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