[SubZero] Vector types support for MIPS

src/IceTargetLoweringMIPS32.cpp

Index: src/IceTargetLoweringMIPS32.cpp
diff --git a/src/IceTargetLoweringMIPS32.cpp b/src/IceTargetLoweringMIPS32.cpp
index 6d6c6b9316f43f8e48f4e759d7493ea7a7eea595..daf7f97556f609a9cecf2fad14e6020003c5ead1 100644
--- a/src/IceTargetLoweringMIPS32.cpp
+++ b/src/IceTargetLoweringMIPS32.cpp
@@ -90,8 +90,9 @@ constexpr uint32_t MIPS32_STACK_ALIGNMENT_BYTES = 16;
 // stack alignment required for the given type.
 uint32_t applyStackAlignmentTy(uint32_t Value, Type Ty) {
   size_t typeAlignInBytes = typeWidthInBytes(Ty);
+  // Vectors are stored on stack with the same alignment as that of int type
   if (isVectorType(Ty))
-    UnimplementedError(getFlags());
+    typeAlignInBytes = typeWidthInBytes(IceType_i32);
   return Utils::applyAlignment(Value, typeAlignInBytes);
 }
 
@@ -228,19 +229,9 @@ void TargetMIPS32::genTargetHelperCallFor(Inst *Instr) {
     const InstArithmetic::OpKind Op =
         llvm::cast<InstArithmetic>(Instr)->getOp();
     if (isVectorType(DestTy)) {
-      switch (Op) {
-      default:
-        break;
-      case InstArithmetic::Fdiv:
-      case InstArithmetic::Frem:
-      case InstArithmetic::Sdiv:
-      case InstArithmetic::Srem:
-      case InstArithmetic::Udiv:
-      case InstArithmetic::Urem:
-        scalarizeArithmetic(Op, Dest, Instr->getSrc(0), Instr->getSrc(1));
-        Instr->setDeleted();
-        return;
-      }
+      scalarizeArithmetic(Op, Dest, Instr->getSrc(0), Instr->getSrc(1));
+      Instr->setDeleted();
+      return;
     }
     switch (DestTy) {
     default:
@@ -303,7 +294,6 @@ void TargetMIPS32::genTargetHelperCallFor(Inst *Instr) {
     const Type SrcTy = Src0->getType();
     auto *CastInstr = llvm::cast<InstCast>(Instr);
     const InstCast::OpKind CastKind = CastInstr->getCastKind();
-
     switch (CastKind) {
     default:
       return;
@@ -424,6 +414,39 @@ void TargetMIPS32::genTargetHelperCallFor(Inst *Instr) {
     Variable *Dest = Instr->getDest();
     auto *IntrinsicCall = llvm::cast<InstIntrinsicCall>(Instr);
     Intrinsics::IntrinsicID ID = IntrinsicCall->getIntrinsicInfo().ID;
+    if (Dest && isVectorType(Dest->getType()) && ID == Intrinsics::Fabs) {
+      Operand *Src0 = IntrinsicCall->getArg(0);
+      GlobalString FabsFloat = Ctx->getGlobalString("llvm.fabs.f32");
+      Operand *CallTarget = Ctx->getConstantExternSym(FabsFloat);
+      GlobalString FabsVec = Ctx->getGlobalString("llvm.fabs.v4f32");
+      bool BadIntrinsic = false;
+      const Intrinsics::FullIntrinsicInfo *FullInfo =
+          Ctx->getIntrinsicsInfo().find(FabsVec, BadIntrinsic);
+      Intrinsics::IntrinsicInfo Info = FullInfo->Info;
+
+      Variable *T = Func->makeVariable(IceType_v4f32);
+      auto *VarVecOn32 = llvm::dyn_cast<VariableVecOn32>(T);
+      VarVecOn32->initVecElement(Func, IceType_v4f32);
+      Context.insert<InstFakeDef>(T);
+
+      for (SizeT I = 0; I < 4; ++I) {
+        auto *Index = Ctx->getConstantInt32(I);
+        auto *Op = Func->makeVariable(IceType_f32);
+        Context.insert<InstExtractElement>(Op, Src0, Index);
+        auto *Res = Func->makeVariable(IceType_f32);
+        Variable *DestT = Func->makeVariable(IceType_v4f32);
+        auto *Call =
+            Context.insert<InstIntrinsicCall>(1, Res, CallTarget, Info);
+        Call->addArg(Op);
+        Context.insert<InstInsertElement>(DestT, T, Res, Index);
+        T = DestT;
+      }
+
+      Context.insert<InstAssign>(Dest, T);
+
+      Instr->setDeleted();
+      return;
+    }
     switch (ID) {
     default:
       return;
@@ -788,8 +811,17 @@ Operand *TargetMIPS32::legalizeUndef(Operand *From, RegNumT RegNum) {
     // overestimated.  If the constant being lowered is a 64 bit value,
     // then the result should be split and the lo and hi components will
     // need to go in uninitialized registers.
-    if (isVectorType(Ty))
-      UnimplementedError(getFlags());
+    if (isVectorType(Ty)) {
+      Variable *Var = makeReg(Ty, RegNum);
+      auto *Reg = llvm::cast<VariableVecOn32>(Var);
+      Reg->initVecElement(Func, Ty);
+      auto *Zero = getZero();
+      Context.insert<InstFakeDef>(Zero);
+      for (SizeT I = 0; I < Reg->getNumContainers(); I++) {
+        _mov(Reg->getContainerAtIndex(I), Zero);
+      }
+      return Reg;
+    }
     return Ctx->getConstantZero(Ty);
   }
   return From;
@@ -859,7 +891,7 @@ TargetMIPS32::CallingConv::CallingConv()
 // number to make register allocation decisions.
 bool TargetMIPS32::CallingConv::argInReg(Type Ty, uint32_t ArgNo,
                                          RegNumT *Reg) {
-  if (isScalarIntegerType(Ty))
+  if (isScalarIntegerType(Ty) || isVectorType(Ty))
     return argInGPR(Ty, Reg);
   if (isScalarFloatingType(Ty)) {
     if (ArgNo == 0) {
@@ -884,6 +916,13 @@ bool TargetMIPS32::CallingConv::argInGPR(Type Ty, RegNumT *Reg) {
     UnimplementedError(getFlags());
     return false;
   } break;
+  case IceType_v4i1:
+  case IceType_v8i1:
+  case IceType_v16i1:
+  case IceType_v16i8:
+  case IceType_v8i16:
+  case IceType_v4i32:
+  case IceType_v4f32:
   case IceType_i32:
   case IceType_f32: {
     Source = &GPRArgs;
@@ -896,6 +935,12 @@ bool TargetMIPS32::CallingConv::argInGPR(Type Ty, RegNumT *Reg) {
 
