https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77333
Martin Jambor <jamborm at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target| |i686-w64-mingw32
Status|UNCONFIRMED |NEW
Last reconfirmed| |2017-01-27
Host| |x86_64-linux
Ever confirmed|0 |1
--- Comment #13 from Martin Jambor <jamborm at gcc dot gnu.org> ---
So although I have not gone as far building my own cross-compiler and
just used the gcc 6 based one from OpenSUSE, I managed to reproduce
the issue myself and can confirm that just marking method
SLPVectorizer::tryToVectorizeList with noclone attribute avoids the
issue.
But, from the logs I gather that the only reason why IPA-CP did that
was to remove the unused this pointer. This makes me wonder whether
this somehow could push its callers and the callee out of sync
regarding what ABI they use for the call?
Apart from that, I have no idea what else could be wrong. I have
quickly skimmed through the diff of the gimple dumps of the function
before and after cloning and did not see any meaningful difference
(lot's of UIDs were different so something might have escaped me but
since this confirmed my observations from the IPA-CP dump, I doubt
it).
One more thing, IPA-CP does this (clone to remove a parameter when
there are no real constants coming from all callers) only since
r231540 (i.e. gcc 6), so you should not really see the issue with gcc
5, at least not because of this.
