On 06/23/2015 02:36 PM, Thomas Helland wrote: > 2015-06-24 23:05 GMT+02:00 Davin McCall <dav...@davmac.org>: >> Hi - I'm new here. >> >> I've recently started poking the Mesa codebase for little reason other than >> personal interest. In the "help wanted" section of the website it mentions >> aliasing violations as a target for newcomers to fix, so with that in mind >> I've attached a patch (against git head) which resolves a few of them, by >> targeting the linked list implementation (list.h) used in the GLSL >> compiler/optimizers. This change slightly increases the storage requirements >> for a list (adds one word) but resolves the blatant aliasing violation that >> was caused by the trick used to conserve that word in the first place. >> >> (I toyed with another approach - using a single sentinel node for both the >> head and tail of a list - but this was much more invasive, and meant that >> you could no longer check whether a particular node was a sentinel node >> unless you had a reference to the list, so I gave up and went with this >> simpler approach). >> >> The most essential change is in the 'exec_list' structure. Three fields >> 'head', 'tail' and 'tail_pred' are removed, and two separate sentinel nodes >> are inserted in their place. The old 'head' is replaced by >> 'head_sentinel.next', 'tail_pred' by 'tail_sentinel.prev', and tail (always >> NULL) by 'head_sentinel.prev' and 'tail_sentinel.next' (both always NULL).
NAK. The datastructure is correct as-is. It has been in common use since at least 1985. See the references in the header file. >> With this patch, I can build a working (though perhaps not 100% bug-free) >> Mesa without using -fno-strict-aliasing during compilation. Before the >> patch, applications using Mesa would hang at runtime. >> >> I don't really know the process you have in place so if I need to do >> anything else to get this patch into the codebase please let me know. Any >> comments and criticisms welcome. >> >> Davin >> >> > > Hi Davin, > > Welcome aboard the Mesa-boat! > I haven't really looked at your patch > (I'll leave that to someone who knows the code), > but here's a few pointers on how things work around here. > (I see Ilia already answered you) > > Have a look at http://www.mesa3d.org/devinfo.html. > This has most of the info you need on how to send patches > and how your source code should be formatted. > > We try to limit lines to aprox 78 chars (no more than 80). > Patches also should have a "location" for the change in the subject. > (In your patch: [PATCH] glsl: Fix strict-aliasing.......) > And subjects in present tense, but you got that right =) > > Until you get commit access someone else will have to > push the patches to upstream for you (usually the reviewer). > > That's a few points of the top of my head. > If there's anything else feel free to ask. > I'm not the most experienced guy in here, but I guess I'm at > least able to answer most of your practical questions =) > > -Thomas > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
