[webkit-dev] Time to remove LIKELY and UNLIKELY macros?
rniwa at webkit.org
Mon Oct 1 23:11:59 PDT 2012
I don't think so. I wrote a code that can be 10% slower without UNLIKELY
several weeks ago:
On Mon, Oct 1, 2012 at 10:55 PM, Adam Barth <abarth at webkit.org> wrote:
> According to <
> __builtin_expect (what our LIKELY and UNLIKELY macros expand to )
> doesn't do anything on modern CPUs. Apparently, these used to be
> important for PowerPC, but I don't think many folks use WebKit on
> PowerPC anymore.
> Should we remove these macros? I wasted some time today experimenting
> with them without realizing that they compile to no-ops in clang.
>  http://trac.webkit.org/browser/trunk/Source/WTF/wtf/Compiler.h#L188
> webkit-dev mailing list
> webkit-dev at lists.webkit.org
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