Am 13.02.2024 um 10:54 schrieb Michael Van Canneyt via fpc-pascal:
On Tue, 13 Feb 2024, James Richters via fpc-pascal wrote:
Sorry for the kind of duplicate post, I submitted it yesterday
morning and I
thought it failed, so I re-did it and tried again.. then after that the
original one showed up.
A thought occurred to me. Since the complier math is expecting all the
constants would be in full precision, then the compiler math doesn't
need to
change, it's just that the reduction in precision is just happening too
soon. It's evaluating and reducing each term of an expression, then the
math is happening, and the answer is not coming out right.
If instead everything was left full precision until after the
compiler math
(because this is what the compiler math expects), and then the final
answer
was reduced in precision where possible, then it would work
flawlessly. So
the reduction in precision function only needs to run once on the final
answer, not on every term before the calculation.
As Jonas said, this would result in less efficient code, since all the
math will then be done at full precision, which is slower.
As usual, it is a trade-off between size (=precision) and speed.
Michael.
But, sorry, because we are talking about compile time math, performance
(nanoseconds) in this case doesn't count, IMO.
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