [[ADD3:%[0-9]+]]:_(<2 x s64>) = G_ADD [[UV3]], [[UV7]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<8 x s64>) = G_MERGE_VALUES [[ADD]](<2 x s64>), [[ADD1]](<2 x s64>), [[ADD2]](<2 x s64>), [[ADD3]](<2 x s64>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<8 x s64>) = G_CONCAT_VECTORS [[ADD]](<2 x s64>), [[ADD1]](<2 x s64>), [[ADD2]](<2 x s64>), [[ADD3]](<2 x s64>)
     ; AVX1: $zmm0 = COPY [[MV]](<8 x s64>)
     ; AVX512F: [[ADD:%[0-9]+]]:_(<8 x s64>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX512F: $zmm0 = COPY [[ADD]](<8 x s64>)
     ; AVX512BW: [[ADD:%[0-9]+]]:_(<8 x s64>) = G_ADD [[DEF]], [[DEF1]]
     ; AVX512BW: $zmm0 = COPY [[ADD]](<8 x s64>)
     ; ALL: RET 0
     %0(<8 x s64>) = IMPLICIT_DEF
     %1(<8 x s64>) = IMPLICIT_DEF
bb.1 (%ir-block.0):
     ; AVX1: [[UV:%[0-9]+]]:_(<16 x s8>), [[UV1:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[COPY]](<32 x s8>)
     ; AVX1: [[UV2:%[0-9]+]]:_(<16 x s8>), [[UV3:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[COPY1]](<32 x s8>)
     ; AVX1: [[UV4:%[0-9]+]]:_(<16 x s8>), [[UV5:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[COPY2]](<32 x s8>)
     ; AVX1: [[UV6:%[0-9]+]]:_(<16 x s8>), [[UV7:%[0-9]+]]:_(<16 x s8>) = G_UNMERGE_VALUES [[COPY3]](<32 x s8>)
     ; AVX1: [[ADD:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV]], [[UV4]]
     ; AVX1: [[ADD1:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV1]], [[UV5]]
     ; AVX1: [[ADD2:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV2]], [[UV6]]
     ; AVX1: [[ADD3:%[0-9]+]]:_(<16 x s8>) = G_ADD [[UV3]], [[UV7]]
-    ; AVX1: [[MV:%[0-9]+]]:_(<32 x s8>) = G_MERGE_VALUES [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>)
-    ; AVX1: [[MV1:%[0-9]+]]:_(<32 x s8>) = G_MERGE_VALUES [[ADD2]](<16 x s8>), [[ADD3]](<16 x s8>)
+    ; AVX1: [[MV:%[0-9]+]]:_(<32 x s8>) = G_CONCAT_VECTORS [[ADD]](<16 x s8>), [[ADD1]](<16 x s8>)
+    ; AVX1: [[MV1:%[0-9]+]]:_(<32 x s8>) = G_CONCAT_VECTORS [[ADD2]](<16 x s8>), [[ADD3]](<16 x s8>)
     ; AVX1: $ymm0 = COPY [[MV]](<32 x s8>)
     ; AVX1: $ymm1 = COPY [[MV1]](<32 x s8>)
     ; AVX512F: [[ADD:%[0-9]+]]:_(<32 x s8>) = G_ADD [[COPY]], [[COPY2]]
     ; AVX512F: [[ADD1:%[0-9]+]]:_(<32 x s8>) = G_ADD [[COPY1]], [[COPY3]]
     ; AVX512F: $ymm0 = COPY [[ADD]](<32 x s8>)
     ; AVX512F: $ymm1 = COPY [[ADD1]](<32 x s8>)
-    ; AVX512BW: [[MV:%[0-9]+]]:_(<64 x s8>) = G_MERGE_VALUES [[COPY]](<32 x s8>), [[COPY1]](<32 x s8>)
-    ; AVX512BW: [[MV1:%[0-9]+]]:_(<64 x s8>) = G_MERGE_VALUES [[COPY2]](<32 x s8>), [[COPY3]](<32 x s8>)
+    ; AVX512BW: [[MV:%[0-9]+]]:_(<64 x s8>) = G_CONCAT_VECTORS [[COPY]](<32 x s8>), [[COPY1]](<32 x s8>)
+    ; AVX512BW: [[MV1:%[0-9]+]]:_(<64 x s8>) = G_CONCAT_VECTORS [[COPY2]](<32 x s8>), [[COPY3]](<32 x s8>)
     ; AVX512BW: [[ADD:%[0-9]+]]:_(<64 x s8>) = G_ADD [[MV]], [[MV1]]
     ; AVX512BW: [[UV:%[0-9]+]]:_(<32 x s8>), [[UV1:%[0-9]+]]:_(<32 x s8>) = G_UNMERGE_VALUES [[ADD]](<64 x s8>)
     ; AVX512BW: $ymm0 = COPY [[UV]](<32 x s8>)
     ; AVX512BW: $ymm1 = COPY [[UV1]](<32 x s8>)
     ; ALL: RET 0, implicit $ymm0, implicit $ymm1
     %2(<32 x s8>) = COPY $ymm0
     %3(<32 x s8>) = COPY $ymm1
     %4(<32 x s8>) = COPY $ymm2
     %5(<32 x s8>) = COPY $ymm3
-    %0(<64 x s8>) = G_MERGE_VALUES %2(<32 x s8>), %3(<32 x s8>)
-    %1(<64 x s8>) = G_MERGE_VALUES %4(<32 x s8>), %5(<32 x s8>)
+    %0(<64 x s8>) = G_CONCAT_VECTORS %2(<32 x s8>), %3(<32 x s8>)
+    %1(<64 x s8>) = G_CONCAT_VECTORS %4(<32 x s8>), %5(<32 x s8>)
     %6(<64 x s8>) = G_ADD %0, %1
     %7(<32 x s8>), %8(<32 x s8>) = G_UNMERGE_VALUES %6(<64 x s8>)
     $ymm0 = COPY %7(<32 x s8>)
     $ymm1 = COPY %8(<32 x s8>)
     RET 0, implicit $ymm0, implicit $ymm1
 
