[Python-Dev] Program runs in 12s on Python 2.7, but 5s on Python 3.5 -- why so much difference?

[Gregory P. Smith]

On Mon, Jul 24, 2017 at 1:49 PM Wang, Peter Xihong <
peter.xihong.wang at intel.com> wrote:

> I believe we have evaluated clang vs gcc before (long time ago), and gcc
> won at that time.
>
>
>
> PGO might have overshadowed impact from computed goto, and thus the latter
> may no longer be needed.
>

Computed goto is still needed.  PGO does not magically replace it.  A PGO
build with computed goto is faster than one without computed goto.

... as tested on gcc 4.9 a couple years ago. I doubt that has changed or
changes between compilers; PGO and computed goto are different types of
optimizations.

-gps
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