support6800/ missing __abx, __adx

[zu2]

I couldn't decide whether it would be better to save A and B on the caller side or on the __abx/adx side. Here, pshb/psha are omitted as they are saved on the caller side.

;
;	Adds the value of the accumulator to X.
;	messing up D
;
	.export __abx
	.export __adx
	.code

__abx:
	stx @tmp	; X where we can manipulate it
	addb @tmp+1
	adca #0
	stab @tmp+1
	staa @tmp
	ldx @tmp
	rts

__adx:
	stx @tmp	; X where we can manipulate it
	addb @tmp+1
	adca @tmp
	stab @tmp+1
	staa @tmp
	ldx @tmp
	rts

When compiling a program with a large local array, tracking of A and B fails. I added invalidate_work(), but there must be a better way.

--- ../Fuzix-Compiler-Kit/be-code-6800.c	2024-10-11 05:18:39
+++ be-code-6800.c	2024-10-11 09:28:00
@@ -503,6 +509,7 @@
 		return rlim;
 	} else {
 		/* This case is (thankfully) fairly rare */
+		invalidate_work();
 		printf("\tpshb\n\tpsha\n");
 		load_d_const(off);
 		printf("\tjsr __adx\n");