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                 ROR     (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                 unsigned short sum = 0; //XXX
 114                 sum += x;
 115                 sum >>= 1;
 116                 sum += x;
 117                 sum >>= 1;
 118                 //nop
 119                 sum >>= 1;
 120                 //nop
 121                 sum >>= 1;
 122                 sum += x;
 123                 sum >>= 1;
 124                 sum += x;
 125                 sum >>= 1;
 126                 //nop
 127                 sum >>= 1;
 128                 //nop
 129                 sum >>= 1;
 130                 x = sum;
 131                 #undef tmp
 132                 t = ((i3&0x01)<<14 | i2<<6 | i1>>2) % 3;
 133                 SUB     (t, n)
 134                 NEG     (t)
 135                 SUBI    (t, -8)
 136                 LDI     (o, 1)
 137                 RCALL   g();
 138                 ADD     (acc, t)
 139
 140                 putchar(acc<<4);
 141                 #define tmp acc
 142                 LDI     (tmp, 0)
 143                 SUBI    (i0, -1)
 144                 ADC     (i1, tmp, !i0)
 145                 ADC     (i2, tmp, !i0&&!i1)
 146                 ADC     (i3, tmp, !i0&&!i1&&!i2)
 147                 #undef tmp
 148         }
 149 }