---

yaml
---
r: 222094
b: refs/heads/tmp
c: f910d27
h: refs/heads/master
v: v3

Author: bluss

[refs]

@@ -25,7 +25,7 @@ refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
 refs/heads/beta: 2b45108ecb944d63daba0f1b5529ac4c8afdc295
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
-refs/heads/tmp: 381d2ed70d3f3c2913e19a950dee0da0149dae1d
+refs/heads/tmp: f910d27f87419e17cc59034265f6795db5247dfa
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f
 refs/tags/homu-tmp: e58601ab085591c71a27ae82137fc313222c2270
 refs/tags/1.0.0-beta: 8cbb92b53468ee2b0c2d3eeb8567005953d40828

branches/tmp/src/libcore/hash/sip.rs

@@ -10,6 +10,7 @@
 
 //! An implementation of SipHash 2-4.
 
+use ptr;
 use prelude::*;
 use super::Hasher;
 
@@ -65,6 +66,20 @@ macro_rules! u8to64_le {
     });
 }
 
+/// Load a full u64 word from a byte stream, in LE order. Use
+/// `copy_nonoverlapping` to let the compiler generate the most efficient way
+/// to load u64 from a possibly unaligned address.
+///
+/// Unsafe because: unchecked indexing at i..i+8
+#[inline]
+unsafe fn load_u64_le(buf: &[u8], i: usize) -> u64 {
+    debug_assert!(i + 8 <= buf.len());
+    let mut data = 0u64;
+    ptr::copy_nonoverlapping(buf.get_unchecked(i),
+                             &mut data as *mut _ as *mut u8, 8);
+    data.to_le()
+}
+
 macro_rules! rotl {
     ($x:expr, $b:expr) =>
     (($x << $b) | ($x >> (64_i32.wrapping_sub($b))))
@@ -151,7 +166,7 @@ impl SipHasher {
 
         let mut i = needed;
         while i < end {
-            let mi = u8to64_le!(msg, i);
+            let mi = unsafe { load_u64_le(msg, i) };
 
             self.v3 ^= mi;
             compress!(self.v0, self.v1, self.v2, self.v3);