---

yaml
---
r: 150835
b: refs/heads/try2
c: be334d5
h: refs/heads/master
i:
  150833: 7a34707
  150831: ae394fc
v: v3

Author: Aatch

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 42b39924d87739f2dcda3e788c6e8655d310954f
+refs/heads/try2: be334d582435a05ea56c1ca7fcb2e512cfc51f24
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/libstd/slice.rs

@@ -762,18 +762,23 @@ impl<'a, T: Clone> CloneableVector<T> for &'a [T] {
     fn to_owned(&self) -> ~[T] {
         let len = self.len();
         let mut result = with_capacity(len);
+        // Unsafe code so this can be optimised to a memcpy (or something
+        // similarly fast) when T is Copy. LLVM is easily confused, so any
+        // extra operations during the loop can prevent this optimisation
         unsafe {
-            // Unsafe code so this can be optimised to a memcpy (or something
-            // similarly fast) when T is Copy. LLVM is easily confused, so any
-            // extra operations during the loop can prevent this optimisation
-            result.set_len(len);
             let mut i = 0;
-            while i < len {
-                mem::move_val_init(
-                    result.unsafe_mut_ref(i),
-                    self.unsafe_ref(i).clone());
-                i = i + 1;
-            }
+            let p = result.as_mut_ptr();
+            // Use try_finally here otherwise the write to length
+            // inside the loop stops LLVM from optimising this.
+            try_finally(
+                &mut i, (),
+                |i, ()| while *i < len {
+                    mem::move_val_init(
+                        &mut(*p.offset(*i as int)),
+                        self.unsafe_ref(*i).clone());
+                    *i += 1;
+                },
+                |i| result.set_len(*i));
         }
         result
     }

branches/try2/src/libstd/vec.rs

@@ -313,21 +313,18 @@ impl<T:Clone> Clone for Vec<T> {
     fn clone(&self) -> Vec<T> {
         let len = self.len;
         let mut vector = Vec::with_capacity(len);
-        vector.len = len;
         // Unsafe code so this can be optimised to a memcpy (or something
         // similarly fast) when T is Copy. LLVM is easily confused, so any
         // extra operations during the loop can prevent this optimisation
         {
-            let slice = vector.as_mut_slice();
             let this_slice = self.as_slice();
-            let mut i = 0;
-            while i < len {
+            while vector.len < len {
                 unsafe {
                     mem::move_val_init(
-                        slice.unsafe_mut_ref(i),
-                        this_slice.unsafe_ref(i).clone());
+                        vector.as_mut_slice().unsafe_mut_ref(vector.len),
+                        this_slice.unsafe_ref(vector.len).clone());
                 }
-                i = i + 1;
+                vector.len += 1;
             }
         }
         vector