diff --git a/src/cmd/compile/internal/ssa/gen/dec64.rules b/src/cmd/compile/internal/ssa/gen/dec64.rules
index 874ee47154..edbe72189e 100644
--- a/src/cmd/compile/internal/ssa/gen/dec64.rules
+++ b/src/cmd/compile/internal/ssa/gen/dec64.rules
@@ -110,7 +110,7 @@
 // Sadly, just because we know that x is non-zero,
 // we don't know whether either component is,
 // so just treat Ctz64NonZero the same as Ctz64.
-(Ctz64NonZero x) -> (Ctz64 x)
+(Ctz64NonZero ...) -> (Ctz64 ...)
 
 (Ctz64 x) ->
 	(Add32 <typ.UInt32>
diff --git a/src/cmd/compile/internal/ssa/rewritedec64.go b/src/cmd/compile/internal/ssa/rewritedec64.go
index 9059904d54..ae6d19142f 100644
--- a/src/cmd/compile/internal/ssa/rewritedec64.go
+++ b/src/cmd/compile/internal/ssa/rewritedec64.go
@@ -24,7 +24,8 @@ func rewriteValuedec64(v *Value) bool {
 	case OpCtz64:
 		return rewriteValuedec64_OpCtz64(v)
 	case OpCtz64NonZero:
-		return rewriteValuedec64_OpCtz64NonZero(v)
+		v.Op = OpCtz64
+		return true
 	case OpEq64:
 		return rewriteValuedec64_OpEq64(v)
 	case OpGeq64:
@@ -431,17 +432,6 @@ func rewriteValuedec64_OpCtz64(v *Value) bool {
 		return true
 	}
 }
-func rewriteValuedec64_OpCtz64NonZero(v *Value) bool {
-	v_0 := v.Args[0]
-	// match: (Ctz64NonZero x)
-	// result: (Ctz64 x)
-	for {
-		x := v_0
-		v.reset(OpCtz64)
-		v.AddArg(x)
-		return true
-	}
-}
 func rewriteValuedec64_OpEq64(v *Value) bool {
 	v_1 := v.Args[1]
 	v_0 := v.Args[0]