;--------------------------------------------------------------------------
;  __strreverse.s
;
;  Copyright (C) 2020-2021, Sergey Belyashov
;
;  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, if you link this library with other files,
;  some of which are compiled with SDCC, to produce an executable,
;  this library 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 ___strreverse
	.globl ___strreverse_reg
;
;void __reverse(char *beg, char *end);
;
___strreverse::
	ex	de, hl
;
;in: HL - pointer to end of string (null symbol), DE - pointer to start of string
;
___strreverse_reg::
	jr	110$
100$:
	add	hl, de
	ld	a, (de)
	ld	c, (hl)
	ld	(hl), a
	ld	a, c
	ld	(de), a
	inc	de
110$:
	dec	hl
	or	a, a
	sbc	hl, de
	jr	NC, 100$
	ret
