code. By the time we optimize the code, we'll be able to decide on new or old
space based on the number of surviving objects after one or more gcs.

The mechanism is a "memento" placed behind objects in the heap. It's currently
done for array and object literals, with plans to use mementos for constructed
objects as well (in a later CL).

The feature is behind the flag allocation_site_pretenuring, currently off.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/40063002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18104 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

A performance regression in array literal creation was caused by refactoring that eliminated a special fast case for shallow arrays. At the same time the general case got a bit slower. This CL restores most of the performance without coding the special fast case. The virtual dispatching is unnecessary because we know what we want to do at compile time. A flag was added to Runtime::CreateArrayLiteral. The flags delivers information about shallowness but also whether or not allocation mementos should be created. This is useful for crankshafted code.

BUG=v8:3008
LOG=Y
R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/77293003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18046 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/24250005


Review URL: https://codereview.chromium.org/27366003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17228 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This reverts commit r17219 due to WebKit failures.

R=mstarzinger@chromium.org
TBR=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/26539010

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17222 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/24250005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17219 ce2b1a6d-e550-0410-aec6-3dcde31c8c00