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                 MOV     (tmp, x)
  90                 LSR     (tmp)
  91                 LSR     (tmp)
  92                 ADD     (tmp, x)
  93                 ROR     (tmp)
  94                 LSR     (tmp)
  95                 ADD     (tmp, x)
  96                 ROR     (tmp)
  97                 LSR     (tmp)
  98                 ADD     (tmp, x)
  99                 ROR     (tmp)
 100                 LSR     (tmp)
 101                 MOV     (x, tmp)
 102                 #undef tmp
 103                 t = ((i3&0x01)<<13 | i2<<5 | i1>>3) % 3;
 104                 ADD     (t, n)
 105                 LDI     (o, 2)
 106                 RCALL   g();
 107                 ADD     (acc, t)
 108
 109                 //voice 4:
 110                 MOV     (x, s)
 111                 INC     (x)
 112                 #define tmp o
 113                 MOV     (tmp, x)
 114                 LSR     (tmp)
 115                 ADD     (tmp, x)
 116                 ROR     (tmp)
 117                 LSR     (tmp)
 118                 LSR     (tmp)
 119                 ADD     (tmp, x)
 120                 ROR     (tmp)
 121                 ADD     (tmp, x)
 122                 ROR     (tmp)
 123                 LSR     (tmp)
 124                 LSR     (tmp)
 125                 MOV     (x, tmp)
 126                 #undef tmp
 127                 t = ((i3&0x01)<<14 | i2<<6 | i1>>2) % 3;
 128                 SUB     (t, n)
 129                 NEG     (t)
 130                 SUBI    (t, -8)
 131                 LDI     (o, 1)
 132                 RCALL   g();
 133                 ADD     (acc, t)
 134
 135                 putchar(acc<<4);
 136                 #define tmp acc
 137                 CLR     (tmp) //NOTE: maybe use dedicated zero register?
 138                 SUBI    (i0, -1)
 139                 ADC     (i1, tmp, !i0)
 140                 ADC     (i2, tmp, !i0&&!i1)
 141                 ADC     (i3, tmp, !i0&&!i1&&!i2)
 142                 #undef tmp
 143         }
 144 }