[x264-devel] x264 build problem under Mac OS X El Capitan

[桃源老師]

> 2016/04/16 6:53 A.M. 桃源老師 <xanadu6291 <at> dream.jp> wrote:
> 
> 
>> 2016/04/16 4:19 A.M. BugMaster <BugMaster <at> narod.ru> wrote:
>> 
>> On Sat, 16 Apr 2016 02:57:57 +0900, 桃源老師 wrote:
>> 
>>> The error is:
>>> error: Could not read profile default.profdata: No such file or directory
>> 
>>> I checked x264 source directory and found there are a file named
>>> "default.profraw".  This file is created under Mac OS X El Capitan only.
>> 
>> 
>>> After this error, I can generate the file "default.profdata" using the following command:
>>> $ xcrun llvm-profdata merge -output=default.profdata default.profraw
>> 
>>> And I can build x264 successfully by running make fprofiled again.
>> 
>>> But in my think, this procedure is irregular.  The error should not be occurred.  Am I right?
>> 
>> 
>> Hi. IMHO currently we don't support fprofiled builds with clang (XCode).
>> We only support use of -fprofile-generate/-fprofile-use options with gcc/clang.
> 
> My meaning of "make fprofiled" is run the command such as:
> $ make fprofiled VIDS="sintel_trailer_2k_480p24.y4m"
> 
> And quoted line of error in previous post is the process/result of above command.  I'm not running gcc command itself.
> 
> Do you mean build of this way is not supported with clang?

I have learned a bit about gcc profiling.  In my understanding, it's a kind of optimization.  Am I right?

So my interest is if x264 does not support "make fprofiled" under clang, is there any performance difference on encoding?

Currently, I can (of course) build x264 just "make" and this x264 passes ffmpeg's FATE.

> 
>> But according to http://clang.llvm.org/docs/UsersManual.html#profiling-with-instrumentation
>> while clang supports this options they looks like don't really equivalent to their GCC
>> counterparts. As it looks like they still need intermediate step for converting profiling
>> data format:
>> llvm-profdata merge -output=default.profdata default.profraw
> 
> So you think this intermediate step for converting profiling data format is required to build x264 under El Capitan?
> 
> Or should I claim this to llvm support team?

If encoding performance difference is ignorable under clang, I will quit to use this tricky way...


Best Regards,


// Miya aka. TougenRoushi

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