Re: New failures related to recent developments
Torbjorn Granlund t...@gmplib.org writes: I compared mpn/fib_table.c with a system that did not report any failures (but this table to was generated with mini-gmp.c). They have the same contents. I compared the output of gen-fib table 32 0, in current gmp and gmp-5.0.2. Result is identical on my machine. But fib-table.h has #define FIB_TABLE_LIMIT 47 #define FIB_TABLE_LUCNUM_LIMIT 47 on one of the failing systems and #define FIB_TABLE_LIMIT 47 #define FIB_TABLE_LUCNUM_LIMIT 46 I also get #define FIB_TABLE_LUCNUM_LIMIT 46 for both current and gmp-5.0.2. So I think we can conclude that's the correct definition. I'm not entirely sure I understand fib-gen is supposed work. luc_limit is only assigned like this, in gen-fib.c:generate, if (mpz_cmp (l, limit) 0) luc_limit = i-1; Looking at mini-gmp.c:mpz_cmp, I've spotted one bug, but I think that's unrelated since it affects negative numbers only. diff -r e21157bb513d mini-gmp/mini-gmp.c --- a/mini-gmp/mini-gmp.c Mon Feb 27 14:37:02 2012 +0100 +++ b/mini-gmp/mini-gmp.c Tue Feb 28 09:26:59 2012 +0100 @@ -1694,7 +1694,7 @@ mpz_cmp (const mpz_t a, const mpz_t b) else if (asize 0) return mpn_cmp (a-_mp_d, b-_mp_d, asize); else if (asize 0) -return -mpn_cmp (a-_mp_d, b-_mp_d, asize); +return -mpn_cmp (a-_mp_d, b-_mp_d, -asize); else return 0; } Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
Re: New failures related to recent developments
ni...@lysator.liu.se (Niels Möller) writes: I'm not entirely sure I understand fib-gen is supposed work. luc_limit is only assigned like this, in gen-fib.c:generate, if (mpz_cmp (l, limit) 0) luc_limit = i-1; Looking at mini-gmp.c:mpz_cmp, I've spotted one bug, but I think that's unrelated since it affects negative numbers only. diff -r e21157bb513d mini-gmp/mini-gmp.c --- a/mini-gmp/mini-gmp.c Mon Feb 27 14:37:02 2012 +0100 +++ b/mini-gmp/mini-gmp.c Tue Feb 28 09:26:59 2012 +0100 @@ -1694,7 +1694,7 @@ mpz_cmp (const mpz_t a, const mpz_t b) else if (asize 0) return mpn_cmp (a-_mp_d, b-_mp_d, asize); else if (asize 0) -return -mpn_cmp (a-_mp_d, b-_mp_d, asize); +return -mpn_cmp (a-_mp_d, b-_mp_d, -asize); else return 0; } Since this happens on just a few systems, I don't think it is a simple logical bug. I would guess it is a dependency on uninitialised data. The failing systems seem to have no working debugging environment (which I understand). -- Torbjörn ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
Re: New failures related to recent developments
Torbjorn Granlund t...@gmplib.org writes: The failing systems seem to have no working debugging environment (which I understand). Printing out the value of limit (ought to be two limbs: 0, 1) and inputs and output of the mpz_cmp call would be helpful, I think. Then we'll see which operation goes wrong. /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
Re: New failures related to recent developments
There is a systematic problem in mini-gmp.c when MPZ_REALLOC is called when a destination variable is the same as some other (source or destination) variable. After MPZ_REALLOC, all cached pointers must be considered to be defunct. I've spotted this error in 4 functions, but I haven't made a proper code review. -- Torbjörn ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
Re: New failures related to recent developments
Torbjorn Granlund t...@gmplib.org writes: After MPZ_REALLOC, all cached pointers must be considered to be defunct. It seems I was only paying attention to the destination pointer. I'll go through all uses of MPZ_REALLOC. Regards, /Niels -- Niels Möller. PGP-encrypted email is preferred. Keyid C0B98E26. Internet email is subject to wholesale government surveillance. ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
Re: New failures related to recent developments
ni...@lysator.liu.se (Niels Möller) writes: Torbjorn Granlund t...@gmplib.org writes: After MPZ_REALLOC, all cached pointers must be considered to be defunct. It seems I was only paying attention to the destination pointer. I'll go through all uses of MPZ_REALLOC. This is a (partial?) patch. It seems to fix the present problem. diff Description: Binary data -- Torbjörn ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
Re: New failures related to recent developments
ni...@lysator.liu.se (Niels Möller) writes: Will you commit these fixes, or do you want me to do that? Please take care of any fixing. It's your baby after all. :-) I have found the same four direct MPZ_REALLOC problems when reviewing the code: mpz_abs_add, mpz_and, mpz_ior and mpz_xor. Then I have loooked for functions which use cached pointers over a call to a function using MPZ_REALLOC. But I didn't find any problems of that type. These other usages all seem to be safe, I finished a review too, since four eyes see more than two. (I think the mini-gmp test suite should have caught these errors. I'd suggest that you enhance it, and make sure these types of errors are actually detected.) -- Torbjörn ___ gmp-devel mailing list gmp-devel@gmplib.org http://gmplib.org/mailman/listinfo/gmp-devel
