GraphicsMagick compiler choice...

[Eric A. Borisch]

On Thu, Feb 23, 2012 at 11:22 AM, Ryan Schmidt <ryandesign at macports.org> wrote:
>
> On Feb 23, 2012, at 11:20, Eric A. Borisch wrote:
>
>> Submitted for your consideration:
>>
>> GraphicsMagick is set to build with clang as llvm fails on x86_64; but
>> building with clang means no OpenMP... but "GraphicsMagick has been
>> transformed to use OpenMP for the 1.3 release series."[1]
>>
>> How about switching (or at least adding a variant for those that want
>> it) the compiler to macports-gcc-4.4?
>
> Using a MacPorts compiler we cannot build universal.

OK, so the +threaded variant could conflict with universal.

> clang is the future of compiling on OS X. Is lack of OpenMP a clang deficiency, or a GraphicsMagick deficiency when using clang? Sounds like something either the developers of clang or the developers of GraphicsMagick need to address.

It's a clang deficiency. [1]

llvm-gcc supports OpenMP, but then fails [2] (the original reason for
the change to clang) when building GraphicsMagick with OpenMP. There
is (apparently) a bug report filed with Apple about LLVM -
GraphicsMagick issues [3]; I don't think it's the same one that
prompted the change, however.

Given all this, and the significant speedup for multi-core users on
some algorithms (single core users please raise your hands...
anyone?), I think having a +threaded-universal (or +gcc44-universal or
whatever you would like to call it) would be nice.

Thanks,
  - Eric

[1] http://www.phoronix.com/scan.php?page=news_item&px=MTA0Mzc
[2] http://lists.macosforge.org/pipermail/macports-users/2011-July/024801.html
[3] http://sourceforge.net/mailarchive/message.php?msg_id=27881558