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From: "eggert at cs dot ucla.edu" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug analyzer/107060] New: -fanalyzer unbearably slow when compiling GNU Emacs Date: Tue, 27 Sep 2022 19:20:09 +0000 [thread overview] Message-ID: <bug-107060-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107060 Bug ID: 107060 Summary: -fanalyzer unbearably slow when compiling GNU Emacs Product: gcc Version: 12.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: analyzer Assignee: dmalcolm at gcc dot gnu.org Reporter: eggert at cs dot ucla.edu Target Milestone: --- Created attachment 53634 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53634&action=edit compressed source file that gcc -S -fanalyzer -O2 compiles verrrry slowly For a while, gcc -fanalyzer has been so unbearably slow when compiling GNU Emacs that we Emacs developers disable -fanalyzer unless the builder specifically asks for it, which almost nobody does because it's sooo slow. I haven't bothered to file a bug report because I assumed the analyzer code was still being worked on and tuned, but I just now tried -fanalyzer again on a new machine and it was still so slow that I am finally filing a bug report. The biggest pole in the tent is when gcc compiles Emacs's xdisp.c file, which is large for Emacs (38 Klines) but not that large. I am attaching the preprocessed output as the file u.i.gz. Compile it with: gzip -d u.i gcc -S -fanalyzer -O2 u.i On my older Fedora 36 desktop (AMD Phenom II X4 910e) with gcc (GCC) 12.2.1 20220819 (Red Hat 12.2.1-2) GCC takes 12 minutes 3 seconds, which is ridiculous. On my newer Ubuntu 22.04 desktop (Intel Xeon W-1350) with gcc-12 (Ubuntu 12.1.0-2ubuntu1~22.04) 12.1.0, GCC takes 3 minutes 43 seconds, which is still way too long. Could you please take a look at this test case and see what's slowing down -fanalyzer? If you can't improve GCC, is there some easy way we Emacs developers can rewrite the source to avoid the performance issue, whatever it is? Thanks.
next reply other threads:[~2022-09-27 19:20 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-27 19:20 eggert at cs dot ucla.edu [this message] 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 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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