   discardUnavailableGPRsAndTheirAliases(Source);
 
+  // If $4 is used for any scalar type (or returining v4f32) then the next
+  // vector type if passed in $6:$7:stack:stack
+  if (isVectorType(Ty)) {
+    alignGPR(Source);
+  }
+
   if (Source->empty()) {
     GPRegsUsed.set();
     return false;
@@ -907,6 +952,21 @@ bool TargetMIPS32::CallingConv::argInGPR(Type Ty, RegNumT *Reg) {
   // Source->back() is marked as unavailable, and it is thus implicitly popped
   // from the stack.
   GPRegsUsed |= RegisterAliases[*Reg];
+
+  // All vector arguments irrespective of their base type are passed in GP
+  // registers. First vector argument is passed in $4:$5:$6:$7 and 2nd
+  // is passed in $6:$7:stack:stack. If it is 1st argument then discard
+  // $4:$5:$6:$7 otherwise discard $6:$7 only.
+  if (isVectorType(Ty)) {
+    if (((unsigned)*Reg) == RegMIPS32::Reg_A0) {
+      GPRegsUsed |= RegisterAliases[RegMIPS32::Reg_A1];
+      GPRegsUsed |= RegisterAliases[RegMIPS32::Reg_A2];
+      GPRegsUsed |= RegisterAliases[RegMIPS32::Reg_A3];
+    } else {
+      GPRegsUsed |= RegisterAliases[RegMIPS32::Reg_A3];
+    }
+  }
+
   return true;
 }
 
@@ -997,6 +1057,27 @@ void TargetMIPS32::lowerArguments() {
   Context.init(Func->getEntryNode());
   Context.setInsertPoint(Context.getCur());
 
+  // v4f32 is returned through stack. $4 is setup by the caller and passed as
+  // first argument implicitly. Callee then copies the return vector at $4.
+  if (isVectorFloatingType(Func->getReturnType())) {
+    Variable *ImplicitRetVec = Func->makeVariable(IceType_i32);
+    ImplicitRetVec->setName(Func, "ImplicitRet_v4f32");
+    ImplicitRetVec->setIsArg();
+    Args.insert(Args.begin(), ImplicitRetVec);
+    Func->setImplicitRet(ImplicitRetVec);
+    Context.insert<InstFakeDef>(ImplicitRetVec);
+    for (CfgNode *Node : Func->getNodes()) {
+      for (Inst &Instr : Node->getInsts()) {
+        if (llvm::isa<InstRet>(&Instr)) {
+          Context.setInsertPoint(Instr);
+          Context.insert<InstFakeUse>(ImplicitRetVec);
+          break;
+        }
+      }
+    }
+    Context.setInsertPoint(Context.getCur());
+  }
+
   for (SizeT I = 0, E = Args.size(); I < E; ++I) {
     Variable *Arg = Args[I];
     Type Ty = Arg->getType();
@@ -1011,16 +1092,40 @@ void TargetMIPS32::lowerArguments() {
     RegisterArg->setIsArg();
     Arg->setIsArg(false);
     Args[I] = RegisterArg;
-    switch (Ty) {
-    default: { RegisterArg->setRegNum(RegNum); } break;
-    case IceType_i64: {
-      auto *RegisterArg64 = llvm::cast<Variable64On32>(RegisterArg);
-      RegisterArg64->initHiLo(Func);
-      RegisterArg64->getLo()->setRegNum(
-          RegNumT::fixme(RegMIPS32::get64PairFirstRegNum(RegNum)));
-      RegisterArg64->getHi()->setRegNum(
-          RegNumT::fixme(RegMIPS32::get64PairSecondRegNum(RegNum)));
-    } break;
+
+    if (isVectorType(Ty)) {
+      auto *RegisterArgVec = llvm::cast<VariableVecOn32>(RegisterArg);
+      RegisterArgVec->initVecElement(Func, Ty);
+      RegisterArgVec->getContainerAtIndex(0)
+          ->setRegNum(RegNumT::fixme((unsigned)RegNum + 0));
+      RegisterArgVec->getContainerAtIndex(1)
+          ->setRegNum(RegNumT::fixme((unsigned)RegNum + 1));
+      // First two elements of second vector argument are passed
+      // in $6:$7 and remaining two on stack. Do not assign register
+      // to this is second vector argument.
+      if (I == 0) {
+        RegisterArgVec->getContainerAtIndex(2)
+            ->setRegNum(RegNumT::fixme((unsigned)RegNum + 2));
+        RegisterArgVec->getContainerAtIndex(3)
+            ->setRegNum(RegNumT::fixme((unsigned)RegNum + 3));
+      } else {
+        RegisterArgVec->getContainerAtIndex(2)
+            ->setRegNum(RegNumT::fixme(RegNumT()));
+        RegisterArgVec->getContainerAtIndex(3)
+            ->setRegNum(RegNumT::fixme(RegNumT()));
+      }
+    } else {
+      switch (Ty) {
+      default: { RegisterArg->setRegNum(RegNum); } break;
+      case IceType_i64: {
+        auto *RegisterArg64 = llvm::cast<Variable64On32>(RegisterArg);
+        RegisterArg64->initHiLo(Func);
+        RegisterArg64->getLo()->setRegNum(
+            RegNumT::fixme(RegMIPS32::get64PairFirstRegNum(RegNum)));
+        RegisterArg64->getHi()->setRegNum(
+            RegNumT::fixme(RegMIPS32::get64PairSecondRegNum(RegNum)));
+      } break;
+      }
     }
     Context.insert<InstAssign>(Arg, RegisterArg);
   }
@@ -1036,20 +1141,46 @@ Type TargetMIPS32::stackSlotType() { return IceType_i32; }
 // recursively on the components, taking care to handle Lo first because of the
 // little-endian architecture. Lastly, this function generates an instruction
 // to copy Arg into its assigned register if applicable.
-void TargetMIPS32::finishArgumentLowering(Variable *Arg, Variable *FramePtr,
+void TargetMIPS32::finishArgumentLowering(Variable *Arg, bool PartialOnStack,
+                                          Variable *FramePtr,
                                           size_t BasicFrameOffset,
                                           size_t *InArgsSizeBytes) {
   const Type Ty = Arg->getType();
   *InArgsSizeBytes = applyStackAlignmentTy(*InArgsSizeBytes, Ty);
 
