https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98226
Oleg Zaikin changed:
What|Removed |Added
Status|UNCONFIRMED |RESOLVED
Resolution|---
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98226
--- Comment #12 from Oleg Zaikin ---
(In reply to Alexander Monakov from comment #10)
> But why you are trying to use a more complex branchy expression in C++17
> mode when you already have a more efficient expression as a "fallback"?
>
> Note
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98226
--- Comment #11 from Oleg Zaikin ---
(In reply to Jonathan Wakely from comment #8)
> That needs to be investigated, but it's a problem with the compiler. It has
> nothing to do with countr_one being implemented using countr_zero (as shown
> by
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98226
--- Comment #7 from Oleg Zaikin ---
(In reply to Jonathan Wakely from comment #5)
> I've removed some redundant code from them, but not changed the indirection
> that this PR complains about. I don't plan to change that.
Thank you! I've got
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98226
--- Comment #6 from Oleg Zaikin ---
(In reply to Jonathan Wakely from comment #2)
> Oh, but you didn't enable any optimization at all, so who cares about the
> performance?
Let me give the whole picture. The issue is very close to that from
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98226
Bug ID: 98226
Summary: Slow std::countr_one
Product: gcc
Version: 10.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
