On 3.6.2013 14:24, Miroslav Lichvar wrote:
On Sat, Jun 01, 2013 at 02:33:55PM +0300, Janne Hyvärinen wrote:
On 1.6.2013 14:24, Janne Hyvärinen wrote:
I can confirm. I see 10% speed improvement with that change on Core i7.
Decoding a 1h18min38.133s long test FLAC -8 encoded file takes with
normal asm optimizations 7.656s (speed: 616,266x realtime) and with
that
tiny change 6.937s (speed: 680,140x realtime).
Thanks for the testing.
I noticed a side effect for this change. Encoding got a bit slower at
least when md5 checksumming is enabled.
That's odd. How much slower was the encoding? Could it be caused by
increase in the size of the function (only with -funroll-loops?) and
not fitting in the cache during encoding?
It might be good to use -funroll-loops only with some files, IIRC it
helped most to stream_encoder.c.
I neglected to mention that the testing was done with MSVC 2012 and on
Windows.
I did some futher testing after your mail and noticed that with GCC the
encoding speed is unaffected. Decoding speed increase is not as big as
with MSVC, only 7% improvement with it.
With MSVC the drop in encoding speed with my test file is 0.4%.
Other perhaps interesting speed results:
MSVC compile with unaltered sources is 1.9% faster than GCC at encoding.
GCC decoding is 8% faster than MSVC before the modification and 5.6%
after the modification.
These results are without changing any compiling options on either compiler.
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