+  // If $4 is used for any scalar type (or returining v4f32) then the next
+  // vector type if passed in $6:$7:stack:stack. Load 3nd and 4th element
+  // from agument stack.
+  if (auto *ArgVecOn32 = llvm::dyn_cast<VariableVecOn32>(Arg)) {
+    if (PartialOnStack == false) {
+      auto *Elem0 = ArgVecOn32->getContainerAtIndex(0);
+      auto *Elem1 = ArgVecOn32->getContainerAtIndex(1);
+      finishArgumentLowering(Elem0, PartialOnStack, FramePtr, BasicFrameOffset,
+                             InArgsSizeBytes);
+      finishArgumentLowering(Elem1, PartialOnStack, FramePtr, BasicFrameOffset,
+                             InArgsSizeBytes);
+    }
+    auto *Elem2 = ArgVecOn32->getContainerAtIndex(2);
+    auto *Elem3 = ArgVecOn32->getContainerAtIndex(3);
+    finishArgumentLowering(Elem2, PartialOnStack, FramePtr, BasicFrameOffset,
+                           InArgsSizeBytes);
+    finishArgumentLowering(Elem3, PartialOnStack, FramePtr, BasicFrameOffset,
+                           InArgsSizeBytes);
+    return;
+  }
+
   if (auto *Arg64On32 = llvm::dyn_cast<Variable64On32>(Arg)) {
     Variable *const Lo = Arg64On32->getLo();
     Variable *const Hi = Arg64On32->getHi();
-    finishArgumentLowering(Lo, FramePtr, BasicFrameOffset, InArgsSizeBytes);
-    finishArgumentLowering(Hi, FramePtr, BasicFrameOffset, InArgsSizeBytes);
+    finishArgumentLowering(Lo, PartialOnStack, FramePtr, BasicFrameOffset,
+                           InArgsSizeBytes);
+    finishArgumentLowering(Hi, PartialOnStack, FramePtr, BasicFrameOffset,
+                           InArgsSizeBytes);
     return;
   }
+
   assert(Ty != IceType_i64);
+  assert(!isVectorType(Ty));
 
   const int32_t ArgStackOffset = BasicFrameOffset + *InArgsSizeBytes;
   *InArgsSizeBytes += typeWidthInBytesOnStack(Ty);
@@ -1262,13 +1393,25 @@ void TargetMIPS32::addProlog(CfgNode *Node) {
   for (Variable *Arg : Args) {
     RegNumT DummyReg;
     const Type Ty = Arg->getType();
+    bool PartialOnStack;
     // Skip arguments passed in registers.
     if (CC.argInReg(Ty, ArgNo, &DummyReg)) {
-      ArgNo++;
-      continue;
+      // Load argument from stack:
+      // 1. If this is first vector argument and return type is v4f32.
+      //    In this case $4 is used to pass stack address implicitly.
+      //    3rd and 4th element of vector argument is passed through stack.
+      // 2. If this is second vector argument.
+      if (ArgNo != 0 && isVectorType(Ty)) {
+        PartialOnStack = true;
+        finishArgumentLowering(Arg, PartialOnStack, FP, TotalStackSizeBytes,
+                               &InArgsSizeBytes);
+      }
     } else {
-      finishArgumentLowering(Arg, FP, TotalStackSizeBytes, &InArgsSizeBytes);
+      PartialOnStack = false;
+      finishArgumentLowering(Arg, PartialOnStack, FP, TotalStackSizeBytes,
+                             &InArgsSizeBytes);
     }
+    ArgNo++;
   }
 
   // Fill in stack offsets for locals.
@@ -1571,6 +1714,47 @@ Operand *TargetMIPS32::loOperand(Operand *Operand) {
   return nullptr;
 }
 
