Thumb Mode

digijohnny · Post by **digijohnny** » Sat Nov 28, 2009 3:27 am

Has anyone noticed any significant speedimprovements with disabling thumb mode with irrlicht?

CuteAlien · Post by **CuteAlien** » Sat Nov 28, 2009 3:08 pm

Probably blaming myself now - but what is a thumb mode?

zet.dp.ua · Post by **zet.dp.ua** » Sat Nov 28, 2009 5:34 pm

It was about 10-20% faster for me, but with -O2 or -O3 i had some "over-optimization" problems. Generally it is recommended to disable thumb mode for intensive floating point operations, but it makes binaries bigger.
Suppose we are talking about iphone+xcode

ym1218 · Post by **ym1218** » Thu Dec 03, 2009 5:34 am

digijohnny wrote:Has anyone noticed any significant speedimprovements with disabling thumb mode with irrlicht?

here is a good reference
http://gamesfromwithin.com/360idev-cran ... ance-to-11

ym1218 · Post by **ym1218** » Thu Dec 03, 2009 5:37 am

zet.dp.ua wrote:It was about 10-20% faster for me, but with -O2 or -O3 i had some "over-optimization" problems. Generally it is recommended to disable thumb mode for intensive floating point operations, but it makes binaries bigger.
Suppose we are talking about iphone+xcode

I tested in my ipod touch 3, it was about 30% faster.
I met the same problems about optimization.

zet.dp.ua · Post by **zet.dp.ua** » Thu Dec 03, 2009 8:20 am

Yes, matrix, vector operations can recieve great performance boost. I'm just using heavily modified for 2d casual games Irrlicht engine. Everyone has to play with compiler's options to achieve the best performance/stability.

Irrlicht Engine

Thumb Mode

Thumb Mode

Re: Thumb Mode