-def: Pat<(i32 (trunc (cttz (i64 DoubleRegs:$Rss)))),
- (S2_ct0p (i64 DoubleRegs:$Rss))>;
-def: Pat<(i32 (trunc (cttz (not (i64 DoubleRegs:$Rss))))),
- (S2_ct1p (i64 DoubleRegs:$Rss))>;
+// Count trailing zeros: 64-bit.
+def: Pat<(i32 (trunc (cttz I64:$Rss))), (S2_ct0p I64:$Rss)>;
+def: Pat<(i32 (trunc (cttz_zero_undef I64:$Rss))), (S2_ct0p I64:$Rss)>;
+
+// Count trailing ones: 64-bit.
+def: Pat<(i32 (trunc (cttz (not I64:$Rss)))), (S2_ct1p I64:$Rss)>;
+def: Pat<(i32 (trunc (cttz_zero_undef (not I64:$Rss)))), (S2_ct1p I64:$Rss)>;
+
+// Define leading/trailing patterns that require zero-extensions to 64 bits.
+def: Pat<(i64 (ctlz I64:$Rss)), (Zext64 (S2_cl0p I64:$Rss))>;
+def: Pat<(i64 (ctlz_zero_undef I64:$Rss)), (Zext64 (S2_cl0p I64:$Rss))>;
+def: Pat<(i64 (cttz I64:$Rss)), (Zext64 (S2_ct0p I64:$Rss))>;
+def: Pat<(i64 (cttz_zero_undef I64:$Rss)), (Zext64 (S2_ct0p I64:$Rss))>;
+def: Pat<(i64 (ctlz (not I64:$Rss))), (Zext64 (S2_cl1p I64:$Rss))>;
+def: Pat<(i64 (ctlz_zero_undef (not I64:$Rss))), (Zext64 (S2_cl1p I64:$Rss))>;
+def: Pat<(i64 (cttz (not I64:$Rss))), (Zext64 (S2_ct1p I64:$Rss))>;
+def: Pat<(i64 (cttz_zero_undef (not I64:$Rss))), (Zext64 (S2_ct1p I64:$Rss))>;
+