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* [Bug driver/108196] New: Incorrect binary search in find_opt
@ 2022-12-21 20:10 hjl.tools at gmail dot com
2022-12-21 20:20 ` [Bug driver/108196] " pinskia at gcc dot gnu.org
2022-12-21 20:31 ` hjl.tools at gmail dot com
0 siblings, 2 replies; 3+ messages in thread
From: hjl.tools at gmail dot com @ 2022-12-21 20:10 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108196
Bug ID: 108196
Summary: Incorrect binary search in find_opt
Product: gcc
Version: 13.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: driver
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
Target Milestone: ---
opts-common.cc has
/* Find mn such this lexicographical inequality holds:
cl_options[mn] <= input < cl_options[mn + 1]. */
while (mx - mn > 1)
{
md = (mn + mx) / 2;
opt_len = cl_options[md].opt_len;
comp = strncmp (input, cl_options[md].opt_text + 1, opt_len);
if (comp < 0)
mx = md;
else
mn = md;
}
When md is the exact match, the search doesn't terminate and we may get the
wrong result.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug driver/108196] Incorrect binary search in find_opt
2022-12-21 20:10 [Bug driver/108196] New: Incorrect binary search in find_opt hjl.tools at gmail dot com
@ 2022-12-21 20:20 ` pinskia at gcc dot gnu.org
2022-12-21 20:31 ` hjl.tools at gmail dot com
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2022-12-21 20:20 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108196
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Can you give an example because this code has been there since
r0-51440-gcf03fd63cd7fd8 (since at least 3.4.0). And exact match has been
happening for a long time now.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug driver/108196] Incorrect binary search in find_opt
2022-12-21 20:10 [Bug driver/108196] New: Incorrect binary search in find_opt hjl.tools at gmail dot com
2022-12-21 20:20 ` [Bug driver/108196] " pinskia at gcc dot gnu.org
@ 2022-12-21 20:31 ` hjl.tools at gmail dot com
1 sibling, 0 replies; 3+ messages in thread
From: hjl.tools at gmail dot com @ 2022-12-21 20:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108196
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> ---
It is a different issue.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-12-21 20:31 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2022-12-21 20:10 [Bug driver/108196] New: Incorrect binary search in find_opt hjl.tools at gmail dot com
2022-12-21 20:20 ` [Bug driver/108196] " pinskia at gcc dot gnu.org
2022-12-21 20:31 ` hjl.tools at gmail dot com
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