Re: Audio data in float format for iOS?
Re: Audio data in float format for iOS?
- Subject: Re: Audio data in float format for iOS?
- From: tahome izwah <email@hidden>
- Date: Mon, 17 Jan 2011 21:58:50 +0100
I don't think that this is true, especially for large chunks of fp
code. Our stuff definitely runs faster with thumb off, for both ARM 6
and 7 targets.
--th
2011/1/17 Gregory Wieber <email@hidden>:
> Again, this is NOT true for arm7 (in which case it is recommended to leave
> thumb ON)
> On Mon, Jan 17, 2011 at 12:41 PM, tahome izwah <email@hidden>
> wrote:
>>
>> Float is usually slow when you're compiling for the thumb instruction
>> set. To see a real speed gain make sure you turn thumb off in Xcode
>> settings when you're doing a lot of fp calculations.
>>
>> --th
>>
>> 2011/1/17 Gregory Wieber <email@hidden>:
>> > Morgan,
>> > Depending on the processor you are using, you may be taking a HUGE hit
>> > for
>> > those conversions between integers and floats. I noticed a giant
>> > speed-up
>> > in my app when I removed any floating point operations and converted
>> > everything to integer calculations (which means you'll most likely have
>> > to
>> > read up on bit shifting, etc).
>> > Again, as I just mentioned though, this was for an app compiled without
>> > Thumb enabled. On newer processors, thumb 2 supports floating point
>> > calculations, so I would also be curious to hear other's
>> > recommendations.
>> > Specifically, to your question: from my limited knowledge on the
>> > subject,
>> > whether you use integers or floats really depends on the processor. I
>> > would
>> > look at whether your app needs to work on older devices where thumb is
>> > not
>> > recommended, and if so, avoid floats. Otherwise, let's see what some of
>> > the
>> > more experienced folks here recommend for the newer processors that
>> > support
>> > floats with thumb 2.
>
>
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden