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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/109071] -Warray-bounds warning when array index checked via inline
Date: Thu, 09 Mar 2023 10:18:35 +0000	[thread overview]
Message-ID: <bug-109071-4-esfvFATmMF@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-109071-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109071

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-03-09

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Yep, so we produce

<bb 2> [local count: 1073741824]:
if (index_3(D) > 3)
  goto <bb 4>; [33.00%]
else
  goto <bb 3>; [67.00%]

<bb 4> [local count: 354334800]:
warn ();
*ptr_5(D) = 0;
_17 = MEM <struct nums> [(int *)sg_2(D)].vals[index_3(D)];
warn ();

<bb 5> [local count: 1073741824]:
# _18 = PHI <_14(3), _17(4)>
*ptr_5(D) = _18;
return;

(and BB 3 with a BB4 duplicate w/o warn () calls).  If warn () were
noreturn this wouldn't happen.

And yes, we do have (plenty?) duplicates.

  parent reply	other threads:[~2023-03-09 10:18 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-08 21:04 [Bug c/109071] New: " kees at outflux dot net
2023-03-08 21:13 ` [Bug tree-optimization/109071] " pinskia at gcc dot gnu.org
2023-03-09 10:18 ` rguenth at gcc dot gnu.org [this message]
2023-03-09 16:15 ` kees at outflux dot net
2023-03-10 15:51 ` qinzhao at gcc dot gnu.org
2024-04-22 19:12 ` [Bug tree-optimization/109071] -Warray-bounds false positive warnings due to code duplication from jump threading qinzhao at gcc dot gnu.org
2024-04-22 19:21 ` kees at outflux dot net
2024-04-22 20:04 ` qinzhao at gcc dot gnu.org
2024-04-22 20:15 ` kees at outflux dot net
2024-04-22 21:19 ` qinzhao at gcc dot gnu.org
2024-05-13 14:21 ` qinzhao at gcc dot gnu.org
2024-05-14 16:19 ` qinzhao at gcc dot gnu.org

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