[FFmpeg-devel] [PATCH] split-radix FFT

[Måns Rullgård]

Michael Niedermayer wrote:
> On Tue, Jul 29, 2008 at 06:26:49PM +0300, Uoti Urpala wrote:
>> On Tue, 2008-07-29 at 17:10 +0200, Michael Niedermayer wrote:
>> > And just to clarify, yes what i considered a good argument was the
>> sentance
>> > above where my reply is. That is to use MANGLE in speed critical code.
>> > That way most textrels are avoided while minimizing the speed impact.
>> >
>> > I do not think you ever argued for that.
>>
>> IIRC I did mention the possibility of omitting -fPIC for a subset of
>> files.
>>
>> >  I remember you strongly arguing
>> > toward replacing all MANGLE by "m" knowing that it would break gcc 2.95
>> > and not really caring that it would slow down code compiled with -fPIC.
>>
>> Of course the code would be slower on x86. If you want it to be as fast
>> as possible then compile it with -fPIC on x86. I don't think it's
>> worthwhile to pick only the globals used inside asm for such special
>> treatment.
>
> x86-64 shared libs require -fPIC, unless that has been fixed.

The x86-64 instruction set hasn't been "fixed", and I doubt it ever
will be.  You simply can't fit a 64-bit offset in a 32-bit immediate
operand.

> so the user does not always have the option to omit -fPIC

But in these cases, forcing a textrel will break the build.

-- 
M?ns Rullg?rd
mans at mansr.com