Improve load forwarding:

Improve load forwarding:
- stores/loads that access different fields can't alias each other;
- if result of the AllocateObject does not escape then stores/loads to it does not alias stores/loads to other objects.

Other:
- rename LoadFieldInstr's value to instance to better convey meaning and match StoreInstanceFieldInstr;
- slightly bump inlining_size_threshold;
- canonicalize UnboxDouble(BoxDouble(v)) and BoxDouble(UnboxDouble(v)) patterns;

R=srdjan@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=22340

[srdjan, 2013-05-02 21:00:54]

LGTM

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_builder.cc
File runtime/vm/flow_graph_builder.cc (right):

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_builder...
runtime/vm/flow_graph_builder.cc:2637:
load->set_field(&Field::ZoneHandle(node->field().raw()));
That works, but I wonder why you do not reuse the handle of node->field()?

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
File runtime/vm/flow_graph_optimizer.cc (right):

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
runtime/vm/flow_graph_optimizer.cc:3490: (instr->IsStoreInstanceField() &&
use->use_index() != 0) ||
Some more parentheses, please.

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
File runtime/vm/flow_graph_optimizer.h (right):

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
runtime/vm/flow_graph_optimizer.h:38: bool Canonicalize();
Please add comment when is true/false returned.

[Vyacheslav Egorov (Google), 2013-05-02 21:20:25]

Thanks for the review. 

Comments addressed. 

Landing.

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_builder.cc
File runtime/vm/flow_graph_builder.cc (right):

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_builder...
runtime/vm/flow_graph_builder.cc:2637:
load->set_field(&Field::ZoneHandle(node->field().raw()));
On 2013/05/02 21:00:54, srdjan wrote:
> That works, but I wonder why you do not reuse the handle of node->field()?

Cleaned this up. set_field was requiring non-const Field

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
File runtime/vm/flow_graph_optimizer.cc (right):

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
runtime/vm/flow_graph_optimizer.cc:3490: (instr->IsStoreInstanceField() &&
use->use_index() != 0) ||
On 2013/05/02 21:00:54, srdjan wrote:
> Some more parentheses, please.

Done.

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
File runtime/vm/flow_graph_optimizer.h (right):

https://codereview.chromium.org/14872002/diff/1/runtime/vm/flow_graph_optimiz...
runtime/vm/flow_graph_optimizer.h:38: bool Canonicalize();
On 2013/05/02 21:00:54, srdjan wrote:
> Please add comment when is true/false returned.

Done.

[Vyacheslav Egorov (Google), 2013-05-02 21:21:03]

Committed patchset #2 manually as r22340 (presubmit successful).