Internal representation of double variables - 3.4.6 vs 4.1.0

[Brian Dessent]

Terry Frankcombe wrote:

> My understanding of -ffloat-store is that it only works when there's
> actually a variable involved.  Is that right?

Right, it's not a guaranteed fix.

> (I'm used to working with Compaq and Intel Fortran compilers, where you
> can set flags that say, effectively, "Use a standard, well-defined and
> portable floating point arithmetic model irrespective of what the CPU's
> trying to do.")

I'd say you pretty much get that with -mfpmath=sse.  The only reason
anyone should ever use 387 is if binary compatibility with ancient
pre-SSE pentiums/K6s is required.  Otherwise, it's an ancient and creaky
fp architecture that would be best obsoleted (which they finally did in
x86_64 AFAIK.)

Brian