From 055806bbad942b364d62cded68a8838b8ae55716 Mon Sep 17 00:00:00 2001
From: Andrew Ekstedt <andrew.ekstedt@gmail.com>
Date: Sat, 5 Oct 2024 20:54:51 -0700
Subject: [PATCH] de-unroll Chi loop in roundGeneric

(reroll? no, that's something else)

makes it more similar to the templatized code in gen.go. this isn't the
optimized code, so performance doesn't matter.
---
 keccak.go | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/keccak.go b/keccak.go
index ccdef4f..a6b75eb 100644
--- a/keccak.go
+++ b/keccak.go
@@ -26,11 +26,9 @@ func roundGeneric(a *[25]uint64) {
 
 	// Chi
 	for y := 0; y < 5; y++ {
-		a[y*5+0] = b[y][0] ^ ^b[y][1]&b[y][2]
-		a[y*5+1] = b[y][1] ^ ^b[y][2]&b[y][3]
-		a[y*5+2] = b[y][2] ^ ^b[y][3]&b[y][4]
-		a[y*5+3] = b[y][3] ^ ^b[y][4]&b[y][0]
-		a[y*5+4] = b[y][4] ^ ^b[y][0]&b[y][1]
+		for x := 0; x < 5; x++ {
+			a[y*5+x] = b[y][x] ^ (^b[y][(x+1)%5] & b[y][(x+2)%5])
+		}
 	}
 }