likely/unlikely equivalent for MSVC

Question

GCC compiler supports __builtin_expect statement that is used to define likely and unlikely macros.

eg.

#define likely(expr)    (__builtin_expect(!!(         


        

Answer 1

C++20 standard will include [[likely]] and [[unlikely]] branch prediction attributes.

The latest revision of attribute proposal can be found from http://wg21.link/p0479

The original attribute proposal can be found from http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0479r0.html

Programmers should prefer PGO. Attributes can easily reduce performance if applied incorrectly or they later become incorrect when program changes.