From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id F39AC3857825; Wed, 25 Aug 2021 08:39:11 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F39AC3857825
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/101145] niter analysis fails for until-wrap
 condition
Date: Wed, 25 Aug 2021 08:39:11 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: tree-optimization
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-101145-4-H7ck0MNnBj@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-101145-4@http.gcc.gnu.org/bugzilla/>
References: <bug-101145-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Wed, 25 Aug 2021 08:39:12 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101145

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jiu Fu Guo <guojiufu@gcc.gnu.org>:

https://gcc.gnu.org/g:3673dcf6d6baeb67bb70ff03d4cb3f92beed0075

commit r12-3136-g3673dcf6d6baeb67bb70ff03d4cb3f92beed0075
Author: Jiufu Guo <guojiufu@linux.ibm.com>
Date:   Wed Jul 7 13:41:01 2021 +0800

    Analyze niter for until-wrap condition [PR101145]

    For code like:
    unsigned foo(unsigned val, unsigned start)
    {
      unsigned cnt =3D 0;
      for (unsigned i =3D start; i > val; ++i)
        cnt++;
      return cnt;
    }

    The number of iterations should be about UINT_MAX - start.

    There is function adjust_cond_for_loop_until_wrap which
    handles similar work for const bases.
    Like adjust_cond_for_loop_until_wrap, this patch enhance
    function number_of_iterations_cond/number_of_iterations_lt
    to analyze number of iterations for this kind of loop.

    gcc/ChangeLog:

    2021-08-25  Jiufu Guo  <guojiufu@linux.ibm.com>

            PR tree-optimization/101145
            * tree-ssa-loop-niter.c (number_of_iterations_until_wrap):
            New function.
            (number_of_iterations_lt): Invoke above function.
            (adjust_cond_for_loop_until_wrap):
            Merge to number_of_iterations_until_wrap.
            (number_of_iterations_cond): Update invokes for
            adjust_cond_for_loop_until_wrap and number_of_iterations_lt.

    gcc/testsuite/ChangeLog:

    2021-08-25  Jiufu Guo  <guojiufu@linux.ibm.com>

            PR tree-optimization/101145
            * gcc.dg/vect/pr101145.c: New test.
            * gcc.dg/vect/pr101145.inc: New test.
            * gcc.dg/vect/pr101145_1.c: New test.
            * gcc.dg/vect/pr101145_2.c: New test.
            * gcc.dg/vect/pr101145_3.c: New test.
            * gcc.dg/vect/pr101145inf.c: New test.
            * gcc.dg/vect/pr101145inf.inc: New test.
            * gcc.dg/vect/pr101145inf_1.c: New test.=