bsv.c

   1 #include <stdio.h>
   2 #include "fakeasm.h"
   3 typedef unsigned char u8;
   4
   5 u8 i0, i1, i2; //MEM
   6 u8 n; //MEM
   7 u8 sample; //MEM
   8 u8 tmp_1; //MEM
   9 u8 acc; //ACC
  10
  11 u8 notes[] = {
  12         0x84, 0x9d, 0xb0, 0x69, 0x9d, 0x84, 0x69, 0x58,
  13         0x75, 0x8c, 0xb0, 0x69, 0x8c, 0x75, 0x69, 0x58
  14 };
  15
  16 void g(void){
  17         u8 notes_ix = acc & 0x7;
  18         if(3&i2)
  19                 notes_ix += 8;
  20         u8 result = ((i1<<8|i0)*notes[notes_ix])>>8;  // keep hi byte
  21         acc = result;
  22 }
  23 void main(void){
  24         CLEAR   (i0)
  25         CLEAR   (i1)
  26         CLEAR   (i2)
  27         for(;;) {
  28                 MOV     (acc, i2)// "mov mem,mem"
  29                 MOV     (n, acc)// does not exist
  30                 SL      (n)
  31                 SL      (n)
  32                 MOV     (acc, i1)
  33                 SWAP    (acc)
  34                 AND     (acc, 0xf)
  35                 SR      (acc)
  36                 SR      (acc)
  37                 OR      (n, acc)
  38
  39                 MOV     (acc, n)
  40                 CALL    (g)
  41                 SWAP    (acc)
  42                 AND     (acc, 0x1)
  43                 MOV     (sample, acc)
  44
  45                 MOV     (acc, i2)
  46                 SL      (acc)
  47                 SL      (acc)
  48                 SL      (acc)
  49                 MOV     (tmp_1, acc) // fresh tmp_1:
  50                 MOV     (acc, i1)
  51                 SWAP    (acc)
  52                 AND     (acc, 0xf)
  53                 SR      (acc)
  54                 OR      (acc, tmp_1) // tmp_1 done.
  55                 XOR     (acc, n)
  56                 CALL    (g)
  57                 SR      (acc)
  58                 AND     (acc, i2)
  59                 SR      (acc)
  60                 AND     (acc, 3)
  61                 ADD     (sample, acc)
  62
  63                 { u8 tmp2 = (i2<<5|i1>>3)%3;//TODO
  64                 MOV     (acc, tmp2)
  65                 ADD     (acc, n)
  66                 CALL    (g)
  67                 } //tmp2
  68                 SR      (acc)
  69                 SR      (acc)
  70                 MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
  71                 MOV     (acc, i2)
  72                 // shift-divide by six
  73                 // note: i2 is max 0x78; so acc will <= 20. (breaks vor values >=128)
  74                 SR      (acc)
  75                 ADD     (acc, i2)
  76                 SR      (acc)
  77                 SR      (acc)
  78                 ADD     (acc, i2)
  79                 SR      (acc)
  80                 SR      (acc)
  81                 ADD     (acc, i2)
  82                 SR      (acc)
  83                 SR      (acc)
  84                 SR      (acc)
  85                 // end divide by six
  86                 AND     (acc, tmp_1) // acc restored from tmp_1
  87                 AND     (acc, 3)
  88                 ADD     (sample, acc)
  89
  90                 MOV     (acc, n)
  91                 ADD     (acc, 8)
  92                 { u8 tmp3 = (i2<<6|i1>>2)%3;
  93                   SUB   (acc, tmp3)
  94                 } // tmp3
  95                 CALL    (g)
  96                 SR      (acc)
  97                 MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
  98                 // shift-divide by ten
  99                 // note: i2 is max 0x78; so acc will <= 12.
 100                 acc = i2/10;//TODO
 101                 // end divide by ten
 102                 AND     (acc, tmp_1) // acc restored from tmp_1
 103                 AND     (acc, 3)
 104                 ADD     (sample, acc)
 105
 106                 MOV     (acc, sample)
 107                 SWAP    (acc)
 108                 putchar(acc);
 109
 110                 INC     (i0)
 111                 i1 += !i0; // ADDC i1
 112                 i2 += !i1 && !i0; // ADDC i2
 113         }
 114 }