V3 PATCH: IRIX configuration

Gabriel Dos Reis gdr@codesourcery.com
Mon Oct 30 02:51:00 GMT 2000


Mark Mitchell <mark@codesourcery.com> writes:

| >>>>> "Gabriel" == Gabriel Dos Reis <gdr@codesourcery.com> writes:
| 
|     Gabriel> Using a higher precision to compute a result, followed by
|     Gabriel> a truncation to the input precision is something
|     Gabriel> generally harmeless (it is just waste of ressource in
|     Gabriel> case computing with higher precision is not necessary nor
|     Gabriel> useful).  That technique is usually used in routines
|     Gabriel> which are sentitive to noise.
| 
| But what about `__complex__ long double'?  That one gets truncated
| first, right?

Hmm, I'm unsure about what you mean here.

For __complex__ float and __complex__ double, the promotion to
__complex__ long double followed by the truncation to float or double
after calculations is safe.

For __complex__ long double, that is just what is requested if I
understood you concern about cabs.

But it is true that there places (if I recall correctly) where we're
computing with double instead of long double for a long double input
precision. That is wrong and we should fix it.

-- Gaby
CodeSourcery, LLC               http://www.codesourcery.com


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