Index: docs/LangRef.rst
===================================================================
--- docs/LangRef.rst
+++ docs/LangRef.rst
@@ -1877,8 +1877,15 @@
     must be a multiple of 8-bits. If omitted, the natural stack
     alignment defaults to "unspecified", which does not prevent any
     alignment promotions.
+``P<address space>``
+    Specifies the address space that corresponds to program memory.
+    Harvard architectures can use this to specify what space LLVM
+    should place things such as functions or switch lookup tables
+    into. If omitted, the program memory space defaults to the
+    default address space of 0, which corresponds to a Von Neumann
+    architecture that has code and data in the same space.
 ``A<address space>``
-    Specifies the address space of  objects created by '``alloca``'.
+    Specifies the address space of objects created by '``alloca``'.
     Defaults to the default address space of 0.
 ``p[n]:<size>:<abi>:<pref>``
     This specifies the *size* of a pointer and its ``<abi>`` and
Index: include/llvm/IR/DataLayout.h
===================================================================
--- include/llvm/IR/DataLayout.h
+++ include/llvm/IR/DataLayout.h
@@ -113,6 +113,7 @@
 
   unsigned AllocaAddrSpace;
   unsigned StackNaturalAlign;
+  unsigned ProgramAddrSpace;
 
   enum ManglingModeT {
     MM_None,
@@ -196,6 +197,7 @@
     BigEndian = DL.isBigEndian();
     AllocaAddrSpace = DL.AllocaAddrSpace;
     StackNaturalAlign = DL.StackNaturalAlign;
+    ProgramAddrSpace = DL.ProgramAddrSpace;
     ManglingMode = DL.ManglingMode;
     LegalIntWidths = DL.LegalIntWidths;
     Alignments = DL.Alignments;
@@ -252,6 +254,8 @@
   unsigned getStackAlignment() const { return StackNaturalAlign; }
   unsigned getAllocaAddrSpace() const { return AllocaAddrSpace; }
 
+  unsigned getProgramAddressSpace() const { return ProgramAddrSpace; }
+
   bool hasMicrosoftFastStdCallMangling() const {
     return ManglingMode == MM_WinCOFFX86;
   }
Index: include/llvm/IR/GlobalValue.h
===================================================================
--- include/llvm/IR/GlobalValue.h
+++ include/llvm/IR/GlobalValue.h
@@ -177,6 +177,7 @@
   GlobalValue(const GlobalValue &) = delete;
 
   unsigned getAlignment() const;
+  unsigned getAddressSpace() const;
 
   enum class UnnamedAddr {
     None,
Index: lib/IR/DataLayout.cpp
===================================================================
--- lib/IR/DataLayout.cpp
+++ lib/IR/DataLayout.cpp
@@ -181,6 +181,7 @@
   BigEndian = false;
   AllocaAddrSpace = 0;
   StackNaturalAlign = 0;
+  ProgramAddrSpace = 0;
   ManglingMode = MM_None;
   NonIntegralAddressSpaces.clear();
 
@@ -358,6 +359,10 @@
       StackNaturalAlign = inBytes(getInt(Tok));
       break;
     }
+    case 'P': { // Function address space.
+      ProgramAddrSpace = inBytes(getInt(Tok));
+      break;
+    }
     case 'A': { // Default stack/alloca address space.
       AllocaAddrSpace = getInt(Tok);
       if (!isUInt<24>(AllocaAddrSpace))
Index: lib/IR/Globals.cpp
===================================================================
--- lib/IR/Globals.cpp
+++ lib/IR/Globals.cpp
@@ -107,6 +107,11 @@
   return cast<GlobalObject>(this)->getAlignment();
 }
 
+unsigned GlobalValue::getAddressSpace() const {
+  PointerType *PtrTy = getType();
+  return PtrTy->getAddressSpace();
+}
+
 void GlobalObject::setAlignment(unsigned Align) {
   assert((Align & (Align-1)) == 0 && "Alignment is not a power of 2!");
   assert(Align <= MaximumAlignment &&
Index: lib/Target/AVR/AVRTargetMachine.cpp
===================================================================
--- lib/Target/AVR/AVRTargetMachine.cpp
+++ lib/Target/AVR/AVRTargetMachine.cpp
@@ -25,7 +25,7 @@
 
 namespace llvm {
 
-static const char *AVRDataLayout = "e-p:16:16:16-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-n8";
+static const char *AVRDataLayout = "e-P1-p:16:16:16-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-n8";
 
 /// Processes a CPU name.
 static StringRef getCPU(StringRef CPU) {