Re: A very "strange" bug in gcc 2.96

["H . J . Lu" <hjl at lucon dot org>]

On Mon, May 22, 2000 at 12:00:15PM +1000, Alan Modra wrote:
> 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...)
> 

That is only ia32. What about others?


H.J.