+Operand *TargetMIPS32::getOperandAtIndex(Operand *Operand, Type BaseType,
+                                         uint32_t Index) {
+  if (!isVectorType(Operand->getType())) {
+    llvm::report_fatal_error("getOperandAtIndex: Operand is not vector");
+    return nullptr;
+  }
+
+  if (auto *Const = llvm::dyn_cast<ConstantInteger64>(Operand)) {
+    llvm::report_fatal_error("getOperandAtIndex: Operand is 64-bit constant");
+    return nullptr;
+  }
+
+  if (auto *Mem = llvm::dyn_cast<OperandMIPS32Mem>(Operand)) {
+    assert(Mem->getAddrMode() == OperandMIPS32Mem::Offset);
+    Variable *Base = Mem->getBase();
+    auto *Offset = llvm::cast<ConstantInteger32>(Mem->getOffset());
+    assert(!Utils::WouldOverflowAdd(Offset->getValue(), 4));
+    int32_t NextOffsetVal =
+        Offset->getValue() + (Index * typeWidthInBytes(BaseType));
+    constexpr bool SignExt = false;
+    if (!OperandMIPS32Mem::canHoldOffset(BaseType, SignExt, NextOffsetVal)) {
+      Constant *Four = Ctx->getConstantInt32(4);
+      Variable *NewBase = Func->makeVariable(Base->getType());
+      lowerArithmetic(InstArithmetic::create(Func, InstArithmetic::Add, NewBase,
+                                             Base, Four));
+      Base = NewBase;
+    } else {
+      Offset =
+          llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(NextOffsetVal));
+    }
+    return OperandMIPS32Mem::create(Func, BaseType, Base, Offset,
+                                    Mem->getAddrMode());
+  }
+
+  if (auto *VarVecOn32 = llvm::dyn_cast<VariableVecOn32>(Operand))
+    return VarVecOn32->getContainerAtIndex(Index);
+
+  llvm_unreachable("Unsupported operand type");
+  return nullptr;
+}
+
 Operand *TargetMIPS32::hiOperand(Operand *Operand) {
   assert(Operand->getType() == IceType_i64);
   if (Operand->getType() != IceType_i64)
@@ -2005,6 +2189,16 @@ void TargetMIPS32::lowerAssign(const InstAssign *Instr) {
     _mov(DestLo, T_Lo);
     _mov(T_Hi, Src0Hi);
     _mov(DestHi, T_Hi);
+  } else if (isVectorType(Dest->getType())) {
+    auto *DstVec = llvm::dyn_cast<VariableVecOn32>(Dest);
+    for (size_t I = 0; I < DstVec->getNumContainers(); I++) {
+      auto *DCont = DstVec->getContainerAtIndex(I);
+      auto *SCont = legalize(
+          getOperandAtIndex(Src0, DstVec->getContainerType(), I), Legal_Reg);
+      auto *TReg = makeReg(DstVec->getContainerType());
+      _mov(TReg, SCont);
+      _mov(DCont, TReg);
+    }
   } else {
     Operand *SrcR;
     if (Dest->hasReg()) {
@@ -2018,11 +2212,7 @@ void TargetMIPS32::lowerAssign(const InstAssign *Instr) {
       // legalize this to a register.
       SrcR = legalize(Src0, Legal_Reg);
     }
-    if (isVectorType(Dest->getType())) {
-      UnimplementedLoweringError(this, Instr);
-    } else {
-      _mov(Dest, SrcR);
-    }
+    _mov(Dest, SrcR);
   }
 }
 
@@ -2112,6 +2302,7 @@ void TargetMIPS32::lowerBr(const InstBr *Instr) {
 }
 
 void TargetMIPS32::lowerCall(const InstCall *Instr) {
+  CfgVector<Variable *> RegArgs;
   NeedsStackAlignment = true;
 
   //  Assign arguments to registers and stack. Also reserve stack.
@@ -2127,23 +2318,78 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
   // Classify each argument operand according to the location where the
   // argument is passed.
 
-  for (SizeT i = 0, NumArgs = Instr->getNumArgs(); i < NumArgs; ++i) {
-    Operand *Arg = legalizeUndef(Instr->getArg(i));
+  // v4f32 is returned through stack. $4 is setup by the caller and passed as
+  // first argument implicitly. Callee then copies the return vector at $4.
+  SizeT ArgNum = 0;
+  Variable *Dest = Instr->getDest();
+  Variable *RetVecFloat = nullptr;
+  if (Dest && isVectorFloatingType(Dest->getType())) {
+    ArgNum = 1;
+    CC.discardReg(RegMIPS32::Reg_A0);
+    RetVecFloat = Func->makeVariable(IceType_i32);
+    auto *ByteCount = ConstantInteger32::create(Ctx, IceType_i32, 16);
+    constexpr SizeT Alignment = 4;
+    lowerAlloca(InstAlloca::create(Func, RetVecFloat, ByteCount, Alignment));
+    RegArgs.emplace_back(
+        legalizeToReg(RetVecFloat, RegNumT::fixme(RegMIPS32::Reg_A0)));
+  }
+
+  for (SizeT I = 0, NumArgs = Instr->getNumArgs(); I < NumArgs; ++I) {
+    Operand *Arg = legalizeUndef(Instr->getArg(I));
     const Type Ty = Arg->getType();
     bool InReg = false;
     RegNumT Reg;
 
