Index: lib/AsmParser/LLLexer.cpp
===================================================================
--- lib/AsmParser/LLLexer.cpp
+++ lib/AsmParser/LLLexer.cpp
@@ -579,6 +579,8 @@
   KEYWORD(arm_aapcscc);
   KEYWORD(arm_aapcs_vfpcc);
   KEYWORD(msp430_intrcc);
+  KEYWORD(avr_intrcc);
+  KEYWORD(avr_signalcc);
   KEYWORD(ptx_kernel);
   KEYWORD(ptx_device);
   KEYWORD(spir_kernel);
Index: lib/AsmParser/LLParser.cpp
===================================================================
--- lib/AsmParser/LLParser.cpp
+++ lib/AsmParser/LLParser.cpp
@@ -1535,6 +1535,8 @@
 ///   ::= 'arm_aapcscc'
 ///   ::= 'arm_aapcs_vfpcc'
 ///   ::= 'msp430_intrcc'
+///   ::= 'avr_intrcc'
+///   ::= 'avr_signalcc'
 ///   ::= 'ptx_kernel'
 ///   ::= 'ptx_device'
 ///   ::= 'spir_func'
@@ -1566,6 +1568,8 @@
   case lltok::kw_arm_aapcscc:    CC = CallingConv::ARM_AAPCS; break;
   case lltok::kw_arm_aapcs_vfpcc:CC = CallingConv::ARM_AAPCS_VFP; break;
   case lltok::kw_msp430_intrcc:  CC = CallingConv::MSP430_INTR; break;
+  case lltok::kw_avr_intrcc:     CC = CallingConv::AVR_INTR; break;
+  case lltok::kw_avr_signalcc:   CC = CallingConv::AVR_SIGNAL; break;
   case lltok::kw_ptx_kernel:     CC = CallingConv::PTX_Kernel; break;
   case lltok::kw_ptx_device:     CC = CallingConv::PTX_Device; break;
   case lltok::kw_spir_kernel:    CC = CallingConv::SPIR_KERNEL; break;
Index: lib/AsmParser/LLToken.h
===================================================================
--- lib/AsmParser/LLToken.h
+++ lib/AsmParser/LLToken.h
@@ -94,6 +94,7 @@
     kw_x86_stdcallcc, kw_x86_fastcallcc, kw_x86_thiscallcc, kw_x86_vectorcallcc,
     kw_arm_apcscc, kw_arm_aapcscc, kw_arm_aapcs_vfpcc,
     kw_msp430_intrcc,
+    kw_avr_intrcc, kw_avr_signalcc,
     kw_ptx_kernel, kw_ptx_device,
     kw_spir_kernel, kw_spir_func,
     kw_x86_64_sysvcc, kw_x86_64_win64cc,
Index: lib/IR/AsmWriter.cpp
===================================================================
--- lib/IR/AsmWriter.cpp
+++ lib/IR/AsmWriter.cpp
@@ -307,6 +307,8 @@
   case CallingConv::ARM_AAPCS:     Out << "arm_aapcscc"; break;
   case CallingConv::ARM_AAPCS_VFP: Out << "arm_aapcs_vfpcc"; break;
   case CallingConv::MSP430_INTR:   Out << "msp430_intrcc"; break;
+  case CallingConv::AVR_INTR:      Out << "avr_intrcc "; break;
+  case CallingConv::AVR_SIGNAL:    Out << "avr_signalcc "; break;
   case CallingConv::PTX_Kernel:    Out << "ptx_kernel"; break;
   case CallingConv::PTX_Device:    Out << "ptx_device"; break;
   case CallingConv::X86_64_SysV:   Out << "x86_64_sysvcc"; break;
Index: test/Bitcode/avr-calling-conventions.ll
===================================================================
--- /dev/null
+++ test/Bitcode/avr-calling-conventions.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-dis < %s.bc | FileCheck %s
+
+; CHECK: define avr_intrcc void @foo(i8)
+define avr_intrcc void @foo(i8) {
+  ret void
+}
+
+; CHECK: define avr_signalcc void @bar(i8)
+define avr_signalcc void @bar(i8) {
+  ret void
+}
+
+; CHECK: define void @baz(i8)
+define void @baz(i8) {
+  ret void
+}