PETSc version 3.17.5

PetscLikely

Hints the compiler that the given condition is usually TRUE

#include <petscmacros.h>
bool PetscLikely(bool cond)

Not Collective

cond

- Boolean expression

Not available from fortran.

This returns the same truth value, it is only a hint to compilers that the result of cond is likely to be true.

  if (PetscLikely(cond)) {
    foo(); // hot path
  } else {
    bar(); // cold path
  }

advanced