Index: llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
===================================================================
--- llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ llvm/trunk/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -5097,7 +5097,7 @@
   SMLoc Loc = Parser.getTok().getLoc();
   const AsmToken &Tok = Parser.getTok();
   if (Tok.isNot(AsmToken::Identifier))
-    return true;
+    return Error(Loc, "illegal shift operator");
   StringRef ShiftName = Tok.getString();
   if (ShiftName == "lsl" || ShiftName == "LSL" ||
       ShiftName == "asl" || ShiftName == "ASL")
Index: llvm/trunk/test/MC/ARM/diagnostics.s
===================================================================
--- llvm/trunk/test/MC/ARM/diagnostics.s
+++ llvm/trunk/test/MC/ARM/diagnostics.s
@@ -60,6 +60,7 @@
         ldr r4, [r5, r6, ror #-1]
         pld r4, [r5, r6, ror #32]
         pld r4, [r5, r6, rrx #0]
+        ldr r4, [r5, r6, not_a_shift]
 
 @ CHECK-ERRORS: error: shift amount must be an immediate
 @ CHECK-ERRORS:         str r1, [r2, r3, lsl #invalid]
@@ -89,6 +90,8 @@
 @ CHECK-ERRORS:         pld r4, [r5, r6, ror #32]
 @ CHECK-ERRORS: error: ']' expected
 @ CHECK-ERRORS:         pld r4, [r5, r6, rrx #0]
+@ CHECK-ERRORS: error: illegal shift operator
+@ CHECK-ERRORS:         ldr r4, [r5, r6, not_a_shift]
         
         @ Out of range 16-bit immediate on BKPT
         bkpt #65536