[Bug debug/78288] Compile time hog (with var-tracking) for libsanitizer/asan/asan_interceptors.cc

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78288

--- Comment #10 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:1212cfad09378bc85860a7de22dde0cf7a19fd01

commit r11-2447-g1212cfad09378bc85860a7de22dde0cf7a19fd01
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jul 24 13:44:09 2020 +0200

    Improve var-tracking dataflow iteration order

    This builds upon the rev_post_order_and_mark_dfs_back_seme improvements
    and makes vt_find_locations iterate over the dataflow problems for
    each toplevel SCC separately, improving memory locality and avoiding
    to process nodes after the SCC before the SCC itself stabilized.

    On the asan_interceptors.cc testcase this for example reduces the
    number of visited blocks from 3751 to 2867.  For stage3-gcc
    this reduces the number of visited blocks by ~4%.

    2020-07-28  Richard Biener  <rguenther@suse.de>

            PR debug/78288
            * var-tracking.c (vt_find_locations): Use
            rev_post_order_and_mark_dfs_back_seme and separately iterate
            over toplevel SCCs.