On Thu, 26 Jul 2018, Martin Liška wrote:
Following patch implements new predictors that annotates malloc-like functions.
These almost every time return a non-null value.
Out of curiosity (the __builtin_expect there doesn't hurt and we don't
need to remove it), does it make __builtin_expect unnecessary in the
implementation of operator new (libstdc++-v3/libsupc++/new_op.cc)? It
looks like
while (__builtin_expect ((p = malloc (sz)) == 0, false))
{
new_handler handler = std::get_new_handler ();
if (! handler)
_GLIBCXX_THROW_OR_ABORT(bad_alloc());
handler ();
}
where being in a loop may trigger opposite heuristics.
--
Marc Glisse
