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