[PATCH] [i386] fma3 instruction generation for 'march=native' in AMD processors

[Jakub Jelinek]

On Wed, May 02, 2012 at 11:12:33AM +0000, Gopalasubramanian, Ganesh wrote:
> For AMD architectures with both fma3 and fma4 instructions' support, GCC generates fma4 by default. Instead, we like to generate fma3 instruction. Below patch enables the fma3 instruction generation for "-march=native".
> 
> Ok for trunk?

You haven't provided ChangeLog entry.

> Index: gcc/config/i386/driver-i386.c
> ===================================================================
> --- gcc/config/i386/driver-i386.c       (revision 186897)
> +++ gcc/config/i386/driver-i386.c       (working copy)
> @@ -472,6 +472,10 @@
>        has_abm = ecx & bit_ABM;
>        has_lwp = ecx & bit_LWP;
>        has_fma4 = ecx & bit_FMA4;
> +      if (((vendor == SIG_AMD)) && (has_fma4) && (has_fma))
> +        {
> +            has_fma4 = 0;
> +        }

And the formatting of this is wrong, 4 unnecessary pairs of (),
one unnecessary {} pair, bad indentation of the has_fma4 = 0;
assignment (should use a tab).

	Jakub