Should -mfma/-mavx and -msse5/-msse4a mutually exclusive?

[rajagopal, dwarak]

I think, Intel's FMA instructions are different from the FMA
instructions covered in -mfma (inside -msse5). I believe Intel's FMA
should be part of a separate switch.

> Also I am not sure if "-mavx -msse5" or "-mavx -msse4a" make any
senses. I
> think
> -mavx should turn off -msse5/-msse4a and vice versa.
>
Yes. We can have -mavx turn off -msse5/-msse4a.

Thanks,
Dwarak

> -----Original Message-----
> From: H.J. Lu [mailto:hjl.tools@gmail.com]
> Sent: Sunday, November 16, 2008 1:04 PM
> To: Uros Bizjak; GCC Development; Ye, Joey; Guo, Xuepeng; rajagopal,
> dwarak
> Subject: Should -mfma/-mavx and -msse5/-msse4a mutually exclusive?
> 
> Hi,
> 
> We are looking into Intel FMA support in gcc. For
> 
> double
> foo (double x, double y, double z)
> {
>   return x * y + z;
> }
> 
> What should "-mfma -msse5" generate? Should -msse5  turn off -mfma and
> vice versa?
> Also I am not sure if "-mavx -msse5" or "-mavx -msse4a" make any
senses. I
> think
> -mavx should turn off -msse5/-msse4a and vice versa.
> 
> Thanks.
> 
> --
> H.J.