sdcc/device/lib/mcs51/crtxpush.asm

   1 ;--------------------------------------------------------------------------
   2 ;  crtxpush.asm :- C run-time: push registers (not R0) to 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 ; Push registers r1..r7 & bits on xstack
  42 ; Expect allocation size in ACC and mask in B
  43 ___sdcc_xpush_regs::
  44         add     a,_spx
  45         mov     _spx,a
  46         xch     a,r0
  47 ___sdcc_xpush::
  48         push    acc
  49         jbc     B.0,00100$      ;if B(0)=0 then
  50         mov     a,bits          ;push bits
  51         dec     r0
  52         movx    @r0,a
  53 00100$:
  54         jbc     B.1,00101$      ;if B(1)=0 then
  55         mov     a,r1            ;push R1
  56         dec     r0
  57         movx    @r0,a
  58 00101$:
  59         jbc     B.2,00102$      ;if B(2)=0 then
  60         mov     a,r2            ;push R2
  61         dec     r0
  62         movx    @r0,a
  63 00102$:
  64         jbc     B.3,00103$      ;if B(3)=0 then
  65         mov     a,r3            ;push R3
  66         dec     r0
  67         movx    @r0,a
  68 00103$:
  69         jbc     B.4,00104$      ;if B(4)=0 then
  70         mov     a,r4            ;push R4
  71         dec     r0
  72         movx    @r0,a
  73 00104$:
  74         jbc     B.5,00105$      ;if B(5)=0 then
  75         mov     a,r5            ;push R5
  76         dec     r0
  77         movx    @r0,a
  78 00105$:
  79         jbc     B.6,00106$      ;if B(6)=0 then
  80         mov     a,r6            ;push R6
  81         dec     r0
  82         movx    @r0,a
  83 00106$:
  84         jbc     B.7,00107$      ;if B(7)=0 then
  85         mov     a,r7            ;push R7
  86         dec     r0
  87         movx    @r0,a
  88 00107$:
  89         pop     ar0
  90         ret