On Mon, Mar 5, 2012 at 6:12 PM, Andi Kleen <a...@firstfloor.org> wrote: > On Mon, Mar 05, 2012 at 03:31:32PM +0400, Kirill Yukhin wrote: >> Adding patch > > I would still remove the "-mrtm" option. I never understood what options > for intrinsics are good for. They are just a pain to add to Makefiles, > but don't give any benefit.
Without -mrtm, the test will just emit a call to __builtin_ia32_xbegin, for instance. You would ge linking error from your app. And the reason to have -mXXX flags is quite obvious. You don't want combiner to optimize the sequence of two supported instructions (SSE level X, for example) to an unsupported one (SSE level X+N) that implements the same functionality. The same goes for integer instructions, but less obvious ;) So, I'm afraid that -mXXX options stay. But you can sprinkle target option pragmas around the code now. Uros.
