[GlobalISel] Use more MachineIRBuilder helper methods

[merge_guards_bot]

Unit tests: pass. 61909 tests passed, 0 failed and 783 were skipped.

clang-tidy: unknown.

clang-format: pass.

Build artifacts: diff.json, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

[arsenm]

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

1441

This should be fixed separately l, but the getZExtValue is unnecessary and will break for wider types

[foad]

Added similar fixes in IRTranslator.cpp.

[foad]

Sorry @arsenm, I updated the patch just before I saw your approval.

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

1995

In case you were wondering about this hunk: the old code left the G_SMULO/UMULO in place, which defined Res, and also created a new G_MUL, which defined Res. This caused an assertion failure when buildAShr tried to constant fold its arguments, because it wasn't expecting to find more than one definition of Res. Is this a general problem in GlobalISel lowering and is my workaround reasonable?

[merge_guards_bot]

Unit tests: pass. 61909 tests passed, 0 failed and 783 were skipped.

clang-tidy: unknown.

clang-format: pass.

Build artifacts: diff.json, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

[arsenm]

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

1989

MIRBuilder.getII()

1995

It looks to me like the old code didn't modify the instruction in place, the new code does. Most places create new defs of the original result before erasing the original instruction, so this might be a widespread issue with the CSEMIRBuilder

[arsenm]

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

1995

Can you split this part into a separate change?

[foad]

Remove G_SMULO/G_UMULO changes which have been split out into D72842.

[merge_guards_bot]

Unit tests: pass. 61909 tests passed, 0 failed and 783 were skipped.

clang-tidy: unknown.

clang-format: pass.

Build artifacts: diff.json, clang-format.patch, CMakeCache.txt, console-log.txt, test-results.xml

[arsenm]

LGTM

[foad]

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

1441

See D72853.

llvm/include/llvm/CodeGen/GlobalISel/MachineIRBuilder.h

public:
   ///
   /// \pre setBasicBlock or setMI must have been called.
   /// \pre \p Res must be a generic virtual register with scalar or vector type.
   /// \pre \p Op must be a generic virtual register with scalar or vector type.
   /// \pre \p Res must be smaller than \p Op
   ///
   /// \return The newly created instruction.
   MachineInstrBuilder buildFPTrunc(const DstOp &Res, const SrcOp &Op,
-                                   Optional<unsigned> FLags = None);
+                                   Optional<unsigned> Flags = None);
 
   /// Build and insert \p Res = G_TRUNC \p Op
   ///
   /// G_TRUNC extracts the low bits of a type. For a vector type each element is
   /// truncated independently before being packed into the destination.
   ///
   /// \pre setBasicBlock or setMI must have been called.
   /// \pre \p Res must be a generic virtual register with scalar or vector type.

   MachineInstrBuilder buildFAdd(const DstOp &Dst, const SrcOp &Src0,
                                 const SrcOp &Src1,
                                 Optional<unsigned> Flags = None) {
     return buildInstr(TargetOpcode::G_FADD, {Dst}, {Src0, Src1}, Flags);
   }
 
   /// Build and insert \p Res = G_FSUB \p Op0, \p Op1
   MachineInstrBuilder buildFSub(const DstOp &Dst, const SrcOp &Src0,
-                                const SrcOp &Src1) {
-    return buildInstr(TargetOpcode::G_FSUB, {Dst}, {Src0, Src1});
+                                const SrcOp &Src1,
+                                Optional<unsigned> Flags = None) {
+    return buildInstr(TargetOpcode::G_FSUB, {Dst}, {Src0, Src1}, Flags);
   }
 
   /// Build and insert \p Res = G_FMA \p Op0, \p Op1, \p Op2
   MachineInstrBuilder buildFMA(const DstOp &Dst, const SrcOp &Src0,
                                const SrcOp &Src1, const SrcOp &Src2,
                                Optional<unsigned> Flags = None) {
     return buildInstr(TargetOpcode::G_FMA, {Dst}, {Src0, Src1, Src2}, Flags);
   }

llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp

if (isa<Constant>(U.getOperand(0)) &&
     Register Op1 = getOrCreateVReg(*U.getOperand(1));
     Register Res = getOrCreateVReg(U);
     uint16_t Flags = 0;
     if (isa<Instruction>(U)) {
       const Instruction &I = cast<Instruction>(U);
       Flags = MachineInstr::copyFlagsFromInstruction(I);
     }
     // Negate the last operand of the FSUB
-    MIRBuilder.buildInstr(TargetOpcode::G_FNEG, {Res}, {Op1}, Flags);
+    MIRBuilder.buildFNeg(Res, Op1, Flags);
     return true;
   }
   return translateBinaryOp(TargetOpcode::G_FSUB, U, MIRBuilder);
 }
 
 bool IRTranslator::translateFNeg(const User &U, MachineIRBuilder &MIRBuilder) {
   Register Op0 = getOrCreateVReg(*U.getOperand(0));
   Register Res = getOrCreateVReg(U);
   uint16_t Flags = 0;
   if (isa<Instruction>(U)) {
     const Instruction &I = cast<Instruction>(U);
     Flags = MachineInstr::copyFlagsFromInstruction(I);
   }
-  MIRBuilder.buildInstr(TargetOpcode::G_FNEG, {Res}, {Op0}, Flags);
+  MIRBuilder.buildFNeg(Res, Op0, Flags);
   return true;
 }
 
