[LTO] Fix C++ thunks

Mark Mitchell mark@codesourcery.com
Tue Dec 30 00:36:00 GMT 2008


Richard Guenther wrote:

> Still better than not supporting the varargs case at all ;)  OTOH - why don't we
> use thunks for the "real" clones?  I suppose because of possible optimizations?

And because I couldn't figure out how to do it at the time.  It's not
just a simple pointer adjustment; you need to set a variable.  It would
be more of a true alternate entry-point scenario.  And, yes, it's going
to make the functions slower; they'll have to check a variable that
right now is optimized away.  But, this would be a good -Os optimization.

Part of the history was that we were originally trying to support both
the old G++ ABI and the new industry-standard ABI, and I was trying to
avoid tearing too much apart all at once.

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713



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