diff --git a/src/libcollections/benches/lib.rs b/src/libcollections/benches/lib.rs
index 42064e9ca57..9f356e4b579 100644
--- a/src/libcollections/benches/lib.rs
+++ b/src/libcollections/benches/lib.rs
@@ -10,7 +10,9 @@
 
 #![deny(warnings)]
 
+#![feature(i128_type)]
 #![feature(rand)]
+#![feature(repr_simd)]
 #![feature(sort_unstable)]
 #![feature(test)]
 
diff --git a/src/libcollections/benches/slice.rs b/src/libcollections/benches/slice.rs
index db523681bc7..0079f2d0103 100644
--- a/src/libcollections/benches/slice.rs
+++ b/src/libcollections/benches/slice.rs
@@ -292,14 +292,14 @@ sort!(sort_unstable, sort_unstable_large_strings, gen_strings, 10000);
 sort_expensive!(sort_unstable_by, sort_unstable_large_random_expensive, gen_random, 10000);
 
 macro_rules! reverse {
-    ($name:ident, $ty:ident) => {
+    ($name:ident, $ty:ty, $f:expr) => {
         #[bench]
         fn $name(b: &mut Bencher) {
             // odd length and offset by 1 to be as unaligned as possible
             let n = 0xFFFFF;
             let mut v: Vec<_> =
                 (0..1+(n / mem::size_of::<$ty>() as u64))
-                .map(|x| x as $ty)
+                .map($f)
                 .collect();
             b.iter(|| black_box(&mut v[1..]).reverse());
             b.bytes = n;
@@ -307,7 +307,11 @@ macro_rules! reverse {
     }
 }
 
-reverse!(reverse_u8, u8);
-reverse!(reverse_u16, u16);
-reverse!(reverse_u32, u32);
-reverse!(reverse_u64, u64);
+reverse!(reverse_u8, u8, |x| x as u8);
+reverse!(reverse_u16, u16, |x| x as u16);
+reverse!(reverse_u8x3, [u8;3], |x| [x as u8, (x>>8) as u8, (x>>16) as u8]);
+reverse!(reverse_u32, u32, |x| x as u32);
+reverse!(reverse_u64, u64, |x| x as u64);
+reverse!(reverse_u128, u128, |x| x as u128);
+#[repr(simd)] struct F64x4(f64, f64, f64, f64);
+reverse!(reverse_simd_f64x4, F64x4, |x| { let x = x as f64; F64x4(x,x,x,x) });