llvmgcc-4.2 llvmg++-4.2 on OS X -- missing GCC __builtin intrinsics

I've had good luck using the llvm-gcc & llvm-g++ on small projects,
but I just discovered that it's apparently missing some of the GCC
intrinsic functions -- specifically, when I try and compile VXL
(http://vxl.sourceforge.net) it dies when it encounters
__builtin_bswap32 .

This is on OS X with the llvm-gcc-4.2 & llvm_g++-42 that are part of
the XCode 3.2.3

I don't know if this was the LLVM-GCC developer's oversight or Apple's
but it keeps me from using llvm-gcc as my default compiler.

Hi Kent, I suggest you open a bug report with a preprocessed testcase.

Best wishes,


I didn't file a bug because as it turns out the problem isn't LLVM,
it's gcc-xml which is part of the CableSwig package.
gcc-xml picked up on the __llvm__ symbol and defined it when it
'compiled' C++ files. Since __llvm__ was defined, but gcc-xml doesn't
know anything about llvm intrinsic functions, it threw an error.

The gcc-xml guys at Kitware are working on fixing this.