On: Beautiful branchless binary search

[berkut]

Yeah, it's mildly annoying there's no (at least to my knowledge?) compiler hint like the '__builtin_expect' ones to tell compilers that the values are very unlikely going to be predictable with enough accuracy to allow the branch predictors to be useful in general, and to use a cmov instead of the traditional branching instructions because of this.

[dist1ll → berkut]

clang has __builtin_unpredictable [0]

[0] https://clang.llvm.org/docs/LanguageExtensions.html#builtin-...

[usefulcat → dist1ll]

It does, but unfortunately it doesn't always work. For example (note the -march=broadwell option):

https://godbolt.org/z/n1Kz4G7GE

[berkut → dist1ll]

Oooooh :)

Thanks!

[gpderetta → berkut]

GCC has __builtin_expect_with_probability now. YMMV.