-    InReg = CC.argInReg(Ty, i, &Reg);
+    InReg = CC.argInReg(Ty, I, &Reg);
 
     if (!InReg) {
-      ParameterAreaSizeBytes =
-          applyStackAlignmentTy(ParameterAreaSizeBytes, Ty);
-      StackArgs.push_back(std::make_pair(Arg, ParameterAreaSizeBytes));
-      ParameterAreaSizeBytes += typeWidthInBytesOnStack(Ty);
+      if (isVectorType(Ty)) {
+        auto *ArgVec = llvm::cast<VariableVecOn32>(Arg);
+        for (SizeT I = 0; I < ArgVec->getNumContainers(); I++) {
+          Operand *Elem = ArgVec->getContainerAtIndex(I);
+          ParameterAreaSizeBytes =
+              applyStackAlignmentTy(ParameterAreaSizeBytes, IceType_i32);
+          StackArgs.push_back(std::make_pair(Elem, ParameterAreaSizeBytes));
+          ParameterAreaSizeBytes += typeWidthInBytesOnStack(IceType_i32);
+        }
+      } else {
+        ParameterAreaSizeBytes =
+            applyStackAlignmentTy(ParameterAreaSizeBytes, Ty);
+        StackArgs.push_back(std::make_pair(Arg, ParameterAreaSizeBytes));
+        ParameterAreaSizeBytes += typeWidthInBytesOnStack(Ty);
+      }
+      ArgNum++;
       continue;
     }
 
-    if (Ty == IceType_i64) {
+    if (isVectorType(Ty)) {
+      auto *ArgVec = llvm::cast<VariableVecOn32>(Arg);
+      Operand *Elem0 = ArgVec->getContainerAtIndex(0);
+      Operand *Elem1 = ArgVec->getContainerAtIndex(1);
+      GPRArgs.push_back(
+          std::make_pair(Elem0, RegNumT::fixme((unsigned)Reg + 0)));
+      GPRArgs.push_back(
+          std::make_pair(Elem1, RegNumT::fixme((unsigned)Reg + 1)));
+      Operand *Elem2 = ArgVec->getContainerAtIndex(2);
+      Operand *Elem3 = ArgVec->getContainerAtIndex(3);
+      // First argument is passed in $4:$5:$6:$7
+      // Second and rest arguments are passed in $6:$7:stack:stack
+      if (ArgNum == 0) {
+        GPRArgs.push_back(
+            std::make_pair(Elem2, RegNumT::fixme((unsigned)Reg + 2)));
+        GPRArgs.push_back(
+            std::make_pair(Elem3, RegNumT::fixme((unsigned)Reg + 3)));
+      } else {
+        ParameterAreaSizeBytes =
+            applyStackAlignmentTy(ParameterAreaSizeBytes, IceType_i32);
+        StackArgs.push_back(std::make_pair(Elem2, ParameterAreaSizeBytes));
+        ParameterAreaSizeBytes += typeWidthInBytesOnStack(IceType_i32);
+        ParameterAreaSizeBytes =
+            applyStackAlignmentTy(ParameterAreaSizeBytes, IceType_i32);
+        StackArgs.push_back(std::make_pair(Elem3, ParameterAreaSizeBytes));
+        ParameterAreaSizeBytes += typeWidthInBytesOnStack(IceType_i32);
+      }
+    } else if (Ty == IceType_i64) {
       Operand *Lo = loOperand(Arg);
       Operand *Hi = hiOperand(Arg);
       GPRArgs.push_back(
@@ -2155,6 +2401,7 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
     } else {
       FPArgs.push_back(std::make_pair(Arg, Reg));
     }
+    ArgNum++;
   }
 
   // Adjust the parameter area so that the stack is aligned. It is assumed that
@@ -2183,7 +2430,7 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
 
   // Generate the call instruction.  Assign its result to a temporary with high
   // register allocation weight.
-  Variable *Dest = Instr->getDest();
+
   // ReturnReg doubles as ReturnRegLo as necessary.
   Variable *ReturnReg = nullptr;
   Variable *ReturnRegHi = nullptr;
@@ -2215,10 +2462,19 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
     case IceType_v16i1:
     case IceType_v16i8:
     case IceType_v8i16:
-    case IceType_v4i32:
+    case IceType_v4i32: {
+      ReturnReg = makeReg(Dest->getType(), RegMIPS32::Reg_V0);
+      auto *RetVec = llvm::dyn_cast<VariableVecOn32>(ReturnReg);
+      RetVec->initVecElement(Func, Dest->getType());
+      for (SizeT I = 0; I < RetVec->getNumContainers(); I++) {
+        RetVec->getContainerAtIndex(I)
+            ->setRegNum(RegNumT::fixme(RegMIPS32::Reg_V0 + I));
+      }
+      break;
+    }
     case IceType_v4f32:
-      UnimplementedLoweringError(this, Instr);
-      return;
+      ReturnReg = makeReg(IceType_i32, RegMIPS32::Reg_V0);
+      break;
     }
   }
   Operand *CallTarget = Instr->getCallTarget();
@@ -2230,7 +2486,6 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
   }
 
   // Copy arguments to be passed in registers to the appropriate registers.
-  CfgVector<Variable *> RegArgs;
   for (auto &FPArg : FPArgs) {
     RegArgs.emplace_back(legalizeToReg(FPArg.first, FPArg.second));
   }
@@ -2251,7 +2506,16 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
   if (VariableAllocaUsed)
     _addiu(SP, SP, -MaxOutArgsSizeBytes);
 
