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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/99296] [11 Regression] ICE:in irange_set_anti_range, at value-range.cc:205 with "-Os -fno-toplevel-reorder -fno-tree-bit-ccp" since r11-5105-ga5f9c27bfc441722
Date: Wed, 17 Mar 2021 10:03:22 +0000	[thread overview]
Message-ID: <bug-99296-4-doKTwmbWTn@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-99296-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99296

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
signed 1 bit precision are always a nightmare to deal with.
      wide_int lim1 = wi::sub (w_min, 1, sign, &ovf);
      gcc_checking_assert (ovf != wi::OVF_OVERFLOW);
1 is not really representable in that type, which is why I think we're getting
the overflow.  So I think we need to use
      wide_int lim1
        = !sign && w_min.get_precision () == 1
          ? wi::add (w_min, -1, sign, &ovf)
          : wi::sub (w_min, 1, sign, &ovf);
instead.
And in the other spot in the same function the other way around (when it is
called on signed precision 1 -1, -1.  One can't wi::add (w_max, 1, sign, &ovf)
either, needs wi::sub (w_max, -1, sign, &ovf).

  parent reply	other threads:[~2021-03-17 10:03 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-27  6:53 [Bug tree-optimization/99296] New: ICE:in irange_set_anti_range, at value-range.cc:205 with "-Os -fno-toplevel-reorder -fno-tree-bit-ccp" suochenyao at 163 dot com
2021-03-01 10:11 ` [Bug tree-optimization/99296] [11 Regression] ICE:in irange_set_anti_range, at value-range.cc:205 with "-Os -fno-toplevel-reorder -fno-tree-bit-ccp" since r11-5105-ga5f9c27bfc441722 marxin at gcc dot gnu.org
2021-03-16 11:51 ` rguenth at gcc dot gnu.org
2021-03-16 13:42 ` aldyh at gcc dot gnu.org
2021-03-17 10:03 ` jakub at gcc dot gnu.org [this message]
2021-03-17 10:08 ` jakub at gcc dot gnu.org
2021-03-18 15:16 ` aldyh at gcc dot gnu.org
2021-03-23  6:58 ` cvs-commit at gcc dot gnu.org
2021-03-23  6:59 ` aldyh at gcc dot gnu.org

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