foo.c

   1 #include <stdio.h>
   2 #include "fakeasm.h"
   3 typedef unsigned char u8;
   4
   5 u8 data[] = {
   6         0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58,
   7         0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58
   8 };
   9 u8 zero; //zero register
  10 u8 i0;
  11 u8 i1;
  12 u8 i2;
  13 u8 i3;
  14 u8 x;
  15 u8 t;
  16 u8 o;
  17 u8 _;
  18 #define Mh o //mod3 vars
  19 #define Ml t // -"-
  20 void mod3(void) { //avail: t, o _
  21 //http://homepage.divms.uiowa.edu/~jones/bcd/mod.shtml
  22     #define tmp _
  23     //unsigned short a = ((Mh) + (Ml)) ;//&0x1ff;
  24     //    Mh = a>>8; //1 bit
  25     //    Ml = a;
  26         ADD     (Ml, Mh)
  27         CLR     (Mh)
  28         ADC     (Mh, zero, carry)
  29     Ml = (Mh<<4|Ml>>4) + (Ml & 0xF);
  30     Ml = (Ml >>  2) + (Ml & 0x3);
  31     Ml = (Ml >>  2) + (Ml & 0x3);
  32     if (Ml > 2) Ml = Ml - 3;
  33     #undef tmp
  34 }
  35 void g(void) {
  36         // g(i, x, t, o) -> t
  37         #define tmp _
  38         ANDI    (t, 0x07)
  39         MOV     (tmp, i2)
  40         ANDI    (tmp, 3)
  41         TST     (tmp)
  42         #undef tmp
  43         BREQ    (skip)
  44         SUBI    (t, -8)
  45         skip:
  46         t = data[t];
  47         /*MOV X_hi==_, data_hi
  48           MOV X_lo==t, data_lo
  49           ADD X_lo, t
  50           ADC X_hi, zero
  51           LD  t, X         */
  52         t = (((i1&0x1f)<<8|i0)*t)>>8; //TODO
  53         t >>= o; //NOTE: o == {1, 2, 4}
  54         AND     (t, x)
  55         ANDI    (t, 3)
  56         RET
  57 };
  58
  59 int main(void) {
  60         u8 n;
  61         u8 s;
  62         u8 acc;
  63         //TODO: clear all vars/registers
  64         for (;;) {
  65                 MOV     (n, i2)
  66                 LSL     (n)
  67                 LSL     (n)
  68                 #define tmp acc
  69                 MOV     (tmp, i1)
  70                 SWAP    (tmp)
  71                 ANDI    (tmp, 0x0f)
  72                 LSR     (tmp)
  73                 LSR     (tmp)
  74                 OR      (n, tmp)
  75                 #undef tmp
  76                 MOV     (s, i3)
  77                 ROR     (s)
  78                 ROR     (s)
  79                 ANDI    (s, 0x80)
  80                 #define tmp acc
  81                 MOV     (tmp, i2)
  82                 LSR     (tmp)
  83                 OR      (s, tmp)
  84                 #undef tmp
  85
  86                 //voice 1:
  87                 LDI     (x, 1)
  88                 MOV     (t, n)
  89                 LDI     (o, 4)
  90                 RCALL   g();
  91                 MOV     (acc, t)
  92
  93                 //voice 2:
  94                 MOV     (x, s)
  95                 #define tmp o
  96                 MOV     (tmp, i2)
  97                 LSL     (tmp)
  98                 LSL     (tmp)
  99                 LSL     (tmp)
 100                 MOV     (t, i1)
 101                 SWAP    (t)
 102                 ANDI    (t, 0xf)
 103                 LSR     (t)
 104                 OR      (t, tmp)
 105                 #undef tmp
 106                 EOR     (t, n)
 107                 LDI     (o, 2)
 108                 RCALL   g();
 109                 ADD     (acc, t)
 110
 111                 //voice 3:
 112                 MOV     (x, s)
 113                 INC     (x)
 114                 #define tmp o
 115                 MOV     (tmp, x)
 116                 LSR     (tmp)
 117                 LSR     (tmp)
 118                 ADD     (tmp, x)
 119                 ROR     (tmp)
 120                 LSR     (tmp)
 121                 ADD     (tmp, x)
 122                 ROR     (tmp)
 123                 LSR     (tmp)
 124                 ADD     (tmp, x)
 125                 ROR     (tmp)
 126                 LSR     (tmp)
 127                 MOV     (x, tmp)
 128                 #undef tmp
 129                 Ml = i2<<5 | i1>>3;
 130                 Mh = i3<<5 | i2>>3;
 131                 RCALL   mod3();
 132                 ADD     (t, n)
 133                 LDI     (o, 2)
 134                 RCALL   g();
 135                 ADD     (acc, t)
 136
 137                 //voice 4:
 138                 MOV     (x, s)
 139                 INC     (x)
 140                 #define tmp o
 141                 MOV     (tmp, x)
 142                 LSR     (tmp)
 143                 ADD     (tmp, x)
 144                 ROR     (tmp)
 145                 LSR     (tmp)
 146                 LSR     (tmp)
 147                 ADD     (tmp, x)
 148                 ROR     (tmp)
 149                 ADD     (tmp, x)
 150                 ROR     (tmp)
 151                 LSR     (tmp)
 152                 LSR     (tmp)
 153                 MOV     (x, tmp)
 154                 #undef tmp
 155                 Ml = i2<<6 | i1>>2;
 156                 Mh = i3<<6 | i2>>2;
 157                 RCALL   mod3();
 158                 SUB     (t, n)
 159                 NEG     (t)
 160                 SUBI    (t, -8)
 161                 LDI     (o, 1)
 162                 RCALL   g();
 163                 ADD     (acc, t)
 164
 165                 putchar(acc<<4); //TODO
 166                 SUBI    (i0, -1)
 167                 ADC     (i1, zero, !i0)
 168                 ADC     (i2, zero, !i0&&!i1)
 169                 ADC     (i3, zero, !i0&&!i1&&!i2)
 170         }
 171 }