-  Inst *NewCall = InstMIPS32Call::create(Func, ReturnReg, CallTarget);
+  Inst *NewCall;
+
+  // We don't need to define the return register if it is a vector.
+  // We have inserted fake defs of it just after the call.
+  if (ReturnReg && isVectorIntegerType(ReturnReg->getType())) {
+    Variable *RetReg = nullptr;
+    NewCall = InstMIPS32Call::create(Func, RetReg, CallTarget);
+  } else {
+    NewCall = InstMIPS32Call::create(Func, ReturnReg, CallTarget);
+  }
   Context.insert(NewCall);
 
   if (VariableAllocaUsed)
@@ -2263,18 +2527,51 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
 
   if (ReturnRegHi)
     Context.insert(InstFakeDef::create(Func, ReturnRegHi));
+
+  if (ReturnReg) {
+    if (auto *RetVec = llvm::dyn_cast<VariableVecOn32>(ReturnReg)) {
+      for (SizeT I = 0; I < RetVec->getNumContainers(); I++) {
+        Context.insert(
+            InstFakeDef::create(Func, RetVec->getContainerAtIndex(I)));
+      }
+    }
+  }
+
   // Insert a register-kill pseudo instruction.
   Context.insert(InstFakeKill::create(Func, NewCall));
+
   // Generate a FakeUse to keep the call live if necessary.
   if (Instr->hasSideEffects() && ReturnReg) {
-    Context.insert<InstFakeUse>(ReturnReg);
+    if (auto *RetVec = llvm::dyn_cast<VariableVecOn32>(ReturnReg)) {
+      for (SizeT I = 0; I < RetVec->getNumContainers(); I++) {
+        Context.insert<InstFakeUse>(RetVec->getContainerAtIndex(I));
+      }
+    } else {
+      Context.insert<InstFakeUse>(ReturnReg);
+    }
   }
+
   if (Dest == nullptr)
     return;
 
   // Assign the result of the call to Dest.
   if (ReturnReg) {
-    if (ReturnRegHi) {
+    if (RetVecFloat) {
+      auto *DestVecOn32 = llvm::cast<VariableVecOn32>(Dest);
+      for (SizeT I = 0; I < DestVecOn32->getNumContainers(); I++) {
+        OperandMIPS32Mem *Mem = OperandMIPS32Mem::create(
+            Func, IceType_i32, RetVecFloat,
+            llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(I * 4)));
+        Variable *Dest = DestVecOn32->getContainerAtIndex(I);
+        _lw(Dest, Mem);
+      }
+    } else if (auto *RetVec = llvm::dyn_cast<VariableVecOn32>(ReturnReg)) {
+      auto *DestVecOn32 = llvm::cast<VariableVecOn32>(Dest);
+      for (SizeT I = 0; I < DestVecOn32->getNumContainers(); I++) {
+        Variable *Dest = DestVecOn32->getContainerAtIndex(I);
+        _mov(Dest, RetVec->getContainerAtIndex(I));
+      }
+    } else if (ReturnRegHi) {
       assert(Dest->getType() == IceType_i64);
       auto *Dest64On32 = llvm::cast<Variable64On32>(Dest);
       Variable *DestLo = Dest64On32->getLo();
@@ -2286,12 +2583,7 @@ void TargetMIPS32::lowerCall(const InstCall *Instr) {
              Dest->getType() == IceType_i8 || Dest->getType() == IceType_i1 ||
              isScalarFloatingType(Dest->getType()) ||
              isVectorType(Dest->getType()));
-      if (isVectorType(Dest->getType())) {
-        UnimplementedLoweringError(this, Instr);
-        return;
-      } else {
-        _mov(Dest, ReturnReg);
-      }
+      _mov(Dest, ReturnReg);
     }
   }
 }
@@ -2453,7 +2745,64 @@ void TargetMIPS32::lowerCast(const InstCast *Instr) {
 }
 
 void TargetMIPS32::lowerExtractElement(const InstExtractElement *Instr) {
-  UnimplementedLoweringError(this, Instr);
+  Variable *Dest = Instr->getDest();
+  Type DestTy = Dest->getType();
+  Operand *Src1 = Instr->getSrc(1);
+  if (const auto *Imm = llvm::dyn_cast<ConstantInteger32>(Src1)) {
+    const uint32_t Index = Imm->getValue();
+    Variable *TDest = makeReg(DestTy);
+    Variable *TReg = makeReg(DestTy);
+    auto *Src0 = legalizeUndef(Instr->getSrc(0));
+    auto *Src0R = llvm::dyn_cast<VariableVecOn32>(Src0);
+    auto *SrcE = Src0R->getVecElementAtIndex(Index);
+    // Number of elements in each container
+    uint32_t ElemPerCont = Src0R->getNumElements() / Src0R->getNumContainers();
+    // Position of the element in the container
+    uint32_t PosInCont = Index % ElemPerCont;
+    if (ElemPerCont == 1) {
+      _mov(TDest, SrcE);
+    } else if (ElemPerCont == 2) {
+      switch (PosInCont) {
+      case 0:
+        _andi(TDest, SrcE, 0xffff);
+        break;
+      case 1:
+        _srl(TDest, SrcE, 16);
+        break;
+      default:
+        llvm::report_fatal_error("ExtractElement: Invalid PosInCont");
+        break;
+      }
+    } else if (ElemPerCont == 4) {
+      switch (PosInCont) {
+      case 0:
+        _andi(TDest, SrcE, 0xff);
+        break;
+      case 1:
+        _srl(TReg, SrcE, 8);
+        _andi(TDest, TReg, 0xff);
+        break;
+      case 2:
+        _srl(TReg, SrcE, 16);
+        _andi(TDest, TReg, 0xff);
+        break;
+      case 3:
+        _srl(TDest, SrcE, 24);
+        break;
+      default:
+        llvm::report_fatal_error("ExtractElement: Invalid PosInCont");
+        break;
+      }
+    }
+    if (Src0R->getElementType() == IceType_i1) {
+      _andi(TReg, TDest, 0x1);
+      _mov(Dest, TReg);
+    } else {
+      _mov(Dest, TDest);
+    }
+    return;
+  }
+  llvm::report_fatal_error("ExtractElement requires a constant index");
 }
 
