On Sat, 2 Jun 2012 11:47:51 -0700 Brett Foster <fost...@edgeandvertex.org> wrote:
> On Sat, Jun 2, 2012 at 11:31 AM, Basile Starynkevitch > <bas...@starynkevitch.net> wrote: > > In the MELT meta-plugin (recall that MELT is a high-level domain specific > > language to > > extend GCC, see http://gcc-melt.org/ for more) we extensively use > > associative hash-tables > > for that. MELT offers homogeneous hash-tables, e.g. hash-table associating > > tree (i.e. > > non-null tree pointers) to arbitrary non-null MELT values (e.g. MELT > > closures, or MELT > > lists, or MELT objects, etc etc), or hash-table associating (non null) > > gimple to non > > null MELT values. > > > > So you can have e.g. an hash-table associating each tree (every tree is in > > GCC a non-null > > pointer to a structure) with data associated to it. Once it has some data > > you know that > > this tree has been visited. > > I'll poke around the MELT source code - > > In Melt, where in source code may I have a look to see how trees and > mapped to the hash table? Are you able to summarize the basics? I.e. > the hash for a specific node tree is derived from what data? Pointer > address? MELT has a generic pointer (using the pointer address as hash function) to MELT value hash table. In its file melt-runtime.c which you can browse at http://gcc.gnu.org/viewcvs/branches/melt-branch/gcc/melt-runtime.c you can find near lines 3795-4020 functions like meltgc_raw_new_mappointers meltgc_raw_put_mappointers melt_raw_get_mappointers ... There are used from inline functions in gcc/melt-runtime.h & gcc/melt/generated/meltrunsup.h ; allocated size of hash tables is a prime number... Feel free to ask more questions about that. (notice that MELT has a low-traffic dedicated list gcc-m...@googlegroups.com etc..) Feel also free to download & try MELT! Cheers -- Basile STARYNKEVITCH http://starynkevitch.net/Basile/ email: basile<at>starynkevitch<dot>net mobile: +33 6 8501 2359 8, rue de la Faiencerie, 92340 Bourg La Reine, France *** opinions {are only mine, sont seulement les miennes} ***
