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:[EMAIL PROTECTED] > 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.
