http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55177
--- Comment #7 from David Woodhouse <dwmw2 at infradead dot org> 2012-11-08 14:29:37 UTC --- Linux kernel patch to use the builtins at http://marc.info/?l=linux-arch&m=135212414925921&w=2 I think I have the GCC version checks right there, for the availability of the builtins? That is, __builtin_bswap32() and __builtin_bswap64() since GCC 4.4, and __builtin_bswap16() since GCC 4.6 on PowerPC or GCC 4.9 on other platforms?