 ...

test/CodeGen/X86/GlobalISel/select-merge-vec256.mir

bb.1 (%ir-block.0):
     ; AVX: RET 0, implicit $ymm0
     ; AVX512VL-LABEL: name: test_merge
     ; AVX512VL: [[DEF:%[0-9]+]]:vr128x = IMPLICIT_DEF
     ; AVX512VL: undef %2.sub_xmm:vr256x = COPY [[DEF]]
     ; AVX512VL: [[VINSERTF32x4Z256rr:%[0-9]+]]:vr256x = VINSERTF32x4Z256rr %2, [[DEF]], 1
     ; AVX512VL: $ymm0 = COPY [[VINSERTF32x4Z256rr]]
     ; AVX512VL: RET 0, implicit $ymm0
     %0(<4 x s32>) = IMPLICIT_DEF
-    %1(<8 x s32>) = G_MERGE_VALUES %0(<4 x s32>), %0(<4 x s32>)
+    %1(<8 x s32>) = G_CONCAT_VECTORS %0(<4 x s32>), %0(<4 x s32>)
     $ymm0 = COPY %1(<8 x s32>)
     RET 0, implicit $ymm0
 
 ...
 

test/CodeGen/X86/GlobalISel/select-merge-vec512.mir

bb.1 (%ir-block.0):
     ; ALL: [[DEF:%[0-9]+]]:vr128x = IMPLICIT_DEF
     ; ALL: undef %2.sub_xmm:vr512 = COPY [[DEF]]
     ; ALL: [[VINSERTF32x4Zrr:%[0-9]+]]:vr512 = VINSERTF32x4Zrr %2, [[DEF]], 1
     ; ALL: [[VINSERTF32x4Zrr1:%[0-9]+]]:vr512 = VINSERTF32x4Zrr [[VINSERTF32x4Zrr]], [[DEF]], 2
     ; ALL: [[VINSERTF32x4Zrr2:%[0-9]+]]:vr512 = VINSERTF32x4Zrr [[VINSERTF32x4Zrr1]], [[DEF]], 3
     ; ALL: $zmm0 = COPY [[VINSERTF32x4Zrr2]]
     ; ALL: RET 0, implicit $zmm0
     %0(<4 x s32>) = IMPLICIT_DEF
-    %1(<16 x s32>) = G_MERGE_VALUES %0(<4 x s32>), %0(<4 x s32>), %0(<4 x s32>), %0(<4 x s32>)
+    %1(<16 x s32>) = G_CONCAT_VECTORS %0(<4 x s32>), %0(<4 x s32>), %0(<4 x s32>), %0(<4 x s32>)
     $zmm0 = COPY %1(<16 x s32>)
     RET 0, implicit $zmm0
 
 ...
 ---
 name:            test_merge_v256
 alignment:       4
 legalized:       true
 regBankSelected: true
 registers:
   - { id: 0, class: vecr }
   - { id: 1, class: vecr }
 body:             |
   bb.1 (%ir-block.0):
 
     ; ALL-LABEL: name: test_merge_v256
     ; ALL: [[DEF:%[0-9]+]]:vr256x = IMPLICIT_DEF
     ; ALL: undef %2.sub_ymm:vr512 = COPY [[DEF]]
     ; ALL: [[VINSERTF64x4Zrr:%[0-9]+]]:vr512 = VINSERTF64x4Zrr %2, [[DEF]], 1
     ; ALL: $zmm0 = COPY [[VINSERTF64x4Zrr]]
     ; ALL: RET 0, implicit $zmm0
     %0(<8 x s32>) = IMPLICIT_DEF
-    %1(<16 x s32>) = G_MERGE_VALUES %0(<8 x s32>), %0(<8 x s32>)
+    %1(<16 x s32>) = G_CONCAT_VECTORS %0(<8 x s32>), %0(<8 x s32>)
     $zmm0 = COPY %1(<16 x s32>)
     RET 0, implicit $zmm0
 
 ...