Original brainfuck distribution by Urban Müller

README

This archive contains the following programs:

 bfc          The compiler for the 'brainfuck' language (240 bytes!)
 bfc.asm      Source for the compiler
 bfi          The interpreter for the 'brainfuck' language
 bfi.c        Source for the interpreter (portable)
 src/         Some example programs in 'brainfuck'
 src/atoi.b   Reads a number from stdin
 src/div10.b  Divides the number under the pointer by 10
 src/hello.b  The ubiquitous "Hello World!"
 src/mul10.b  Multiplies the number under the pointer by 10
 src/prime.b  Computes the primes up the a variable limit
 src/varia.b  Small program elements like SWAP, DUP etc.


WHATS NEW
=========

Yes, I squeezed another ridiculous 56 bytes out of the compiler. They have
their price, though: The new compiler requires OS 2.0, operates on a byte 
array instead of longwords, and generates executables that are always 64K 
in size. Apart from that the language hasn't changed. Again:
***  OS 2.0 *required* for the compiler and the compiled programs  *** 
The interpreter works fine under any OS version. And yes, thanks to Chris
Schneider for his ideas how to make the compiler shorter.


THE LANGUAGE
============

The language 'brainfuck' knows the following commands:

 Cmd  Effect                                 Equivalent in C
 ---  ------                                 ---------------
 +    Increases element under pointer        array[p]++;
 -    Decrases element under pointer         array[p]--;
 >    Increases pointer                      p++;
 <    Decreases pointer                      p--;
 [    Starts loop, counter under pointer     while(array[p]) {
 ]    Indicates end of loop                  }
 .    Outputs ASCII code under pointer       putchar(array[p]);
 ,    Reads char and stores ASCII under ptr  array[p]=getchar();

All other characters are ignored. The 30000 array elements and p are being
initialized to zero at the beginning.  Now while this seems to be a pretty
useless language, it can be proven that it can compute every solvable
mathematical problem (if we ignore the array size limit and the executable
size limit).


THE COMPILER
============

The compiler does not check for balanced brackets; they better be. It reads
the source from stdin and writes the executable to stdout. Note that the 
executable is always 65536 bytes long, and usually won't be executable if
brackets aren't balanced. OS 2.0 required for the compiler and the compiled
program.


THE INTERPRETER
===============

For debugging, there's also an interpreter. It expects the name of the 
program to  interpret on the command line and accepts an additional command:
Whenever a '#' is met in the source and a second argument was passwd to
the interpreter, the first few elements of the array are written to stdout
as numbers


   Enjoy

     -Urban Mueller     <[email protected]>

bfc

bfc.asm

	EXEOBJ
	OUTPUT	bfc

OBJSIZE	EQU	65536
CODSIZE	EQU	32000

read	EQU	-$2a
write	EQU	-$30
input	EQU	-$36
output	EQU	-$3c
closlib EQU	-$19e

; d0
; d1   len
; d2
; d3   1
; d4   byte
; d5   offset
; d6   
; d7

; a0
; a1
; a2   stack
; a3   cdptr
; a4   4
; a5   code
; a6


initcode:
	dc.l	$3f3,0,1,0,0,OBJSIZE/4-9,$3e9,OBJSIZE/4-9

	lea	(CODSIZE,pc),a5
	moveq	#4,d0
	move.l	d0,a4
	move.l	(a4),a6
	jsr	-810(a6)
	move.l	d0,a6
	moveq	#1,d3
initcode2:



clrmem
	move.l	a5,a2
	moveq	#-1,d5
..	clr.b	(a2)+
	dbra	d5,..
	move.w	#$3f2,-(a2)
	move.l	a5,a2



	move.b	d3,(a5)
mainloop
	move.b	(a5),d4
	lea	(code,pc),a3

..	move.b	(a3)+,d5
	move.b	(a3)+,d1
	cmp.b	(a3)+,d4
	blo.b	..
	bne.b	advance
	add.l	d5,a3

copy	move.b	(a3)+,(a5)+
	subq.b	#1,d1
	bne.b	copy

	addq.b	#8,d5
	bcc.s	noloop
	move.l	a5,-(a2)
noloop

	addq.b	#3,d5
	bne.s	noendl
	move.l	(a2)+,a0
	move.l	a0,d0
	sub.l	a5,d0
	move.w	d0,(a5)+
	neg.w	d0
	subq.w	#4,d0
	move.w	d0,-(a0)
noendl


advance
	clr.b	(a5)
readbyte
	jsr	input(a6)
	move.l	d0,d1
 	move.l	a5,d2
	jsr	read(a6)
readbyte2

	tst.b	d4
	bne.s	mainloop

	move.l	a2,a5
	swap	d3
writebyte
	jsr	output(a6)
	move.l	d0,d1
	move.l	a5,d2
	jsr	write(a6)
writebyte2