 bool IRTranslator::translateCompare(const User &U,
                                     MachineIRBuilder &MIRBuilder) {
   auto *CI = dyn_cast<CmpInst>(&U);
   Register Op0 = getOrCreateVReg(*U.getOperand(0));
   Register Op1 = getOrCreateVReg(*U.getOperand(1));
   Register Res = getOrCreateVReg(U);
   CmpInst::Predicate Pred =
       CI ? CI->getPredicate() : static_cast<CmpInst::Predicate>(
                                     cast<ConstantExpr>(U).getPredicate());
   if (CmpInst::isIntPredicate(Pred))
     MIRBuilder.buildICmp(Pred, Res, Op0, Op1);
   else if (Pred == CmpInst::FCMP_FALSE)
     MIRBuilder.buildCopy(
         Res, getOrCreateVReg(*Constant::getNullValue(U.getType())));
   else if (Pred == CmpInst::FCMP_TRUE)
     MIRBuilder.buildCopy(
         Res, getOrCreateVReg(*Constant::getAllOnesValue(U.getType())));
   else {
     assert(CI && "Instruction should be CmpInst");
-    MIRBuilder.buildInstr(TargetOpcode::G_FCMP, {Res}, {Pred, Op0, Op1},
-                          MachineInstr::copyFlagsFromInstruction(*CI));
+    MIRBuilder.buildFCmp(Pred, Res, Op0, Op1,
   }
 
   return true;
 }
 
 bool IRTranslator::translateRet(const User &U, MachineIRBuilder &MIRBuilder) {
   const ReturnInst &RI = cast<ReturnInst>(U);
   const Value *Ret = RI.getReturnValue();
//  if (SwitchBB->getBasicBlock() != CB.FalseBB->getBasicBlock())
     addMachineCFGPred({SwitchBB->getBasicBlock(), CB.FalseBB->getBasicBlock()},
                       CB.ThisBB);
 
   // If the lhs block is the next block, invert the condition so that we can
   // fall through to the lhs instead of the rhs block.
   if (CB.TrueBB == CB.ThisBB->getNextNode()) {
     std::swap(CB.TrueBB, CB.FalseBB);
     auto True = MIB.buildConstant(i1Ty, 1);
-    Cond = MIB.buildInstr(TargetOpcode::G_XOR, {i1Ty}, {Cond, True}, None)
-               .getReg(0);
+    Cond = MIB.buildXor(i1Ty, Cond, True).getReg(0);
   }
 
   MIB.buildBrCond(Cond, *CB.TrueBB);
   MIB.buildBr(*CB.FalseBB);
   MIB.setDebugLoc(OldDbgLoc);
 }
 
 bool IRTranslator::lowerJumpTableWorkItem(SwitchCG::SwitchWorkListItem W,
bool IRTranslator::translateSelect(const User &U,
   ArrayRef<Register> Op1Regs = getOrCreateVRegs(*U.getOperand(2));
 
   const SelectInst &SI = cast<SelectInst>(U);
   uint16_t Flags = 0;
   if (const CmpInst *Cmp = dyn_cast<CmpInst>(SI.getCondition()))
     Flags = MachineInstr::copyFlagsFromInstruction(*Cmp);
 
   for (unsigned i = 0; i < ResRegs.size(); ++i) {
-    MIRBuilder.buildInstr(TargetOpcode::G_SELECT, {ResRegs[i]},
-                          {Tst, Op0Regs[i], Op1Regs[i]}, Flags);
+    MIRBuilder.buildSelect(ResRegs[i], Tst, Op0Regs[i], Op1Regs[i], Flags);
   }
 
   return true;
 }
 
 bool IRTranslator::translateBitCast(const User &U,
                                     MachineIRBuilder &MIRBuilder) {
   // If we're bitcasting to the source type, we can reuse the source vreg.
bool IRTranslator::translateMemFunc(const CallInst &CI,
 
   return true;
 }
 
 void IRTranslator::getStackGuard(Register DstReg,
                                  MachineIRBuilder &MIRBuilder) {
   const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
   MRI->setRegClass(DstReg, TRI->getPointerRegClass(*MF));
-  auto MIB = MIRBuilder.buildInstr(TargetOpcode::LOAD_STACK_GUARD);
-  MIB.addDef(DstReg);
+  auto MIB =
+      MIRBuilder.buildInstr(TargetOpcode::LOAD_STACK_GUARD, {DstReg}, {});
 
   auto &TLI = *MF->getSubtarget().getTargetLowering();
   Value *Global = TLI.getSDagStackGuard(*MF->getFunction().getParent());
   if (!Global)
     return;
 
   MachinePointerInfo MPInfo(Global);
   auto Flags = MachineMemOperand::MOLoad | MachineMemOperand::MOInvariant |
                MachineMemOperand::MODereferenceable;
   MachineMemOperand *MemRef =
       MF->getMachineMemOperand(MPInfo, Flags, DL->getPointerSizeInBits() / 8,
                                DL->getPointerABIAlignment(0).value());
   MIB.setMemRefs({MemRef});
 }
 
 bool IRTranslator::translateOverflowIntrinsic(const CallInst &CI, unsigned Op,
                                               MachineIRBuilder &MIRBuilder) {
   ArrayRef<Register> ResRegs = getOrCreateVRegs(CI);
-  MIRBuilder.buildInstr(Op)
-      .addDef(ResRegs[0])
-      .addDef(ResRegs[1])
-      .addUse(getOrCreateVReg(*CI.getOperand(0)))
-      .addUse(getOrCreateVReg(*CI.getOperand(1)));
+  MIRBuilder.buildInstr(
+      Op, {ResRegs[0], ResRegs[1]},
+      {getOrCreateVReg(*CI.getOperand(0)), getOrCreateVReg(*CI.getOperand(1))});
 
   return true;
 }
 
 unsigned IRTranslator::getSimpleIntrinsicOpcode(Intrinsic::ID ID) {
   switch (ID) {
     default:
       break;
case Intrinsic::vaend:
     // does. Simplest intrinsic ever!
     return true;
   case Intrinsic::vastart: {
     auto &TLI = *MF->getSubtarget().getTargetLowering();
     Value *Ptr = CI.getArgOperand(0);
     unsigned ListSize = TLI.getVaListSizeInBits(*DL) / 8;
 
