Reviewers: danno,
Description:
8-byte align zone allocations of objects that may require it.
Please review this at http://codereview.chromium.org/8539008/
SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/
Affected files:
M src/zone-inl.h
M src/zone.h
Index: src/zone-inl.h
===================================================================
--- src/zone-inl.h (revision 9962)
+++ src/zone-inl.h (working copy)
@@ -53,6 +53,14 @@
// Round up the requested size to fit the alignment.
size = RoundUp(size, kAlignment);
+ // If the allocation size is divisible by 8 then we return an 8-byte
aligned
+ // address.
+ if (kPointerSize == 4 && kAlignment == 4) {
+ position_ += ((~size) & 4) & (reinterpret_cast<intptr_t>(position_) &
4);
+ } else {
+ ASSERT(kAlignment >= kPointerSize);
+ }
+
// Check if the requested size is available without expanding.
Address result = position_;
Index: src/zone.h
===================================================================
--- src/zone.h (revision 9962)
+++ src/zone.h (working copy)
@@ -86,7 +86,9 @@
friend class Isolate;
friend class ZoneScope;
- // All pointers returned from New() have this alignment.
+ // All pointers returned from New() have this alignment. In addition,
if the
+ // object being allocated has a size that is divisible by 8 then its
alignment
+ // will be 8.
static const int kAlignment = kPointerSize;
// Never allocate segments smaller than this size in bytes.
--
v8-dev mailing list
[email protected]
http://groups.google.com/group/v8-dev
