{"action":"created","issue":{"url":"https://api.github.com/repos/cilkplus/clang/issues/22","repository_url":"https://api.github.com/repos/cilkplus/clang","labels_url":"https://api.github.com/repos/cilkplus/clang/issues/22/labels{/name}","comments_url":"https://api.github.com/repos/cilkplus/clang/issues/22/comments","events_url":"https://api.github.com/repos/cilkplus/clang/issues/22/events","html_url":"https://github.com/cilkplus/clang/issues/22","id":165202294,"number":22,"title":"Slow execution on tight loops with hyperobjects","user":{"login":"hvdieren","id":1257662,"avatar_url":"https://avatars.githubusercontent.com/u/1257662?v=3","gravatar_id":"","url":"https://api.github.com/users/hvdieren","html_url":"https://github.com/hvdieren","followers_url":"https://api.github.com/users/hvdieren/followers","following_url":"https://api.github.com/users/hvdieren/following{/other_user}","gists_url":"https://api.github.com/users/hvdieren/gists{/gist_id}","starred_url":"https://api.github.com/users/hvdieren/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/hvdieren/subscriptions","organizations_url":"https://api.github.com/users/hvdieren/orgs","repos_url":"https://api.github.com/users/hvdieren/repos","events_url":"https://api.github.com/users/hvdieren/events{/privacy}","received_events_url":"https://api.github.com/users/hvdieren/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":2,"created_at":"2016-07-12T23:11:52Z","updated_at":"2016-07-14T22:50:24Z","closed_at":null,"body":"Hi,\r\n\r\nWe have been seeing slow performance with Cilkplus and clang for tight loops using hyperobjects.\r\nApparently, the Intel compiler manages to hoist __cilkrts_hyper_lookup() out of the critical loops while clang leaves the call in the inner loop, causing significant performance degradation (we have observed up to 2x).\r\n\r\nWill you be looking into this?\r\n\r\nKind regards,\r\nHans Vandierendonck"},"comment":{"url":"https://api.github.com/repos/cilkplus/clang/issues/comments/232815121","html_url":"https://github.com/cilkplus/clang/issues/22#issuecomment-232815121","issue_url":"https://api.github.com/repos/cilkplus/clang/issues/22","id":232815121,"user":{"login":"hvdieren","id":1257662,"avatar_url":"https://avatars.githubusercontent.com/u/1257662?v=3","gravatar_id":"","url":"https://api.github.com/users/hvdieren","html_url":"https://github.com/hvdieren","followers_url":"https://api.github.com/users/hvdieren/followers","following_url":"https://api.github.com/users/hvdieren/following{/other_user}","gists_url":"https://api.github.com/users/hvdieren/gists{/gist_id}","starred_url":"https://api.github.com/users/hvdieren/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/hvdieren/subscriptions","organizations_url":"https://api.github.com/users/hvdieren/orgs","repos_url":"https://api.github.com/users/hvdieren/repos","events_url":"https://api.github.com/users/hvdieren/events{/privacy}","received_events_url":"https://api.github.com/users/hvdieren/received_events","type":"User","site_admin":false},"created_at":"2016-07-14T22:50:23Z","updated_at":"2016-07-14T22:50:23Z","body":"Andrey,\r\n\r\nThanks for the quick response.\r\nHint taken.\r\nIs it possible to discuss, perhaps off-line, on what basis the Intel compiler decides to hoist the call out of loops?\r\n\r\nKind regards,\r\nHans.\r\n"}}
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