X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=device%2Flib%2Fz80%2Fmemmove.s;h=d718c910c17b4abdd902f6a7d954a1968e78a1b7;hb=5a1d5e778e85664f4e6657019348b4756b16eacb;hp=76d21a2ccede241ebc57ef7d6c12bca906f53633;hpb=871e6c6aefc06309a03c295ce0d3c9d4bbb4a742;p=fw%2Fsdcc

diff --git a/device/lib/z80/memmove.s b/device/lib/z80/memmove.s
index 76d21a2c..d718c910 100644
--- a/device/lib/z80/memmove.s
+++ b/device/lib/z80/memmove.s
@@ -1,3 +1,31 @@
+; Copyright (C) 2008-2009
+; Philipp Klaus Krause, Marco Bodrato
+
+; This file is part of the sdcc Library.  This library is free
+; software; you can redistribute it and/or modify it under the
+; terms of the GNU General Public License as published by the
+; Free Software Foundation; either version 2, or (at your option)
+; any later version.
+
+; This library is distributed in the hope that it will be useful,
+; but WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+; GNU General Public License for more details.
+
+; You should have received a copy of the GNU General Public License along
+; with this library; see the file COPYING.  If not, write to the Free
+; Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+; USA.
+
+; As a special exception, you may use this file as part of a free software
+; library without restriction.  Specifically, if other files instantiate
+; templates or use macros or inline functions from this file, or you compile
+; this file and link it with other files to produce an executable, this
+; file does not by itself cause the resulting executable to be covered by
+; the GNU General Public License.  This exception does not however
+; invalidate any other reasons why the executable file might be covered by
+; the GNU General Public License.
+
         .area   _CODE
 
 	.globl _memmove
@@ -5,40 +33,33 @@
 ; The Z80 has the ldir and lddr instructions, which are perfect for implementing memmove().
 
 _memmove:
-	push	ix
-	ld	ix, #0
-	add	ix, sp
-	ld	c, 8(ix)
-	ld	b, 9(ix)
+	pop	af
+	pop	hl
+	pop	de
+	pop	bc
+	push	bc
+	push	de
+	push	hl
+	push	af
 	ld	a, c
 	or	a, b
-	jr	Z, memmove_end
-	ld	e, 4(ix)
-	ld	d, 5(ix)
-	ld	l, 6(ix)
-	ld	h, 7(ix)
-	ld	a, l
-	sbc	hl, de	; or above cleared carry.
-	ld	l, a
-	ld	h, 7(ix)
-	jr	NC, memmove_up
+	ret	Z
+	push	hl
+	sbc	hl, de		; or above cleared carry.
+	add	hl, de		; same carry as the line before
+	jr	C, memmove_up
 memmove_down:
+	dec	bc
+	add	hl, bc
+	ex      de, hl
 	add	hl, bc
-	dec	hl
-	ld	a, e
-	add	a, c
-	ld	e, a
-	ld	a, d
-	adc	a, b
-	ld	d, a
-	dec	de
+	inc	bc
 	lddr
-	jr	memmove_end
+	pop	hl
+	ret
 memmove_up:
+	ex      de, hl
 	ldir
-memmove_end:
-	ld	l, 4(ix)
-	ld	h, 5(ix)
-	pop	ix
+	pop	hl
 	ret