[std-interval] discontinuity flag

Lawrence Crowl Lawrence at Crowl.org
Thu Oct 5 12:16:26 PDT 2006

On 10/5/06, Prof.Dr.J.Wolff von Gudenberg
<wolff at informatik.uni-wuerzburg.de> wrote:
> Another point: We are afraid of delegating some of the behavior
> (semantics) to the compiler.

Since all initial implementations are likely to be library-based,
this is a good choice.

> Experience with compilers has shown that
> they usually do not understand the proper handling of arithmetic flags
> or settings, see the switching of the rounding mode, e.g.

The compiler writer understand the proper handling.  When optimizing
they tend to shortcut that handling because most programmers (a)
write code as though float == real and (b) do not want to pay
the performance penalty of correct handling.  Some compiler will
respect full IEEE semantics, but sometimes you have to tell them
your desire explicitly.

Lawrence Crowl

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