 void TargetMIPS32::lowerFcmp(const InstFcmp *Instr) {
@@ -2765,7 +3114,108 @@ void TargetMIPS32::lowerIcmp(const InstIcmp *Instr) {
 }
 
 void TargetMIPS32::lowerInsertElement(const InstInsertElement *Instr) {
-  UnimplementedLoweringError(this, Instr);
+  Variable *Dest = Instr->getDest();
+  Type DestTy = Dest->getType();
+  Operand *Src2 = Instr->getSrc(2);
+  if (const auto *Imm = llvm::dyn_cast<ConstantInteger32>(Src2)) {
+    const uint32_t Index = Imm->getValue();
+    // Vector to insert in
+    auto *Src0R = llvm::dyn_cast<VariableVecOn32>(Instr->getSrc(0));
+    // Source Element
+    auto *SrcE = Src0R->getVecElementAtIndex(Index);
+    // Dest is a vector
+    auto *VDest = llvm::dyn_cast<VariableVecOn32>(Dest);
+    VDest->initVecElement(Func, DestTy);
+    // Temp vector variable
+    auto *TDest = makeReg(DestTy);
+    auto *TVDest = llvm::dyn_cast<VariableVecOn32>(TDest);
+    TVDest->initVecElement(Func, DestTy);
+    // Destination element
+    auto *DstE = TVDest->getVecElementAtIndex(Index);
+    // Element to insert
+    auto *Src1R = legalizeToReg(Instr->getSrc(1));
+    auto *TReg1 = makeReg(Src1R->getType());
+    auto *TReg2 = makeReg(Src1R->getType());
+    auto *TReg3 = makeReg(Src1R->getType());
+    auto *TReg4 = makeReg(Src1R->getType());
+    auto *TReg5 = makeReg(Src1R->getType());
+    // Number of elements in each container
+    uint32_t ElemPerCont = Src0R->getNumElements() / Src0R->getNumContainers();
+    // Position of the element in the container
+    uint32_t PosInCont = Index % ElemPerCont;
+    // Load source vector in a temporary vector
+    for (size_t I = 0; I < TVDest->getNumContainers(); I++) {
+      auto *DCont = TVDest->getContainerAtIndex(I);
+      // Do not define DstE as we are going to redefine it
+      if (DCont == DstE)
+        continue;
+      auto *SCont = Src0R->getContainerAtIndex(I);
+      auto *TReg = makeReg(TVDest->getContainerType());
+      _mov(TReg, SCont);
+      _mov(DCont, TReg);
+    }
+    // Insert the element
+    if (ElemPerCont == 1) {
+      _mov(DstE, Src1R);
+    } else if (ElemPerCont == 2) {
+      switch (PosInCont) {
+      case 0:
+        _andi(TReg1, Src1R, 0xffff); // Clear upper 16-bits of source
+        _srl(TReg2, SrcE, 16);
+        _sll(TReg3, TReg2, 16); // Clear lower 16-bits of element
+        _or(DstE, TReg1, TReg3);
+        break;
+      case 1:
+        _sll(TReg1, Src1R, 16); // Clear lower 16-bits  of source
+        _sll(TReg2, SrcE, 16);
+        _srl(TReg3, TReg2, 16); // Clear upper 16-bits of element
+        _or(DstE, TReg1, TReg3);
+        break;
+      default:
+        llvm::report_fatal_error("InsertElement: Invalid PosInCont");
+        break;
+      }
+    } else if (ElemPerCont == 4) {
+      switch (PosInCont) {
+      case 0:
+        _andi(TReg1, Src1R, 0xff); // Clear bits[31:8] of source
+        _srl(TReg2, SrcE, 8);
+        _sll(TReg3, TReg2, 8); // Clear bits[7:0] of element
+        _or(DstE, TReg1, TReg3);
+        break;
+      case 1:
+        _andi(TReg1, Src1R, 0xff); // Clear bits[31:8] of source
+        _sll(TReg5, TReg1, 8);     // Position in the destination
+        _lui(TReg2, Ctx->getConstantInt32(0xffff));
+        _ori(TReg3, TReg2, 0x00ff);
+        _and(TReg4, SrcE, TReg3); // Clear bits[15:8] of element
+        _or(DstE, TReg5, TReg4);
+        break;
+      case 2:
+        _andi(TReg1, Src1R, 0xff); // Clear bits[31:8] of source
+        _sll(TReg5, TReg1, 16);    // Position in the destination
+        _lui(TReg2, Ctx->getConstantInt32(0xff00));
+        _ori(TReg3, TReg2, 0xffff);
+        _and(TReg4, SrcE, TReg3); // Clear bits[15:8] of element
+        _or(DstE, TReg5, TReg4);
+        break;
+      case 3:
+        _srl(TReg1, Src1R, 24); // Position in the destination
+        _sll(TReg2, SrcE, 8);
+        _srl(TReg3, TReg2, 8); // Clear bits[31:24] of element
+        _or(DstE, TReg1, TReg3);
+        break;
+      default:
+        llvm::report_fatal_error("InsertElement: Invalid PosInCont");
+        break;
+      }
+    }
+    // Write back temporary vector to the destination
+    auto *Assign = InstAssign::create(Func, Dest, TDest);
+    lowerAssign(Assign);
+    return;
+  }
+  llvm::report_fatal_error("InsertElement requires a constant index");
 }
 
