[Bug tree-optimization/102943] [12 Regression] Jump threader compile-time hog with 521.wrf_r

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102943

--- Comment #36 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:83bc478d3ba6a40fe3cec72dc9057ceca4dc9137

commit r12-7590-g83bc478d3ba6a40fe3cec72dc9057ceca4dc9137
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Mar 10 12:40:02 2022 +0100

    tree-optimization/102943 - avoid (re-)computing dominance bitmap

    Currently back_propagate_equivalences tries to optimize dominance
    queries in a smart way but it fails to notice that when fast indexes
    are available the dominance query is fast (when called from DOM).
    It also re-computes the dominance bitmap for each equivalence recorded
    on an edge, which for FP are usually several.  Finally it fails to
    use the tree bitmap view for efficiency.  Overall this cuts 7
    seconds of compile-time from originally 77 in the slowest LTRANS
    unit when building 521.wrf_r.

    2022-03-10  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/102943
            * tree-ssa-dom.cc (back_propagate_equivalences): Only
            populate the dominance bitmap if fast queries are not
            available.  Use a tree view bitmap.
            (record_temporary_equivalences): Cache the dominance bitmap
            across all equivalences on the edge.