Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -5851,6 +5851,114 @@
 #include "clang/Basic/BuiltinsHexagon.def"
 };
 
+class LanaiTargetInfo : public TargetInfo {
+  // Class for Lanai (32-bit).
+  // The CPU profiles supported by the Lanai backend
+  enum CPUKind {
+    CK_NONE,
+    CK_V11,
+  } CPU;
+
+  static const Builtin::Info BuiltinInfo[];
+  static const TargetInfo::GCCRegAlias GCCRegAliases[];
+  static const char *const GCCRegNames[];
+  bool SoftFloat;
+
+ public:
+  LanaiTargetInfo(const llvm::Triple &Triple) : TargetInfo(Triple) {
+    // Description string has to be kept in sync with backend.
+    DataLayoutString =
+        "E"         // Big endian
+        "-m:e"      // ELF name manging
+        "-p:32:32"  // 32 bit pointers, 32 bit aligned
+        "-i64:64"   // 64 bit integers, 64 bit aligned
+        "-a:0:32"   // 32 bit alignment of objects of aggregate type
+        "-n32"      // 32 bit native integer width
+        "-S64";     // 64 bit natural stack alignment
+
+    // Setting RegParmMax equal to what mregparm was set to in the old
+    // toolchain
+    RegParmMax = 4;
+
+    // Set the default CPU to V11
+    CPU = CK_V11;
+
+    // Temporary approach to make everything at least word-aligned and allow for
+    // safely casting between pointers with different alignment requirements.
+    // TODO: Remove this when there are no more cast align warnings on the
+    // firmware.
+    MinGlobalAlign = 32;
+  }
+
+  void getTargetDefines(const LangOptions &Opts,
+                        MacroBuilder &Builder) const override {
+    // Define __lanai__ when building for target lanai.
+    Builder.defineMacro("__lanai__");
+
+    // Set define for the CPU specified.
+    switch (CPU) {
+      case CK_V11:
+        Builder.defineMacro("__LANAI_V11__");
+        break;
+      default:
+        llvm_unreachable("Unhandled target CPU");
+    }
+  }
+
+  bool setCPU(const std::string &Name) override {
+    CPU = llvm::StringSwitch<CPUKind>(Name)
+      .Case("v11", CK_V11)
+      .Default(CK_NONE);
+
+    return CPU != CK_NONE;
+  }
+
+  bool hasFeature(StringRef Feature) const override {
+    return llvm::StringSwitch<bool>(Feature)
+             .Case("lanai", true)
+             .Default(false);
+  }
+
+  BuiltinVaListKind getBuiltinVaListKind() const override {
+    return TargetInfo::VoidPtrBuiltinVaList;
+  }
+  ArrayRef<const char *>  getGCCRegNames() const override;
+  ArrayRef<TargetInfo::GCCRegAlias>  getGCCRegAliases() const override;
+
+  ArrayRef<Builtin::Info> getTargetBuiltins() const override {
+    return None;
+  }
+
+  bool validateAsmConstraint(const char *&Name,
+                             TargetInfo::ConstraintInfo &info) const override {
+    return false;
+  }
+  const char *getClobbers() const override { return ""; }
+};
+
+const char *const LanaiTargetInfo::GCCRegNames[] = {
+    "r0",  "r1",  "r2",  "r3",  "r4",  "r5",  "r6",  "r7",  "r8",  "r9",  "r10",
+    "r11", "r12", "r13", "r14", "r15", "r16", "r17", "r18", "r19", "r20", "r21",
+    "r22", "r23", "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31"};
+
+ArrayRef<const char *> LanaiTargetInfo::getGCCRegNames() const {
+  return llvm::makeArrayRef(GCCRegNames);
+}
+
+const TargetInfo::GCCRegAlias LanaiTargetInfo::GCCRegAliases[] = {
+    {{"pc"}, "r2"},
+    {{"sp"}, "r4"},
+    {{"fp"}, "r5"},
+    {{"rv"}, "r8"},
+    {{"rr1"}, "r10"},
+    {{"rr2"}, "r11"},
+    {{"rca"}, "r15"},
+};
+
+ArrayRef<TargetInfo::GCCRegAlias> LanaiTargetInfo::getGCCRegAliases() const {
+  return llvm::makeArrayRef(GCCRegAliases);
+}
+
 // Shared base class for SPARC v8 (32-bit) and SPARC v9 (64-bit).
 class SparcTargetInfo : public TargetInfo {
   static const TargetInfo::GCCRegAlias GCCRegAliases[];
@@ -7543,6 +7651,9 @@
   case llvm::Triple::hexagon:
     return new HexagonTargetInfo(Triple);
 
