F90-related question

[Toon Moene]

On 12/10/2013 04:41 PM, Steve Kargl wrote:

> Yeah, I forgot about that additional bit of stupidity with the
> -fdefault-real-8 option.  REAL, REAL*4 and REAL(4) are all default
> real kind types, yet the option treats them differently.

Nope, only the REAL declaration indicates a *default* real.

You seem to forget what this option is for: In the 70s, lots of code was 
developed on Cray supercomputers, for which REAL meant a 64-bit floating 
point number.

To ease the transition of code written for these computers, 
-fdefault-real-8 supplied a sweeping, change-all-default-reals (like 
variables declared REAL, or constants like 0.1) into 64 bit quantities.

That's what it is supposed to do, and that is what it does.  The other 
conversions have other uses, but they don't serve *this* purpose.

-- 
Toon Moene - e-mail: toon@moene.org - phone: +31 346 214290
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