cleanup
	move.l	a6,a1
	move.l	(a4),a6
	jsr	closlib(a6)
	moveq	#0,d0
	rts
cleanup2

rightcode:
	addq.l	#1,a5
leftcode:
	subq.l	#1,a5

endwcode
addcode:
	addq.b	#1,(a5)
subcode:
	subq.b	#1,(a5)
	dc.w	$6600
endwcode2

whilecode:
	dc.w	$6000
whilecode2

code:
endw:	dc.b	endwcode-endw-3,6,']'
while:	dc.b	whilecode-while-3,4,'['
right:	dc.b	rightcode-right-3,2,'>'
left:	dc.b	leftcode-left-3,2,'<'

out:	dc.b	writebyte-out-3,writebyte2-writebyte,'.'
sub:	dc.b	subcode-sub-3,2,'-'
in:	dc.b	readbyte-in-3,readbyte2-readbyte,','
add:	dc.b	addcode-add-3,2,'+'

beg:	dc.b	(initcode-beg-3)&$FF,initcode2-initcode,1
end:	dc.b	cleanup-end-3,cleanup2-cleanup,0

	dx.b	OBJSIZE+CODSIZE

	END

bfi

bfi.c

#include <stdio.h>

int  p, r, q;
char a[5000], f[5000], b, o, *s=f;

void interpret(char *c)
{
	char *d;

	r++;
	while( *c ) {
		//if(strchr("<>+-,.[]\n",*c))printf("%c",*c);
		switch(o=1,*c++) {
		case '<': p--;        break;
		case '>': p++;        break;
		case '+': a[p]++;     break;
		case '-': a[p]--;     break;
		case '.': putchar(a[p]); fflush(stdout); break;
		case ',': a[p]=getchar();fflush(stdout); break;
		case '[':
			for( b=1,d=c; b && *c; c++ )
				b+=*c=='[', b-=*c==']';
			if(!b) {
				c[-1]=0;
				while( a[p] )
					interpret(d);
				c[-1]=']';
				break;
			}
		case ']':
			puts("UNBALANCED BRACKETS"), exit(0);
		case '#':
			if(q>2)
				printf("%2d %2d %2d %2d %2d %2d %2d %2d %2d %2d\n%*s\n",
				       *a,a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],3*p+2,"^");
			break;
		default: o=0;
		}
		if( p<0 || p>100)
			puts("RANGE ERROR"), exit(0);
	}
	r--;
	chkabort();
}

main(int argc,char *argv[])
{
	FILE *z;

	q=argc;

	if(z=fopen(argv[1],"r")) {
		while( (b=getc(z))>0 )
			*s++=b;
		*s=0;
		interpret(f);
	}
}

src.bf.atoi.b

==== ==== ====
cont digi num
==== ==== ====

+
[
 -                         cont=0
 >,
 ======SUB10======
 ----------
 
 [                         not 10
  <+>                      cont=1
  =====SUB38======
  ----------
  ----------
  ----------
  --------

  >
  =====MUL10=======
  [>+>+<<-]>>[<<+>>-]<     dup

  >>>+++++++++
  [
   <<<
   [>+>+<<-]>>[<<+>>-]<    dup
   [<<+>>-]
   >>-
  ]
  <<<[-]<
  ======RMOVE1======
  <
  [>+<-]
 ]
 <
]
>>[<<+>>-]<<
#

src.bf.div10.b

==== ==== ==== ==== ====
num  ten  tmp  bool div
==== ==== ==== ==== ====

>+++++++++<
[
 >>>+<<                bool= 1
 [>+>[-]<<-]           bool= ten==0
 >[<+>-]               ten = tmp
 >[<<++++++++++>>>+<-] if ten=0 ten=10  inc div
 <<-                   dec ten     
 <-                    dec num
]
>>>>[<<<<+>>>>-]<<<<   copy div to num
>[-]<                  clear ten

src.bf.hello.b

>+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]>++++++++[<++++>-]
<.#>+++++++++++[<+++++>-]<.>++++++++[<+++>-]<.+++.------.--------.[-]>++++++++[
<++++>-]<+.[-]++++++++++.

src.bf.mul10.b

=====MUL10=======
[>+<-]>         ; move num one right ie num2=num
>>++++++++++    ; load 10 into fourth element
[
 <<[<+>>+<-]    ; add num2 to first and third element
 >[<+>-]>       ; num2=third element
 -              ; loop ten times
]
<<[-]<          ; clear num2
#

src.bf.prime.b

===================================================================
======================== OUTPUT STRING ============================
===================================================================
>++++++++[<++++++++>-]<++++++++++++++++.[-]
>++++++++++[<++++++++++>-]<++++++++++++++.[-]
>++++++++++[<++++++++++>-]<+++++.[-]
>++++++++++[<++++++++++>-]<+++++++++.[-]
>++++++++++[<++++++++++>-]<+.[-]
>++++++++++[<++++++++++>-]<+++++++++++++++.[-]
>+++++[<+++++>-]<+++++++.[-]
>++++++++++[<++++++++++>-]<+++++++++++++++++.[-]
>++++++++++[<++++++++++>-]<++++++++++++.[-]
>+++++[<+++++>-]<+++++++.[-]
>++++++++++[<++++++++++>-]<++++++++++++++++.[-]
>++++++++++[<++++++++++>-]<+++++++++++.[-]
>+++++++[<+++++++>-]<+++++++++.[-]
>+++++[<+++++>-]<+++++++.[-]