+  case llvm::Triple::lanai:
+    return new LanaiTargetInfo(Triple);
+
   case llvm::Triple::aarch64:
     if (Triple.isOSDarwin())
       return new DarwinAArch64TargetInfo(Triple);
Index: lib/CodeGen/TargetInfo.cpp
===================================================================
--- lib/CodeGen/TargetInfo.cpp
+++ lib/CodeGen/TargetInfo.cpp
@@ -19,6 +19,7 @@
 #include "CodeGenFunction.h"
 #include "clang/AST/RecordLayout.h"
 #include "clang/CodeGen/CGFunctionInfo.h"
+#include "clang/Driver/DriverDiagnostic.h"
 #include "clang/Frontend/CodeGenOptions.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/Triple.h"
@@ -6488,6 +6489,107 @@
 }
 
 //===----------------------------------------------------------------------===//
+// Lanai ABI Implementation
+//===----------------------------------------------------------------------===//
+
+class LanaiABIInfo : public DefaultABIInfo {
+  enum Class { Integer, Float };
+
+  Class classify(QualType Ty) const;
+
+public:
+  LanaiABIInfo(CodeGen::CodeGenTypes &CGT) : DefaultABIInfo(CGT) {}
+
+  static bool isRegisterSize(unsigned Size) {
+    return (Size == 8 || Size == 16 || Size == 32);
+  }
+
+  bool shouldUseInReg(QualType Ty, CCState &State) const;
+
+  void computeInfo(CGFunctionInfo &FI) const override {
+    CCState State(FI.getCallingConvention());
+    // Lanai uses 4 registers to pass arguments unless the function has the
+    // regparm attribute set.
+    if (FI.getHasRegParm()) {
+      State.FreeRegs = FI.getRegParm();
+    } else {
+      State.FreeRegs = 4;
+    }
+
+    if (!getCXXABI().classifyReturnType(FI))
+      FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
+    for (auto &I : FI.arguments())
+      I.info = classifyArgumentType(I.type, State);
+  }
+
+  ABIArgInfo classifyArgumentType(QualType RetTy, CCState &State) const;
+};
+
+LanaiABIInfo::Class LanaiABIInfo::classify(QualType Ty) const {
+  const Type *T = isSingleElementStruct(Ty, getContext());
+  if (T == nullptr)
+    T = Ty.getTypePtr();
+
+  if (const BuiltinType *BT = T->getAs<BuiltinType>()) {
+    BuiltinType::Kind K = BT->getKind();
+    if (K == BuiltinType::Float || K == BuiltinType::Double)
+      return Float;
+  }
+  return Integer;
+}
+
+bool LanaiABIInfo::shouldUseInReg(QualType Ty, CCState &State) const {
+  Class C = classify(Ty);
+  if (C == Float)
+    return false;
+
+  unsigned Size = getContext().getTypeSize(Ty);
+  unsigned SizeInRegs = (Size + 31) / 32;
+
+  if (SizeInRegs == 0)
+    return false;
+
+  if (SizeInRegs > State.FreeRegs) {
+    State.FreeRegs = 0;
+    return false;
+  }
+
+  State.FreeRegs -= SizeInRegs;
+
+  return true;
+}
+
+ABIArgInfo LanaiABIInfo::classifyArgumentType(QualType Ty,
+                                              CCState &State) const {
+  if (isAggregateTypeForABI(Ty))
+    return getNaturalAlignIndirect(Ty);
+
+  // Treat an enum type as its underlying type.
+  if (const EnumType *EnumTy = Ty->getAs<EnumType>())
+    Ty = EnumTy->getDecl()->getIntegerType();
+
+  bool InReg = shouldUseInReg(Ty, State);
+  if (Ty->isPromotableIntegerType()) {
+    if (InReg) {
+      return ABIArgInfo::getDirectInReg();
+    }
+    return ABIArgInfo::getExtend();
+  }
+  if (InReg)
+    return ABIArgInfo::getDirectInReg();
+
+  return ABIArgInfo::getDirect();
+}
+
+namespace {
+class LanaiTargetCodeGenInfo : public TargetCodeGenInfo {
+public:
+  LanaiTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
+      : TargetCodeGenInfo(new LanaiABIInfo(CGT)) {}
+};
+}
+
+//===----------------------------------------------------------------------===//
 // AMDGPU ABI Implementation
 //===----------------------------------------------------------------------===//
 
