• #ponce <ponce deleteme.adinpsz.org> Mar 04 2010

#ponce <ponce deleteme.adinpsz.org> writes:

 Is SSE(2) inherently faster then (at least in real-world implementations) than
 x87, even when you don't vectorize?  Would I be able to expect any speedup from
 going from x87 to SSE(2) for code that has a decent amount of implicit
instruction
 level parallelism but wasn't explicitly vectorized either by me or the
compiler?


There is a couple of interesting scalar instructions in SSE

- cvttss2si : floorf without modifying the rounding mode (SSE2)
- 32-bit float square root and inverse square root
- min, max

SSE doesn't suffer from denormalization which can be very useful.
I personnally don't mind if the compiler use them or not, provided one can use
inline assembly :)