2014/10/15 下午 10:14:20

iphone Programming Glossary: speedup

http://stackoverflow.com/questions/11219240/maximum-speed-from-ios-ipad-iphone

90 values lookup tables. Speedup was huge This is somewhat opposite to PC where such optimizations does not give any speedup. There was code working in degrees and this value was converted to radians for sin and cos . This code was removed too...

What's the difference between NSNumber and NSInteger?

http://stackoverflow.com/questions/1285098/whats-the-difference-between-nsnumber-and-nsinteger

largely on how much of an efficiency gap there is on those machines for those sizes. In some cases there's no real speedup for using 32 bits vs 64 bits so you might as well use 64 bits. If you've declared things as CGFloat 's you suddenly get..

iPhone app without using Interface Builder

http://stackoverflow.com/questions/2472691/iphone-app-without-using-interface-builder

to be had using purely programmatic interfaces but Matt Gallagher ran a series of benchmarks and found that this speedup is only typically on the order of 5 10 . If you really want to shave that last bit off of your application's startup time..

iPhone GCC / LLVM GCC or LLVM?

http://stackoverflow.com/questions/3739783/iphone-gcc-llvm-gcc-or-llvm

New in the LLVM Compiler for more on this as well as the sessions on LLVM from WWDC 2009 if you have them. I saw a 20 speedup going from GCC to LLVM 1.5 in an informal benchmark within one of my applications but it wasn't a rigorous test so consider.. 4 has full support for C and promises additional optimizations for compiled applications along with more compile time speedups. Xcode 4 even uses Clang as the syntax highlighting code correction engine in the IDE. It's clear the direction that Apple..

ASIHTTPRequest vs NSURLConnection

http://stackoverflow.com/questions/4035451/asihttprequest-vs-nsurlconnection

for caching which NSURLConnection doesn't if you enable that and it's applicable for your use it gets you a major speedup. ASIHTTPRequest also does a lot of things for you for free it can transparently handle HTTP Proxy authentication if you..

Is number recognition on iPhone possible in real-time?

http://stackoverflow.com/questions/4887313/is-number-recognition-on-iphone-possible-in-real-time

that there's a lot of potential in the programmable GPUs on the newer iOS devices. In my benchmarks I saw a 14X 28X speedup when using the iPhone 4's GPU for simple image processing. While few people are looking at this right now something like..

How can I optimize the rendering of a large model in OpenGL ES 1.1?

http://stackoverflow.com/questions/5718846/how-can-i-optimize-the-rendering-of-a-large-model-in-opengl-es-1-1

vertex color information. The overhead from the few extra draw calls this requires will be vastly outweighed by the speedup you get from not having to send all that color information. I saw a ~18 reduction in rendering time by binning the colors..

Faster alternative to glReadPixels in iPhone OpenGL ES 2.0

http://stackoverflow.com/questions/9550297/faster-alternative-to-glreadpixels-in-iphone-opengl-es-2-0

I have some code in this answer that I've used for raw pixel extraction. It also experiences a significant speedup in practice when compared to using glReadPixels although less than I see with the pixel buffer pool I use with AVAssetWriter...