Revision: 9965
Author: [email protected]
Date: Fri Nov 11 03:23:39 2011
Log: 8-byte align zone allocations of objects that may require it.
Review URL: http://codereview.chromium.org/8539008
http://code.google.com/p/v8/source/detail?r=9965
Modified:
/branches/bleeding_edge/src/zone-inl.h
/branches/bleeding_edge/src/zone.h
=======================================
--- /branches/bleeding_edge/src/zone-inl.h Fri Sep 9 05:41:58 2011
+++ /branches/bleeding_edge/src/zone-inl.h Fri Nov 11 03:23:39 2011
@@ -52,6 +52,14 @@
ASSERT(ZoneScope::nesting() > 0);
// 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_;
=======================================
--- /branches/bleeding_edge/src/zone.h Mon Aug 29 02:14:59 2011
+++ /branches/bleeding_edge/src/zone.h Fri Nov 11 03:23:39 2011
@@ -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.
--
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