On Fri, Jul 20, 2001 at 05:30:50PM -0400, Thor Lancelot Simon wrote:
> Interestingly, SSE2 includes register-to-register scalar floating point
> operations -- in other words, with SSE2, you can ditch the hoary old
> stack-based x87 floating point architecture alltogether.  SSE2 is really
> a whole new FPU architecture for the x86.  With kernel and compiler support,
> you can achieve significantly better floating-point performance with SSE2
> than with anyone's implementation of x87 stack floating point; this is
> one of the major wins of the much-misunderstood Pentium 4.

SSE2 does have some cool features, but for the 'hardcore' floating
point ops you still need the original x87 instructions (exp, ln,
trig functions, etc). Which mostly work on the fp stack. And moving data
directly between the fp stack and sse2 registers isn't possible, which
is a bit of a pain.. Still, sse2 is useful.

- Frank

-- 
Frank van der Linden                           fvdl@wasabisystems.com
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