Index: include/llvm/ADT/Triple.h
===================================================================
--- include/llvm/ADT/Triple.h
+++ include/llvm/ADT/Triple.h
@@ -50,6 +50,7 @@
     armeb,      // ARM (big endian): armeb
     aarch64,    // AArch64 (little endian): aarch64
     aarch64_be, // AArch64 (big endian): aarch64_be
+    avr,        // AVR: Atmel AVR microcontroller
     bpfel,      // eBPF or extended BPF or 64-bit BPF (little endian)
     bpfeb,      // eBPF or extended BPF or 64-bit BPF (big endian)
     hexagon,    // Hexagon: hexagon
Index: lib/Support/Triple.cpp
===================================================================
--- lib/Support/Triple.cpp
+++ lib/Support/Triple.cpp
@@ -25,6 +25,7 @@
   case aarch64_be:  return "aarch64_be";
   case arm:         return "arm";
   case armeb:       return "armeb";
+  case avr:         return "avr";
   case bpfel:       return "bpfel";
   case bpfeb:       return "bpfeb";
   case hexagon:     return "hexagon";
@@ -80,6 +81,8 @@
   case thumb:
   case thumbeb:     return "arm";
 
+  case avr:         return "avr";
+
   case ppc64:
   case ppc64le:
   case ppc:         return "ppc";
@@ -227,6 +230,7 @@
     .Case("arm64", aarch64) // "arm64" is an alias for "aarch64"
     .Case("arm", arm)
     .Case("armeb", armeb)
+    .Case("avr", avr)
     .StartsWith("bpf", BPFArch)
     .Case("mips", mips)
     .Case("mipsel", mipsel)
@@ -343,6 +347,7 @@
     .Case("armeb", Triple::armeb)
     .Case("thumb", Triple::thumb)
     .Case("thumbeb", Triple::thumbeb)
+    .Case("avr", Triple::avr)
     .Case("msp430", Triple::msp430)
     .Cases("mips", "mipseb", "mipsallegrex", Triple::mips)
     .Cases("mipsel", "mipsallegrexel", Triple::mipsel)
@@ -1029,6 +1034,7 @@
   case llvm::Triple::UnknownArch:
     return 0;
 
+  case llvm::Triple::avr:
   case llvm::Triple::msp430:
     return 16;
 
@@ -1098,6 +1104,7 @@
   case Triple::aarch64:
   case Triple::aarch64_be:
   case Triple::amdgcn:
+  case Triple::avr:
   case Triple::bpfel:
   case Triple::bpfeb:
   case Triple::msp430:
@@ -1152,6 +1159,7 @@
   case Triple::UnknownArch:
   case Triple::arm:
   case Triple::armeb:
+  case Triple::avr:
   case Triple::hexagon:
   case Triple::kalimba:
   case Triple::msp430:
@@ -1208,6 +1216,7 @@
   case Triple::amdgcn:
   case Triple::amdil64:
   case Triple::amdil:
+  case Triple::avr:
   case Triple::hexagon:
   case Triple::hsail64:
   case Triple::hsail:
@@ -1280,6 +1289,7 @@
   case Triple::amdil64:
   case Triple::amdil:
   case Triple::arm:
+  case Triple::avr:
   case Triple::bpfel:
   case Triple::hexagon:
   case Triple::hsail64:
Index: unittests/ADT/TripleTest.cpp
===================================================================
--- unittests/ADT/TripleTest.cpp
+++ unittests/ADT/TripleTest.cpp
@@ -194,6 +194,18 @@
   EXPECT_EQ(Triple::UnknownOS, T.getOS());
   EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
 
+  T = Triple("avr-unknown-unknown");
+  EXPECT_EQ(Triple::avr, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::UnknownOS, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
+  T = Triple("avr");
+  EXPECT_EQ(Triple::avr, T.getArch());
+  EXPECT_EQ(Triple::UnknownVendor, T.getVendor());
+  EXPECT_EQ(Triple::UnknownOS, T.getOS());
+  EXPECT_EQ(Triple::UnknownEnvironment, T.getEnvironment());
+
   T = Triple("huh");
   EXPECT_EQ(Triple::UnknownArch, T.getArch());
 }
@@ -463,6 +475,11 @@
   EXPECT_FALSE(T.isArch16Bit());
   EXPECT_FALSE(T.isArch32Bit());
   EXPECT_TRUE(T.isArch64Bit());
+
+  T.setArch(Triple::avr);
+  EXPECT_TRUE(T.isArch16Bit());
+  EXPECT_FALSE(T.isArch32Bit());
+  EXPECT_FALSE(T.isArch64Bit());
 }
 
 TEST(TripleTest, BitWidthArchVariants) {