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;        //r16
  10 u8 acc;         //r17
  11 u8 i0;          //r18
  12 u8 i1;          //r19
  13 u8 i2;          //r20
  14 u8 i3;          //r21
  15 u8 n;           //r22
  16 u8 s;           //r23
  17 u8 _;           //r24
  18                 //r25
  19 u8 t;/*==Ml*/   //r26 (Xlo)
  20 u8 x;/*==Mh*/   //r27 (Xhi)
  21                 //r28
  22                 //r29
  23 /*fakestack_l*/ //r30 (Zlo)
  24 /*fakestack_h*/ //r31 (Zhi)
  25 #define Mh x //mod3 vars
  26 #define Ml t // -"-
  27 //http://homepage.divms.uiowa.edu/~jones/bcd/mod.shtml
  28 void mod3(void) {
  29         // mod3(Mh.Ml) -> t
  30         #define tmp _
  31         ADD     (Ml, Mh)
  32         CLR     (Mh)
  33         ADC     (Mh, zero, carry) //Mh only holds the carry bit
  34         MOV     (tmp, Ml)
  35         SWAP    (tmp)
  36         ANDI    (tmp, 0x0f)
  37         SWAP    (Mh)
  38         OR      (tmp, Mh)
  39         ANDI    (Ml, 0x0f)
  40         ADD     (Ml, tmp)
  41         MOV     (tmp, Ml)
  42         LSR     (tmp)
  43         LSR     (tmp)
  44         ANDI    (Ml, 0x03)
  45         ADD     (Ml, tmp)
  46         MOV     (tmp, Ml)
  47         LSR     (tmp)
  48         LSR     (tmp)
  49         ANDI    (Ml, 0x03)
  50         ADD     (Ml, tmp)
  51         CPI     (Ml, 3)
  52         BRPL    (skip)
  53         SUBI    (Ml, 3)
  54         skip:;
  55         RET
  56         #undef tmp
  57 }
  58 void g(void) {
  59         // g(i, t) -> t
  60         // tempvars: `x` and `_`
  61         #define tmp _
  62         ANDI    (t, 0x07)
  63         MOV     (tmp, i2)
  64         ANDI    (tmp, 3)
  65         TST     (tmp)
  66         #undef tmp
  67         BREQ    (skip)
  68         SUBI    (t, -8)
  69         skip:
  70         t = data[t];
  71         /*MOV X_hi==x, data_hi
  72           MOV X_lo==t, data_lo
  73           ADD X_lo, t
  74           ADC X_hi, zero
  75           LD  t, X         */
  76         t &= 0xfd; //hint
  77         t = (((i1&0x1f)<<8|i0)*t)>>8; //TODO
  78         t &= 0x1e; //hint
  79         RET //TODO: replace CALL/RET with IJMP?
  80 };
  81
  82 int main(void) {
  83         CLR     (zero)
  84         CLR     (i0)
  85         CLR     (i1)
  86         CLR     (i2)
  87         CLR     (i3)
  88         for (;;) {
  89                 MOV     (n, i2)
  90                 LSL     (n)
  91                 LSL     (n)
  92                 #define tmp _
  93                 MOV     (tmp, i1)
  94                 SWAP    (tmp)
  95                 ANDI    (tmp, 0x0f)
  96                 LSR     (tmp)
  97                 LSR     (tmp)
  98                 OR      (n, tmp)
  99                 #undef tmp
 100                 MOV     (s, i3)
 101                 ROR     (s)
 102                 ROR     (s)
 103                 ANDI    (s, 0x80)
 104                 #define tmp _
 105                 MOV     (tmp, i2)
 106                 LSR     (tmp)
 107                 OR      (s, tmp)
 108                 #undef tmp
 109
 110                 //voice 1:
 111                 MOV     (t, n)
 112                 RCALL   g();
 113                 SWAP    (t)
 114                 //ANDI  (t, 1)
 115                 MOV     (acc, t)
 116
 117                 //voice 2:
 118                 #define tmp _
 119                 MOV     (tmp, i2)
 120                 LSL     (tmp)
 121                 LSL     (tmp)
 122                 LSL     (tmp)
 123                 MOV     (t, i1)
 124                 SWAP    (t)
 125                 ANDI    (t, 0xf)
 126                 LSR     (t)
 127                 OR      (t, tmp)
 128                 #undef tmp
 129                 EOR     (t, n)
 130                 RCALL   g();
 131                 LSR     (t)
 132                 LSR     (t)
