Hi,

I cannot answer why, but I can confirm what you have seen. Even on OSX10.9, 
where the system clang is

MacBookPro ~ > clang -v
Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn)
Target: x86_64-apple-darwin13.3.0
Thread model: posix

So I would guess closer to MacPorts clang 3.4 than it is on OSX10.6, build with 
the system clang is significantly faster than MacPorts…

cheers Chris

On 5 Jul 2014, at 2:08pm, René J.V. Bertin <[email protected]> wrote:

> In hope it's not completely out of place to discuss this here, but has anyone 
> else noticed that clang's supposedly better build performance (as opposed to 
> gcc) is no longer an accurate selling argument, at least for version 3.4? 
> 
> Comparing build times of a port I'm working on, KDE's rekonq so mostly C++:
> 
>> port clean rekonq ; time port -v destroot rekonq # uses Apple's gcc-4.2 on 
>> OS X 10.6.8
> 2:59 total_time
>> port clean rekonq ; time port -v destroot rekonq configure.compiler=clang # 
>> uses Apple's clang-3.0 on OS X 10.6.8
> 1:42 total_time
>> port clean rekonq ; time port -v destroot rekonq 
>> configure.compiler=macports-clang-3.4
> 4:04 total_time
>> port clean rekonq ; time port -v destroot rekonq 
>> configure.compiler=macports-gcc-4.8
> 2:22 total_time
> 
> That's on an i7 with 2 cores x 2 hyperthreads; I'm getting in a bit over 200% 
> CPU when using 4 concurrent build jobs.
> 
> I haven't yet done a similar comparison under Linux, but could this be due to 
> how MacPort's llvm & clang are built?
> _______________________________________________
> macports-users mailing list
> [email protected]
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