     // FIXME: Get alignment
-    MIRBuilder.buildInstr(TargetOpcode::G_VASTART)
-        .addUse(getOrCreateVReg(*Ptr))
+    MIRBuilder.buildInstr(TargetOpcode::G_VASTART, {}, {getOrCreateVReg(*Ptr)})
         .addMemOperand(MF->getMachineMemOperand(
             MachinePointerInfo(Ptr), MachineMemOperand::MOStore, ListSize, 1));
     return true;
   }
   case Intrinsic::dbg_value: {
     // This form of DBG_VALUE is target-independent.
     const DbgValueInst &DI = cast<DbgValueInst>(CI);
     const Value *V = DI.getValue();
case Intrinsic::fmuladd: {
     Register Op0 = getOrCreateVReg(*CI.getArgOperand(0));
     Register Op1 = getOrCreateVReg(*CI.getArgOperand(1));
     Register Op2 = getOrCreateVReg(*CI.getArgOperand(2));
     if (TM.Options.AllowFPOpFusion != FPOpFusion::Strict &&
         TLI.isFMAFasterThanFMulAndFAdd(*MF,
                                        TLI.getValueType(*DL, CI.getType()))) {
       // TODO: Revisit this to see if we should move this part of the
       // lowering to the combiner.
-      MIRBuilder.buildInstr(TargetOpcode::G_FMA, {Dst}, {Op0, Op1, Op2},
-                            MachineInstr::copyFlagsFromInstruction(CI));
+      MIRBuilder.buildFMA(Dst, Op0, Op1, Op2,
     } else {
       LLT Ty = getLLTForType(*CI.getType(), *DL);
-      auto FMul = MIRBuilder.buildInstr(TargetOpcode::G_FMUL, {Ty}, {Op0, Op1},
-                                        MachineInstr::copyFlagsFromInstruction(CI));
-      MIRBuilder.buildInstr(TargetOpcode::G_FADD, {Dst}, {FMul, Op2},
-                            MachineInstr::copyFlagsFromInstruction(CI));
+      auto FMul = MIRBuilder.buildFMul(
+          Ty, Op0, Op1, MachineInstr::copyFlagsFromInstruction(CI));
+      MIRBuilder.buildFAdd(Dst, FMul, Op2,
     }
     return true;
   }
   case Intrinsic::memcpy:
   case Intrinsic::memmove:
   case Intrinsic::memset:
     return translateMemFunc(CI, MIRBuilder, ID);
   case Intrinsic::eh_typeid_for: {
bool IRTranslator::translateKnownIntrinsic(const CallInst &CI, Intrinsic::ID ID,
   case Intrinsic::ctlz: {
     ConstantInt *Cst = cast<ConstantInt>(CI.getArgOperand(1));
     bool isTrailing = ID == Intrinsic::cttz;
     unsigned Opcode = isTrailing
                           ? Cst->isZero() ? TargetOpcode::G_CTTZ
                                           : TargetOpcode::G_CTTZ_ZERO_UNDEF
                           : Cst->isZero() ? TargetOpcode::G_CTLZ
                                           : TargetOpcode::G_CTLZ_ZERO_UNDEF;
-    MIRBuilder.buildInstr(Opcode)
-        .addDef(getOrCreateVReg(CI))
-        .addUse(getOrCreateVReg(*CI.getArgOperand(0)));
+    MIRBuilder.buildInstr(Opcode, {getOrCreateVReg(CI)},
+                          {getOrCreateVReg(*CI.getArgOperand(0))});
     return true;
   }
   case Intrinsic::invariant_start: {
     LLT PtrTy = getLLTForType(*CI.getArgOperand(0)->getType(), *DL);
     Register Undef = MRI->createGenericVirtualRegister(PtrTy);
     MIRBuilder.buildUndef(Undef);
     return true;
   }
   case Intrinsic::invariant_end:
     return true;
   case Intrinsic::assume:
   case Intrinsic::var_annotation:
   case Intrinsic::sideeffect:
     // Discard annotate attributes, assumptions, and artificial side-effects.
     return true;
   case Intrinsic::read_register: {
     Value *Arg = CI.getArgOperand(0);
-    MIRBuilder.buildInstr(TargetOpcode::G_READ_REGISTER)
-      .addDef(getOrCreateVReg(CI))
+    MIRBuilder
+        .buildInstr(TargetOpcode::G_READ_REGISTER, {getOrCreateVReg(CI)}, {})
         .addMetadata(cast<MDNode>(cast<MetadataAsValue>(Arg)->getMetadata()));
     return true;
   }
   }
   return false;
 }
 
