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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/112305] [11/12/13/14 Regression] Wrong code at -O1/2/3/s on x86_64-pc-linux-gnu
Date: Tue, 31 Oct 2023 09:10:20 +0000 [thread overview]
Message-ID: <bug-112305-4-KZh9QpnQNK@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-112305-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112305
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
Status|NEW |ASSIGNED
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
final value replacement introduces
<bb 5> [local count: 118111600]:
- # e_14 = PHI <e_10(4)>
- # d_23 = PHI <d_11(4)>
+ _7 = e_20 + 4;
+ _12 = e_20 <= 19;
+ _25 = (unsigned int) e_20;
+ _26 = 19 - _25;
+ _27 = _26 / 4;
+ _28 = (int) _27;
+ _29 = _28 * 4;
+ _30 = _12 ? _29 : 0;
+ e_14 = _7 + _30;
+ _31 = e_20 <= 19;
+ _32 = (unsigned int) e_20;
+ _33 = 19 - _32;
+ _34 = _33 / 4;
+ _35 = _34 * 4294967293;
+ _36 = _31 ? _35 : 0;
+ _37 = d_19 + _36;
+ d_23 = _37 + 4294967293;
which is e_20 + 4 + (e_20 <= 19 ? 4 * (int)((19 - (unsigned int) e_20) / 4): 0)
and ((e_20 <= 19 ? ((19 - (unsigned int) e_20) / 4) * 4294967293 : 0) + d_19) +
4294967293
I think there's another bug noting that final value replacement with
COND_EXPRs should eventually materialize control-flow.
I have a patch to do more rewriting to unsigned instead.
next prev parent reply other threads:[~2023-10-31 9:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-31 6:51 [Bug middle-end/112305] New: [13/14 " jwzeng at nuaa dot edu.cn
2023-10-31 7:00 ` [Bug middle-end/112305] " pinskia at gcc dot gnu.org
2023-10-31 7:02 ` pinskia at gcc dot gnu.org
2023-10-31 7:07 ` [Bug middle-end/112305] [11/12/13/14 " pinskia at gcc dot gnu.org
2023-10-31 7:08 ` pinskia at gcc dot gnu.org
2023-10-31 9:10 ` rguenth at gcc dot gnu.org [this message]
2023-10-31 12:10 ` cvs-commit at gcc dot gnu.org
2023-10-31 12:18 ` [Bug middle-end/112305] [11/12/13 " rguenth at gcc dot gnu.org
2024-05-21 9:18 ` jakub at gcc dot gnu.org
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