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Re: Reporting bugs: there is nothing to gain in frustrating reporters
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 :-)