This is turning out to be more difficult than I had anticipated. I've modified jtxplus to use mpn_add (and mpn_sub and a macro workalike for the inlined mpn_neg, which in turn uses mpn_com - necessary because the mpn_ family of routines works on unsigned limb sequences). And, it *mostly* works.
However, when running script/testga.sh, I encounter a double free problem. My current best guess is that somewhere I'm relying on a container test (XNUM/RAT) instead of relying on the ISGMP() test. But I looked through m.c and I'm not seeing anything there that looks plausible. I did notice that the frgmp() macro is not referenced anywhere, and I used the corresponding fr() macro in my implementation rather than mf() - but if that's an issue, I need a better understanding of this part of the internal api. So... anyways... before I dig this hole too deep, I figure I should ask for advice on how to proceed. Thoughts? Thanks, -- Raul On Wed, Oct 25, 2023 at 3:12 AM Henry Rich <[email protected]> wrote: > > OK, I see now. The implementation using low-level GMP would be more > parallel with Roger's original version, right? > > That would end up being simpler than having reserve memory, as well as > stabler. > > Since you currently mark blocks that are to be freed by GMP, you could > make this change piecemeal, right? When you rewrite addition to use the > low-level routines, you mark the blocks allocated by addition as J not > GMP, and everything else follows automatically. > > Tbat's a great idea. > > hhr > > On 10/24/2023 8:34 PM, Raul Miller wrote: > > libzahl is not thread safe, and even if it was, it's not clear to me > > that it adequately supports enough architectures. > > > > Meanwhile, libgmp's problems are addressable. I just have to use a > > different part of its API. > > > > (Also, on windows, we're using mpir rather than libgmp.) > > > > (J currently uses parts of the libgmp high level API, which performs > > memory allocations within the libgmp library routines, using callbacks > > whose implementation I supply. But it also exposes the low level > > routines used to build those high level routines, and those low level > > routines do not perform memory allocation, which means that we can > > manage the memory outside of the API.) > > > > ((The problem with libgmp's high level API is that if a memory > > allocation fails, it exits the program. So we came up with a > > workaround which reserves a memory pool, and limits arguments to > > certain routines, so successful memory allocations will succeed even > > under low memory conditions. That's not ideal, but it has been "good > > enough, so far". But libgmp supports another approach. It's a little > > more work, but not an excessive amount of work.)) > > > > I hope this makes sense, > > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
