Commit c2024585 authored by bp's avatar bp
Browse files

Forward label declaration 


git-svn-id: https://www.forth-ev.de/repos/b16@290 3b8d8251-53f3-0310-8f3b-fd1cb8370982
parent d8f6c0c1

b16.asm

+4 −3
Original line number Diff line number Diff line 
#! /usr/bin/gforth b16-asm.fs

: reset			\ label reset

    fw jmp		\ jump forward to boot

   ' boot jmp		\ jump forward to boot

: stack			\ stack test

    1 #c 2 #c 3 #	\ fill stack with 1 2 3 4 5 6 7 8 9 A B

    4 # 5 #c 6 #c
@@ -52,11 +52,12 @@ 
    0 # com      cIF  drop 5 # + THEN

    0 #c 0 #c + -cIF  drop 6 # + THEN

;			\ return to caller

: boot THEN		\ resolve forward jump from reset

: boot			\ resolve forward jump from reset

    stack		\ call stack test

    alu			\ call ALU test

    $1234 # $5678 # mul	\ multiply 1234 with 5678 (hex)

    $789a # div drop drop \ divide by 789A, drop results

    jumps -jumps	\ call jump tests

    BEGIN jmp ;		\ endless loop

;			\ endless loop

.end			\ end of test program

.hex

b16.fs

+29 −3
Original line number Diff line number Diff line
@@ -274,9 +274,35 @@ Forth 
: .end inst, ;

: macro: : ;

: end-macro postpone ; ; immediate

: : Create  inst, IP @ , DOES> @ inst, 1 jmp, ;

: | Create  inst, IP @ , DOES> @ ;

: ' ' >body @ ;



\ label handling

: :-does DOES> @ inst, 1 jmp, ;

: |-does DOES> @ ;

: label-resolve ( addr -- )

    cell+ @  BEGIN

	dup -1 <> WHILE

	    dup >r @ $FC00 [ b16-asm ] THEN [ Forth ] r> cell+ @

    REPEAT  drop ;



: ?Create >in @ >r name find  IF

	rdrop  lastcfa !  inst,

	IP @ lastcfa @ >body !

	lastcfa @ >body label-resolve

	lastcfa @ >body cell+ off

    ELSE  drop r> >in ! Create inst, IP @ , 0 ,  THEN ;



: : ?Create  :-does ;

: | ?Create  |-does ;

: ' ( "name" -- addr )

    >in @ >r name find

    IF  >body dup @ swap cell+

	dup @ IF  here IP @ , over @ , swap !

	    IP @ $FC00 and

	ELSE  drop  THEN  rdrop

    ELSE

	drop r> >in !

	Create 0 , here cell+ , IP @ $FC00 and dup , -1 , |-does

    THEN ;



$00 inst nop

$01 2 insts3 exec goto