Hmm, not sure I understand why my comment is wrong then?

Isn't it the preprocessor that tries to evaluate '0 - var'?

/Ruben


> No, this isn't a preprocessor issue. The preprocessor doesn't 'know' the
> address of anything. It just manipulates text.
>=20
> -- Bob Ammerman
> RAm Systems
>=20
> -----Original Message-----
> From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf =
Of
> Ruben J=F6nsson
> Sent: Thursday, October 03, 2013 7:14 AM
> To: Microcontroller discussion list - Public.
> Subject: Re: [PIC] Load the address of a variable as 2's complement?
>=20
>=20
> > Hello,
> >=20
> > Some time ago I wrote an Insertion sort algorithm for Mid-range PICs=20
> > and today decided to optimize it as much as possible. For this I need=20
> > to load the negative value of an address of a variable. Using 'movlw =20
> > 0 - var' or 'addlw 0 - var', where var is a file register is not=20
> > accepted by MPASM, and 'Error[151] : Operand contains unresolvable=20
> > labels or is too complex' is issued.
> >=20
> > Currently I found 2 workarounds - one needs an extra instruction to=20
> > convert the loaded address to a negative number, and the other defines=
=20
> > an absolute address of 'var' in RAM and then a precalculated negative=20
> > value of that address is used in the code.
> >=20
> > Both of these do not seem right, so I'm searching for a trick to=20
> > negate the address of 'var' in the preprocessor, without triggering an
> error.
> >=20
>=20
> The preprocessor doesn't know the address of var.
>=20
> /Ruben
>=20


=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
Ruben J=F6nsson
AB Liros Electronic
Box 9124
200 39 Malm=F6 Sweden
www.liros.se
Tel +46 40142078
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

--=20
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