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; //XXX
  90                 sum >>= 1;
  91                 sum += x;
  92                 sum >>= 1;
  93                 //nop
  94                 sum >>= 1;
  95                 sum += x;
  96                 sum >>= 1;
  97                 //nop
  98                 sum >>= 1;
  99                 sum += x;
 100                 sum >>= 1;
 101                 //nop
 102                 sum >>= 1;
 103                 sum += x;
 104                 sum >>= 1;
 105                 //nop
 106                 sum >>= 1;
 107                 x = sum;
 108                 #undef tmp
 109                 t = ((i3&0x01)<<13 | i2<<5 | i1>>3) % 3;
 110                 ADD     (t, n)
 111                 LDI     (o, 2)
 112                 RCALL   g();
 113                 ADD     (acc, t)
 114
 115                 //voice 4:
 116                 MOV     (x, s)
 117                 INC     (x)
 118                 #define tmp o
 119                 sum = 0; //XXX
 120                 sum >>= 1;
 121                 sum += x;
 122                 sum >>= 1;
 123                 sum += x;
 124                 sum >>= 1;
 125                 //nop
 126                 sum >>= 1;
 127                 //nop
 128                 sum >>= 1;
 129                 sum += x;
 130                 sum >>= 1;
 131                 sum += x;
 132                 sum >>= 1;
 133                 //nop
 134                 sum >>= 1;
 135                 //nop
 136                 sum >>= 1;
 137                 x = sum;
 138                 #undef tmp
 139                 t = ((i3&0x01)<<14 | i2<<6 | i1>>2) % 3;
 140                 SUB     (t, n)
 141                 NEG     (t)
 142                 SUBI    (t, -8)
 143                 LDI     (o, 1)
 144                 RCALL   g();
 145                 ADD     (acc, t)
 146
 147                 putchar(acc<<4);
 148                 #define tmp acc
 149                 LDI     (tmp, 0)
 150                 SUBI    (i0, -1)
 151                 ADC     (i1, tmp, !i0)
 152                 ADC     (i2, tmp, !i0&&!i1)
 153                 ADC     (i3, tmp, !i0&&!i1&&!i2)
 154                 #undef tmp
 155         }
 156 }