Don't store redundant compile-type at values.

Don't store redundant compile-type at values.

If the computed reaching type is the same as the definition's type,
there is no need to store it.

Don't cache the type of the definition at the uses if the reaching
type is NULL.

R=vegorov@google.com

Committed: https://code.google.com/p/dart/source/detail?r=41843

[Florian Schneider, 2014-11-19 13:57:26]

fschneider@google.com changed reviewers:
+ vegorov@google.com

[Vyacheslav Egorov (Google), 2014-11-19 14:05:20]

lgtm

https://codereview.chromium.org/740703002/diff/1/runtime/vm/flow_graph_type_p...
File runtime/vm/flow_graph_type_propagator.cc (right):

https://codereview.chromium.org/740703002/diff/1/runtime/vm/flow_graph_type_p...
runtime/vm/flow_graph_type_propagator.cc:245: value->SetReachingType(type);
I suggest:

if (type == value->definition()->Type()) {
  return;
}

then we will not print redundant tracing down there.

I wonder if we should also do to reflect that we don't have any interesting
information at this point?

if (type == value->definition()->Type()) {
  value->SetReachingType(NULL);
  return;
}

[Florian Schneider, 2014-11-19 16:40:53]

I had to add type propagation after allocation sinking to compute types for phis
created there.

https://codereview.chromium.org/740703002/diff/1/runtime/vm/flow_graph_type_p...
File runtime/vm/flow_graph_type_propagator.cc (right):

https://codereview.chromium.org/740703002/diff/1/runtime/vm/flow_graph_type_p...
runtime/vm/flow_graph_type_propagator.cc:245: value->SetReachingType(type);
On 2014/11/19 14:05:20, Vyacheslav Egorov (Google) wrote:
> I suggest:
> 
> if (type == value->definition()->Type()) {
>   return;
> }
> 
> then we will not print redundant tracing down there.
> 
> I wonder if we should also do to reflect that we don't have any interesting
> information at this point?
> 
> if (type == value->definition()->Type()) {
>   value->SetReachingType(NULL);
>   return;
> }

Done.

[Florian Schneider, 2014-11-20 11:16:33]

Committed patchset #2 (id:20001) manually as r41843 (presubmit successful).