macros vs sub (fibonacci)

my \A = now; say fib-s 1000;
my \B = now; say fib-m 1000;
my \C = now; say "sub: {B - A} vs macro: {C - B}";

sub fib-s (\n) { (0, 1, * + * ... Inf)[n] }

use experimental :macros;
macro fib-m (\n) { {{{ fib-s n }}} }