Reporting bugs: there is nothing to gain in frustrating reporters

[Robert Dewar]

Vincent Lefevre wrote:

> BTW, unpredictability, such as in bug 323, is not a bug (according
> to the C standard). This may be seen as a bad behavior and changing
> this behavior would be a great improvement, but I don't complain
> about it here when saying "bug".

Everyone would agree that per se unnecessary non-determinism is a
bad thing. However, most people would also agree that poor performance
is a bad thing.

All this stuff about allowing extra precision is actually about
allowing efficient code.

Lacking in this discussion is a good quantitative measurement
over a reasonable set of benchmarks as to what eliminating the
excess precision in all cases would cost.

Note that just setting the precision to 64-bits is not enough if
you agree with Vincent that 32-bit float variables have to be
normalized on every assignment.

Data would help. Almost everyone will agree with eliminating the
extra precision if it has only a 3% impact, almost everyone
will disagree if it doubles execution time (I suspect the asnwer
is in that range :-)