http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60545
--- Comment #2 from Josh Triplett <josh at joshtriplett dot org> --- (In reply to Andrew Pinski from comment #1) > The attribute is ms_abi. It is documented in 4.4.0 and above. > > From GCC 4.5.0 docuemtnation: > http://gcc.gnu.org/onlinedocs/gcc-4.45.0/gcc/Function-Attributes. > html#Function-Attributes > > ms_abi/sysv_abi > On 64-bit x86_64-*-* targets, you can use an ABI attribute to indicate which > calling convention should be used for a function. The ms_abi attribute tells > the compiler to use the Microsoft ABI, while the sysv_abi attribute tells > the compiler to use the ABI used on GNU/Linux and other systems. The default > is to use the Microsoft ABI when targeting Windows. On all other systems, > the default is the AMD ABI. > Note, the ms_abi attribute for Windows targets currently requires the > -maccumulate-outgoing-args option. Thanks for the clarification.