[Bug debug/104544] New: [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O2

[asolokha at gmx dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104544

            Bug ID: 104544
           Summary: [10/11/12 Regression] '-fcompare-debug' failure
                    (length) w/ -O2
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: compare-debug-failure
          Severity: normal
          Priority: P3
         Component: debug
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---
            Target: aarch64-linux-gnu

Created attachment 52444
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52444&action=edit
gkd diff

gcc 12.0.1 20220213 snapshot (g:58aeb75d4097010ad9bb72b964265b18ab284f93) fails
-fcompare-debug check when compiling the following testcase w/ -O2:

int m, n;
__int128 q;

void
bar (unsigned __int128 x, int y)
{
  if (x)
    q += y;
}

void
foo (void)
{
  bar (!!q - 1, (m += m ? m : 1) < n);
}

% aarch64-linux-gnu-gcc-12.0.1 -O2 -fcompare-debug -c tod26vmj.c
aarch64-linux-gnu-gcc-12.0.1: error: tod26vmj.c: '-fcompare-debug' failure
(length)

gkd diff attached.