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.
  74
  75                 SR      (acc)
  76                 ADD     (acc, i2)
  77
  78                 SR      (acc)
  79                 //ADD acc, 0
  80
  81                 SR      (acc)
  82                 ADD     (acc, i2)
  83
  84                 SR      (acc)
  85                 //ADD acc, 0
  86
  87                 SR      (acc)
  88                 ADD     (acc, i2)
  89
  90                 SR      (acc)
  91                 //ADD acc, 0
  92
  93                 SR      (acc)
  94                 //ADD acc, 0
  95                 SR      (acc)
  96                 //ADD acc, 0
  97
  98                 // end divide by six
  99                 AND     (acc, tmp_1) // acc restored from tmp_1
 100                 AND     (acc, 3)
 101                 ADD     (sample, acc)
 102
 103                 MOV     (acc, n)
 104                 ADD     (acc, 8)
 105                 { u8 tmp3 = (i2<<6|i1>>2)%3;
 106                   SUB   (acc, tmp3)
 107                 } // tmp3
 108                 CALL    (g)
 109                 SR      (acc)
 110                 MOV     (tmp_1, acc) // acc saved in tmp_1; fresh acc
 111                 // shift-divide by ten
 112                 // note: i2 is max 0x78; so acc will <= 12.
 113                 acc = i2/10;//TODO
 114                 // end divide by ten
 115                 AND     (acc, tmp_1) // acc restored from tmp_1
 116                 AND     (acc, 3)
 117                 ADD     (sample, acc)
 118
 119                 MOV     (acc, sample)
 120                 SWAP    (acc)
 121                 putchar(acc);
 122
 123                 INC     (i0)
 124                 i1 += !i0; // ADDC i1
 125                 i2 += !i1 && !i0; // ADDC i2
 126         }
 127 }