Re: [PATCH V2] [x86]: Compiler Option Os is better on latest x86

2013-01-27 Thread Ling Ma
Hi Ingo Thanks for your correcting. Because thinking of most of 32bit CPU belong to low-end CPUs(smaller cache), they should more emphasize i-cache miss, I chose Os for them. I will test it and send out result ASAP. Regards Ling 2013/1/27, Ingo Molnar : > > * ling.ma.prog...@gmail.com wrote:

Re: [PATCH V2] [x86]: Compiler Option Os is better on latest x86

2013-01-27 Thread Ingo Molnar
* ling.ma.prog...@gmail.com wrote: > In this version we also append CONFIG_CC_OPTIMIZE_FOR_SIZE for i386. Were those measurements done on i386 as well? I'd be content with keeping the current minimal - and mostly documentary - patch that only does this on 64-bit. I just wanted to record the

[PATCH V2] [x86]: Compiler Option Os is better on latest x86

2013-01-26 Thread ling . ma . program
From: Ma Ling Currently we use O2 as compiler option for better performance, although it will enlarge code size, in modern CPUs larger instructon and unified cache, sophisticated instruction prefetch weaken instruction cache miss, meanwhile flags such as -falign-functions, -falign-jumps, -falig