This is a follow-up to the discussion in: https://public-inbox.org/git/20180822030344.ga14...@sigill.intra.peff.net/
The general idea is that the majority of callers don't care about actual plus/minus ordering from oidcmp() and hashcmp(); they just want to know if two oids are equal. The stricter equality check can be optimized better by the compiler. Due to the simplicity of the current code and our inlining, the compiler can usually figure this out for now. So I wouldn't expect this patch to actually improve performance right away. But as that discussion shows, we are likely to take a performance hit as we move to more runtime determination of the_hash_algo parameters. Having these callers use the more strict form will potentially help us recover that. So in that sense we _could_ simply punt on this series until then (and it's certainly post-v2.19 material). But I think it's worth doing now, simply from a readability/annotation standpoint. IMHO the resulting code is more clear (though I've long since taught myself to read !foocmp() as equality). If we do punt, patch 1 could still be picked up now, as it's a related cleanup that stands on its own. The diffstat is scary, but the vast majority of that is purely mechanical via coccinelle. There's some discussion in the individual patches. We also don't _have_ to convert all sites now. I strongly suspect that only a few calls are actual measurable bottlenecks (the one in lookup_object() is the one I was primarily interested in). But it's just as easy to do it all at once with coccinelle, rather than try to measure each one (and once we add the coccinelle patches, we have to convert everything, or "make coccicheck" will nag people to do so). I didn't bother to hold back changes for any topics in flight. There are a handful of conflicts with "pu", but they're mostly trivial. The only big one is due to some code movement in ds/reachable. But though the conflict is big, the resolution is still easy (you can even just take the other side and "make coccicheck" to do it automatically). [1/9]: coccinelle: use <...> for function exclusion [2/9]: introduce hasheq() and oideq() [3/9]: convert "oidcmp() == 0" to oideq() [4/9]: convert "hashcmp() == 0" to hasheq() [5/9]: convert "oidcmp() != 0" to "!oideq()" [6/9]: convert "hashcmp() != 0" to "!hasheq()" [7/9]: convert hashmap comparison functions to oideq() [8/9]: read-cache: use oideq() in ce_compare functions [9/9]: show_dirstat: simplify same-content check bisect.c | 6 ++-- blame.c | 8 ++--- builtin/am.c | 2 +- builtin/checkout.c | 2 +- builtin/describe.c | 10 +++--- builtin/diff.c | 2 +- builtin/difftool.c | 4 +-- builtin/fast-export.c | 2 +- builtin/fetch.c | 6 ++-- builtin/fmt-merge-msg.c | 6 ++-- builtin/index-pack.c | 8 ++--- builtin/log.c | 6 ++-- builtin/merge-tree.c | 2 +- builtin/merge.c | 6 ++-- builtin/pack-objects.c | 4 +-- builtin/pull.c | 4 +-- builtin/receive-pack.c | 4 +-- builtin/remote.c | 2 +- builtin/replace.c | 6 ++-- builtin/rm.c | 2 +- builtin/show-branch.c | 6 ++-- builtin/tag.c | 2 +- builtin/unpack-objects.c | 4 +-- builtin/update-index.c | 4 +-- bulk-checkin.c | 2 +- bundle.c | 2 +- cache-tree.c | 2 +- cache.h | 22 +++++++++---- combine-diff.c | 4 +-- commit-graph.c | 10 +++--- commit.c | 2 +- connect.c | 2 +- contrib/coccinelle/commit.cocci | 4 +-- contrib/coccinelle/object_id.cocci | 50 ++++++++++++++++++++++++------ diff-lib.c | 4 +-- diff.c | 23 ++++++-------- diffcore-break.c | 2 +- diffcore-rename.c | 2 +- dir.c | 6 ++-- fast-import.c | 10 +++--- fetch-pack.c | 2 +- http-push.c | 2 +- http-walker.c | 4 +-- http.c | 2 +- log-tree.c | 6 ++-- match-trees.c | 2 +- merge-recursive.c | 4 +-- notes-merge.c | 24 +++++++------- notes.c | 8 ++--- object.c | 2 +- oidmap.c | 12 +++---- pack-check.c | 6 ++-- pack-objects.c | 2 +- pack-write.c | 4 +-- packfile.c | 12 +++---- patch-ids.c | 8 ++--- read-cache.c | 12 +++---- ref-filter.c | 2 +- refs.c | 8 ++--- refs/files-backend.c | 6 ++-- refs/packed-backend.c | 2 +- refs/ref-cache.c | 2 +- remote.c | 8 ++--- revision.c | 2 +- sequencer.c | 40 ++++++++++++------------ sha1-array.c | 2 +- sha1-file.c | 12 +++---- sha1-name.c | 2 +- submodule-config.c | 4 +-- submodule.c | 2 +- t/helper/test-dump-cache-tree.c | 2 +- transport.c | 2 +- tree-diff.c | 2 +- unpack-trees.c | 6 ++-- wt-status.c | 10 +++--- xdiff-interface.c | 2 +- 76 files changed, 259 insertions(+), 224 deletions(-)
