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
@@ -1786,9 +1786,15 @@
   AddrSpace = DefaultAS;
   if (!EatIfPresent(lltok::kw_addrspace))
     return false;
-  return parseToken(lltok::lparen, "expected '(' in address space") ||
-         parseUInt32(AddrSpace) ||
-         parseToken(lltok::rparen, "expected ')' in address space");
+  SMLoc loc = Lex.getLoc();
+  bool HaveError = parseToken(lltok::lparen, "expected '(' in address space") ||
+                   parseUInt32(AddrSpace) ||
+                   parseToken(lltok::rparen, "expected ')' in address space");
+  if (HaveError)
+    return true;
+  if (AddrSpace >= (1 << 24))
+    return error(loc, "address space too large to fit in 24 bits");
+  return false;
 }
 
 /// parseStringAttribute