System V Application Binary Interface 0.99.5

[Jan Hubicka]

> On 01/30/2013 04:49 PM, Michael Matz wrote:
> > Hmm?  GCC generates code that doesn't rely on the extension taking place.
> 
> Sure, I didn't mean to suggest it was: it's LLVM that's incorrect.

Yes, that is LLVM bug.  I am surprised that it went unnoticed for so long,
but I guess it is difficult to have not extended call except for libffi
and hand written asm code.

Doing the extensions at caller side always is however IMO a preformance bug in
GCC.  We can definitly drop them at -Os, for non-PRS targets and for calls
within compilation unit where we know that GCC is not really producing
code like in Michael's testcase.

Honza