sdcc/device/lib/mos65c02/_memcmp.s

   1 ;-------------------------------------------------------------------------
   2 ;   memcmp.s - standarc C library
   3 ;
   4 ;   Copyright (C) 2003, Ullrich von Bassewitz
   5 ;   Copyright (C) 2009, Christian Krueger
   6 ;   Copyright (C) 2023, Gabriele Gorla
   7 ;
   8 ;   This library is free software; you can redistribute it and/or modify it
   9 ;   under the terms of the GNU General Public License as published by the
  10 ;   Free Software Foundation; either version 2, or (at your option) any
  11 ;   later version.
  12 ;
  13 ;   This library is distributed in the hope that it will be useful,
  14 ;   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;   GNU General Public License for more details.
  17 ;
  18 ;   You should have received a copy of the GNU General Public License
  19 ;   along with this library; see the file COPYING. If not, write to the
  20 ;   Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
  21 ;   MA 02110-1301, USA.
  22 ;
  23 ;   As a special exception, if you link this library with other files,
  24 ;   some of which are compiled with SDCC, to produce an executable,
  25 ;   this library does not by itself cause the resulting executable to
  26 ;   be covered by the GNU General Public License. This exception does
  27 ;   not however invalidate any other reasons why the executable file
  28 ;   might be covered by the GNU General Public License.
  29 ;-------------------------------------------------------------------------
  30
  31         .module memcmp
  32
  33 ;--------------------------------------------------------
  34 ; exported symbols
  35 ;--------------------------------------------------------
  36         .globl _memcmp_PARM_2
  37         .globl _memcmp_PARM_3
  38         .globl _memcmp
  39
  40 ;--------------------------------------------------------
  41 ; overlayable function parameters in zero page
  42 ;--------------------------------------------------------
  43         .area   OSEG    (PAG, OVR)
  44 _memcmp_PARM_2:
  45         .ds 2
  46 _memcmp_PARM_3:
  47         .ds 2
  48
  49 ;--------------------------------------------------------
  50 ; local aliases
  51 ;--------------------------------------------------------
  52         .define s1    "DPTR"
  53         .define s2    "_memcmp_PARM_2"
  54         .define count "_memcmp_PARM_3"
  55
  56 ;--------------------------------------------------------
  57 ; code
  58 ;--------------------------------------------------------
  59         .area CODE
  60
  61 ;--------------------------------------------------------
  62 ; int memcmp (int *s1, int *s2, int count)
  63 ;--------------------------------------------------------
  64
  65 _memcmp:
  66         sta     *s1+0
  67         stx     *s1+1
  68         ldy     #0
  69         ldx     *count+1
  70         beq     endhi
  71 hiloop:
  72         lda     [s1],y
  73         cmp     [s2],y
  74         bne     noteq
  75         iny
  76         bne     hiloop
  77         inc     *s1+1
  78         inc     *s2+1
  79         dex
  80         bne     hiloop
  81 endhi:
  82         ldx     *count+0
  83         beq     end
  84 loloop:
  85         lda     [s1],y
  86         cmp     [s2],y
  87         bne     noteq
  88         iny
  89         dex
  90         bne     loloop
  91 end:
  92         txa
  93         rts
  94 noteq:
  95         bcs     L2
  96         ldx     #0xFF
  97         rts
  98 L2:
  99         ldx     #0x01
 100         rts