Re: A very "strange" bug in gcc 2.96

[Alan Modra <alan at linuxcare dot com dot au>]

On 21 May 2000, Eric W. Biederman wrote:

> "H . J . Lu" <hjl@lucon.org> writes:
> 
> > There is the ia32 asm ouput from gcc 2.96 with -O2. Please notice that
> > 
> > 	jmp	foo
> > 
> > is generated, instead of
> > 
> >         call foo
> >         leave
> >         ret
> > 
> > It is ok if foo () is a static function. But for extern, they are
> > not the same. The GNU linker supports shared libraries even without
> > -fPIC. With "jmp foo", it doesn't work anymore. If it is intentional,
> > we should declare PIC is required for building shared libraries.
> > Personally, I don't like compiler does this behind my back. It took
> > me several days to figure out why things stopped working.
> > 
> > Thanks.
> 
> What would need to change with gnu as and gnu ld to cause this to work?
> Is it simply that as needs to emit a location record when jumping
> to labels declared .globl?

For x86, gas/config/tc-i386.c:md_estimate_size_before_relax needs to be
taught how to handle this case properly.  (I think that's all that's
needed...)

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