 bool IRTranslator::translateInlineAsm(const CallInst &CI,
                                       MachineIRBuilder &MIRBuilder) {
bool IRTranslator::translateAlloca(const User &U,
   return true;
 }
 
 bool IRTranslator::translateVAArg(const User &U, MachineIRBuilder &MIRBuilder) {
   // FIXME: We may need more info about the type. Because of how LLT works,
   // we're completely discarding the i64/double distinction here (amongst
   // others). Fortunately the ABIs I know of where that matters don't use va_arg
   // anyway but that's not guaranteed.
-  MIRBuilder.buildInstr(TargetOpcode::G_VAARG)
-    .addDef(getOrCreateVReg(U))
-    .addUse(getOrCreateVReg(*U.getOperand(0)))
-    .addImm(DL->getABITypeAlignment(U.getType()));
+  MIRBuilder.buildInstr(TargetOpcode::G_VAARG, {getOrCreateVReg(U)},
+                        {getOrCreateVReg(*U.getOperand(0)),
+                         uint64_t(DL->getABITypeAlignment(U.getType()))});
   return true;
 }
 
 bool IRTranslator::translateInsertElement(const User &U,
                                           MachineIRBuilder &MIRBuilder) {
   // If it is a <1 x Ty> vector, use the scalar as it is
   // not a legal vector type in LLT.
   if (U.getType()->getVectorNumElements() == 1) {
bool IRTranslator::translateExtractElement(const User &U,
   return true;
 }
 
 bool IRTranslator::translateShuffleVector(const User &U,
                                           MachineIRBuilder &MIRBuilder) {
   SmallVector<int, 8> Mask;
   ShuffleVectorInst::getShuffleMask(cast<Constant>(U.getOperand(2)), Mask);
   ArrayRef<int> MaskAlloc = MF->allocateShuffleMask(Mask);
-  MIRBuilder.buildInstr(TargetOpcode::G_SHUFFLE_VECTOR)
-      .addDef(getOrCreateVReg(U))
-      .addUse(getOrCreateVReg(*U.getOperand(0)))
-      .addUse(getOrCreateVReg(*U.getOperand(1)))
+  MIRBuilder
+      .buildInstr(TargetOpcode::G_SHUFFLE_VECTOR, {getOrCreateVReg(U)},
+                  {getOrCreateVReg(*U.getOperand(0)),
+                   getOrCreateVReg(*U.getOperand(1))})
       .addShuffleMask(MaskAlloc);
   return true;
 }
 
 bool IRTranslator::translatePHI(const User &U, MachineIRBuilder &MIRBuilder) {
   const PHINode &PI = cast<PHINode>(U);
 
   SmallVector<MachineInstr *, 4> Insts;

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

case TargetOpcode::G_SEXTLOAD: {
     Register DstReg = MI.getOperand(0).getReg();
     Register PtrReg = MI.getOperand(1).getReg();
 
     Register TmpReg = MRI.createGenericVirtualRegister(NarrowTy);
     auto &MMO = **MI.memoperands_begin();
     if (MMO.getSizeInBits() == NarrowSize) {
       MIRBuilder.buildLoad(TmpReg, PtrReg, MMO);
     } else {
-      unsigned ExtLoad = ZExt ? TargetOpcode::G_ZEXTLOAD
-        : TargetOpcode::G_SEXTLOAD;
-      MIRBuilder.buildInstr(ExtLoad)
-        .addDef(TmpReg)
-        .addUse(PtrReg)
-        .addMemOperand(&MMO);
+      MIRBuilder.buildLoadInstr(MI.getOpcode(), TmpReg, PtrReg, MMO);
     }
 
     if (ZExt)
       MIRBuilder.buildZExt(DstReg, TmpReg);
     else
       MIRBuilder.buildSExt(DstReg, TmpReg);
 
     MI.eraseFromParent();
if (NarrowTy.getScalarSizeInBits() >= SizeInBits) {
       // sign-extending the dst.
       MachineOperand &MO1 = MI.getOperand(1);
       auto TruncMIB = MIRBuilder.buildTrunc(NarrowTy, MO1.getReg());
       MO1.setReg(TruncMIB->getOperand(0).getReg());
 
       MachineOperand &MO2 = MI.getOperand(0);
       Register DstExt = MRI.createGenericVirtualRegister(NarrowTy);
       MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
-      MIRBuilder.buildInstr(TargetOpcode::G_SEXT, {MO2.getReg()}, {DstExt});
+      MIRBuilder.buildSExt(MO2.getReg(), DstExt);
       MO2.setReg(DstExt);
       Observer.changedInstr(MI);
       return Legalized;
     }
 
     // Break it apart. Components below the extension point are unmodified. The
     // component containing the extension point becomes a narrower SEXT_INREG.
     // Components above it are ashr'd from the component containing the
for (int i = 0; i < NumParts; ++i) {
         DstRegs.push_back(SrcRegs[i]);
       else if (i * NarrowTy.getScalarSizeInBits() > SizeInBits) {
         assert(PartialExtensionReg &&
                "Expected to visit partial extension before full");
         if (FullExtensionReg) {
           DstRegs.push_back(FullExtensionReg);
           continue;
         }
-        DstRegs.push_back(MIRBuilder
-                              .buildInstr(TargetOpcode::G_ASHR, {NarrowTy},
-                                          {PartialExtensionReg, AshrCstReg})
-                              ->getOperand(0)
-                              .getReg());
+        DstRegs.push_back(
+            MIRBuilder.buildAShr(NarrowTy, PartialExtensionReg, AshrCstReg)
         FullExtensionReg = DstRegs.back();
       } else {
         DstRegs.push_back(
             MIRBuilder
                 .buildInstr(
                     TargetOpcode::G_SEXT_INREG, {NarrowTy},
                     {SrcRegs[i], SizeInBits % NarrowTy.getScalarSizeInBits()})
                 ->getOperand(0)
void LegalizerHelper::widenScalarSrc(MachineInstr &MI, LLT WideTy,
   MachineOperand &MO = MI.getOperand(OpIdx);
   auto ExtB = MIRBuilder.buildInstr(ExtOpcode, {WideTy}, {MO.getReg()});
   MO.setReg(ExtB->getOperand(0).getReg());
 }
 
