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) //don't rely on carry empty after mov | ror only after add
  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                 //nop
 118                 LSR     (tmp)
 119                 //nop
 120                 LSR     (tmp)
 121                 ADD     (tmp, x)
 122                 ROR     (tmp)
 123                 ADD     (tmp, x)
 124                 ROR     (tmp)
 125                 //nop
 126                 LSR     (tmp)
 127                 //nop
 128                 LSR     (tmp)
 129                 x = tmp;
 130                 #undef tmp
 131                 t = ((i3&0x01)<<14 | i2<<6 | i1>>2) % 3;
 132                 SUB     (t, n)
 133                 NEG     (t)
 134                 SUBI    (t, -8)
 135                 LDI     (o, 1)
 136                 RCALL   g();
 137                 ADD     (acc, t)
 138
 139                 putchar(acc<<4);
 140                 #define tmp acc
 141                 LDI     (tmp, 0)
 142                 SUBI    (i0, -1)
 143                 ADC     (i1, tmp, !i0)
 144                 ADC     (i2, tmp, !i0&&!i1)
 145                 ADC     (i3, tmp, !i0&&!i1&&!i2)
 146                 #undef tmp
 147         }
 148 }