chomp vs substr benchmarks

use v6;
use Benchmark;

my $string = "a b c d \n";

my %results = timethese(1000, {
    "chomp" => sub { $string.chomp },
    "chop" =>  sub { $string.chop if $string.substr(-1) == any("\n", "\r\n") },
    "flip" =>  sub { $string.flip.substr(1).flip if $string.substr(-1) == any("\n", "\r\n") },
    "substr" => sub { $string.substr(0,-1) if $string.substr(-1) == any("\n", "\r\n") },
});
say ~%results;