 void LegalizerHelper::narrowScalarSrc(MachineInstr &MI, LLT NarrowTy,
                                       unsigned OpIdx) {
   MachineOperand &MO = MI.getOperand(OpIdx);
-  auto ExtB = MIRBuilder.buildInstr(TargetOpcode::G_TRUNC, {NarrowTy},
-                                    {MO.getReg()});
+  auto ExtB = MIRBuilder.buildTrunc(NarrowTy, MO.getReg());
   MO.setReg(ExtB->getOperand(0).getReg());
 }
 
 void LegalizerHelper::widenScalarDst(MachineInstr &MI, LLT WideTy,
                                      unsigned OpIdx, unsigned TruncOpcode) {
   MachineOperand &MO = MI.getOperand(OpIdx);
   Register DstExt = MRI.createGenericVirtualRegister(WideTy);
   MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
LegalizerHelper::widenScalar(MachineInstr &MI, unsigned TypeIdx, LLT WideTy) {
   case TargetOpcode::G_MERGE_VALUES:
     return widenScalarMergeValues(MI, TypeIdx, WideTy);
   case TargetOpcode::G_UNMERGE_VALUES:
     return widenScalarUnmergeValues(MI, TypeIdx, WideTy);
   case TargetOpcode::G_UADDO:
   case TargetOpcode::G_USUBO: {
     if (TypeIdx == 1)
       return UnableToLegalize; // TODO
-    auto LHSZext = MIRBuilder.buildInstr(TargetOpcode::G_ZEXT, {WideTy},
-                                         {MI.getOperand(2).getReg()});
-    auto RHSZext = MIRBuilder.buildInstr(TargetOpcode::G_ZEXT, {WideTy},
-                                         {MI.getOperand(3).getReg()});
+    auto LHSZext = MIRBuilder.buildZExt(WideTy, MI.getOperand(2).getReg());
+    auto RHSZext = MIRBuilder.buildZExt(WideTy, MI.getOperand(3).getReg());
     unsigned Opcode = MI.getOpcode() == TargetOpcode::G_UADDO
                           ? TargetOpcode::G_ADD
                           : TargetOpcode::G_SUB;
     // Do the arithmetic in the larger type.
     auto NewOp = MIRBuilder.buildInstr(Opcode, {WideTy}, {LHSZext, RHSZext});
     LLT OrigTy = MRI.getType(MI.getOperand(0).getReg());
     APInt Mask = APInt::getAllOnesValue(OrigTy.getSizeInBits());
-    auto AndOp = MIRBuilder.buildInstr(
-        TargetOpcode::G_AND, {WideTy},
-        {NewOp, MIRBuilder.buildConstant(WideTy, Mask.getZExtValue())});
+    auto AndOp = MIRBuilder.buildAnd(
+        WideTy, NewOp, MIRBuilder.buildConstant(WideTy, Mask.getZExtValue()));
     // There is no overflow if the AndOp is the same as NewOp.
     MIRBuilder.buildICmp(CmpInst::ICMP_NE, MI.getOperand(1).getReg(), NewOp,
                          AndOp);
     // Now trunc the NewOp to the original result.
     MIRBuilder.buildTrunc(MI.getOperand(0).getReg(), NewOp);
     MI.eraseFromParent();
     return Legalized;
   }
case TargetOpcode::G_CTPOP: {
 
     // Perform the operation at the larger size.
     auto MIBNewOp = MIRBuilder.buildInstr(MI.getOpcode(), {WideTy}, {MIBSrc});
     // This is already the correct result for CTPOP and CTTZs
     if (MI.getOpcode() == TargetOpcode::G_CTLZ ||
         MI.getOpcode() == TargetOpcode::G_CTLZ_ZERO_UNDEF) {
       // The correct result is NewOp - (Difference in widety and current ty).
       unsigned SizeDiff = WideTy.getSizeInBits() - CurTy.getSizeInBits();
-      MIBNewOp = MIRBuilder.buildInstr(
-          TargetOpcode::G_SUB, {WideTy},
-          {MIBNewOp, MIRBuilder.buildConstant(WideTy, SizeDiff)});
+      MIBNewOp = MIRBuilder.buildSub(
+          WideTy, MIBNewOp, MIRBuilder.buildConstant(WideTy, SizeDiff));
     }
 
     MIRBuilder.buildZExtOrTrunc(MI.getOperand(0), MIBNewOp);
     MI.eraseFromParent();
     return Legalized;
   }
   case TargetOpcode::G_BSWAP: {
     Observer.changingInstr(MI);
     Register DstReg = MI.getOperand(0).getReg();
 
     Register ShrReg = MRI.createGenericVirtualRegister(WideTy);
     Register DstExt = MRI.createGenericVirtualRegister(WideTy);
     Register ShiftAmtReg = MRI.createGenericVirtualRegister(WideTy);
     widenScalarSrc(MI, WideTy, 1, TargetOpcode::G_ANYEXT);
 
