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* [Bug tree-optimization/110434] New: tree-nrv introduces incorrect CLOBBER(eol)
@ 2023-06-27 10:48 kristerw at gcc dot gnu.org
2023-06-28 9:32 ` [Bug tree-optimization/110434] " rguenth at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: kristerw at gcc dot gnu.org @ 2023-06-27 10:48 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110434
Bug ID: 110434
Summary: tree-nrv introduces incorrect CLOBBER(eol)
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: kristerw at gcc dot gnu.org
Target Milestone: ---
The tree-nrv pass may introduce incorrect CLOBBER(eol) of the form
<retval> ={v} {CLOBBER(eol)};
return <retval>;
One example of this can be seen by compiling gcc.c-torture/execute/921204-1.c
for x86 using the flags "-O -m32", where it changes the IR
union bu o;
...
o = i;
MEM[(union *)&o].b18 = _11;
MEM[(union *)&o].b20 = _11;
<retval> = o;
o ={v} {CLOBBER(eol)};
return <retval>;
to just use <retval> instead of o
union bu o [value-expr: <retval>];
...
<retval> = i;
MEM[(union *)&<retval>].b18 = _11;
MEM[(union *)&<retval>].b20 = _11;
<retval> ={v} {CLOBBER(eol)};
return <retval>;
so the CLOBBER(eol) now refers to <retval>.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/110434] tree-nrv introduces incorrect CLOBBER(eol)
2023-06-27 10:48 [Bug tree-optimization/110434] New: tree-nrv introduces incorrect CLOBBER(eol) kristerw at gcc dot gnu.org
@ 2023-06-28 9:32 ` rguenth at gcc dot gnu.org
2023-06-28 13:55 ` cvs-commit at gcc dot gnu.org
2023-06-28 13:56 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-06-28 9:32 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110434
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
Ever confirmed|0 |1
Last reconfirmed| |2023-06-28
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/110434] tree-nrv introduces incorrect CLOBBER(eol)
2023-06-27 10:48 [Bug tree-optimization/110434] New: tree-nrv introduces incorrect CLOBBER(eol) kristerw at gcc dot gnu.org
2023-06-28 9:32 ` [Bug tree-optimization/110434] " rguenth at gcc dot gnu.org
@ 2023-06-28 13:55 ` cvs-commit at gcc dot gnu.org
2023-06-28 13:56 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2023-06-28 13:55 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110434
--- Comment #1 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:
https://gcc.gnu.org/g:4bf76b5b6db8e68755788ec91012c5a686440720
commit r14-2164-g4bf76b5b6db8e68755788ec91012c5a686440720
Author: Richard Biener <rguenther@suse.de>
Date: Wed Jun 28 11:27:45 2023 +0200
tree-optimization/110434 - avoid <retval> ={v} {CLOBBER} from NRV
When NRV replaces a local variable with <retval> it also replaces
occurences in clobbers. This leads to <retval> being clobbered
before the return of it which is strictly invalid but harmless in
practice since there's no pass after NRV which would remove
earlier stores.
The following fixes this nevertheless.
PR tree-optimization/110434
* tree-nrv.cc (pass_nrv::execute): Remove CLOBBERs of
VAR we replace with <retval>.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/110434] tree-nrv introduces incorrect CLOBBER(eol)
2023-06-27 10:48 [Bug tree-optimization/110434] New: tree-nrv introduces incorrect CLOBBER(eol) kristerw at gcc dot gnu.org
2023-06-28 9:32 ` [Bug tree-optimization/110434] " rguenth at gcc dot gnu.org
2023-06-28 13:55 ` cvs-commit at gcc dot gnu.org
@ 2023-06-28 13:56 ` rguenth at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2023-06-28 13:56 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110434
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |FIXED
Status|ASSIGNED |RESOLVED
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed. Thanks for reporting.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2023-06-27 10:48 [Bug tree-optimization/110434] New: tree-nrv introduces incorrect CLOBBER(eol) kristerw at gcc dot gnu.org
2023-06-28 9:32 ` [Bug tree-optimization/110434] " rguenth at gcc dot gnu.org
2023-06-28 13:55 ` cvs-commit at gcc dot gnu.org
2023-06-28 13:56 ` rguenth at gcc dot gnu.org
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