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From: "ebotcazou at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug bootstrap/95940] [11 Regression] bootstrap broken by -Wmaybe-unintialized warnings
Date: Wed, 01 Jul 2020 07:46:53 +0000 [thread overview]
Message-ID: <bug-95940-4-uULs2I0bPd@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-95940-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95940
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|WAITING |NEW
Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|[11 Regression] |[11 Regression] bootstrap
|sparc64-linux bootstrap |broken by
|with gcc-9.3 broken |-Wmaybe-unintialized
| |warnings
CC| |ebotcazou at gcc dot gnu.org
--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
The first -Wmaybe-unintialized warning is issued for the read in this
statement:
SR.1076_294 = D.75512.D.16218.val[1];
in the following basic block:
<bb 24> [local count: 130803720]:
# SR.268_98 = PHI <_104(23), _75(39)>
D.75553 ={v} {CLOBBER};
D.75512 ={v} {CLOBBER};
xi ={v} {CLOBBER};
SR.1076_294 = D.75512.D.16218.val[1]; <<< warning
SR.1077_296 = D.75512.D.16218.val[2]; <<< warning
D.75512 ={v} {CLOBBER};
D.75513 ={v} {CLOBBER};
goto <bb 33>; [100.00%]
Since D.75512 is clobbered just prior to the read from it I think the warning
is justified. Subsequent warnings follow a similar pattern:
<bb 26> [local count: 349243402]:
# SR.268_123 = PHI <_129(25), -1(41)>
D.75575 ={v} {CLOBBER};
D.75514 ={v} {CLOBBER};
xi ={v} {CLOBBER};
SR.1076_230 = D.75514.D.16218.val[1]; <<< warning
SR.1077_105 = D.75514.D.16218.val[2]; <<< warning
D.75514 ={v} {CLOBBER};
D.75515 ={v} {CLOBBER};
goto <bb 33>; [100.00%]
...
<bb 31> [local count: 68586742]:
# SR.268_148 = PHI <_154(30), -1(40)>
D.75597 ={v} {CLOBBER};
D.75516 ={v} {CLOBBER};
xi ={v} {CLOBBER};
SR.1076_219 = D.75516.D.16218.val[1]; <<< warning
SR.1077_220 = D.75516.D.16218.val[2]; <<< warning
D.75516 ={v} {CLOBBER};
D.75517 ={v} {CLOBBER};
goto <bb 33>; [100.00%]
--- Comment #5 from Martin Sebor <msebor at gcc dot gnu.org> ---
The first -Wmaybe-unintialized warning is issued for the read in this
statement:
SR.1076_294 = D.75512.D.16218.val[1];
in the following basic block:
<bb 24> [local count: 130803720]:
# SR.268_98 = PHI <_104(23), _75(39)>
D.75553 ={v} {CLOBBER};
D.75512 ={v} {CLOBBER};
xi ={v} {CLOBBER};
SR.1076_294 = D.75512.D.16218.val[1]; <<< warning
SR.1077_296 = D.75512.D.16218.val[2]; <<< warning
D.75512 ={v} {CLOBBER};
D.75513 ={v} {CLOBBER};
goto <bb 33>; [100.00%]
Since D.75512 is clobbered just prior to the read from it I think the warning
is justified. Subsequent warnings follow a similar pattern:
<bb 26> [local count: 349243402]:
# SR.268_123 = PHI <_129(25), -1(41)>
D.75575 ={v} {CLOBBER};
D.75514 ={v} {CLOBBER};
xi ={v} {CLOBBER};
SR.1076_230 = D.75514.D.16218.val[1]; <<< warning
SR.1077_105 = D.75514.D.16218.val[2]; <<< warning
D.75514 ={v} {CLOBBER};
D.75515 ={v} {CLOBBER};
goto <bb 33>; [100.00%]
...
<bb 31> [local count: 68586742]:
# SR.268_148 = PHI <_154(30), -1(40)>
D.75597 ={v} {CLOBBER};
D.75516 ={v} {CLOBBER};
xi ={v} {CLOBBER};
SR.1076_219 = D.75516.D.16218.val[1]; <<< warning
SR.1077_220 = D.75516.D.16218.val[2]; <<< warning
D.75516 ={v} {CLOBBER};
D.75517 ={v} {CLOBBER};
goto <bb 33>; [100.00%]
--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> From the look of it, something is already miscompiled.
No, not at all, it's just warnings turned into errors.
next prev parent reply other threads:[~2020-07-01 7:46 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-27 11:43 [Bug bootstrap/95940] New: sparc64-linux bootstrap with gcc-9.3 broken hp at gcc dot gnu.org
2020-06-29 10:35 ` [Bug bootstrap/95940] [11 Regression] " rguenth at gcc dot gnu.org
2020-06-29 14:48 ` msebor at gcc dot gnu.org
2020-06-29 20:49 ` hp at gcc dot gnu.org
2020-06-29 20:53 ` hp at gcc dot gnu.org
2020-07-01 7:46 ` ebotcazou at gcc dot gnu.org [this message]
2020-07-02 3:15 ` [Bug bootstrap/95940] [11 Regression] bootstrap broken by -Wmaybe-unintialized warnings hp at gcc dot gnu.org
2020-07-02 6:57 ` ebotcazou at gcc dot gnu.org
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