 void TargetMIPS32::lowerIntrinsicCall(const InstIntrinsicCall *Instr) {
@@ -3201,8 +3651,47 @@ void TargetMIPS32::lowerRet(const InstRet *Instr) {
       Context.insert<InstFakeUse>(R1);
       break;
     }
+    case IceType_v4i1:
+    case IceType_v8i1:
+    case IceType_v16i1:
+    case IceType_v16i8:
+    case IceType_v8i16:
+    case IceType_v4i32: {
+      auto *SrcVec = llvm::dyn_cast<VariableVecOn32>(Src0);
+      Variable *V0 =
+          legalizeToReg(SrcVec->getContainerAtIndex(0), RegMIPS32::Reg_V0);
+      Variable *V1 =
+          legalizeToReg(SrcVec->getContainerAtIndex(1), RegMIPS32::Reg_V1);
+      Variable *A0 =
+          legalizeToReg(SrcVec->getContainerAtIndex(2), RegMIPS32::Reg_A0);
+      Variable *A1 =
+          legalizeToReg(SrcVec->getContainerAtIndex(3), RegMIPS32::Reg_A1);
+      Reg = V0;
+      Context.insert<InstFakeUse>(V1);
+      Context.insert<InstFakeUse>(A0);
+      Context.insert<InstFakeUse>(A1);
+      break;
+    }
+    case IceType_v4f32: {
+      auto *SrcVec = llvm::dyn_cast<VariableVecOn32>(Src0);
+      Reg = Func->getImplicitRet();
+      auto *RegT = legalizeToReg(Reg);
+      // Return the vector through buffer in implicit argument a0
+      for (size_t I = 0; I < SrcVec->getNumContainers(); I++) {
+        OperandMIPS32Mem *Mem = OperandMIPS32Mem::create(
+            Func, IceType_f32, RegT,
+            llvm::cast<ConstantInteger32>(Ctx->getConstantInt32(I * 4)));
+        Variable *Var = legalizeToReg(SrcVec->getContainerAtIndex(I));
+        _sw(Var, Mem);
+      }
+      Variable *V0 = makeReg(IceType_i32, RegMIPS32::Reg_V0);
+      _mov(V0, Reg); // move v0,a0
+      Context.insert<InstFakeUse>(Reg);
+      Context.insert<InstFakeUse>(V0);
+      break;
+    }
     default:
-      UnimplementedLoweringError(this, Instr);
+      break;
     }
   }
   _ret(getPhysicalRegister(RegMIPS32::Reg_RA), Reg);
@@ -3265,6 +3754,14 @@ void TargetMIPS32::lowerStore(const InstStore *Instr) {
     Variable *ValueLo = legalizeToReg(loOperand(Value));
     _sw(ValueHi, llvm::cast<OperandMIPS32Mem>(hiOperand(NewAddr)));
     _sw(ValueLo, llvm::cast<OperandMIPS32Mem>(loOperand(NewAddr)));
+  } else if (isVectorType(Value->getType())) {
+    auto *DataVec = llvm::dyn_cast<VariableVecOn32>(Value);
+    for (size_t I = 0; I < DataVec->getNumContainers(); I++) {
+      auto *DCont = legalizeToReg(DataVec->getContainerAtIndex(I));
+      auto *MCont = llvm::cast<OperandMIPS32Mem>(
+          getOperandAtIndex(NewAddr, DataVec->getContainerType(), I));
+      _sw(DCont, MCont);
+    }
   } else {
     Variable *ValueR = legalizeToReg(Value);
     _sw(ValueR, NewAddr);
@@ -3496,7 +3993,7 @@ Variable *TargetMIPS32::copyToReg(Operand *Src, RegNumT RegNum) {
   Type Ty = Src->getType();
   Variable *Reg = makeReg(Ty, RegNum);
   if (isVectorType(Ty)) {
-    UnimplementedError(getFlags());
+    llvm::report_fatal_error("Invalid copy from vector type.");
   } else {
     if (auto *Mem = llvm::dyn_cast<OperandMIPS32Mem>(Src)) {
       _lw(Reg, Mem);
@@ -3568,6 +4065,11 @@ Operand *TargetMIPS32::legalize(Operand *From, LegalMask Allowed,
   }
 
   if (llvm::isa<Constant>(From)) {
+    if (llvm::isa<ConstantUndef>(From)) {
+      From = legalizeUndef(From, RegNum);
+      if (isVectorType(Ty))
+        return From;
+    }
     if (auto *C = llvm::dyn_cast<ConstantRelocatable>(From)) {
       (void)C;
       // TODO(reed kotler): complete this case for proper implementation
@@ -3576,23 +4078,15 @@ Operand *TargetMIPS32::legalize(Operand *From, LegalMask Allowed,
       return Reg;
     } else if (auto *C32 = llvm::dyn_cast<ConstantInteger32>(From)) {
       const uint32_t Value = C32->getValue();
-      // Check if the immediate will fit in a Flexible second operand,
-      // if a Flexible second operand is allowed. We need to know the exact
-      // value, so that rules out relocatable constants.
-      // Also try the inverse and use MVN if possible.
-      // Do a movw/movt to a register.
-      Variable *Reg;
-      if (RegNum.hasValue())
-        Reg = getPhysicalRegister(RegNum);
-      else
-        Reg = makeReg(Ty, RegNum);
+      // Use addiu if the immediate is a 16bit value. Otherwise load it
+      // using a lui-ori instructions.
+      Variable *Reg = makeReg(Ty, RegNum);
       if (isInt<16>(int32_t(Value))) {
         Variable *Zero = getPhysicalRegister(RegMIPS32::Reg_ZERO, Ty);
         Context.insert<InstFakeDef>(Zero);
         _addiu(Reg, Zero, Value);
       } else {
         uint32_t UpperBits = (Value >> 16) & 0xFFFF;
-        (void)UpperBits;
         uint32_t LowerBits = Value & 0xFFFF;
         Variable *TReg = makeReg(Ty, RegNum);
         if (LowerBits) {