@@ -7600,6 +7702,16 @@
   }
   case llvm::Triple::hexagon:
     return *(TheTargetCodeGenInfo = new HexagonTargetCodeGenInfo(Types));
+  case llvm::Triple::lanai:
+    // Allow compiling with mregparm unset (NumRegisterParameters is 0) or
+    // mregparm=4.
+    if (CodeGenOpts.NumRegisterParameters == 0 ||
+        CodeGenOpts.NumRegisterParameters == 4) {
+      return *(TheTargetCodeGenInfo = new LanaiTargetCodeGenInfo(Types));
+    } else {
+      getDiags().Report(diag::err_drv_unsupported_opt_for_target) << "-mregparm"
+                                                                  << "lanai";
+    }
   case llvm::Triple::r600:
     return *(TheTargetCodeGenInfo = new AMDGPUTargetCodeGenInfo(Types));
   case llvm::Triple::amdgcn:
Index: lib/Driver/Driver.cpp
===================================================================
--- lib/Driver/Driver.cpp
+++ lib/Driver/Driver.cpp
@@ -2344,6 +2344,9 @@
       case llvm::Triple::hexagon:
         TC = new toolchains::HexagonToolChain(*this, Target, Args);
         break;
+      case llvm::Triple::lanai:
+        TC = new toolchains::LanaiToolChain(*this, Target, Args);
+        break;
       case llvm::Triple::xcore:
         TC = new toolchains::XCoreToolChain(*this, Target, Args);
         break;
Index: lib/Driver/ToolChains.h
===================================================================
--- lib/Driver/ToolChains.h
+++ lib/Driver/ToolChains.h
@@ -867,6 +867,14 @@
   std::string LibSuffix;
 };
 
+class LLVM_LIBRARY_VISIBILITY LanaiToolChain : public Generic_ELF {
+public:
+  LanaiToolChain(const Driver &D, const llvm::Triple &Triple,
+                 const llvm::opt::ArgList &Args)
+      : Generic_ELF(D, Triple, Args) {}
+  bool IsIntegratedAssemblerDefault() const override { return true; }
+};
+
 class LLVM_LIBRARY_VISIBILITY HexagonToolChain : public Linux {
 protected:
   GCCVersion GCCLibAndIncVersion;
Index: lib/Driver/Tools.h
===================================================================
--- lib/Driver/Tools.h
+++ lib/Driver/Tools.h
@@ -82,6 +82,8 @@
                         llvm::opt::ArgStringList &CmdArgs) const;
   void AddHexagonTargetArgs(const llvm::opt::ArgList &Args,
                             llvm::opt::ArgStringList &CmdArgs) const;
+  void AddLanaiTargetArgs(const llvm::opt::ArgList &Args,
+                          llvm::opt::ArgStringList &CmdArgs) const;
   void AddWebAssemblyTargetArgs(const llvm::opt::ArgList &Args,
                                 llvm::opt::ArgStringList &CmdArgs) const;
 
Index: lib/Driver/Tools.cpp
===================================================================
--- lib/Driver/Tools.cpp
+++ lib/Driver/Tools.cpp
@@ -1555,6 +1555,13 @@
   return "";
 }
 
+static std::string getLanaiTargetCPU(const ArgList &Args) {
+  if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
+    return A->getValue();
+  }
+  return "";
+}
+
 void Clang::AddSparcTargetArgs(const ArgList &Args,
                                ArgStringList &CmdArgs) const {
   const Driver &D = getToolChain().getDriver();
@@ -1772,6 +1779,9 @@
     return "hexagon" +
            toolchains::HexagonToolChain::GetTargetCPUVersion(Args).str();
 
+  case llvm::Triple::lanai:
+    return getLanaiTargetCPU(Args);
+
   case llvm::Triple::systemz:
     return getSystemZTargetCPU(Args);
 
@@ -2081,6 +2091,16 @@
   CmdArgs.push_back("-machine-sink-split=0");
 }
 
+void Clang::AddLanaiTargetArgs(const ArgList &Args,
+                               ArgStringList &CmdArgs) const {
+  if (Arg *A = Args.getLastArg(options::OPT_mcpu_EQ)) {
+    StringRef CPUName = A->getValue();
+
+    CmdArgs.push_back("-target-cpu");
+    CmdArgs.push_back(Args.MakeArgString(CPUName));
+  }
+}
+
 void Clang::AddWebAssemblyTargetArgs(const ArgList &Args,
                                      ArgStringList &CmdArgs) const {
   // Default to "hidden" visibility.
@@ -4093,6 +4113,10 @@
     AddX86TargetArgs(Args, CmdArgs);
     break;
 
