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 t;
  15 u8 x;
  16 u8 _;
  17 #define Mh x //mod3 vars
  18 #define Ml t // -"-
  19 //http://homepage.divms.uiowa.edu/~jones/bcd/mod.shtml
  20 void mod3(void) {
  21         // mod3(Mh.Ml) -> t
  22         #define tmp _
  23         ADD     (Ml, Mh)
  24         CLR     (Mh)
  25         ADC     (Mh, zero, carry) //Mh only holds the carry bit
  26         MOV     (tmp, Ml)
  27         SWAP    (tmp)
  28         ANDI    (tmp, 0x0f)
  29         SWAP    (Mh)
  30         OR      (tmp, Mh)
  31         ANDI    (Ml, 0x0f)
  32         ADD     (Ml, tmp)
  33         MOV     (tmp, Ml)
  34         LSR     (tmp)
  35         LSR     (tmp)
  36         ANDI    (Ml, 0x03)
  37         ADD     (Ml, tmp)
  38         MOV     (tmp, Ml)
  39         LSR     (tmp)
  40         LSR     (tmp)
  41         ANDI    (Ml, 0x03)
  42         ADD     (Ml, tmp)
  43         CPI     (Ml, 3)
  44         BRPL    (skip)
  45         SUBI    (Ml, 3)
  46         skip:;
  47         RET
  48         #undef tmp
  49 }
  50 void g(void) {
  51         // g(i, t) -> t
  52         // tempvars: `x` and `_`
  53         #define tmp _
  54         ANDI    (t, 0x07)
  55         MOV     (tmp, i2)
  56         ANDI    (tmp, 3)
  57         TST     (tmp)
  58         #undef tmp
  59         BREQ    (skip)
  60         SUBI    (t, -8)
  61         skip:
  62         t = data[t];
  63         /*MOV X_hi==_, data_hi
  64           MOV X_lo==t, data_lo
  65           ADD X_lo, t
  66           ADC X_hi, zero
  67           LD  t, X         */
  68         t = (((i1&0x1f)<<8|i0)*t)>>8; //TODO
  69         RET //TODO: CALL/RET is expensive; store next-instruction-position in Z register and RJMP, then JRMP back (maybe unnecessary, since timer might need stack anyways)
  70 };
  71
  72 int main(void) {
  73         u8 n;
  74         u8 s;
  75         u8 acc;
  76         //TODO: clear all vars/registers
  77         for (;;) {
  78                 MOV     (n, i2)
  79                 LSL     (n)
  80                 LSL     (n)
  81                 #define tmp acc
  82                 MOV     (tmp, i1)
  83                 SWAP    (tmp)
  84                 ANDI    (tmp, 0x0f)
  85                 LSR     (tmp)
  86                 LSR     (tmp)
  87                 OR      (n, tmp)
  88                 #undef tmp
  89                 MOV     (s, i3)
  90                 ROR     (s)
  91                 ROR     (s)
  92                 ANDI    (s, 0x80)
  93                 #define tmp acc
  94                 MOV     (tmp, i2)
  95                 LSR     (tmp)
  96                 OR      (s, tmp)
  97                 #undef tmp
  98
  99                 //voice 1:
 100                 MOV     (t, n)
 101                 RCALL   g();
 102                 SWAP    (t)
 103                 ANDI    (t, 0x0f)
 104                 ANDI    (t, 1)
 105                 MOV     (acc, t)
 106
 107                 //voice 2:
 108                 #define tmp _
 109                 MOV     (tmp, i2)
 110                 LSL     (tmp)
 111                 LSL     (tmp)
 112                 LSL     (tmp)
 113                 MOV     (t, i1)
 114                 SWAP    (t)
 115                 ANDI    (t, 0xf)
 116                 LSR     (t)
 117                 OR      (t, tmp)
 118                 #undef tmp
 119                 EOR     (t, n)
 120                 RCALL   g();
 121                 LSR     (t)
 122                 LSR     (t)
 123                 ANDI    (t, 3)
 124                 AND     (t, s)
 125                 ADD     (acc, t)
 126
 127                 //voice 3:
