Re: [webkit-dev] Transformations precision: double - float

2012-10-15 Thread Gabor Rapcsanyi
On 10/12/2012 11:23 AM, Tom Hudson wrote: Do you have particular bottleneck functions that you have reason to believe would benefit from ARM SIMD optimizations? Under what workloads, and how much benefit? We've see a few ridiculously expensive transform functions in WebKit that my colleagues in

Re: [webkit-dev] Transformations precision: double - float

2012-10-15 Thread Benjamin Poulain
On Mon, Oct 15, 2012 at 9:35 AM, Gabor Rapcsanyi rga...@inf.u-szeged.huwrote: On 10/12/2012 11:23 AM, Tom Hudson wrote: Do you have particular bottleneck functions that you have reason to believe would benefit from ARM SIMD optimizations? Under what workloads, and how much benefit? We've

Re: [webkit-dev] Transformations precision: double - float

2012-10-12 Thread Gabor Rapcsanyi
Yes I agree that we need to do some measures to see the benefits of floats. But it's not just about the performance and memory gain of the floats, I would like to make ARM SIMD optimizations for the transformation functions to fasten up them, but ARM NEON technology only works with floats

Re: [webkit-dev] Transformations precision: double - float

2012-10-10 Thread Gabor Rapcsanyi
on all the platforms. Don -Original Message- From: webkit-dev-boun...@lists.webkit.org [mailto:webkit-dev-boun...@lists.webkit.org] On Behalf Of Simon Fraser Sent: Monday, May 21, 2012 10:35 AM To: Zoltan Herczeg Cc: webkit-dev@lists.webkit.org Subject: Re: [webkit-dev] Transformations

Re: [webkit-dev] Transformations precision: double - float

2012-05-22 Thread kui zheng
Hi, I have the same questions. Using float, It's easier to map to OGLES2, Decrease memory usage and accelerated using ARM SIMD. if you do profiling for CSS transformation/Animation, you'll find TransformationMatrix hotspots that should be well optimized using NEON. -Kuii On Mon, May 21, 2012

Re: [webkit-dev] Transformations precision: double - float

2012-05-22 Thread Wasim Abbas
: webkit-dev-boun...@lists.webkit.org [mailto:webkit-dev-boun...@lists.webkit.org] On Behalf Of kui zheng Sent: 22 May 2012 14:04 To: Stephen Chenney Cc: webkit-dev@lists.webkit.org Subject: Re: [webkit-dev] Transformations precision: double - float Hi, I have the same questions. Using float, It's

Re: [webkit-dev] Transformations precision: double - float

2012-05-22 Thread Olmstead, Don
, 2012 10:35 AM To: Zoltan Herczeg Cc: webkit-dev@lists.webkit.org Subject: Re: [webkit-dev] Transformations precision: double - float TransformationMatrix started out as floats, then got changed to doubles in http://trac.webkit.org/changeset/40761 This was done because on most hardware

[webkit-dev] Transformations precision: double - float

2012-05-21 Thread Zoltan Herczeg
Hi, is there any reason why the transformations in WebKit use doubles? We could optimize some functions further with ARM SIMD if they would be floats. Is there any objection to make them float if the change would have no other side effects except some rounding because of the lower precision?

Re: [webkit-dev] Transformations precision: double - float

2012-05-21 Thread Simon Fraser
TransformationMatrix started out as floats, then got changed to doubles in http://trac.webkit.org/changeset/40761 This was done because on most hardware there is no penalty for using doubles over floats, and provided a better match with our system APIs that used doubles. I'd prefer to take a

Re: [webkit-dev] Transformations precision: double - float

2012-05-21 Thread Ryosuke Niwa
Maybe you can add a typedef in Platform.h to make it configurable? e.g. maybe you want to be able to use long double instead of regular double in the future. - Ryosuke On Mon, May 21, 2012 at 10:34 AM, Simon Fraser simon.fra...@apple.comwrote: TransformationMatrix started out as floats, then

Re: [webkit-dev] Transformations precision: double - float

2012-05-21 Thread Stephen Chenney
Ideally WebKit would avoid casts by consistently using either double or floats everywhere a floating point representation is needed. I don't think it's as simple as adding a typedef, but maybe it is. In any event it would have to be spelled out in the style guide. My gut feeling is that floats