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* [Bug tree-optimization/115381] New: Missed deoptimization opportunity when comparing two different linker symbols
@ 2024-06-07 4:45 user202729 at protonmail dot com
2024-06-07 6:14 ` [Bug tree-optimization/115381] " rguenth at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: user202729 at protonmail dot com @ 2024-06-07 4:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115381
Bug ID: 115381
Summary: Missed deoptimization opportunity when comparing two
different linker symbols
Product: gcc
Version: 15.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: user202729 at protonmail dot com
Target Milestone: ---
Code:
```
int x();
int y();
int z(){ return &x == &y; }
```
Clang optimizes this to 0. GCC doesn't.
Godbolt link: https://godbolt.org/z/8rGbbdrbe
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug tree-optimization/115381] Missed deoptimization opportunity when comparing two different linker symbols 2024-06-07 4:45 [Bug tree-optimization/115381] New: Missed deoptimization opportunity when comparing two different linker symbols user202729 at protonmail dot com @ 2024-06-07 6:14 ` rguenth at gcc dot gnu.org 2024-06-07 6:18 ` rguenth at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2024-06-07 6:14 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115381 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- -fno-semantic-interposition ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/115381] Missed deoptimization opportunity when comparing two different linker symbols 2024-06-07 4:45 [Bug tree-optimization/115381] New: Missed deoptimization opportunity when comparing two different linker symbols user202729 at protonmail dot com 2024-06-07 6:14 ` [Bug tree-optimization/115381] " rguenth at gcc dot gnu.org @ 2024-06-07 6:18 ` rguenth at gcc dot gnu.org 2024-06-07 14:16 ` pinskia at gcc dot gnu.org 2024-06-07 14:17 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2024-06-07 6:18 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115381 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed| |2024-06-07 Status|UNCONFIRMED |NEW Ever confirmed|0 |1 CC| |hubicka at gcc dot gnu.org --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Doesn't seem to help here. Related testcase: extern int x; extern int y; int z(){ return &x == &y; } possibly -fno-semantic-interposition doesn't cover the definitions being aliases of each other. Defining TU: int x(){} int __attribute__((alias("x"))) y(); I believe this is wrong-code from clang. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/115381] Missed deoptimization opportunity when comparing two different linker symbols 2024-06-07 4:45 [Bug tree-optimization/115381] New: Missed deoptimization opportunity when comparing two different linker symbols user202729 at protonmail dot com 2024-06-07 6:14 ` [Bug tree-optimization/115381] " rguenth at gcc dot gnu.org 2024-06-07 6:18 ` rguenth at gcc dot gnu.org @ 2024-06-07 14:16 ` pinskia at gcc dot gnu.org 2024-06-07 14:17 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-06-07 14:16 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115381 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=43565 Severity|normal |enhancement ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug tree-optimization/115381] Missed deoptimization opportunity when comparing two different linker symbols 2024-06-07 4:45 [Bug tree-optimization/115381] New: Missed deoptimization opportunity when comparing two different linker symbols user202729 at protonmail dot com ` (2 preceding siblings ...) 2024-06-07 14:16 ` pinskia at gcc dot gnu.org @ 2024-06-07 14:17 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-06-07 14:17 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115381 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |DUPLICATE --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Yes this is a dup of bug 43565. *** This bug has been marked as a duplicate of bug 43565 *** ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2024-06-07 14:17 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-06-07 4:45 [Bug tree-optimization/115381] New: Missed deoptimization opportunity when comparing two different linker symbols user202729 at protonmail dot com 2024-06-07 6:14 ` [Bug tree-optimization/115381] " rguenth at gcc dot gnu.org 2024-06-07 6:18 ` rguenth at gcc dot gnu.org 2024-06-07 14:16 ` pinskia at gcc dot gnu.org 2024-06-07 14:17 ` pinskia at gcc dot gnu.org
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