diff --git a/lib/Target/ARM/ARMSubtarget.h b/lib/Target/ARM/ARMSubtarget.h
index 8b469cf..fcf3490 100644
--- a/lib/Target/ARM/ARMSubtarget.h
+++ b/lib/Target/ARM/ARMSubtarget.h
@@ -105,6 +105,7 @@
   bool isAAPCS_ABI() const { return TargetABI == ARM_ABI_AAPCS; }
 
   bool isThumb() const { return IsThumb; }
+  bool isThumb1() const { return IsThumb && (ThumbMode == Thumb1); }
   bool isThumb2() const { return IsThumb && (ThumbMode >= Thumb2); }
 
   bool useThumbBacktraces() const { return UseThumbBacktraces; }