     MI.getOperand(0).setReg(DstExt);
 
     MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
 
     LLT Ty = MRI.getType(DstReg);
     unsigned DiffBits = WideTy.getScalarSizeInBits() - Ty.getScalarSizeInBits();
     MIRBuilder.buildConstant(ShiftAmtReg, DiffBits);
-    MIRBuilder.buildInstr(TargetOpcode::G_LSHR)
-      .addDef(ShrReg)
-      .addUse(DstExt)
-      .addUse(ShiftAmtReg);
+    MIRBuilder.buildLShr(ShrReg, DstExt, ShiftAmtReg);
 
     MIRBuilder.buildTrunc(DstReg, ShrReg);
     Observer.changedInstr(MI);
     return Legalized;
   }
   case TargetOpcode::G_BITREVERSE: {
     Observer.changingInstr(MI);
 
LegalizerHelper::lower(MachineInstr &MI, unsigned TypeIdx, LLT Ty) {
   switch(MI.getOpcode()) {
   default:
     return UnableToLegalize;
   case TargetOpcode::G_BITCAST:
     return lowerBitcast(MI);
   case TargetOpcode::G_SREM:
   case TargetOpcode::G_UREM: {
     Register QuotReg = MRI.createGenericVirtualRegister(Ty);
-    MIRBuilder.buildInstr(MI.getOpcode() == G_SREM ? G_SDIV : G_UDIV)
-        .addDef(QuotReg)
-        .addUse(MI.getOperand(1).getReg())
-        .addUse(MI.getOperand(2).getReg());
+    MIRBuilder.buildInstr(
+        MI.getOpcode() == G_SREM ? G_SDIV : G_UDIV, {QuotReg},
+        {MI.getOperand(1).getReg(), MI.getOperand(2).getReg()});
 
     Register ProdReg = MRI.createGenericVirtualRegister(Ty);
     MIRBuilder.buildMul(ProdReg, QuotReg, MI.getOperand(2).getReg());
     MIRBuilder.buildSub(MI.getOperand(0).getReg(), MI.getOperand(1).getReg(),
                         ProdReg);
     MI.eraseFromParent();
     return Legalized;
   }
   case TargetOpcode::G_SADDO:
   case TargetOpcode::G_SSUBO:
     return lowerSADDO_SSUBO(MI);
   case TargetOpcode::G_SMULO:
   case TargetOpcode::G_UMULO: {
     // Generate G_UMULH/G_SMULH to check for overflow and a normal G_MUL for the
     // result.
     Register Res = MI.getOperand(0).getReg();
     Register Overflow = MI.getOperand(1).getReg();
     Register LHS = MI.getOperand(2).getReg();
     Register RHS = MI.getOperand(3).getReg();
 
-    MIRBuilder.buildMul(Res, LHS, RHS);
-
     unsigned Opcode = MI.getOpcode() == TargetOpcode::G_SMULO
                           ? TargetOpcode::G_SMULH
                           : TargetOpcode::G_UMULH;
 
+    Observer.changingInstr(MI);
+    auto &TII = *MI.getMF()->getSubtarget().getInstrInfo();
+    MI.setDesc(TII.get(TargetOpcode::G_MUL));
+    MI.RemoveOperand(1);
+    Observer.changedInstr(MI);
+
+    MIRBuilder.setInsertPt(MIRBuilder.getMBB(), ++MIRBuilder.getInsertPt());
+
     Register HiPart = MRI.createGenericVirtualRegister(Ty);
-    MIRBuilder.buildInstr(Opcode)
-      .addDef(HiPart)
-      .addUse(LHS)
-      .addUse(RHS);
+    MIRBuilder.buildInstr(Opcode, {HiPart}, {LHS, RHS});
 
     Register Zero = MRI.createGenericVirtualRegister(Ty);
     MIRBuilder.buildConstant(Zero, 0);
 
