[Bug middle-end/126103] ranger: incoming range to a threading path is ignored

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126103

--- Comment #13 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Aldy Hernandez <[email protected]>:

https://gcc.gnu.org/g:8a8a022c81b6105f70f72dfe2dc7b368353b49e6

commit r17-3187-g8a8a022c81b6105f70f72dfe2dc7b368353b49e6
Author: Aldy Hernandez <[email protected]>
Date:   Mon Aug 10 06:59:36 2026 +0000

    Add --param=dom-jump-threading to disable DOM jump threading [PR126103]

    As discussed in PR126103, the first step to removing DOM is untangling
    its threader from the rest of DOM.  I've started auditing what we're
    missing in PRE + backwards threader, and need a way to disable DOM's
    threading for the barrage of PRs I'm about to file.

    We already have a way to disable all jump threads, but no way to
    disable just DOM's.  This patch does jhust this with
    --param=dom-jump-threading=[01].  It's in line with what we
    temporarily did for ranger-threading and ranger VRP.

    The --param disables jump threading in DOM, but everything else DOM
    does is unaffected.

    Tested on ppc64le Linux.

            PR tree-optimization/126103

    gcc/ChangeLog:

            * doc/params.texi (dom-jump-threading): Document.
            * params.opt (-param=dom-jump-threading=): New.
            * tree-ssa-dom.cc (dom_opt_dom_walker::after_dom_children): Honor
            param_dom_jump_threading.

    gcc/testsuite/ChangeLog:

            * gcc.dg/tree-ssa/dom-jump-threading-1.c: New test.
            * gcc.dg/tree-ssa/dom-jump-threading-2.c: New test.