===================================================================
======================== INPUT NUMBER  ============================
===================================================================
+                          cont=1
[
 -                         cont=0
 >,
 ======SUB10======
 ----------
 
 [                         not 10
  <+>                      cont=1
  =====SUB38======
  ----------
  ----------
  ----------
  --------

  >
  =====MUL10=======
  [>+>+<<-]>>[<<+>>-]<     dup

  >>>+++++++++
  [
   <<<
   [>+>+<<-]>>[<<+>>-]<    dup
   [<<+>>-]
   >>-
  ]
  <<<[-]<
  ======RMOVE1======
  <
  [>+<-]
 ]
 <
]
>>[<<+>>-]<<

===================================================================
======================= PROCESS NUMBER  ===========================
===================================================================

==== ==== ==== ====
numd numu teid teiu
==== ==== ==== ====

>+<-
[
 >+
 ======DUP======
 [>+>+<<-]>>[<<+>>-]<

 >+<--

 >>>>>>>>+<<<<<<<<   isprime=1

 [
  >+

  <-

  =====DUP3=====
  <[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<<<

  =====DUP2=====
  >[>>+>+<<<-]>>>[<<<+>>>-]<<< <


  >>>


  ====DIVIDES=======
  [>+>+<<-]>>[<<+>>-]<   DUP i=div
  
  <<
  [
    >>>>>+               bool=1
    <<<
    [>+>+<<-]>>[<<+>>-]< DUP
    [>>[-]<<-]           IF i THEN bool=0
    >>
    [                    IF i=0
      <<<<
      [>+>+<<-]>>[<<+>>-]< i=div
      >>>
      -                  bool=0
    ]
    <<<
    -                    DEC i
    <<
    -
  ]
  
  +>>[<<[-]>>-]<<          
  >[-]<                  CLR div
  =====END DIVIDES====


  [>>>>>>[-]<<<<<<-]     if divides then isprime=0


  <<

  >>[-]>[-]<<<
 ]

 >>>>>>>>
 [
  -
  <<<<<<<[-]<<

  [>>+>+<<<-]>>>[<<<+>>>-]<<<

  >>




  ===================================================================
  ======================== OUTPUT NUMBER  ===========================
  ===================================================================
  [>+<-]>
 
  [
   ======DUP======
   [>+>+<<-]>>[<<+>>-]<
  
  
   ======MOD10====
   >+++++++++<
   [
    >>>+<<              bool= 1
    [>+>[-]<<-]         bool= ten==0
    >[<+>-]             ten = tmp
    >[<<++++++++++>>-]  if ten=0 ten=10
    <<-                 dec ten     
    <-                  dec num
   ]
   +++++++++            num=9
   >[<->-]<             dec num by ten
  
   =======RROT======
      [>+<-]
   <  [>+<-]
   <  [>+<-]
   >>>[<<<+>>>-]
   <
  
   =======DIV10========
   >+++++++++<
   [
    >>>+<<                bool= 1
    [>+>[-]<<-]           bool= ten==0
    >[<+>-]               ten = tmp
    >[<<++++++++++>>>+<-] if ten=0 ten=10  inc div
    <<-                   dec ten     
    <-                    dec num
   ]
   >>>>[<<<<+>>>>-]<<<<   copy div to num
   >[-]<                  clear ten
  
   =======INC1=========
   <+>
  ]
  
  <
  [
   =======MOVER=========
   [>+<-]
  
   =======ADD48========
   +++++++[<+++++++>-]<->
  
   =======PUTC=======
   <.[-]>
  
   ======MOVEL2========
   >[<<+>>-]<
  
   <-
  ]
 
  >++++[<++++++++>-]<.[-]
 
  ===================================================================
  =========================== END FOR ===============================
  ===================================================================


  >>>>>>>
 ]
 <<<<<<<<



 >[-]<
  [-]
 <<-
]
 
======LF========
 
++++++++++.[-]

src.bf.varia.b

[
most of these require the the numbers to the right of the pointer to be 0

CLR  =   [-]
ADD  =   [<+>-]<
DUP  =   [>+>+<<-]>>[<<+>>-]
SWAP =   [>+<-]<[>+<-]>>[<<+>>-]<
MUL  =   >[-]>[-]<< <[>[>+>+<<-] >[<+>-] <-] >>>[<<<+>>>-]<<<
IF   =   >[-]<[>[-]+<-]> (your program here) <

]