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 i0;
  10 u8 i1;
  11 u8 i2;
  12 u8 i3;
  13 u8 x;
  14 u8 t;
  15 u8 o;
  16 void g(void) {
  17         // g(i, x, t, o) -> t
  18         u8 tmp;
  19         ANDI    (t, 0x07)
  20         MOV     (tmp, i2)
  21         ANDI    (tmp, 3)
  22         TST     (tmp)
  23         BREQ    (skip)
  24         SUBI    (t, -8)
  25         skip:
  26         t = data[t];
  27         t = ((i3<<24|i2<<16|i1<<8|i0)*t) >> o;
  28         AND     (t, x)
  29         ANDI    (t, 3)
  30         RET
  31 };
  32
  33 int main(void) {
  34         unsigned short n;
  35         unsigned short s;
  36         u8 acc;
  37         //TODO: clear all vars/registers
  38         for (;;) {
  39                 acc = 0;
  40                 n = (i2<<2 | i1>>6);
  41                 s = (i3<<7 | i2>>1);
  42
  43                 //voice 1:
  44                 LDI     (x, 1)
  45                 MOV     (t, n)
  46                 LDI     (o, 12)
  47                 RCALL   g();
  48                 MOV     (acc, t)
  49
  50                 //voice 2:
  51                 MOV     (x, s)
  52                 t = n ^ (i2<<3 | i1>>5);
  53                 LDI     (o, 10)
  54                 RCALL   g();
  55                 ADD     (acc, t)
  56
  57                 //voice 3:
  58                 x = s / 3;
  59                 t = n + ((i3<<13 | i2<<5 | i1>>3) % 3);
  60                 LDI     (o, 10)
  61                 RCALL   g();
  62                 ADD     (acc, t)
  63
  64                 //voice 4:
  65                 x = s / 5;
  66                 t = 8 + n - ((i3<<14 | i2<<6 | i1>>2) % 3);
  67                 LDI     (o, 9)
  68                 RCALL   g();
  69                 ADD     (acc, t)
  70
  71                 putchar(acc<<4);
  72                 #define tmp acc
  73                 LDI     (tmp, 0)
  74                 SUBI    (i0, -1)
  75                 ADC     (i1, tmp, !i0)
  76                 ADC     (i2, tmp, !i0&&!i1)
  77                 ADC     (i3, tmp, !i0&&!i1&&!i2)
  78         }
  79 }