On Wed, Aug 24, 2016 at 10:14:29AM +0930, Alan Modra wrote:
> Given a hidden visibility function declaration, the toolchain can say
> that the function is local to the module. This generally means that a
> call to the function can be direct, ie. doesn't need to go via the PLT
> even in a shared library. However, ifunc breaks this promise. GNU
> indirect functions may resolve non-locally, and are implemented by
> always using a PLT call.
>
> This causes trouble for targets like ppc32 where the -msecure-plt PIC
> PLT call stub needs a valid GOT pointer. Any call that potentially
> might be to an ifunc therefore requires a GOT pointer, and can't be a
> sibling call (because the GOT pointer on ppc32 is a caller saved reg).
>
> So unless we require that all ifuncs are declared as ifunc, it seems
> that ppc32 can't assume extern or weak functions are local. This
> patch does the latter. Boostrapped and regression tested
> powerpc64-linux biarch. OK to apply?
Okay for trunk. (Unless "boostrapped" means that it failed horribly ;-) )
> diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
> index 58dccdd..07e79ab 100644
> --- a/gcc/config/rs6000/rs6000.md
> +++ b/gcc/config/rs6000/rs6000.md
> @@ -10278,8 +10278,10 @@
This doesn't show what pattern this is. If you make a ".gitattributes"
somewhere in your tree (I have it in the gcc/ subdir), containing
*.md diff=md
and then in your git config (say, in .git/config in the GCC source tree)
you have
[diff "md"]
xfuncname = "^\\(define.*$"
then magic happens.
Cheers,
Segher
