libstdc++/4150: catastrophic performance decrease in C++ code

Loren James Rittle rittle@latour.rsch.comm.mot.com
Mon Apr 15 17:14:00 GMT 2002


In article <wvl1ydgy15s.fsf@prospero.cambridge.redhat.com>,
Jason Merrill <jason@redhat.com> writes:

>>>>>> "Loren" == Loren James Rittle <rittle@latour.rsch.comm.mot.com> writes:
>> Having attempted patches similar to your proposal, I think the hammer
>> breaks those test cases that exercise interleaving between C and C++ IO.

> I don't think so.  If we're synced to stdio, we get buffers of size 1, so
> it doesn't matter which end we're calculating from.

OK, cool.  I am playing with your exact patch for a while.  After
rebuilding libstdc++-v3 with it and ensuring no regressions on any
platforms I can personally check; I will look at the interactive
stream cases that have been posted over the years.

Regards,
Loren



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