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* [Bug middle-end/114669] New: use >= comparison when testing high bits
@ 2024-04-09 22:23 goon.pri.low at gmail dot com
2024-04-09 22:27 ` [Bug tree-optimization/114669] " pinskia at gcc dot gnu.org
2024-04-09 22:36 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: goon.pri.low at gmail dot com @ 2024-04-09 22:23 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114669
Bug ID: 114669
Summary: use >= comparison when testing high bits
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: goon.pri.low at gmail dot com
Target Milestone: ---
Example C functions
#include <stdint.h>
#include <stdbool.h>
bool unopt(uint32_t x) {
return (x & 0xfff00000) == 0xfff00000;
}
bool opt(uint32_t x) {
return x >= 0xfff00000;
}
Generated assembly
unopt:
not edi
and edi, -1048576
sete al
ret
opt:
cmp edi, -1048577
seta al
ret
^ permalink raw reply [flat|nested] 3+ messages in thread* [Bug tree-optimization/114669] use >= comparison when testing high bits 2024-04-09 22:23 [Bug middle-end/114669] New: use >= comparison when testing high bits goon.pri.low at gmail dot com @ 2024-04-09 22:27 ` pinskia at gcc dot gnu.org 2024-04-09 22:36 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-04-09 22:27 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114669 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|middle-end |tree-optimization CC| |pinskia at gcc dot gnu.org --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- This is almost definitely a dup ... ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/114669] use >= comparison when testing high bits 2024-04-09 22:23 [Bug middle-end/114669] New: use >= comparison when testing high bits goon.pri.low at gmail dot com 2024-04-09 22:27 ` [Bug tree-optimization/114669] " pinskia at gcc dot gnu.org @ 2024-04-09 22:36 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-04-09 22:36 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114669 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Severity|normal |enhancement Last reconfirmed| |2024-04-09 Ever confirmed|0 |1 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2024-04-09 22:36 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-04-09 22:23 [Bug middle-end/114669] New: use >= comparison when testing high bits goon.pri.low at gmail dot com 2024-04-09 22:27 ` [Bug tree-optimization/114669] " pinskia at gcc dot gnu.org 2024-04-09 22:36 ` pinskia at gcc dot gnu.org
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