$caller = "My::Class::Path::myfunc";

# Fastest method
# regex-with-prematch
my ($func) = $caller =~ /::([^:]*)$/;
my $class = $`; # aka. $PREMATCH

# Second place; only .09sec in 100,000 iterations slower
# split-pop-join
my (@objpath) = split(/::/, $caller);
my ($func)  = pop @objpath;
my ($class) = join('::', @objpath);

# Third place; 25% slower
# globalrx-pop-join
my (@objpath) = $caller =~ /([^:]+)/g;
my ($func)  = pop @objpath;
my ($class) = join('::', @objpath);