Well, if they're /not/ mutually exclusive, another question that comes up is...
If a program is compiled with sse or sse2 support on a Pentium II, will the program run slower than it otherwise would? (Some of the programs I have are compiled and then distributed to servers with different CPUs--P-IIs and P-IVs, mainly.) Raphael Melo de Oliveira Bastos Sales wrote: >Certain program have support for either of these extentions. The >program will most likely use the best one for the job. > >They can be mutually exclusive, however, if you use the CFLAG >-mfpmath=sse,387. As far as I know it, it will try to use SSE >instructions for math where possible, in detriment of using the 387 >math co-processor. But this only get any advantage when using AMD64 >processors. > >I never tested it, I just copied what the Gentoo Wiki says about it. ;P > >2006/1/12, Willie Wong <[EMAIL PROTECTED]>: > > >>On Thu, Jan 12, 2006 at 03:09:40PM -0700, Penguin Lover Tom Smith squawked: >> >> >>>Are these flags mutually exclusive? >>> >>>I know, for example, that if I have a Pentium II that the MMX flag >>>should apply while the sse and sse2 flags would not. >>> >>>But what if I have a Pentium III or IV? Would I only use the most recent >>>"optimization" or do I need to add all three to take advantage of each one? >>> >>>I checked the USE flag descriptions and there wasn't anything indicating >>>indicating whether the can or should be used together. >>> >>> >>> >>Not quite sure how it works officially. But I run a Pentium IV, and I >>have mmx mmxext sse sse2 enabled, so they are at least NOT mutually >>exclusive. >> >>W >>-- >>All science is either physics or stamp collecting. >> ~Ernest Rutherford >>Sortir en Pantoufles: up 61 days, 15:40 >>-- >>gentoo-user@gentoo.org mailing list >> >> >> >> > > > -- gentoo-user@gentoo.org mailing list
