On 04/06/20 10:34 +0300, Ville Voutilainen via Libstdc++ wrote:
On Thu, 4 Jun 2020 at 10:22, Marc Glisse <marc.gli...@inria.fr> wrote:
> So the change is correct. Can we test the change somehow?
It passes the testsuite, and libc++ has been doing it this way for years.
What I feared was some regression where it would yield worse code in some
cases, or lose some property (not guaranteed by the standard) like
triviality (to the point of affecting the ABI?), but I couldn't see
anything like that happening.
(we still have PR86173 causing unnecessary memset in some cases)
Right, I was just wondering whether we can reasonably verify in a test
that the whole
shebang is not zeroed. That may need a tree-dump scan in the test, and probably
should go into PR86173 anyway, so I'm not saying such a thing needs to be a part
of this fix.
I'm kindly suggesting to Jonathan that this should be OK, and backports too.
Yes, looks good to me. Thanks, Marc. OK for master and gcc-10.
I could be persuaded that it should go on gcc-9 too, if anybody feels
strongly. Let's not change this in gcc-8 though, it's not required for
correctness and isn't a codegen regression, and if it does cause a
problem we won't get a chance to fix it after the next gcc-8 release.
