Store offset between fixed typed array base and data start in object

Store offset between fixed typed array base and data start in object

The layout of fixed typed array base is then capable of handling
external typed arrays as well. In a follow-up CL, I'll delete external
typed arrays, and use fixed typed array base instead

BUG=v8:3996
R=jarin@chromium.org,mstarzinger@chromium.org
LOG=n

Committed: https://crrev.com/4da289c55acc4fff325d1fbd62387d431a5033d8
Cr-Commit-Position: refs/heads/master@{#29786}

[jochen (gone - plz use gerrit), 2015-07-21 13:39:52]

jochen@chromium.org changed reviewers:
+ mstarzinger@chromium.org

[jochen (gone - plz use gerrit), 2015-07-21 13:42:52]

ptal

this CL uses the fancy new HAdd and migrates on-heap typed arrays to the new
unified layout.

Instead of hard-coding the offset from the FixedTypedArrayBase to the start of
the data (in elements-kinds.cc), it's now stored as an external reference in the
object.

I had to remove a bunch of DCHECKs() that a fixed typed array element access is
done via a tagged pointer (because it's now via the result of the HAdd which is
an external pointer).

I also had to modify StoreNamedField to allow for storing a constant external
reference.

[jochen (gone - plz use gerrit), 2015-07-22 08:57:09]

fixed the arm64 crash... the LAddE instruction clamped the pointers to 32bit..

[Jarin, 2015-07-22 09:00:20]

Ouch, my eyes! lgtm.

https://codereview.chromium.org/1248483007/diff/20001/src/heap/heap.cc
File src/heap/heap.cc (right):

https://codereview.chromium.org/1248483007/diff/20001/src/heap/heap.cc#newcod...
src/heap/heap.cc:4012: kHeapObjectTag),
Can't you say ExternalReference::fixed_typed_array_base_data_offset().address()
here?

https://codereview.chromium.org/1248483007/diff/20001/src/ia32/lithium-codege...
File src/ia32/lithium-codegen-ia32.cc (right):

https://codereview.chromium.org/1248483007/diff/20001/src/ia32/lithium-codege...
src/ia32/lithium-codegen-ia32.cc:4097: Comment(";;; LOL Store");
What is LOL?

[jochen (gone - plz use gerrit), 2015-07-22 09:08:13]

https://codereview.chromium.org/1248483007/diff/20001/src/heap/heap.cc
File src/heap/heap.cc (right):

https://codereview.chromium.org/1248483007/diff/20001/src/heap/heap.cc#newcod...
src/heap/heap.cc:4012: kHeapObjectTag),
On 2015/07/22 at 09:00:20, jarin wrote:
> Can't you say
ExternalReference::fixed_typed_array_base_data_offset().address() here?

done

https://codereview.chromium.org/1248483007/diff/20001/src/ia32/lithium-codege...
File src/ia32/lithium-codegen-ia32.cc (right):

https://codereview.chromium.org/1248483007/diff/20001/src/ia32/lithium-codege...
src/ia32/lithium-codegen-ia32.cc:4097: Comment(";;; LOL Store");
On 2015/07/22 at 09:00:20, jarin wrote:
> What is LOL?

I, uhm, just wanted to check whether you actually read all the changes...
removed.

[jochen (gone - plz use gerrit), 2015-07-22 09:59:37]

The CQ bit was checked by jochen@chromium.org

[jochen (gone - plz use gerrit), 2015-07-22 09:59:37]

The patchset sent to the CQ was uploaded after l-g-t-m from jarin@chromium.org
Link to the patchset: https://codereview.chromium.org/1248483007/#ps60001
(title: "updates")

[commit-bot: I haz the power, 2015-07-22 09:59:46]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1248483007/60001

[commit-bot: I haz the power, 2015-07-22 10:25:57]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2015-07-22 10:32:33]

Patchset 4 (id:??) landed as
https://crrev.com/4da289c55acc4fff325d1fbd62387d431a5033d8
Cr-Commit-Position: refs/heads/master@{#29786}