Is GMP working properly if it compiles gmp functions w/o errors?

Andre Biere andre.biere at
Fri Feb 8 17:02:58 CET 2008

Hi everyone,

I am new to the mailing list, so I hope that someone can read my message and eventually help me. 

I am currently working on a multiprecision implementation of different algorithms to invert laplace transforms (Whynn Rho, Gaver Stehfest,...). 

Actually I am quite new to C/C++ and its environments. I chose Windows and Windows Visual Studio, since I am used to work at home with Windows. With the help of installation manuals, i think, i succeeded to build the gmp library. At least, I can include gmp.h and use functions like mpf_add, mpf_sub, etc. w/o errors.

My question is basicly, if this necessarily means that these function work properly? So far, I have only implemented (+, -, *, /) in the algorithms, but the results seem to be not good enough. E.g. switching from mpf_set_default_prec(50) to mpf_set_default_prec(1000) does not change a lot - and thereafter it stays constant for a precision >1000. Theres a lot of exp, log, factorials and binomial coefficients involved too, that is still computed in double precision. Do you think that the gmp library is working and the main round off problems are in these parts, which could be a reason why the basic arithmetic in gmp does not change too much!?!
If this is the case, could s.o. please give me a hint how to implement exp, log? I couldnt find sth. about this in the documentation.

Many thanks in advance,


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