How to test if float is NaN?

[Jarrett Billingsley]

"Don Clugston" <dac at nospam.com.au> wrote in message 
news:e5e621$2232$1 at digitaldaemon.com...

> I really think that 'real' should not be viewed as a built-in type, it 
> should be a typedef, since that's how it behaves.
> The built-in types could have really obscure names to discourage their 
> use:
> eg
> typedef float80pad96 real;  // a Linux32 80-bit real
> typedef float80pad128 real; // a Linux64 80-bit real
> typedef float80pad80 real;  // a Win32 80-bit real

I agree.

> (a) Are there any signs of Intel or AMD actually implementing 128 -bit 
> floats?

Well, as far as I know (and as you probably already know and could have been 
on the designing committee for it), IEEE has already defined the 754 spec 
for 128-bit floats.  Considering that we've got (I suppose) 10-15 years 
before the 128-bit processor generation begins, and considering the 
ever-increasing demand for multimedia and floating-point performance, and 
considering Intel/AMD's desire to phase out x87 instructions in favor of the 
SSE/2/3/4 instructions (which have 32- and 64-bit float support already), 
I'd say the chances of 128-bit floats being created, maybe in just a couple 
years, is pretty high.  SSE5?