[FFmpeg-devel] [PATCH] Heavy optimization of IFF decoder

Måns Rullgård mans
Tue Apr 27 17:18:28 CEST 2010

"Ronald S. Bultje" <rsbultje at gmail.com> writes:

> Hi,
> On Mon, Apr 26, 2010 at 7:39 PM, Sebastian Vater
> <cdgs.basty at googlemail.com> wrote:
>> This one is the original decodeplane8 high speed patch patched against
>> git HEAD.
>> +        const uint32_t v = lut[get_bits(&gb, 4)];
>> +        AV_WN32A(dst+i, AV_RN32A(dst+i) | v);
> The v isn't really needed, just write this over one line.

AV_WN32A and friends are macros.  Beware of multiple evaluation.
Also, gcc really hates complicated expressions.  Breaking them up
often improves the code a lot.

M?ns Rullg?rd
mans at mansr.com

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