Re: [PATCH 20/22] x86,word-at-a-time: Remove .fixup usage

On Tue, Nov 9, 2021 at 1:21 PM Peter Zijlstra [off-list ref] wrote:

On Tue, Nov 09, 2021 at 12:59:12PM -0800, Bill Wendling wrote:

quoted

Adding attributes to labels shouldn't be difficult, as you mention. In
the case of cold/hot, it's adjusting some of the metadata that already
exists on some basic blocks. It might be enough to allow the normal
block placement algorithms to move the hot and cold blocks around for
us. The question becomes how many attributes does GCC allow on labels?

I'm aware of 3: unused, hot, cold. Also:

  https://gcc.gnu.org/onlinedocs/gcc/Label-Attributes.html

Re: unused:
Being able to selectively disable -Wunused-label via
__attribute__((unused)); seems useful, too.
-- 
Thanks,
~Nick Desaulniers