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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
end of thread, other threads:[~2023-06-28 13:56 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 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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