I don't really know much about MPFR.

I needed a predictable accuracy for pow(6e7) of a decimal fraction. (a highly constructed use case)

BigFloat is decimal thus avoiding binary rounding errors in this case and the limited number of multiplications allowed a boundary for the necessary precision.( 1 extra digit per multiplication)

I have no doubt that other algorithms can be faster or more accurate with less digits.

This whole thread is somehow spooky for me, financial transactions follow their own rules and rarely involve exponents bigger 100.

Natural processes in science have no reason to be decimal. If a measurement is expressed as a decimal this already involves an errormargin. (bacterias don't grow exactly x%)

I.e. decimals are normally human made!

So if accuracy is a problem this can't be fully solved with a general purpose library.

Eg IIRC do some fiscal authorities or banks calculate with special rounding units.

That's not solved with 128 digits accuracy...

Cheers Rolf

PS: Je suis Charlie!

In reply to Re^8: Decimal Floating Point (DFP) and does Perl needs DFP? by LanX
in thread Decimal Floating Point (DFP) and does Perl needs DFP? by flexvault

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