This is the mail archive of the
gcc-bugs@gcc.gnu.org
mailing list for the GCC project.
[Bug target/59874] Missing builtin (__builtin_clzs) when compiling with g++
- From: "ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 13 Dec 2016 11:14:20 +0000
- Subject: [Bug target/59874] Missing builtin (__builtin_clzs) when compiling with g++
- Auto-submitted: auto-generated
- References: <bug-59874-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59874
--- Comment #6 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Allan Jensen from comment #5)
> This is more problematic to fix in Qt itself. How can we determine if we
> should/can use __builtin_clzs or __lzcnt16?
>
> Note the former is practically standard being supported by both older gcc
> and clang. There is also the problem that we need to call a builtin, because
> the C-intrinsics don't work as constexpr.
Well, if the change makes so much pain, let's put these intrinsics back.