"SSE instruction set disabled?"

[R. Kelley Cook]

 >>>From Andrew Pinski:
 >>> 	try with the -msse option.
 >>
 >> Ah-ha! Thank you.
 >>
 >> This makes me wonder if -msse should be implied by -mfpmath=sse, or
 >> vice versa.
 >if -mfpmath=sse impled -msse and not -msse2 most people on P4 system
 >would never enable SSE2 support then.
 >Perhaps we can drop -msse now and require people to use
 >non-contradicitng -march=XXX (ie not asking for -mfpmath=sse and 
 >tunning for CPU with no SSE support in it)

This makes absolute complete sense.

"-mmmx", "-msse", "-msse2", and "-m3dnow" (and their coresponding 
-mno-xxx) should just go away.

They already are implied by -march=blahblah that we have.  If someone 
wants code tuned for a pentium4, but without any SSE or MMX support then 
they can type "-march=pentiumpro -mcpu=pentium4"

Although, in my opinion "-mcpu=" should be renamed "-mtune=" like was 
debated ages ago: http://gcc.gnu.org/ml/gcc/1999-01n/msg01004.html

One more question: Why isn't "-mfpmath=sse" the default on archs that 
support it?

Kelley Cook