From a6cf05c1ff6b3b4ab1bb37c732875e8e54e60583 Mon Sep 17 00:00:00 2001
From: shikhin <draumr.shikhin@gmail.com>
Date: Sun, 19 Mar 2023 16:02:49 +0530
Subject: [PATCH] Minor optimizations in drawing rects

---
 ponydos.asm | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/ponydos.asm b/ponydos.asm
index 269a168..4a9c574 100644
--- a/ponydos.asm
+++ b/ponydos.asm
@@ -156,26 +156,20 @@ draw_rect:
 	shl cx, 1
 
 	.loop:
-		; Any rows left to copy?
-		cmp dx, 0
-		je .end
-		dec dx
-
 		; Copy a row
-		push cx
+		pusha
 		rep movsb
-		pop cx
+		popa
 
 		; Move to the next row in the input buffer
 		add si, bx
-		sub si, cx
 
 		; Move to the next row in the screen buffer
 		add di, 2*COLUMNS
-		sub di, cx
 
-		jmp .loop
-	.end:
+		dec dx
+		; Any rows left to copy?
+		jnz .loop
 
 	pop es
 	popa