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