cscg22-gearboy

CSCG 2022 Challenge 'Gearboy'
git clone https://git.sinitax.com/sinitax/cscg22-gearboy
Log | Files | Refs | sfeed.txt

setjmp.s (2658B)

      1;--------------------------------------------------------------------------
      2;  setjmp.s
      3;
      4;  Copyright (C) 2011-2014, Philipp Klaus Krause
      5;
      6;  This library is free software; you can redistribute it and/or modify it
      7;  under the terms of the GNU General Public License as published by the
      8;  Free Software Foundation; either version 2, or (at your option) any
      9;  later version.
     10;
     11;  This library is distributed in the hope that it will be useful,
     12;  but WITHOUT ANY WARRANTY; without even the implied warranty of
     13;  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     14;  GNU General Public License for more details.
     15;
     16;  You should have received a copy of the GNU General Public License
     17;  along with this library; see the file COPYING. If not, write to the
     18;  Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
     19;   MA 02110-1301, USA.
     20;
     21;  As a special exception, if you link this library with other files,
     22;  some of which are compiled with SDCC, to produce an executable,
     23;  this library does not by itself cause the resulting executable to
     24;  be covered by the GNU General Public License. This exception does
     25;  not however invalidate any other reasons why the executable file
     26;   might be covered by the GNU General Public License.
     27;--------------------------------------------------------------------------
     28
     29        .module longjmp
     30
     31        .area   _HOME
     32
     33        .globl ___setjmp
     34
     35___setjmp:
     36        pop     bc
     37        pop     de
     38        push    de
     39        push    bc
     40
     41        ; Store stack pointer.
     42        ldhl    sp, #0
     43        push    de
     44        push    hl
     45        pop     de
     46        pop     hl
     47        ld      (hl), e
     48        inc     hl
     49        ld      (hl), d
     50        inc     hl
     51
     52        ; Store return address.
     53        ld      (hl), c
     54        inc     hl
     55        ld      (hl), b
     56
     57        ; Return 0.
     58        xor     a, a
     59        ld      e, a
     60        ld      d, a
     61        ret
     62
     63.globl _longjmp
     64
     65_longjmp:
     66        pop     af
     67        pop     hl
     68        pop     de
     69
     70        ; Ensure that return value is non-zero.
     71        ld      a, e
     72        or      a, d
     73        jr      NZ, 0001$
     74        inc     de
     750001$:
     76
     77        ; Get stack pointer.
     78        ld      c, (hl)
     79        inc     hl
     80        ld      b, (hl)
     81        inc     hl
     82
     83        ; Adjust stack pointer.
     84        push    hl
     85        push    bc
     86        pop     hl
     87        pop     bc
     88        ld      sp, hl
     89        push    bc
     90        pop     hl
     91
     92        ; Get return address.
     93        ld      c, (hl)
     94        inc     hl
     95        ld      b, (hl)
     96
     97        ; Set return address.
     98        pop     af
     99        push    bc
    100
    101        ; Return value is in de.
    102
    103        ; Jump.
    104        ret
    105