sdcc/device/lib/mcs51/crtxpop.asm

   1 ;--------------------------------------------------------------------------
   2 ;  crtxpop.asm - C run-time: pop registers (not bits) from xstack
   3 ;
   4 ;  Copyright (C) 2009, Maarten Brock
   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 ;--------------------------------------------------------
  30 ; overlayable bit register bank
  31 ;--------------------------------------------------------
  32         .area BIT_BANK  (REL,OVR,DATA)
  33 bits:
  34         .ds 1
  35
  36         ar0 = 0x00
  37         ar1 = 0x01
  38
  39         .area HOME    (CODE)
  40
  41 ; Pop registers r1..r7 & bits from xstack
  42 ; Expect mask in B
  43 ___sdcc_xpop_regs::
  44         mov     a,r0
  45         mov     r0,_spx
  46 ___sdcc_xpop::
  47         push acc
  48         jbc     B.0,00100$      ;if B(0)=0 then
  49         dec     r0
  50         movx    a,@r0           ;pop bits
  51         mov     bits,a
  52 00100$:
  53         jbc     B.1,00101$      ;if B(1)=0 then
  54         dec     r0
  55         movx    a,@r0           ;pop R1
  56         mov     r1,a
  57 00101$:
  58         jbc     B.2,00102$      ;if B(2)=0 then
  59         dec     r0
  60         movx    a,@r0           ;pop R2
  61         mov     r2,a
  62 00102$:
  63         jbc     B.3,00103$      ;if B(3)=0 then
  64         dec     r0
  65         movx    a,@r0           ;pop R3
  66         mov     r3,a
  67 00103$:
  68         jbc     B.4,00104$      ;if B(4)=0 then
  69         dec     r0
  70         movx    a,@r0           ;pop R4
  71         mov     r4,a
  72 00104$:
  73         jbc     B.5,00105$      ;if B(5)=0 then
  74         dec     r0
  75         movx    a,@r0           ;pop R5
  76         mov     r5,a
  77 00105$:
  78         jbc     B.6,00106$      ;if B(6)=0 then
  79         dec     r0
  80         movx    a,@r0           ;pop R6
  81         mov     r6,a
  82 00106$:
  83         jbc     B.7,00107$      ;if B(7)=0 then
  84         dec     r0
  85         movx    a,@r0           ;pop R7
  86         mov     r7,a
  87 00107$:
  88         mov     _spx,r0
  89         pop     ar0
  90         ret