     // For *signed* multiply, overflow is detected by checking:
     // (hi != (lo >> bitwidth-1))
     if (Opcode == TargetOpcode::G_SMULH) {
       Register Shifted = MRI.createGenericVirtualRegister(Ty);
       Register ShiftAmt = MRI.createGenericVirtualRegister(Ty);
       MIRBuilder.buildConstant(ShiftAmt, Ty.getSizeInBits() - 1);
-      MIRBuilder.buildInstr(TargetOpcode::G_ASHR)
-        .addDef(Shifted)
-        .addUse(Res)
-        .addUse(ShiftAmt);
+      MIRBuilder.buildAShr(Shifted, Res, ShiftAmt);
       MIRBuilder.buildICmp(CmpInst::ICMP_NE, Overflow, HiPart, Shifted);
     } else {
       MIRBuilder.buildICmp(CmpInst::ICMP_NE, Overflow, HiPart, Zero);
     }
-    MI.eraseFromParent();
     return Legalized;
   }
   case TargetOpcode::G_FNEG: {
     // TODO: Handle vector types once we are able to
     // represent them.
     if (Ty.isVector())
       return UnableToLegalize;
     Register Res = MI.getOperand(0).getReg();
case TargetOpcode::G_FNEG: {
     default:
       llvm_unreachable("unexpected floating-point type");
     }
     ConstantFP &ZeroForNegation =
         *cast<ConstantFP>(ConstantFP::getZeroValueForNegation(ZeroTy));
     auto Zero = MIRBuilder.buildFConstant(Ty, ZeroForNegation);
     Register SubByReg = MI.getOperand(1).getReg();
     Register ZeroReg = Zero->getOperand(0).getReg();
-    MIRBuilder.buildInstr(TargetOpcode::G_FSUB, {Res}, {ZeroReg, SubByReg},
-                          MI.getFlags());
+    MIRBuilder.buildFSub(Res, ZeroReg, SubByReg, MI.getFlags());
     MI.eraseFromParent();
     return Legalized;
   }
   case TargetOpcode::G_FSUB: {
     // Lower (G_FSUB LHS, RHS) to (G_FADD LHS, (G_FNEG RHS)).
     // First, check if G_FNEG is marked as Lower. If so, we may
     // end up with an infinite loop as G_FSUB is used to legalize G_FNEG.
     if (LI.getAction({G_FNEG, {Ty}}).Action == Lower)
       return UnableToLegalize;
     Register Res = MI.getOperand(0).getReg();
     Register LHS = MI.getOperand(1).getReg();
     Register RHS = MI.getOperand(2).getReg();
     Register Neg = MRI.createGenericVirtualRegister(Ty);
-    MIRBuilder.buildInstr(TargetOpcode::G_FNEG).addDef(Neg).addUse(RHS);
-    MIRBuilder.buildInstr(TargetOpcode::G_FADD, {Res}, {LHS, Neg}, MI.getFlags());
+    MIRBuilder.buildFNeg(Neg, RHS);
+    MIRBuilder.buildFAdd(Res, LHS, Neg, MI.getFlags());
     MI.eraseFromParent();
     return Legalized;
   }
   case TargetOpcode::G_FMAD:
     return lowerFMad(MI);
   case TargetOpcode::G_INTRINSIC_ROUND:
     return lowerIntrinsicRound(MI);
   case TargetOpcode::G_ATOMIC_CMPXCHG_WITH_SUCCESS: {
case TargetOpcode::G_SEXT_INREG: {
     int64_t SizeInBits = MI.getOperand(2).getImm();
 
     Register DstReg = MI.getOperand(0).getReg();
     Register SrcReg = MI.getOperand(1).getReg();
     LLT DstTy = MRI.getType(DstReg);
     Register TmpRes = MRI.createGenericVirtualRegister(DstTy);
 
     auto MIBSz = MIRBuilder.buildConstant(DstTy, DstTy.getScalarSizeInBits() - SizeInBits);
-    MIRBuilder.buildInstr(TargetOpcode::G_SHL, {TmpRes}, {SrcReg, MIBSz->getOperand(0).getReg()});
-    MIRBuilder.buildInstr(TargetOpcode::G_ASHR, {DstReg}, {TmpRes, MIBSz->getOperand(0).getReg()});
+    MIRBuilder.buildShl(TmpRes, SrcReg, MIBSz->getOperand(0).getReg());
+    MIRBuilder.buildAShr(DstReg, TmpRes, MIBSz->getOperand(0).getReg());
     MI.eraseFromParent();
     return Legalized;
   }
   case G_SHUFFLE_VECTOR:
     return lowerShuffleVector(MI);
   case G_DYN_STACKALLOC:
     return lowerDynStackAlloc(MI);
   case G_EXTRACT:
if (NarrowTy.isVector()) {
     NarrowTy1 = SrcTy.getElementType();
   }
 
   SmallVector<Register, 4> SrcRegs, DstRegs;
   extractParts(SrcReg, NarrowTy1, NumParts, SrcRegs);
 
   for (unsigned I = 0; I < NumParts; ++I) {
     Register DstReg = MRI.createGenericVirtualRegister(NarrowTy0);
-    MachineInstr *NewInst = MIRBuilder.buildInstr(MI.getOpcode())
-      .addDef(DstReg)
-      .addUse(SrcRegs[I]);
+    MachineInstr *NewInst =
+        MIRBuilder.buildInstr(MI.getOpcode(), {DstReg}, {SrcRegs[I]});
 
