dart2js cps: Retain refinement nodes and update refinements after GVN.

dart2js cps: Retain refinement nodes and update refinements after GVN.

Refinement nodes are retained throughout the optimization pipeline.

GVN can improve refinements, so a new pass after GVN updated references
to use the best refinement in scope.  For example:

    x.f.g();
    x.f.h();

  ==>

    v0 = x.f;
    v0.g();
    v0.h();

The receiver of h() is known to be non-null after GVN because the two
uses of x.f were proven to be the same value.

BUG=
R=sra@google.com

Committed: https://github.com/dart-lang/sdk/commit/22bf979646f14d306544c97cc1187a553dedfff8

[asgerf, 2015-12-10 18:33:27]

Patchset #2 (id:20001) has been deleted

[asgerf, 2015-12-10 18:35:30]

asgerf@google.com changed reviewers:
+ kmillikin@google.com, sra@google.com

[sra1, 2015-12-11 02:44:15]

lgtm

https://codereview.chromium.org/1519513002/diff/40001/pkg/compiler/lib/src/tr...
File pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart (right):

https://codereview.chromium.org/1519513002/diff/40001/pkg/compiler/lib/src/tr...
pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart:457: objectIsNotNull:
!node.object.definition.type.isNullable);
Explain why the refined type is not appropriate

[asgerf, 2015-12-11 10:18:19]

https://codereview.chromium.org/1519513002/diff/40001/pkg/compiler/lib/src/tr...
File pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart (right):

https://codereview.chromium.org/1519513002/diff/40001/pkg/compiler/lib/src/tr...
pkg/compiler/lib/src/tree_ir/tree_ir_builder.dart:457: objectIsNotNull:
!node.object.definition.type.isNullable);
On 2015/12/11 02:44:15, sra1 wrote:
> Explain why the refined type is not appropriate

It is the refined type.

[asgerf, 2015-12-14 14:01:36]

Description was changed from

==========
dart2js cps: Retain refinement nodes and update refinements after GVN.

Refinement nodes are retained throughout the optimization pipeline.

GVN can improve refinements, so a new pass after GVN updated references
to use the best refinement in scope.  For example:

    x.f.g();
    x.f.h();

  ==>

    v0 = x.f;
    v0.g();
    v0.h();

The receiver of h() is known to be non-null after GVN because the two
uses of x.f were proven to be the same value.

BUG=
==========

to

==========
dart2js cps: Retain refinement nodes and update refinements after GVN.

Refinement nodes are retained throughout the optimization pipeline.

GVN can improve refinements, so a new pass after GVN updated references
to use the best refinement in scope.  For example:

    x.f.g();
    x.f.h();

  ==>

    v0 = x.f;
    v0.g();
    v0.h();

The receiver of h() is known to be non-null after GVN because the two
uses of x.f were proven to be the same value.

BUG=
R=sra@google.com

Committed:
https://github.com/dart-lang/sdk/commit/22bf979646f14d306544c97cc1187a553dedfff8
==========

[asgerf, 2015-12-14 14:01:38]

Committed patchset #4 (id:80001) manually as
22bf979646f14d306544c97cc1187a553dedfff8 (presubmit successful).