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From: "msebor at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/107038] [13 Regression] Bogus -Wstringop-overflow= since r13-2789-gb40b3035879cf695
Date: Mon, 26 Sep 2022 16:16:37 +0000 [thread overview]
Message-ID: <bug-107038-4-ivZAuR2tuC@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-107038-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107038
--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
Just a quick note from what I see in GDB. The warning is issued by the 2nd run
of the waccess pass (-fdump-tree-waccess2) for the following statement in bb 22
in pread():
iftmp.21_88 = __pread_alias (_50, _82, _81, _79);
_81's range reported by range_query::range_of_expr (vr, exp, stmt) is [58,
ULONG_MAX], matching the range in the warning.
A partial output of debug_ranger() for the function is below. I must be
reading it wrong because I don't see what the range above is derived from.
=========== BB 19 ============
Imports: recvd_78 _83
Exports: _51 recvd_78 recvd.17_80 _83 _94 _116 _125
_83 [irange] UNDEFINED
<bb 19> [local count: 169058114]:
if (_83 == 18446744073709551615)
goto <bb 22>; [34.00%]
else
goto <bb 20>; [66.00%]
19->22 (T) _83 : [irange] UNDEFINED
19->20 (F) _83 : [irange] UNDEFINED
=========== BB 20 ============
Imports: _81 _83
Exports: _81 _83 _85 _86 _87
_85 : _81(I) _83(I)
_86 : _81(I) _83(I) _85
_87 : _81(I) _83(I) _85 _86
_81 [irange] long unsigned int VARYING
_83 [irange] long unsigned int VARYING
<bb 20> [local count: 280636469]:
_85 = _81 <= _83;
_86 = (int) _85;
_87 = __builtin_constant_p (_86);
if (_87 != 0)
goto <bb 21>; [50.00%]
else
goto <bb 24>; [50.00%]
_86 : [irange] int [0, 1] NONZERO 0x1
_87 : [irange] int [0, 0] NONZERO 0x0
20->21 (T) _81 : [irange] UNDEFINED
20->21 (T) _83 : [irange] UNDEFINED
20->21 (T) _85 : [irange] UNDEFINED
20->21 (T) _86 : [irange] UNDEFINED
20->21 (T) _87 : [irange] UNDEFINED
20->24 (F) _86 : [irange] int [0, 1] NONZERO 0x1
20->24 (F) _87 : [irange] int [0, 0] NONZERO 0x0
=========== BB 21 ============
Imports: recvd_78 _81 _83
Exports: _51 recvd_78 recvd.17_80 _81 _83 _94 _116 _125
_81 [irange] UNDEFINED
_83 [irange] UNDEFINED
<bb 21> [local count: 140318235]:
if (_81 <= _83)
goto <bb 22>; [50.00%]
else
goto <bb 23>; [50.00%]
21->22 (T) _81 : [irange] UNDEFINED
21->22 (T) _83 : [irange] UNDEFINED
21->23 (F) _81 : [irange] UNDEFINED
21->23 (F) _83 : [irange] UNDEFINED
=========== BB 22 ============
<bb 22> [local count: 127638877]:
iftmp.21_88 = __pread_alias (_50, _82, _81, _79);
goto <bb 25>; [100.00%]
next prev parent reply other threads:[~2022-09-26 16:16 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-26 8:36 [Bug tree-optimization/107038] New: " marxin at gcc dot gnu.org
2022-09-26 9:30 ` [Bug tree-optimization/107038] " rguenth at gcc dot gnu.org
2022-09-26 14:29 ` siddhesh at gcc dot gnu.org
2022-09-26 14:31 ` marxin at gcc dot gnu.org
2022-09-26 16:16 ` msebor at gcc dot gnu.org [this message]
2022-09-26 18:32 ` siddhesh at gcc dot gnu.org
2022-09-26 18:41 ` siddhesh at gcc dot gnu.org
2022-09-26 19:16 ` marxin at gcc dot gnu.org
2022-10-07 19:06 ` [Bug tree-optimization/107038] Bogus -Wstringop-overflow in dead code siddhesh at gcc dot gnu.org
2022-10-07 19:08 ` siddhesh at gcc dot gnu.org
2022-10-07 19:09 ` siddhesh at gcc dot gnu.org
2023-04-26 6:56 ` rguenth at gcc dot gnu.org
2023-07-27 9:23 ` rguenth at gcc dot gnu.org
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