     NewInst->setFlags(MI.getFlags());
     DstRegs.push_back(DstReg);
   }
 
   if (NarrowTy.isVector())
     MIRBuilder.buildConcatVectors(DstReg, DstRegs);
   else
case TargetOpcode::G_CTLZ_ZERO_UNDEF: {
     Observer.changedInstr(MI);
     return Legalized;
   }
   case TargetOpcode::G_CTLZ: {
     Register SrcReg = MI.getOperand(1).getReg();
     unsigned Len = Ty.getSizeInBits();
     if (isSupported({TargetOpcode::G_CTLZ_ZERO_UNDEF, {Ty, Ty}})) {
       // If CTLZ_ZERO_UNDEF is supported, emit that and a select for zero.
-      auto MIBCtlzZU = MIRBuilder.buildInstr(TargetOpcode::G_CTLZ_ZERO_UNDEF,
-                                             {Ty}, {SrcReg});
+      auto MIBCtlzZU = MIRBuilder.buildCTLZ_ZERO_UNDEF(Ty, SrcReg);
       auto MIBZero = MIRBuilder.buildConstant(Ty, 0);
       auto MIBLen = MIRBuilder.buildConstant(Ty, Len);
       auto MIBICmp = MIRBuilder.buildICmp(CmpInst::ICMP_EQ, LLT::scalar(1),
                                           SrcReg, MIBZero);
       MIRBuilder.buildSelect(MI.getOperand(0).getReg(), MIBICmp, MIBLen,
                              MIBCtlzZU);
       MI.eraseFromParent();
       return Legalized;
     }
     // for now, we do this:
     // NewLen = NextPowerOf2(Len);
     // x = x | (x >> 1);
     // x = x | (x >> 2);
     // ...
     // x = x | (x >>16);
     // x = x | (x >>32); // for 64-bit input
     // Upto NewLen/2
     // return Len - popcount(x);
     //
     // Ref: "Hacker's Delight" by Henry Warren
     Register Op = SrcReg;
     unsigned NewLen = PowerOf2Ceil(Len);
     for (unsigned i = 0; (1U << i) <= (NewLen / 2); ++i) {
       auto MIBShiftAmt = MIRBuilder.buildConstant(Ty, 1ULL << i);
-      auto MIBOp = MIRBuilder.buildInstr(
-          TargetOpcode::G_OR, {Ty},
-          {Op, MIRBuilder.buildInstr(TargetOpcode::G_LSHR, {Ty},
-                                     {Op, MIBShiftAmt})});
+      auto MIBOp =
+          MIRBuilder.buildOr(Ty, Op, MIRBuilder.buildLShr(Ty, Op, MIBShiftAmt));
       Op = MIBOp->getOperand(0).getReg();
     }
-    auto MIBPop = MIRBuilder.buildInstr(TargetOpcode::G_CTPOP, {Ty}, {Op});
-    MIRBuilder.buildInstr(TargetOpcode::G_SUB, {MI.getOperand(0).getReg()},
-                          {MIRBuilder.buildConstant(Ty, Len), MIBPop});
+    auto MIBPop = MIRBuilder.buildCTPOP(Ty, Op);
+    MIRBuilder.buildSub(MI.getOperand(0).getReg(),
+                        MIRBuilder.buildConstant(Ty, Len), MIBPop);
     MI.eraseFromParent();
     return Legalized;
   }
   case TargetOpcode::G_CTTZ_ZERO_UNDEF: {
     // This trivially expands to CTTZ.
     Observer.changingInstr(MI);
     MI.setDesc(TII.get(TargetOpcode::G_CTTZ));
     Observer.changedInstr(MI);
     return Legalized;
   }
   case TargetOpcode::G_CTTZ: {
     Register SrcReg = MI.getOperand(1).getReg();
     unsigned Len = Ty.getSizeInBits();
     if (isSupported({TargetOpcode::G_CTTZ_ZERO_UNDEF, {Ty, Ty}})) {
       // If CTTZ_ZERO_UNDEF is legal or custom, emit that and a select with
       // zero.
-      auto MIBCttzZU = MIRBuilder.buildInstr(TargetOpcode::G_CTTZ_ZERO_UNDEF,
-                                             {Ty}, {SrcReg});
+      auto MIBCttzZU = MIRBuilder.buildCTTZ_ZERO_UNDEF(Ty, SrcReg);
       auto MIBZero = MIRBuilder.buildConstant(Ty, 0);
       auto MIBLen = MIRBuilder.buildConstant(Ty, Len);
       auto MIBICmp = MIRBuilder.buildICmp(CmpInst::ICMP_EQ, LLT::scalar(1),
                                           SrcReg, MIBZero);
       MIRBuilder.buildSelect(MI.getOperand(0).getReg(), MIBICmp, MIBLen,
                              MIBCttzZU);
       MI.eraseFromParent();
       return Legalized;
     }
     // for now, we use: { return popcount(~x & (x - 1)); }
     // unless the target has ctlz but not ctpop, in which case we use:
     // { return 32 - nlz(~x & (x-1)); }
     // Ref: "Hacker's Delight" by Henry Warren
     auto MIBCstNeg1 = MIRBuilder.buildConstant(Ty, -1);
-    auto MIBNot =
-        MIRBuilder.buildInstr(TargetOpcode::G_XOR, {Ty}, {SrcReg, MIBCstNeg1});
-    auto MIBTmp = MIRBuilder.buildInstr(
-        TargetOpcode::G_AND, {Ty},
-        {MIBNot, MIRBuilder.buildInstr(TargetOpcode::G_ADD, {Ty},
-                                       {SrcReg, MIBCstNeg1})});
+    auto MIBNot = MIRBuilder.buildXor(Ty, SrcReg, MIBCstNeg1);
+    auto MIBTmp = MIRBuilder.buildAnd(
+        Ty, MIBNot, MIRBuilder.buildAdd(Ty, SrcReg, MIBCstNeg1));
     if (!isSupported({TargetOpcode::G_CTPOP, {Ty, Ty}}) &&
         isSupported({TargetOpcode::G_CTLZ, {Ty, Ty}})) {
       auto MIBCstLen = MIRBuilder.buildConstant(Ty, Len);
-      MIRBuilder.buildInstr(
-          TargetOpcode::G_SUB, {MI.getOperand(0).getReg()},
-          {MIBCstLen,
-           MIRBuilder.buildInstr(TargetOpcode::G_CTLZ, {Ty}, {MIBTmp})});
+      MIRBuilder.buildSub(MI.getOperand(0).getReg(), MIBCstLen,
+                          MIRBuilder.buildCTLZ(Ty, MIBTmp));
       MI.eraseFromParent();
       return Legalized;
     }
     MI.setDesc(TII.get(TargetOpcode::G_CTPOP));
     MI.getOperand(1).setReg(MIBTmp->getOperand(0).getReg());
     return Legalized;
   }
   }