Fix unaligned access to TypedData from native code.

Fix unaligned access to TypedData from native code.

Split unaligned access test and mark the float half as failing on Android.

R=zra@google.com

Committed: https://github.com/dart-lang/sdk/commit/d5580f3b00f1631b6e735e9b757be09a9eb72896

[rmacnak, 2016-11-01 21:14:21]

Description was changed from

==========
Fix unaligned access to TypeData from native code.

Split unaligned access test and mark the float half as failing on Android.
==========

to

==========
Fix unaligned access to TypedData from native code.

Split unaligned access test and mark the float half as failing on Android.
==========

[rmacnak, 2016-11-01 21:41:38]

rmacnak@google.com changed reviewers:
+ johnmccutchan@google.com, zra@google.com

[zra, 2016-11-01 21:46:01]

https://codereview.chromium.org/2473553002/diff/1/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/2473553002/diff/1/runtime/vm/object.h#newcode...
runtime/vm/object.h:7937: memmove(&result, DataAddr(byte_offset), sizeof(type));
                    \
Should we specialize this by architecture?

[Cutch, 2016-11-01 21:48:22]

https://codereview.chromium.org/2473553002/diff/1/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/2473553002/diff/1/runtime/vm/object.h#newcode...
runtime/vm/object.h:7937: memmove(&result, DataAddr(byte_offset), sizeof(type));
                    \
On 2016/11/01 21:46:01, zra wrote:
> Should we specialize this by architecture?

+1 We should avoid calling memmove on architectures that don't need it.

[rmacnak, 2016-11-01 22:39:15]

Ifdef'd about Intel.

[Cutch, 2016-11-01 22:45:09]

https://codereview.chromium.org/2473553002/diff/20001/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/2473553002/diff/20001/runtime/vm/object.h#new...
runtime/vm/object.h:7938: memmove(&result, DataAddr(byte_offset), sizeof(type));
                    \
You are still calling memmove on IA32/X64.

[rmacnak, 2016-11-01 23:25:15]

https://codereview.chromium.org/2473553002/diff/20001/runtime/vm/object.h
File runtime/vm/object.h (right):

https://codereview.chromium.org/2473553002/diff/20001/runtime/vm/object.h#new...
runtime/vm/object.h:7938: memmove(&result, DataAddr(byte_offset), sizeof(type));
                    \
On 2016/11/01 22:45:09, Cutch wrote:
> You are still calling memmove on IA32/X64.

Oops, fixed.

[zra, 2016-11-02 22:26:28]

lgtm

It looks like the arm benchmark bot is going again (albeit slowly). We need to
fix this bug, but could you do a run there and see if we need to worry about
performance?

[rmacnak, 2016-11-02 22:52:56]

On 2016/11/02 22:26:28, zra wrote:
> lgtm
> 
> It looks like the arm benchmark bot is going again (albeit slowly). We need to
> fix this bug, but could you do a run there and see if we need to worry about
> performance?

From my ARM64 board:

rmacnak@dragon:~$ ./dart_before
benchmarks/ParticleSystem/dart/ParticleSystem.dart 
ParticleSystemUpdate(RunTime): 84541.66666666667 us.
ParticleSystemPaint(RunTime): 83080.0 us.
rmacnak@dragon:~$ ./dart_after
benchmarks/ParticleSystem/dart/ParticleSystem.dart 
ParticleSystemUpdate(RunTime): 83625.0 us.
ParticleSystemPaint(RunTime): 75259.25925925926 us.

[rmacnak, 2016-11-02 22:53:30]

Description was changed from

==========
Fix unaligned access to TypedData from native code.

Split unaligned access test and mark the float half as failing on Android.
==========

to

==========
Fix unaligned access to TypedData from native code.

Split unaligned access test and mark the float half as failing on Android.

R=zra@google.com

Committed:
https://github.com/dart-lang/sdk/commit/d5580f3b00f1631b6e735e9b757be09a9eb72896
==========

[rmacnak, 2016-11-02 22:53:31]

Committed patchset #3 (id:40001) manually as
d5580f3b00f1631b6e735e9b757be09a9eb72896 (presubmit successful).