ARM: Support %_SwapElements in the full compiler

ARM: Support %_SwapElements in the full compiler

Committed: http://code.google.com/p/v8/source/detail?r=7033

[Karl Klose, 2011-03-02 15:04:39]

LGTM

http://codereview.chromium.org/6597106/diff/3001/src/arm/full-codegen-arm.cc
File src/arm/full-codegen-arm.cc (right):

http://codereview.chromium.org/6597106/diff/3001/src/arm/full-codegen-arm.cc#...
src/arm/full-codegen-arm.cc:3137: // Check the object's elements are in fast
case and writable.
What does writable mean here?

[Søren Thygesen Gjesse, 2011-03-03 07:34:31]

http://codereview.chromium.org/6597106/diff/3001/src/arm/full-codegen-arm.cc
File src/arm/full-codegen-arm.cc (right):

http://codereview.chromium.org/6597106/diff/3001/src/arm/full-codegen-arm.cc#...
src/arm/full-codegen-arm.cc:3137: // Check the object's elements are in fast
case and writable.
On 2011/03/02 15:04:39, Karl Klose wrote:
> What does writable mean here?

It means that it is not copy-on-write (copy-on-write JSArrays has a different
map).

[Søren Thygesen Gjesse, 2011-03-03 07:35:38]

On 2011/03/03 07:34:31, Søren Gjesse wrote:
> http://codereview.chromium.org/6597106/diff/3001/src/arm/full-codegen-arm.cc
> File src/arm/full-codegen-arm.cc (right):
> 
>
http://codereview.chromium.org/6597106/diff/3001/src/arm/full-codegen-arm.cc#...
> src/arm/full-codegen-arm.cc:3137: // Check the object's elements are in fast
> case and writable.
> On 2011/03/02 15:04:39, Karl Klose wrote:
> > What does writable mean here?
> 
> It means that it is not copy-on-write (copy-on-write JSArrays has a different
> map).

It is the fixed array holding the data for a JSArray that has a different map in
the cow case - not the JSArray itself.