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 = (((i1&0x1f)<<8|i0)*t)>>8 >> o;
  28         AND     (t, x)
  29         ANDI    (t, 3)
  30         RET
  31 };
  32
  33 int main(void) {
  34         u8 n;
  35         u8 s;
  36         u8 acc;
  37         //TODO: clear all vars/registers
  38         for (;;) {
  39                 MOV     (n, i2)
  40                 LSL     (n)
  41                 LSL     (n)
  42                 #define tmp acc
  43                 MOV     (tmp, i1)
  44                 SWAP    (tmp)
  45                 ANDI    (tmp, 0x0f)
  46                 LSR     (tmp)
  47                 LSR     (tmp)
  48                 OR      (n, tmp)
  49                 #undef tmp
  50                 MOV     (s, i3)
  51                 ROR     (s)
  52                 ROR     (s)
  53                 ANDI    (s, 0x80)
  54                 #define tmp acc
  55                 MOV     (tmp, i2)
  56                 LSR     (tmp)
  57                 OR      (s, tmp)
  58                 #undef tmp
  59
  60                 //voice 1:
  61                 LDI     (x, 1)
  62                 MOV     (t, n)
  63                 LDI     (o, 4)
  64                 RCALL   g();
  65                 MOV     (acc, t)
  66
  67                 //voice 2:
  68                 MOV     (x, s)
  69                 #define tmp o
  70                 MOV     (tmp, i2)
  71                 LSL     (tmp)
  72                 LSL     (tmp)
  73                 LSL     (tmp)
  74                 MOV     (t, i1)
  75                 SWAP    (t)
  76                 ANDI    (t, 0xf)
  77                 LSR     (t)
  78                 OR      (t, tmp)
  79                 #undef tmp
  80                 EOR     (t, n)
  81                 LDI     (o, 2)
  82                 RCALL   g();
  83                 ADD     (acc, t)
  84
  85                 //voice 3:
  86                 MOV     (x, s)
  87                 INC     (x)
  88                 #define tmp o
  89                 unsigned short sum = 0;
  90                 for(int loop = 0; loop < 4; loop ++) {
  91                 sum >>= 1;
  92                 sum += x;
  93                 sum >>= 1;
  94                 //nop
  95                 }
  96                 sum >>= 1;
  97                 x = sum;
  98
  99                 #undef tmp
 100                 t = ((i3&0x01)<<13 | i2<<5 | i1>>3) % 3;
 101                 ADD     (t, n)
 102                 LDI     (o, 2)
 103                 RCALL   g();
 104                 ADD     (acc, t)
 105
 106                 //voice 4:
 107                 MOV     (x, s)
 108                 INC     (x)
 109                 #define tmp o
 110                 x = (x*0x33)>>8;
 111                 #undef tmp
 112                 t = ((i3&0x01)<<14 | i2<<6 | i1>>2) % 3;
 113                 SUB     (t, n)
 114                 NEG     (t)
 115                 SUBI    (t, -8)
 116                 LDI     (o, 1)
 117                 RCALL   g();
 118                 ADD     (acc, t)
 119
 120                 putchar(acc<<4);
 121                 #define tmp acc
 122                 LDI     (tmp, 0)
 123                 SUBI    (i0, -1)
 124                 ADC     (i1, tmp, !i0)
 125                 ADC     (i2, tmp, !i0&&!i1)
 126                 ADC     (i3, tmp, !i0&&!i1&&!i2)
 127                 #undef tmp
 128         }
 129 }