[llvm-commits] [llvm] r52928 - /llvm/trunk/include/llvm/ADT/SmallVector.h

[Dan Gohman]

Author: djg
Date: Mon Jun 30 16:45:13 2008
New Revision: 52928

URL: http://llvm.org/viewvc/llvm-project?rev=52928&view=rev
Log:
Make SmallVector's grow use memcpy in common cases
instead of std::uninitialized_copy, which uses memmove.

Modified:
    llvm/trunk/include/llvm/ADT/SmallVector.h

Modified: llvm/trunk/include/llvm/ADT/SmallVector.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/SmallVector.h?rev=52928&r1=52927&r2=52928&view=diff

==============================================================================
--- llvm/trunk/include/llvm/ADT/SmallVector.h (original)
+++ llvm/trunk/include/llvm/ADT/SmallVector.h Mon Jun 30 16:45:13 2008
@@ -15,6 +15,7 @@
 #define LLVM_ADT_SMALLVECTOR_H
 
 #include "llvm/ADT/iterator.h"
+#include "llvm/Support/type_traits.h"
 #include <algorithm>
 #include <memory>
 
@@ -349,7 +350,11 @@
   T *NewElts = static_cast<T*>(operator new(NewCapacity*sizeof(T)));
   
   // Copy the elements over.
-  std::uninitialized_copy(Begin, End, NewElts);
+  if (is_class<T>::value)
+    std::uninitialized_copy(Begin, End, NewElts);
+  else
+    // Use memcpy for PODs (std::uninitialized_copy optimizes to memmove).
+    memcpy(NewElts, Begin, CurSize * sizeof(T));
   
   // Destroy the original elements.
   destroy_range(Begin, End);