Re: [Openexr-devel] OpenEXR from shared libs.

[Florian Kainz]

At least on Linux, the #else version of the AutoArray code,
which allocates memory on the stack, is significantly faster
than the #if version, which calls new[] and delete[].  I tried
reading a sequence of piz-compressed frames (1000x750 pixels,
Y, RY and BY channels) using three parallel threads.  The #if
and #else versions of the AutoArray code run at 25fps and 34fps
respectively.

I wonder if there is a way to construct and destroy AutoArrays
faster on systems that have small per-thread run-time stacks.

Florian


Florian Kainz wrote:
> I'll do a couple of tests to see whether there's a significant
> speed difference between the #if and the #else versions of the
> code.  If they are close, I think I'll remove the #else version
> alltogether.
>
> darby johnston wrote:
> > --- Florian Kainz <address@hidden> wrote:
> >
> > > I wonder if the problem has something to do with the
> > > size
> > > of the stack when threads are enabled.
> >
> > Nice one; looks like that fixed it.
> > How about:
> >
> > #if defined (HAVE_DARWIN) || defined (_WIN32) \
> >   || defined (_WIN64) || defined(__FreeBSD__)
> >
> > Or would a test in the configure script be better?
> >
> >
> > Thanks, Darby
> >
> >
> >
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