 133                 ANDI    (t, 3)
 134                 AND     (t, s)
 135                 ADD     (acc, t)
 136
 137                 //voice 3:
 138                 MOV     (Ml, i2)
 139                 SWAP    (Ml)
 140                 ANDI    (Ml, 0xf0)
 141                 LSL     (Ml)
 142                 #define tmp _
 143                 MOV     (tmp, i1)
 144                 LSR     (tmp)
 145                 LSR     (tmp)
 146                 LSR     (tmp)
 147                 OR      (Ml, tmp)
 148                 #undef tmp
 149                 MOV     (Mh, i3)
 150                 SWAP    (Mh)
 151                 ANDI    (Mh, 0xf0)
 152                 LSL     (Mh)
 153                 #define tmp _
 154                 MOV     (tmp, i2)
 155                 LSR     (tmp)
 156                 LSR     (tmp)
 157                 LSR     (tmp)
 158                 OR      (Mh, tmp)
 159                 #undef tmp
 160                 RCALL   mod3();
 161                 ADD     (t, n)
 162                 RCALL   g();
 163                 LSR     (t)
 164                 LSR     (t)
 165                 ANDI    (t, 3)
 166                 MOV     (x, s)
 167                 INC     (x)
 168                 #define tmp _
 169                 MOV     (tmp, x)
 170                 LSR     (tmp)
 171                 LSR     (tmp)
 172                 ADD     (tmp, x)
 173                 ROR     (tmp)
 174                 LSR     (tmp)
 175                 ADD     (tmp, x)
 176                 ROR     (tmp)
 177                 LSR     (tmp)
 178                 ADD     (tmp, x)
 179                 ROR     (tmp)
 180                 LSR     (tmp)
 181                 MOV     (x, tmp)
 182                 #undef tmp
 183                 AND     (t, x)
 184                 ADD     (acc, t)
 185
 186                 //voice 4:
 187                 MOV     (Ml, i2)
 188                 SWAP    (Ml)
 189                 ANDI    (Ml, 0xf0)
 190                 LSL     (Ml)
 191                 LSL     (Ml)
 192                 #define tmp _
 193                 MOV     (tmp, i1)
 194                 LSR     (tmp)
 195                 LSR     (tmp)
 196                 OR      (Ml, tmp)
 197                 #undef tmp
 198                 MOV     (Mh, i3)
 199                 SWAP    (Mh)
 200                 ANDI    (Mh, 0xf0)
 201                 LSL     (Mh)
 202                 LSL     (Mh)
 203                 #define tmp _
 204                 MOV     (tmp, i2)
 205                 LSR     (tmp)
 206                 LSR     (tmp)
 207                 OR      (Mh, tmp)
 208                 #undef tmp
 209                 RCALL   mod3();
 210                 SUB     (t, n)
 211                 NEG     (t)
 212                 SUBI    (t, -8)
 213                 RCALL   g();
 214                 LSR     (t)
 215                 ANDI    (t, 3)
 216                 MOV     (x, s)
 217                 INC     (x)
 218                 #define tmp _
 219                 MOV     (tmp, x)
 220                 LSR     (tmp)
 221                 ADD     (tmp, x)
 222                 ROR     (tmp)
 223                 LSR     (tmp)
 224                 LSR     (tmp)
 225                 ADD     (tmp, x)
 226                 ROR     (tmp)
 227                 ADD     (tmp, x)
 228                 ROR     (tmp)
 229                 LSR     (tmp)
 230                 LSR     (tmp)
 231                 MOV     (x, tmp)
 232                 #undef tmp
 233                 AND     (t, x)
 234                 ADD     (acc, t)
 235
 236                 putchar(acc<<4); //TODO
 237                 SUBI    (i0, -1)
 238                 ADC     (i1, zero, !i0)
 239                 ADC     (i2, zero, !i0&&!i1)
 240                 ADC     (i3, zero, !i0&&!i1&&!i2)
 241         }
 242 }