<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">Doing a `grep "find_first" * -r` over llvm shows you it is a common pattern, which IMO should be something we can do in 1 for. If anything you could rewrite the internal representation to work on strides, but I am not convinced it is worth the complexity today until someone shows me a case where it actually matters.</div><div class=""><br class=""></div><div class="">- Matthias</div><div class=""><br class=""></div><div><blockquote type="cite" class=""><div class="">On Apr 13, 2017, at 5:53 PM, Zachary Turner <<a href="mailto:zturner@google.com" class="">zturner@google.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class="">Would it really be that unhandy? You would only need to iterate from iter->first to iter->second to get the same effect.<br class=""><br class="">Granted it wouldn't work with existing algorithms that take predicates or functions with integer arguments, but I wonder if anyone would even notice that limitation. And when the bits happen to be clustered together , which is not uncommon, it will be vastly more efficient <br class=""><div class="gmail_quote"><div dir="ltr" class="">On Thu, Apr 13, 2017 at 5:44 PM Matthias Braun <<a href="mailto:matze@braunis.de" class="">matze@braunis.de</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word" class=""><div class="">While more efficient, this seems unhandy to me...</div><div class=""><br class=""></div><div class="">Using a BitVector as a replacement for a std::set<unsigned> is a common pattern and in this case I would expect the iterator to return all the elements that I put into the set before...</div></div><div style="word-wrap:break-word" class=""><div class=""><br class=""></div><div class="">- Matthias</div></div><div style="word-wrap:break-word" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Apr 13, 2017, at 5:41 PM, Zachary Turner <<a href="mailto:zturner@google.com" target="_blank" class="">zturner@google.com</a>> wrote:</div><br class="m_-8876891372759186519Apple-interchange-newline"><div class="">Instead of having the value type be an index, how about having it be a range? Eg if bits,1,2,3,6,8,9 are set then have it return (1,4), (6,7), and (8,10) on successive iterations. This should be much more efficient. For a bits_unset iterator, the above would return (0,1), (4, 6), (7,8), (10, size())<br class=""><div class="gmail_quote"><div dir="ltr" class="">On Thu, Apr 13, 2017 at 5:29 PM Matthias Braun via Phabricator <<a href="mailto:reviews@reviews.llvm.org" target="_blank" class="">reviews@reviews.llvm.org</a>> wrote:<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">MatzeB added reviewers: dblaikie, chandlerc, mehdi_amini.<br class="">
MatzeB added a comment.<br class="">
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Adding a few reviewers who often have comments on ADT changes.<br class="">
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<a href="https://reviews.llvm.org/D32060" rel="noreferrer" target="_blank" class="">https://reviews.llvm.org/D32060</a><br class="">
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