 128                 MOV     (Ml, i2)
 129                 SWAP    (Ml)
 130                 ANDI    (Ml, 0xf0)
 131                 LSL     (Ml)
 132                 #define tmp Mh
 133                 MOV     (tmp, i1)
 134                 LSR     (tmp)
 135                 LSR     (tmp)
 136                 LSR     (tmp)
 137                 OR      (Ml, tmp)
 138                 #undef tmp
 139                 MOV     (Mh, i3)
 140                 SWAP    (Mh)
 141                 ANDI    (Mh, 0xf0)
 142                 LSL     (Mh)
 143                 #define tmp _
 144                 MOV     (tmp, i2)
 145                 LSR     (tmp)
 146                 LSR     (tmp)
 147                 LSR     (tmp)
 148                 OR      (Mh, tmp)
 149                 #undef tmp
 150                 RCALL   mod3();
 151                 ADD     (t, n)
 152                 RCALL   g();
 153                 LSR     (t)
 154                 LSR     (t)
 155                 ANDI    (t, 3)
 156                 MOV     (x, s)
 157                 INC     (x)
 158                 #define tmp _
 159                 MOV     (tmp, x)
 160                 LSR     (tmp)
 161                 LSR     (tmp)
 162                 ADD     (tmp, x)
 163                 ROR     (tmp)
 164                 LSR     (tmp)
 165                 ADD     (tmp, x)
 166                 ROR     (tmp)
 167                 LSR     (tmp)
 168                 ADD     (tmp, x)
 169                 ROR     (tmp)
 170                 LSR     (tmp)
 171                 MOV     (x, tmp)
 172                 #undef tmp
 173                 AND     (t, x)
 174                 ADD     (acc, t)
 175
 176                 //voice 4:
 177                 MOV     (Ml, i2)
 178                 SWAP    (Ml)
 179                 ANDI    (Ml, 0xf0)
 180                 LSL     (Ml)
 181                 LSL     (Ml)
 182                 #define tmp Mh
 183                 MOV     (tmp, i1)
 184                 LSR     (tmp)
 185                 LSR     (tmp)
 186                 OR      (Ml, tmp)
 187                 #undef tmp
 188                 MOV     (Mh, i3)
 189                 SWAP    (Mh)
 190                 ANDI    (Mh, 0xf0)
 191                 LSL     (Mh)
 192                 LSL     (Mh)
 193                 #define tmp _
 194                 MOV     (tmp, i2)
 195                 LSR     (tmp)
 196                 LSR     (tmp)
 197                 OR      (Mh, tmp)
 198                 #undef tmp
 199                 RCALL   mod3();
 200                 SUB     (t, n)
 201                 NEG     (t)
 202                 SUBI    (t, -8)
 203                 RCALL   g();
 204                 LSR     (t)
 205                 ANDI    (t, 3)
 206                 MOV     (x, s)
 207                 INC     (x)
 208                 #define tmp _
 209                 MOV     (tmp, x)
 210                 LSR     (tmp)
 211                 ADD     (tmp, x)
 212                 ROR     (tmp)
 213                 LSR     (tmp)
 214                 LSR     (tmp)
 215                 ADD     (tmp, x)
 216                 ROR     (tmp)
 217                 ADD     (tmp, x)
 218                 ROR     (tmp)
 219                 LSR     (tmp)
 220                 LSR     (tmp)
 221                 MOV     (x, tmp)
 222                 #undef tmp
 223                 AND     (t, x)
 224                 ADD     (acc, t)
 225
 226                 putchar(acc<<4); //TODO
 227                 SUBI    (i0, -1)
 228                 ADC     (i1, zero, !i0)
 229                 ADC     (i2, zero, !i0&&!i1)
 230                 ADC     (i3, zero, !i0&&!i1&&!i2)
 231         }
 232 }