t...@gmplib.org (Torbjörn Granlund) writes: > We should at least make sure the algorithms' corner cases are exercised, > e.g., that large quotient are generated for Euclid's algorithm and that > remainders of +-epsilon are used for division.
The mini-gmp testsuite is a bit hairy because it uses both gmp and mini-gmp. This works fine with linking, thanks to the name mangling of gmp symbols, but we can't include both gmp.h and mini-gmp.h in the same compilation unit, and we have to types called mpz_t which in general aren't compatible. Most of the current tests works by invoking a function which uses the real gmp to produce random inputs and a reference answer. E.g., (a, b, a+b), or (a, b, gcd(a,b)). These are then translated between gmp mpz_t and mini-gmp mpz_t via hex representation. I think this is reasonable for simple things like add and mul, but maybe not for the more complex things. In particular, for division and gcd(ext), where the result is easy to validate using multiplication and addition, there are different ways to do things. We need to call into gmp to generate inputs or pieces of inputs (because mini-gmp lacks mpz_urandom and mpz_rrandom). And we obviously want to do the operation under test using mini-gmp. But we can choose freely whether or not the code to produce inputs and validate outputs should use gmp or mini-gmp. One opposite way to organize the tests would be to have the main part of the test programs use the real gmp, i.e., include gmp.h rather than mini-gmp.h. And then do wrapper functions for the functions under test, e.g, a mini_mpz_gcd which accepts gmp mpz_t as inputs, converts to hex, passes on to a separate compilation unit which uses mini-gmp.h rather than gmp.h to convert the hex inputs to mini-gmp mpz_t, call the corresponding mini-gmp function, and convert back. That should make it easier to copy testcases from the real gmp. The main drawback I see is that testcases get less clear if there's a hairy wrapper between the the testcode and the function it's testing. Complex wrappers around generation of test inputs and validation of results somehow suits my taste better, but I have no good rational motivation for that. Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid 368C6677. Internet email is subject to wholesale government surveillance. _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel
