Not romable z80 compiler

- mostly executable code
- mostly not reentrant functions store locals inside code

data types:

- flag	z or cy
- int8	mostly in register A
- int16	mostly in register HL
- int32	mostly in register DEHL

ABI calling convention:

- last argument passed in A/HL/DEHL dep. on size
- other arguments passed on stack
- return value in A/HL/DEHL/c/z or none (void)
- register BC must be preserved (used for local variables)

Locals in code: (unless source is compiled reentrantrant or function is marked recursive)


/*
	Source Example
*/
void foo ( int16 bar -- )
{
	int8 i = 0;
	do
	{
		print "i=", i, '\n';
		i++;
		while (i < bar );
	}
}


Intermediate code:

		lvar.i16 bar
		lvar.i8  i

P_foo:	lset.w 	bar
		ival.b 	0
		lset.b 	i
l1:		istr 	"i="
		print_str
		lget.b	i
		print_i8
		ival.b	'\n'
		print_char
		lvar 	i
		incr.b
		lget.b	i
		cast_i8_to_i16
		lget.w	bar
		lt.i16
		jp		true,l1
		return


Assembly source:  "-O0"

#local
_bar:	data 2			; i16: bar	(arg1)
_i:		data 1			; i8:  i  	(lvar)
_str1:	db	"i=", 0		; "i="		(reusable)

foo_i16::	ld	(_bar), hl	; store arg1 in lvar
		xor	a			; 0
		ld	(_i), a		; i!
l1:						; do
		ld	hl, _str1		; "i="
		call print_str 	; .
		ld	a, (_i)		; i?
		call print_i8		; .
		ld	a, '\n'		; '\n'
		call print_c8		; .
		ld	hl, _i		; i++
		inc	(hl)			;
		ld	a, (_i)		; i?
		call	cast_i8__i16	;
		push hl			; bar?
		ld	hl, (_bar)	;
		call lt_i16__c		; <
		jr	c, l1		; while
		ret				; return ;
#endlocal


Assembly source:  "-O1"

;_bar	data 2
_i		equ B
_str1:	db	"i=",0

		pop	 hl
P_foo:	push bc
		ld	 (_bar),hl
		ld	 _i,0
l1:		ld	 hl,_str1
		call print_str
		ld	 hl,(_i)
		call print_int
		ld	 hl,'\n'
		call print_char
		inc	 _i
		ld	 a,_i
		call cast_i8_to_i16
		ex	 de,hl
_bar = $+1
		ld	 hl,0 ; ld hl,(_bar)
		call cmp_lt
		jr	 c, l1
		pop  bc
		ret

---------
_bar	data 2
_i		data 2
_str1:	db	"i=",0
retaddr: db 2
p_foo:
	ld	(_bar),hl
	ld	(retaddr),sp
	ld	sp,vcode
	ret
	align 2
vcode:
	dw	ival, 0
	dw	vset, _i
l1:	dw	ival, _str1
	dw	print_str
	dw	vget, _i
	dw	print_int
	dw	ival, '\n'
	dw	print_char
	dw	ival, _i
	dw	incr
	dw	vget, _i
	dw	vget, _bar
	dw	cmp_lt
	dw	jp_true, l1
	dw	real
	ld	sp,(retaddr)
	ret






Source example:

void foo ( int16 bar -- )
{
	int8 i = 0;
	do
	{
		print "i=", i, '\n';
		i++;
		while (i < bar );
	}
}


function: 'foo' ( int16 -- void )
does:
	lvar: 'bar' ( -- int16& )
	instruction:
		arg1: on_stack   ( -- int16 )
		arg2: lvar 'bar' ( -- int16& )
		does: poke (int16& int16 -- )
	lvar: 'i' ( -- int8& )
	label 'L1'
	instruction:
		arg1: istr "i="
		does: print ( string -- )
	instruction:
		arg1: lvar 'i'
			 peek ( int8& -- int8 )
		does: print ( int8 -- )
	instruction:
		arg1: ival 10
		does: print ( char -- )
	instruction:
		arg1: lvar 'i'
		does: incr ( int8& -- )
	instruction:
		a1:	expression ( -- bool )
			a1:	lvar 'i'   ( -- int8& )
				peek8      ( int8& -- int8 )
				casti8i16  ( int8 -- int16 )
			a2:	lvar 'bar' ( -- int16& )
				peek16	 ( int16& -- int16 )
			does:oper '<'  ( int16 int16 -- bool )
		a2:  label 'L1'
		does:jp_if1 ( bool label -- )
	instruction:
		does: return ( -- )