"SSE instruction set disabled?"

[Scott Robert Ladd]

> -mfpmath=sse changes behaviour of floating point execution by not using
> 80bit temporaries like x87 code does.  This breaks some things (glibc)
> and makes other happy (those who want numberic stability).
> I am inclined to argue to make -mfpmath=sse default when SSE is
> available however last time I lost the battle.

I hadn't even considered this problem -- and I was just about to send off a
raft of questions about gcc and IEC 60559 compliance, so floating-point is
definitely on my mind. I have a major free documentation project underway
about numerical programming in C99...

I need to dig out the Intel processor docs again; it's been a while since I
looked over all the various instructions sets and their implications.
Implied -fpmath=sse may *not* be a good thing under certain circumstances...

..Scott