[LLVMdev] recreate optimized clang output

[Jean-Daniel Dupas]

Le 27 janv. 2011 à 21:46, Hendrix_ at gmx.net a écrit :

> 
> On 27.01.2011, at 21:12, Devang Patel wrote:
> 
>> 
>> On Jan 27, 2011, at 12:02 PM, Hendrix_ at gmx.net wrote:
>> 
>>> OK, I am looking for "LTO"/global optimization. So the function definition will remain "somewhere else" (externally), and the optimizer will find in some other module to possibly inline it later on.
>>> 
>>> I am planning to concat all the *.ll (eg "link" the files) and pass them to the "global" optimizer, as "size" is a very important optimization criterium to me. After that, the back-end will be invoked.
>>> Is that a good approach?
>> 
>> How about just add -O4 on clang (or llvm-gcc) command line to get LTO optimizations ?
>> See	http://llvm.org/docs/LinkTimeOptimization.html
>> 	http://llvm.org/docs/GoldPlugin.html
>> 	On Mac OS X, it is a checkbox in Xcode.
>> -
>> Devang
> 
> Sry for spam... I already have XCode 3.2.5... what is the lto option called, or is it only available in XCode 4 preview?

This build setting is  LLVM_LTO show as "Link Time Optimization" in the build settings panel.
It is available only with clang and llvm-gcc AFAIK.

-- Jean-Daniel