diff --git a/src/libcoretest/str.rs b/src/libcoretest/str.rs
index 375564c39bb..308c5282a92 100644
--- a/src/libcoretest/str.rs
+++ b/src/libcoretest/str.rs
@@ -121,3 +121,110 @@ fn test_utf16_code_units() {
     assert_eq!(Utf16Encoder::new(vec!['é', '\u{1F4A9}'].into_iter()).collect::<Vec<u16>>(),
                vec![0xE9, 0xD83D, 0xDCA9])
 }
+
+
+// rm x86_64-unknown-linux-gnu/stage1/test/coretesttest-x86_64-unknown-linux-gnu; env PLEASE_BENCH=1 make check-stage1-coretest TESTNAME=str::bench
+
+mod bench {
+    macro_rules! make_test_inner {
+        ($s:ident, $code:expr, $name:ident, $str:expr) => {
+            #[bench]
+            fn $name(bencher: &mut Bencher) {
+                let mut $s = $str;
+                black_box(&mut $s);
+                bencher.iter(|| $code);
+            }
+        }
+    }
+
+    macro_rules! make_test {
+        ($name:ident, $s:ident, $code:expr) => {
+            mod $name {
+                use test::Bencher;
+                use test::black_box;
+
+                // Short strings: 65 bytes each
+                make_test_inner!($s, $code, short_ascii,
+                    "Mary had a little lamb, Little lamb Mary had a littl lamb, lamb!");
+                make_test_inner!($s, $code, short_mixed,
+                    "ศไทย中华Việt Nam; Mary had a little lamb, Little lam!");
+                make_test_inner!($s, $code, short_pile_of_poo,
+                    "💩💩💩💩💩💩💩💩💩💩💩💩💩💩💩💩!");
+                make_test_inner!($s, $code, long_lorem_ipsum,"\
+Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse quis lorem sit amet dolor \
+ultricies condimentum. Praesent iaculis purus elit, ac malesuada quam malesuada in. Duis sed orci \
+eros. Suspendisse sit amet magna mollis, mollis nunc luctus, imperdiet mi. Integer fringilla non \
+sem ut lacinia. Fusce varius tortor a risus porttitor hendrerit. Morbi mauris dui, ultricies nec \
+tempus vel, gravida nec quam.
+
+In est dui, tincidunt sed tempus interdum, adipiscing laoreet ante. Etiam tempor, tellus quis \
+sagittis interdum, nulla purus mattis sem, quis auctor erat odio ac tellus. In nec nunc sit amet \
+diam volutpat molestie at sed ipsum. Vestibulum laoreet consequat vulputate. Integer accumsan \
+lorem ac dignissim placerat. Suspendisse convallis faucibus lorem. Aliquam erat volutpat. In vel \
+eleifend felis. Sed suscipit nulla lorem, sed mollis est sollicitudin et. Nam fermentum egestas \
+interdum. Curabitur ut nisi justo.
+
+Sed sollicitudin ipsum tellus, ut condimentum leo eleifend nec. Cras ut velit ante. Phasellus nec \
+mollis odio. Mauris molestie erat in arcu mattis, at aliquet dolor vehicula. Quisque malesuada \
+lectus sit amet nisi pretium, a condimentum ipsum porta. Morbi at dapibus diam. Praesent egestas \
+est sed risus elementum, eu rutrum metus ultrices. Etiam fermentum consectetur magna, id rutrum \
+felis accumsan a. Aliquam ut pellentesque libero. Sed mi nulla, lobortis eu tortor id, suscipit \
+ultricies neque. Morbi iaculis sit amet risus at iaculis. Praesent eget ligula quis turpis \
+feugiat suscipit vel non arcu. Interdum et malesuada fames ac ante ipsum primis in faucibus. \
+Aliquam sit amet placerat lorem.
+
+Cras a lacus vel ante posuere elementum. Nunc est leo, bibendum ut facilisis vel, bibendum at \
+mauris. Nullam adipiscing diam vel odio ornare, luctus adipiscing mi luctus. Nulla facilisi. \
+Mauris adipiscing bibendum neque, quis adipiscing lectus tempus et. Sed feugiat erat et nisl \
+lobortis pharetra. Donec vitae erat enim. Nullam sit amet felis et quam lacinia tincidunt. Aliquam \
+suscipit dapibus urna. Sed volutpat urna in magna pulvinar volutpat. Phasellus nec tellus ac diam \
+cursus accumsan.
+
+Nam lectus enim, dapibus non nisi tempor, consectetur convallis massa. Maecenas eleifend dictum \
+feugiat. Etiam quis mauris vel risus luctus mattis a a nunc. Nullam orci quam, imperdiet id \
+vehicula in, porttitor ut nibh. Duis sagittis adipiscing nisl vitae congue. Donec mollis risus eu \
+leo suscipit, varius porttitor nulla porta. Pellentesque ut sem nec nisi euismod vehicula. Nulla \
+malesuada sollicitudin quam eu fermentum!");
+            }
+        }
+    }
+
+    make_test!(chars_count, s, s.chars().count());
+
+    make_test!(contains_bang_str, s, s.contains("!"));
+    make_test!(contains_bang_char, s, s.contains_char('!'));
+
+    make_test!(match_indices_a_str, s, s.match_indices("a").count());
+
+    make_test!(split_str_a_str, s, s.split_str("a").count());
+
+    make_test!(trim_ascii_char, s, {
+        use std::ascii::AsciiExt;
+        s.trim_matches(|&mut: c: char| c.is_ascii())
+    });
+    make_test!(trim_left_ascii_char, s, {
+        use std::ascii::AsciiExt;
+        s.trim_left_matches(|&mut: c: char| c.is_ascii())
+    });
+    make_test!(trim_right_ascii_char, s, {
+        use std::ascii::AsciiExt;
+        s.trim_right_matches(|&mut: c: char| c.is_ascii())
+    });
+
+    make_test!(find_underscore_char, s, s.find('_'));
+    make_test!(rfind_underscore_char, s, s.rfind('_'));
+    make_test!(find_underscore_str, s, s.find_str("_"));
+
+    make_test!(find_zzz_char, s, s.find('\u{1F4A4}'));
+    make_test!(rfind_zzz_char, s, s.rfind('\u{1F4A4}'));
+    make_test!(find_zzz_str, s, s.find_str("\u{1F4A4}"));
+
+    make_test!(split_space_char, s, s.split(' ').count());
+    make_test!(split_terminator_space_char, s, s.split_terminator(' ').count());
+
+    make_test!(splitn_space_char, s, s.splitn(10, ' ').count());
+    make_test!(rsplitn_space_char, s, s.rsplitn(10, ' ').count());
+
+    make_test!(split_str_space_str, s, s.split_str(" ").count());
+    make_test!(split_str_ad_str, s, s.split_str("ad").count());
+}