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