Hi James, thanks for that impressive bit of detective work; I recently ran into that problem again but didn't have the nerve/time to look into it more closely.
FWIW I've switched to clang/llvm on OS X and that works too (and supposedly produces better code), so it seems to be the gcc-llvm frontend that's at fault. Cheers, /ulrich On 15/09/11 0:47 , James Turner wrote: > I've encountered a problem with the osg/Math header, which a few previous > emails on > this list have alluded to (based on searching the recent archives), but which > has an > interesting explanation. > > osg/Math defines the 'f' versions of cos/sin/floor/etc in terms of the double > versions, > on various platforms, including Mac. The implementation is an inline > function, which > casts the input argument, and calls the 'base' version from math.h > > Unfortunately, LLVM (or the GCC frontend) is smart enough to turn the cast + > call of > the base version back into the floating point version - but the symbol > look-up then > resolves to the osg wrapper - and hence the problem we're seeing. Since > osg/Math was > created, OS-X does define the 'f' versions - but I'm not sure which version > started > doing so - the 10.6 SDK math.h includes the 'f' variants, but plain gcc 4.2 > wasn't > smart enough to turn the cast-to-double + call pattern into the float version. > > The local workaround is simply to remove the __APPLE__ case around line 48 of > osg/Math, > but really it would be changed to a MAC_OS_X_VERSION_10_z, if someone can > identify what > value 'z' should have. If anyone still has a 10.5 SDK, they could check > '/usr/include/architecture/i386/math.h' and see if the 'f' variants of the > math > functions are present. > > (What's the minimum version OSG claims to support at this time? 10.5 or still > holding > out with 10.4?) (Potentially this affects iOS too, though I'm not sure if > Apple have > enabled gcc-llvm for ARM yet, by de default) > > James _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
