In article <3c9071ba@news.povray.org> , "Vadim Sytnikov" <syt### [at] rucom>
wrote:

>> In section 6.2 you mention that the Intel compiler will turn multiple
>> divisions by the same number into one division and then uses
> multiplications
>> for floating-point numbers.  Do you know if in its current version the
> Intel
>> compiler still does this?
>
> I don't know -- I did not use Intel compiler for several years now. What I
> do know is that neither Visual C 6.0 nor GCC 2.95 (the compilers I'm
> currently using) can do this...

Which is a good thing because this change is an "illegal optimization", or
less friendly formulated a serious flaw in the compiler - at no point may a
compiler alter the result of a computation.  If it does alter the result of a
computation it has to be considered a bug.  Looks like whoever implemented
this didn't read the various articles and book chapters about floating-point
optimizations that are incorrect... :-(

    Thorsten

____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

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