Re: gcc m68k: pc-relative addressing for code?

Re: gcc m68k: pc-relative addressing for code?

[D. Jeff Dionne]

> 
>   In message < 19980221120121.42072@nemesis >you write:
>   > is it possible to have gcc create output which only uses PC-relative
>   > addressing for code references? 
> Unfortunately I do not believe such an option exists on the m68k.

Of course it does :-)  get the gcc-pic-coff patches from 
ftp://ryeham.ee.ryerson.ca/pub/uClinux  Makes possible all sorts of cool
stuff, like Linux on a 68000 without an MMU for instance.

Done by Kresten Krab Thorup and myself, I am the maintainer.  I've
not yet had success geting together all the stuff needed for RMS to
accept the copyright assignment, let alone look after updating the
Changelog.

D. Jeff Dionne

> 
> jeff
> 

Re: always use collect2

[Jeffrey A Law]

  In message < 19980221105411.A26167@kailash.cse.iitb.ernet.in >you write:
  > I have a SPARC machine running UNIX SVR4.
  > 
  > Why is USE_COLLECT2 always defined? Doesnt egcs work with the binutils
  > 2.8.1 linker?
It still works with the 2.8.1 linker, but collect2 is still needed
to deal with certain shared library issues.

jeff

gcc m68k: pc-relative addressing for code?

[Michael Schwingen]

Hi,

is it possible to have gcc create output which only uses PC-relative
addressing for code references? 

I need this for ROM code which is moved around during PMMU initialization -
however, variables are in a constant place in RAM and shall *not* be
referenced PC-relative, so -fpic or -fPIC seems not to be usable in this
case, and the addressing via GOT seems to be a bit inefficient, too - the
PC-relative addressing mode would be better (32k code limit is not a
problem).

(a nice thing to have would be if all variables could be referenced relative
to an address register, which is *not* reloaded by gcc - however, I can live
without).

cu
Michael
-- 
In the beginning there was nothing, which exploded.

Re: gcc m68k: pc-relative addressing for code?

[Jeffrey A Law]

  In message < 19980221120121.42072@nemesis >you write:
  > is it possible to have gcc create output which only uses PC-relative
  > addressing for code references? 
Unfortunately I do not believe such an option exists on the m68k.

jeff

Re: gcc m68k: pc-relative addressing for code?

[Philippe De Muyter]

> 
>   In message < 19980221120121.42072@nemesis >you write:
>   > is it possible to have gcc create output which only uses PC-relative
>   > addressing for code references? 
> Unfortunately I do not believe such an option exists on the m68k.

Do you mean `m68k', or `m68k port of gcc' ? Does that imply that it exists
for other gcc targets ?

Re: gcc m68k: pc-relative addressing for code?

[Jeffrey A Law]

  In message < 199802220651.HAA10158@mail.macqel.be >you write:
  > > 
  > >   In message < 19980221120121.42072@nemesis >you write:
  > >   > is it possible to have gcc create output which only uses PC-relative
  > >   > addressing for code references? 
  > > Unfortunately I do not believe such an option exists on the m68k.
  > 
  > Do you mean `m68k', or `m68k port of gcc' ? Does that imply that it exists
  > for other gcc targets ?
Some ports use pc-relative addressing modes to access items in the
constant pool or readonly data.

Such features require machine dependent work, which I don't think
was ever submitted for teh m68k.
jeff