Convert to multi if blocks with in-place reverse

secret_handshake.go

@@ -25,19 +25,22 @@ func Handshake(i int) (h []string) {
 		return h
 	}
 
-	// Pre-define the ordered key sets.
-	keys := []int{wnk, bli, clo, jmp}
-	bkwd := []int{jmp, clo, bli, wnk}
-
-	// Use the reversed key set if the 5th bit is set.
-	if i&rev != 0 {
-		keys = bkwd
+	if i&wnk != 0 {
+		h = append(h, m[wnk])
+	}
+	if i&bli != 0 {
+		h = append(h, m[bli])
+	}
+	if i&clo != 0 {
+		h = append(h, m[clo])
+	}
+	if i&jmp != 0 {
+		h = append(h, m[jmp])
 	}
 
-	// Build the string slice based on the bitmask.
-	for _, k := range keys {
-		if i&k != 0 {
-			h = append(h, m[k])
+	if i&rev != 0 {
+		for i, j := 0, len(h)-1; i < j; i, j = i+1, j-1 {
+			h[i], h[j] = h[j], h[i]
 		}
 	}
 
@@ -47,4 +50,4 @@ func Handshake(i int) (h []string) {
 // Revision 1 benchmark:
 //
 // PASS
-// BenchmarkHandshake-12	 2000000	       718 ns/op
+// BenchmarkHandshake-12	 2000000	       734 ns/op