On Oct 2, 2011, at 04:17, vincent habchi wrote: > I haven’t been much presently lately, but I was taken away by my work and > also pondering on various bugs I encountered lately, especially with the > Atlas port. I am now sure something is definitely rotten in OS 10.7 kingdom. > > The starting point is Atlas not being compiled properly by clang. The source > compiles fine, but the resulting library crashes on various calls. Then, > there are sparse bugs related to ar(1) or ranlib(1) that prevents gcc46, > atlas with standard ar or even qt4.8 beta to build properly. At this point, I > am deeply convinced that this is caused by clang miscompilations: either we > are plagued by clang producing weirds object files, or the tools themselves > (MacOS 10.7 has been built with clang/llvm, AFAIK) are buggy. Unfortunately, > I am more inclined towards the latter possibility, since the ar bugs > manifests itself during the libgfortran archiving, where clang plays no role. > I have filed various radars apropos, but while they have been acknowledged, > no patch has been released yet. My opinion is that Apple has moved far too > fast to clang for obvious political reasons, resulting in a flawed OS. > > Then there is another knot: the ‘as’ assembler, bundled with OS 10.7, and > used by our various gcc, is antiquated: GNU assembler version 1.38 (output of > as -v – this is probably the last GPL v.2 version). This means no Sandy > bridge AVX support (unknown instructions), so no possibility to compile or > assemble code with gcc -mavx switch on: that’s a waste of power, and means > inferior performance on floating point code (at best); with Ivy bridge > processor looming, the gap will increase if we find no quick fix to this. > > Trying to build the gas included in libtools fails: the configure script > reports an unknown configuration and won’t build the assembler. The llvm > toolchain won’t help us, since it is based on a wholly different structure, > and won’t accept GNU assembler files as input, so our last hope is to try > using ‘yasm’ with gcc: did anybody already test this? > > We can’t count on Apple helping us, since they are forbidden to touch every > GPL v.3 tool. Besides, clang support for AVX instructions is currently broken. > > So folks, question is: how can we get out of this trap?
I don't know. I would talk with the developers of atlas and get them to support the version of clang and llvm-gcc-4.2 in Lion's Xcode, since that's what's out there. _______________________________________________ macports-dev mailing list macports-dev@lists.macosforge.org http://lists.macosforge.org/mailman/listinfo.cgi/macports-dev
