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Re: [GCC 3.x] Performance testing for QA
- From: Kevin Atkinson <kevina at gnu dot org>
- To: Robert Dewar <dewar at gnat dot com>
- Cc: Peter dot Sasi at t-systems dot co dot hu, <aj at suse dot de>, <gcc at gcc dot gnu dot org>,<tjw at omnigroup dot com>
- Date: Tue, 3 Sep 2002 16:40:58 -0400 (EDT)
- Subject: Re: [GCC 3.x] Performance testing for QA
On Tue, 3 Sep 2002, Robert Dewar wrote:
> <<However, encoding/decoding (especially encoding) is one area were speed
> really matters. Encoding in real time (with out sacrificing quality) is
> still not passable with many codecs except on the newest machines.
> Unfortunately, because video work is so computationally extensive significant
> portions of the code are often rewritten is assembly to take advantage of
> MMX etc instructions that many compilers do not produce normally. This
> means that that pure C versions may not exist or if they do they are not
> coded optimally.
> >>
>
> This is all true.
>
> But what does it have to do with being a good benchmark?
The type of operations that encoder decoders use (lots of arithmetic and
data movement) should somehow be incorporate as a benchmark test gcc
should optimize for. The ideal goal would be to make the code fast enough
that hand written assembly would not be necessary. Thus using an encoder as
a benchmark would be beneficial. Even if it concentrates on tight loops.
---
http://kevin.atkinson.dhs.org