[Bug bootstrap/100373] [12 Regression] Darwin, Compare-debug fail after r12-248-gb58dc0b803057

["cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100373

--- Comment #13 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:b5254d6b75fe6be669396cd1261f1cba829cc451

commit r12-558-gb5254d6b75fe6be669396cd1261f1cba829cc451
Author: Richard Biener <rguenther@suse.de>
Date:   Wed May 5 10:15:27 2021 +0200

    ipa/100373 - fix emutls lowering compare-debug issue

    emutls figured that tls uses in debug-insns need lowering but
    that obviously has effects on code-generation as can be seen
    in the following IL diff with the new testcase:

       <bb 2> [local count: 1073741824]:
    -  a = 0;
    +  # DEBUG BEGIN_STMT
       _4 = __builtin___emutls_get_address (&__emutls_v.b);
    +  # DEBUG D#1 => *_4
    +  # DEBUG d => (long int) D#1
    +  # DEBUG BEGIN_STMT
    +  a = 0;
    +  # DEBUG BEGIN_STMT
       *_4 = 0;
       return;

    where it figured the debug use of b in the original

      <bb 2> [local count: 1073741824]:
      # DEBUG BEGIN_STMT
      # DEBUG D#1 => b
      # DEBUG d => (long int) D#1
      # DEBUG BEGIN_STMT
      a = 0;

    needs lowering (it maybe does when we want to produce perfect
    debug but that's just bad luck).

    The following patch fixes this by avoiding to create a new
    emutls address when visiting debug stmts and instead resets them.
    Another option might be to simply not lower debug stmt uses
    but I have no way to verify actual debug info for this.

    2021-05-05  Richard Biener  <rguenther@suse.de>

            PR ipa/100373
            * tree-emutls.c (gen_emutls_addr): Pass in whether we're
            dealing with a debug use and only query existing addresses
            if so.
            (lower_emutls_1): Avoid splitting out addresses for debug
            stmts, reset the debug stmt when we fail to find existing
            lowered addresses.
            (lower_emutls_phi_arg): Set wi.stmt.

            * gcc.dg/pr100373.c: New testcase.