+  case llvm::Triple::lanai:
+    AddLanaiTargetArgs(Args, CmdArgs);
+    break;
+
   case llvm::Triple::hexagon:
     AddHexagonTargetArgs(Args, CmdArgs);
     break;
Index: test/CodeGen/lanai-arguments.c
===================================================================
--- test/CodeGen/lanai-arguments.c
+++ test/CodeGen/lanai-arguments.c
@@ -0,0 +1,75 @@
+// RUN: %clang_cc1 -triple wasm32-unknown-unknown %s -emit-llvm -o - \
+// RUN:   | FileCheck %s -check-prefix=LANAI
+
+// Basic argument/attribute tests for Lanai.
+
+// LANAI: define void @f0(i32 %i, i32 %j, i64 %k)
+void f0(int i, long j, long long k) {}
+
+typedef struct {
+  int aa;
+  int bb;
+} s1;
+// LANAI: define void @f1(%struct.s1* byval align 4 %i)
+void f1(s1 i) {}
+
+typedef struct {
+  int cc;
+} s2;
+// LANAI: define i32 @f2()
+s2 f2() {
+  s2 foo;
+  return foo;
+}
+
+typedef struct {
+  int cc;
+  int dd;
+} s3;
+// LANAI: define void @f3(%struct.s3* noalias sret %agg.result)
+s3 f3() {
+  s3 foo;
+  return foo;
+}
+
+// LANAI: define void @f4(i64 %i)
+void f4(long long i) {}
+
+// LANAI: define void @f5(i8 signext %a, i16 signext %b)
+void f5(char a, short b) {}
+
+// LANAI: define void @f6(i8 zeroext %a, i16 zeroext %b)
+void f6(unsigned char a, unsigned short b) {}
+
+enum my_enum {
+  ENUM1,
+  ENUM2,
+  ENUM3,
+};
+// Enums should be treated as the underlying i32.
+// LANAI: define void @f7(i32 %a)
+void f7(enum my_enum a) {}
+
+enum my_big_enum {
+  ENUM4 = 0xFFFFFFFFFFFFFFFF,
+};
+// Big enums should be treated as the underlying i64.
+// LANAI: define void @f8(i64 %a)
+void f8(enum my_big_enum a) {}
+
+union simple_union {
+  int a;
+  char b;
+};
+// Unions should be passed as byval structs.
+// LANAI: define void @f9(%union.simple_union* byval align 4 %s)
+void f9(union simple_union s) {}
+
+typedef struct {
+  int b4 : 4;
+  int b3 : 3;
+  int b8 : 8;
+} bitfield1;
+// Bitfields should be passed as byval structs.
+// LANAI: define void @f10(%struct.bitfield1* byval align 4 %bf1)
+void f10(bitfield1 bf1) {}
Index: test/CodeGen/lanai-regparm.c
===================================================================
--- test/CodeGen/lanai-regparm.c
+++ test/CodeGen/lanai-regparm.c
@@ -0,0 +1,18 @@
+// RUN: %clang_cc1 -triple lanai-unknown-unknown -mregparm 4 %s -emit-llvm -o - | FileCheck %s
+
+void f1(int a, int b, int c, int d,
+        int e, int f, int g, int h);
+
+void f2(int a, int b) __attribute((regparm(0)));
+
+void f0() {
+// CHECK: call void @f1(i32 inreg 1, i32 inreg 2, i32 inreg 3, i32 inreg 4,
+// CHECK: i32 5, i32 6, i32 7, i32 8)
+  f1(1, 2, 3, 4, 5, 6, 7, 8);
+// CHECK: call void @f2(i32 1, i32 2)
+  f2(1, 2);
+}
+
+// CHECK: declare void @f1(i32 inreg, i32 inreg, i32 inreg, i32 inreg,
+// CHECK: i32, i32, i32, i32)
+// CHECK: declare void @f2(i32, i32)
Index: test/CodeGen/target-data.c
===================================================================
--- test/CodeGen/target-data.c
+++ test/CodeGen/target-data.c
@@ -86,6 +86,10 @@
 // RUN: FileCheck %s -check-prefix=WEBASSEMBLY64
 // WEBASSEMBLY64: target datalayout = "e-m:e-p:64:64-i64:64-n32:64-S128"
 
