Sorry for the delayed response on this topic, things got busy. To pick this back up, this is where we stand now:
- There's a bug in gcc's x86intrin.h. They assume that under x64, longs are always 8 bytes. For native Windows (ie not cygwin), that's not correct, and leads to incorrect results for the intrinsics _lrotr and _lrotl. It's possible to do a work-around using undef + define. - In addition to the bug in x86intrin, there are incorrect prototypes for _lrotr and _lrotl in intrin.h, stdlib.h and winnt.h. I see 3 reasonable courses of action: 1) We could fix our prototypes plus add the work-around everywhere we include x86intrin.h. This is what my previous patch did. However, as Kai (correctly) points out, this puts the same code in a multiple places. That's both inefficient, and harder to maintain. 2) We could fix our prototypes plus put the work-around in a wrapper file (ie x86intrin-fix.h). Then instead of including x86intrin.h, we'd include x86intrin-fix.h in our headers (winnt.h & intrin.h). This fix (as well as any future fixes for x86intrin) could be done in one place. Also, when gcc fixes this problem in their code, we can put an #ifdef to see if the fix is still needed in a single place. 3) We could fix our prototypes, then open a ticket against gcc to fix their bug in x86intrin.h. Neither #1 or #2 fix the problem if users include x86intrin.h directly. Also, this problem has been there a long time, and I haven't seen anyone (besides me) screaming for a fix. If we needed an immediate fix, I could see going with #2, but the cleanest (and my current preference) is #3. I'm prepared to write #2 or #3 (or #4 if someone has a better idea), but before I spend the time, I'd like to know which would get approved. dw ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk _______________________________________________ Mingw-w64-public mailing list Mingw-w64-public@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mingw-w64-public
