diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -3590,6 +3590,11 @@
 Pointer types may have an optional address space attribute defining
 the numbered address space where the pointed-to object resides. For
 example, ``ptr addrspace(5)`` is a pointer to address space 5.
+In addition to integer constants, ``addrspace`` can also reference one of the
+address spaces defined in the :ref:`datalayout string<langref_datalayout>`.
+``addrspace("A")`` will use the alloca address space, ``addrspace("G")``
+the default globals address space and ``addrspace("P")`` the program address
+space.
 
 The default address space is number zero.
 
diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -1787,8 +1787,29 @@
   AddrSpace = DefaultAS;
   if (!EatIfPresent(lltok::kw_addrspace))
     return false;
+
+  auto ParseAddrspaceValue = [&](unsigned &AddrSpace) -> bool {
+    if (Lex.getKind() == lltok::StringConstant) {
+      auto AddrSpaceStr = Lex.getStrVal();
+      if (AddrSpaceStr == "A") {
+        AddrSpace = M->getDataLayout().getAllocaAddrSpace();
+      } else if (AddrSpaceStr == "G") {
+        AddrSpace = M->getDataLayout().getDefaultGlobalsAddressSpace();
+      } else if (AddrSpaceStr == "P") {
+        AddrSpace = M->getDataLayout().getProgramAddressSpace();
+      } else {
+        return tokError("invalid symbolic addrspace '" + AddrSpaceStr + "'");
+      }
+      Lex.Lex();
+      return false;
+    } else if (Lex.getKind() != lltok::APSInt) {
+      return tokError("expected integer or string constant");
+    }
+    return parseUInt32(AddrSpace);
+  };
+
   return parseToken(lltok::lparen, "expected '(' in address space") ||
-         parseUInt32(AddrSpace) ||
+         ParseAddrspaceValue(AddrSpace) ||
          parseToken(lltok::rparen, "expected ')' in address space");
 }
 
diff --git a/llvm/test/Assembler/symbolic-addrspace.ll b/llvm/test/Assembler/symbolic-addrspace.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Assembler/symbolic-addrspace.ll
@@ -0,0 +1,73 @@
+;; Check that we can parse symbolic addres space constants "A", "G", "P".
+;; NB: These do not round-trip via llvm-as, they are purely for initial parsing
+;; and will be converted to a numerical constant that does not depend on the
+;; datalayout by the .ll parser.
+; RUN: split-file %s %t --leading-lines
+; RUN: llvm-as < %t/valid.ll | llvm-dis | FileCheck %s
+; RUN: llvm-as < %t/alloca-in-other-as.ll | llvm-dis | FileCheck %s --check-prefix ALLOCA-IN-GLOBALS
+; RUN: not llvm-as < %t/bad-not-string.ll 2>&1 | FileCheck %s --check-prefix=ERR-NOT-STR
+; RUN: not llvm-as < %t/bad-unknown-char.ll 2>&1 | FileCheck %s --check-prefix=ERR-BAD-CHAR
+; RUN: not llvm-as < %t/bad-multiple-valid-chars.ll 2>&1 | FileCheck %s --check-prefix=ERR-MULTIPLE-CHARS
+; RUN: not llvm-as < %t/bad-using-at-symbol.ll 2>&1 | FileCheck %s --check-prefix=ERR-AT-SYMBOL
+; RUN: not llvm-as < %t/bad-number-in-quotes.ll 2>&1 | FileCheck %s --check-prefix=ERR-NUMBER-IN-QUOTES
+
+;--- valid.ll
+target datalayout = "A1-G2-P3"
+; CHECK: target datalayout = "A1-G2-P3"
+
+; CHECK: @str = private addrspace(2) constant [4 x i8] c"str\00"
+@str = private addrspace("G") constant [4 x i8] c"str\00"
+
+define void @foo() {
+  ; CHECK: %alloca = alloca i32, align 4, addrspace(1)
+  %alloca = alloca i32, addrspace("A")
+  ret void
+}
+
+; CHECK: define void @bar() addrspace(3) {
+define void @bar() addrspace("P") {
+  ; CHECK: call addrspace(3) void @foo()
+  call addrspace("P") void @foo()
+  ret void
+}
+
+;--- alloca-in-other-as.ll
+target datalayout = "A1-G2-P3"
+; ALLOCA-IN-GLOBALS: target datalayout = "A1-G2-P3"
+
+define void @foo() {
+  ; ALLOCA-IN-GLOBALS: %alloca = alloca i32, align 4, addrspace(2){{$}}
+  ; ALLOCA-IN-GLOBALS: %alloca2 = alloca i32, align 4, addrspace(1){{$}}
+  ; ALLOCA-IN-GLOBALS: %alloca3 = alloca i32, align 4{{$}}
+  ; ALLOCA-IN-GLOBALS: %alloca4 = alloca i32, align 4, addrspace(3){{$}}
+  %alloca = alloca i32, addrspace("G")
+  %alloca2 = alloca i32, addrspace("A")
+  %alloca3 = alloca i32
+  %alloca4 = alloca i32, addrspace("P")
+  ret void
+}
+
+;--- bad-not-string.ll
+target datalayout = "G2"
+@str = private addrspace(D) constant [4 x i8] c"str\00"
+; ERR-NOT-STR: [[#@LINE-1]]:26: error: expected integer or string constant
+
+;--- bad-unknown-char.ll
+target datalayout = "G2"
+@str = private addrspace("D") constant [4 x i8] c"str\00"
+; ERR-BAD-CHAR: [[#@LINE-1]]:26: error: invalid symbolic addrspace 'D'
+
+;--- bad-multiple-valid-chars.ll
+target datalayout = "A1-G2"
+@str = private addrspace("AG") constant [4 x i8] c"str\00"
+; ERR-MULTIPLE-CHARS: [[#@LINE-1]]:26: error: invalid symbolic addrspace 'AG'
+
+;--- bad-using-at-symbol.ll
+target datalayout = "A1-G2"
+@str = private addrspace(@A) constant [4 x i8] c"str\00"
+; ERR-AT-SYMBOL: [[#@LINE-1]]:26: error: expected integer or string constant
+
+;--- bad-number-in-quotes.ll
+target datalayout = "A1-G2"
+@str = private addrspace("10") constant [4 x i8] c"str\00"
+; ERR-NUMBER-IN-QUOTES: [[#@LINE-1]]:26: error: invalid symbolic addrspace '10'