Let DescriptorArray::Append insert at proper position, avoiding need for resorting.

Let DescriptorArray::Append insert at proper position, avoiding need for resorting.

Using insertion-sort won't have too much of an overhead for the short arrays for bootstrapping (which are probably snapshot anyway).
CopyAppendCallbackDescriptors was extending and sorting the array in a loop. By using an append that inserts at the right position we do not need to resort in each iteration.

Additionally remove Sort and rename SortUnchecked to Sort. The IsSortedNoDuplicates check is moved into InitializeDescriptor.

Committed: https://code.google.com/p/v8/source/detail?r=12136

[Toon Verwaest, 2012-07-18 14:43:16]

PTAL.

More refactoring towards tunneling all descriptor array changes over the map.

[Jakob Kummerow, 2012-07-18 15:17:55]

lgtm

https://chromiumcodereview.appspot.com/10808011/diff/1/src/factory.cc
File src/factory.cc (right):

https://chromiumcodereview.appspot.com/10808011/diff/1/src/factory.cc#newcode933
src/factory.cc:933: // Return the old descriptor array if there were no new
elements.
nit: outdated comment. Suggestion: s/Return the old/Don't replace the/

https://chromiumcodereview.appspot.com/10808011/diff/1/src/objects-inl.h
File src/objects-inl.h (right):

https://chromiumcodereview.appspot.com/10808011/diff/1/src/objects-inl.h#newc...
src/objects-inl.h:2126: Descriptor desc(key, value, details);
nit: I don't like shadowing variables. Can you pick another name for this (e.g.
"descriptor" or "moved_descriptor")?

https://chromiumcodereview.appspot.com/10808011/diff/1/src/objects-inl.h#newc...
src/objects-inl.h:3511: for (int i = 1; i <= len; ++i) {
Not sure if it's worth the effort, but we *could* make this check faster by
using an array :-)
Or you could hide it behind FLAG_enable_slow_asserts and/or add a TODO comment.

[Toon Verwaest, 2012-07-18 15:40:26]

Addressed comments.