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Re: V3 PATCH: IRIX configuration
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