Index: llvm/include/llvm/Support/MathExtras.h
===================================================================
--- llvm/include/llvm/Support/MathExtras.h
+++ llvm/include/llvm/Support/MathExtras.h
@@ -461,6 +461,12 @@
   return N >= 64 || (minIntN(N) <= x && x <= maxIntN(N));
 }
 
+/// Checks if an unsigned integer is an N bit number shifted left by S.  Dynamic
+/// version of isShiftedUInt.
+inline bool isShiftedUIntN(unsigned N, unsigned S, uint64_t x) {
+  return isUIntN(N + S, x) && (x % (UINT64_C(1) << S) == 0);
+}
+
 /// Return true if the argument is a non-empty sequence of ones starting at the
 /// least significant bit with the remainder zero (32 bit version).
 /// Ex. isMask_32(0x0000FFFFU) == true.