Index: llvm/lib/Target/AArch64/AArch64InstrInfo.td
===================================================================
--- llvm/lib/Target/AArch64/AArch64InstrInfo.td
+++ llvm/lib/Target/AArch64/AArch64InstrInfo.td
@@ -2050,9 +2050,9 @@
 def  REV16Xr : OneXRegData<0b001, "rev16", null_frag>;

 def : Pat<(cttz GPR32:$Rn),
-          (CLZWr (RBITWr GPR32:$Rn))>;
+          (ANDWri (CLZWr (RBITWr GPR32:$Rn)), (i32 4))>;
 def : Pat<(cttz GPR64:$Rn),
-          (CLZXr (RBITXr GPR64:$Rn))>;
+          (ANDXri (CLZXr (RBITXr GPR64:$Rn)), (i64 5))>;
 def : Pat<(ctlz (or (shl (xor (sra GPR32:$Rn, (i64 31)), GPR32:$Rn), (i64 1)),
                 (i32 1))),
           (CLSWr GPR32:$Rn)>;