From: Greg Long (cc65_at_maneuveringspeed.com)
Date: 2003-03-08 07:20:05
The problems I reported seem to be indeed as reported, however, I now
realize that the cc65 assembler does not have all its labels global,
unlike assemblers I worked with back in "The Day" listening to the
latest Guns&Roses or that brand new band, Pearl Jam.
So, my goal of being able to call inline assembly from other functions
containing inline assembly won't work. I guess I'm going to have to use
the Macro assembler for these and declare these functions global. I'll
start playing with the assembler and dive into the docs.
Still, inline labels do seem to have issues.
-----Original Message-----
From: owner-cc65_at_musoftware.de [mailto:owner-cc65_at_musoftware.de] On
Behalf Of Greg Long
Sent: Friday, March 07, 2003 9:17 PM
To: cc65_at_musoftware.de
Subject: [cc65] Possible bug: All labels but first are added to .s file
using inline assy
Playing around to learn using C and Assembly together, it occurred to me
it would be nice to have a hexout routine I can call both from C and
from Assembly. Note the C code calls the assembly code.
The code is not ideal, but that's not the point here. I'm using the c64
cassette buffer as an area to communicate between assembly and C, which
works for now. The problem is, in this example, hexoutchr label is not
inserted into the assembly code at compile time. I am NOT using -O to
optimize.
As you can tell, I was able to successfully use labels together, but
there are issues: they seem to not completely ignore whitespace...I
found deleting tabs after the "bcc hexoutchr1" line enabled it to
resolve as local and not external (the latter of which generated an
error).
.c file first, .s file to follow:
//source
char hexout_char(unsigned char c)
{
POKE(998,c);
asm("jsr hexoutchr");
return 0;
//first digit
asm("hexoutchr: nop");
asm(" lda 998 ");
asm(" lsr ");
asm(" lsr ");
asm(" lsr ");
asm(" lsr ");
asm(" ora #48 ");
asm(" cmp #58 ");
asm(" bcc hexoutchr1");
asm(" clc ");
asm(" adc #7 ");
asm("hexoutchr1: jsr $ffd2");
//second digit
asm(" lda 998 ");
asm(" and #15 ");
asm(" ora #48 ");
asm(" cmp #58 ");
asm(" bcc hexoutchr2");
asm(" clc ");
asm(" adc #7 ");
asm("hexoutchr2: jsr $ffd2 ");
asm(" rts ");
}
//end source
; ---------------------------------------------------------------
; unsigned char hexout_char (unsigned char)
; ---------------------------------------------------------------
.segment "CODE"
.proc _hexout_char
ldy #$00
lda (sp),y
sta $03E6
jsr hexoutchr
ldx #$00
lda #$00
jmp L0166
nop ;NOTE MISSING LABEL 'hexoutchr' here.
lda 998
lsr
lsr
lsr
lsr
ora #48
cmp #58
bcc hexoutchr1
clc
adc #7
hexoutchr1:
jsr $ffd2
lda 998
and #15
ora #48
cmp #58
bcc hexoutchr2
clc
adc #7
hexoutchr2:
jsr $ffd2
rts
L0166: jsr incsp1
rts
.endproc
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