Function Multiversioning in GCC6

[O Mahony, Billy]

Hi Xi,

Thanks for the clarification/confirmation.

Regards,
Billy.
 
> -----Original Message-----
> From: Xi Ruoyao [mailto:ryxi@stu.xidian.edu.cn]
> Sent: Thursday, March 23, 2017 9:21 AM
> To: O Mahony, Billy <billy.o.mahony@intel.com>
> Cc: ryxi@stu.xidian.edu.cn; gcc-help@gcc.gnu.org
> Subject: Re: Function Multiversioning in GCC6
> 
> On 2017-03-22 10:51 +0000, O Mahony, Billy wrote:
> 
> > However when I compile the first example in this LWN article
> > https://lwn.net/Articles/691932/ with gcc-6 C compiler it fails with
> > (error: redefinition of
> > 'foo'...) .
> 
> The document <https://gcc.gnu.org/onlinedocs/gcc-6.3.0/gcc/Function-
> Multiversioning.html> said:
> 
>     With the GNU *C++* front end, for x86 targets, you may specify multiple
> versions of the function.
> 
> FMV doesn't work with C FE.  In C, __attribute__((target("sse4.2"))) just
> means to compile this function with -msse4.2, see
> <https://gcc.gnu.org/onlinedocs/gcc-6.3.0/gcc/Common-Function-
> Attributes.html>.
> 
> --
> Xi Ruoyao <ryxi@stu.xidian.edu.cn>
> School of Aerospace Science and Technology, Xidian University