+// RUN: %clang_cc1 -triple lanai-unknown-unknown -o - -emit-llvm %s | \
+// RUN: FileCheck %s -check-prefix=LANAI
+// LANAI: target datalayout = "E-m:e-p:32:32-i64:64-a:0:32-n32-S64"
+
 // RUN: %clang_cc1 -triple powerpc-unknown -o - -emit-llvm %s | \
 // RUN: FileCheck %s -check-prefix=PPC
 // PPC: target datalayout = "E-m:e-p:32:32-i64:64-n32"
Index: test/Driver/lanai-toolchain.c
===================================================================
--- test/Driver/lanai-toolchain.c
+++ test/Driver/lanai-toolchain.c
@@ -0,0 +1,2 @@
+// RUN: %clang -target lanai-unknown-unknown -v 2> %t
+// RUN: grep 'Target: lanai-unknown-unknown' %t
Index: test/Driver/lanai-unknown-unknown.cpp
===================================================================
--- test/Driver/lanai-unknown-unknown.cpp
+++ test/Driver/lanai-unknown-unknown.cpp
@@ -0,0 +1,86 @@
+// RUN: %clang -target lanai-unknown-unknown -### %s -emit-llvm-only -c 2>&1 \
+// RUN:   | FileCheck %s -check-prefix=ECHO
+// RUN: %clang -target lanai-unknown-unknown %s -emit-llvm -S -o - \
+// RUN:   | FileCheck %s
+
+// ECHO: {{.*}} "-cc1" {{.*}}lanai-unknown-unknown.c
+
+typedef __builtin_va_list va_list;
+typedef __SIZE_TYPE__ size_t;
+typedef __PTRDIFF_TYPE__ ptrdiff_t;
+
+extern "C" {
+
+// CHECK: @align_c = global i32 1
+int align_c = __alignof(char);
+
+// CHECK: @align_s = global i32 2
+int align_s = __alignof(short);
+
+// CHECK: @align_i = global i32 4
+int align_i = __alignof(int);
+
+// CHECK: @align_l = global i32 4
+int align_l = __alignof(long);
+
+// CHECK: @align_ll = global i32 8
+int align_ll = __alignof(long long);
+
+// CHECK: @align_p = global i32 4
+int align_p = __alignof(void*);
+
+// CHECK: @align_vl = global i32 4
+int align_vl = __alignof(va_list);
+
+// Check types
+
+// CHECK: signext i8 @check_char()
+char check_char() { return 0; }
+
+// CHECK: signext i16 @check_short()
+short check_short() { return 0; }
+
+// CHECK: i32 @check_int()
+int check_int() { return 0; }
+
+// CHECK: i32 @check_long()
+long check_long() { return 0; }
+
+// CHECK: i64 @check_longlong()
+long long check_longlong() { return 0; }
+
+// CHECK: zeroext i8 @check_uchar()
+unsigned char check_uchar() { return 0; }
+
+// CHECK: zeroext i16 @check_ushort()
+unsigned short check_ushort() { return 0; }
+
+// CHECK: i32 @check_uint()
+unsigned int check_uint() { return 0; }
+
+// CHECK: i32 @check_ulong()
+unsigned long check_ulong() { return 0; }
+
+// CHECK: i64 @check_ulonglong()
+unsigned long long check_ulonglong() { return 0; }
+
+// CHECK: i32 @check_size_t()
+size_t check_size_t() { return 0; }
+
+}
+
+template<int> void Switch();
+template<> void Switch<4>();
+template<> void Switch<8>();
+template<> void Switch<16>();
+
+void check_pointer_size() {
+  // CHECK: SwitchILi4
+  Switch<sizeof(void*)>();
+
+  // CHECK: SwitchILi8
+  Switch<sizeof(long long)>();
+
+  // CHECK: SwitchILi4
+  Switch<sizeof(va_list)>();
+}
Index: test/Preprocessor/init.c
===================================================================
--- test/Preprocessor/init.c
+++ test/Preprocessor/init.c
@@ -8412,6 +8412,9 @@
 // RUN: %clang_cc1 -triple arm-linux-androideabi -E -dM < /dev/null | FileCheck -check-prefix ANDROID %s
 // ANDROID: __ANDROID__ 1
 //
+// RUN: %clang_cc1 -triple lanai-unknown-unknown -E -dM < /dev/null | FileCheck -check-prefix LANAI %s
+// LANAI: __lanai__ 1
+//
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=powerpc64-unknown-freebsd < /dev/null | FileCheck -check-prefix PPC64-FREEBSD %s
 // PPC64-FREEBSD-NOT: #define __LONG_DOUBLE_128__ 1
 //