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From: "dmalcolm at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/107060] -fanalyzer unbearably slow when compiling GNU Emacs Date: Wed, 28 Sep 2022 15:01:03 +0000 [thread overview] Message-ID: <bug-107060-4-bPCUperk35@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-107060-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107060 David Malcolm <dmalcolm at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Depends on| |99390 --- Comment #5 from David Malcolm <dmalcolm at gcc dot gnu.org> --- The real issue here is that -fanalyzer-call-summaries is off by default (due to being buggy). Poring over the dumps shows that without trying to summarize the effects of calls, the analyzer is brute-forcing the exploration of the call graph, leading to an explosion of deep paths, expensively achieving very poor coverage. Enabling -fanalyzer-call-summaries speeds things up from ~10 minutes to ~1m20s (7.5x), but makes it emit lots of -Wanalyzer-use-of-uninitialized-value false positives. Am about to file a bug about that... Sorry about this; I'd recommend disabling -fanalyzer on Emacs until it's reasonable to enable -fanalyzer-call-summaries on it. The dumps show some other issues, like the analyzer seems to be creating lots of regions for tracking "alloca" (~45000 of them in one dump), so I may need to also fix how alloca is handled. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99390 [Bug 99390] [meta-bug] tracker bug for call summaries in -fanalyzer
next prev parent reply other threads:[~2022-09-28 15:01 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-27 19:20 [Bug analyzer/107060] New: " eggert at cs dot ucla.edu 2022-09-27 20:55 ` [Bug analyzer/107060] " dmalcolm at gcc dot gnu.org 2022-09-27 21:31 ` dmalcolm at gcc dot gnu.org 2022-09-27 22:22 ` dmalcolm at gcc dot gnu.org 2022-09-28 13:57 ` dmalcolm at gcc dot gnu.org 2022-09-28 15:01 ` dmalcolm at gcc dot gnu.org [this message] 2022-09-29 8:10 ` rguenth at gcc dot gnu.org 2022-10-05 17:54 ` cvs-commit at gcc dot gnu.org 2022-10-05 18:20 ` dmalcolm at gcc dot gnu.org 2023-03-02 18:26 ` dmalcolm at gcc dot gnu.org
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