From a89572fb64fb3d9d6e64fa5a34ba3fb3e294956e Mon Sep 17 00:00:00 2001
From: Mario Lang <mlang@blind.guru>
Date: Tue, 22 Oct 2024 00:52:01 +0200
Subject: [PATCH] Improve performance by 1% by eliminating pnr

---
 src/Game/Chess/Internal/QuadBitboard.hs | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/src/Game/Chess/Internal/QuadBitboard.hs b/src/Game/Chess/Internal/QuadBitboard.hs
index a6cb0b3..3586e75 100644
--- a/src/Game/Chess/Internal/QuadBitboard.hs
+++ b/src/Game/Chess/Internal/QuadBitboard.hs
@@ -72,14 +72,13 @@ data QuadBitboard = QBB { black, pbq, nbk, rqk :: {-# UNPACK #-} !Word64 }
 
 instance NFData QuadBitboard
 
-occupied, pnr, white, pawns, knights, bishops, rooks, queens, kings :: QuadBitboard -> Word64
+occupied, white, pawns, knights, bishops, rooks, queens, kings :: QuadBitboard -> Word64
 occupied = liftA2 (.|.) pbq $ liftA2 (.|.) nbk rqk
-pnr      = liftA2  xor  pbq $ liftA2  xor  nbk rqk
 white    = liftA2  xor  occupied black
-pawns    = liftA2 (.&.) pnr pbq
-knights  = liftA2 (.&.) pnr nbk
+pawns    = liftA2 (.&.) pbq $ liftA2 (.&.) (complement . nbk) (complement . rqk)
+knights  = liftA2 (.&.) (complement . pbq) $ liftA2 (.&.) nbk (complement . rqk)
 bishops  = liftA2 (.&.) pbq nbk
-rooks    = liftA2 (.&.) pnr rqk
+rooks    = liftA2 (.&.) (complement . pbq) $ liftA2 (.&.) (complement . nbk) rqk
 queens   = liftA2 (.&.) pbq rqk
 kings    = liftA2 (.&.) nbk rqk
 
@@ -99,7 +98,6 @@ bRooks   = liftA2 (.&.) rooks black
 bQueens  = liftA2 (.&.) queens black
 bKings   = liftA2 (.&.) kings black
 
-{-# INLINE pnr #-}
 {-# INLINE occupied #-}
 {-# INLINE white #-}
 {-# INLINE pawns #-}