dart2js cps: Add instruction for null checks.

dart2js cps: Add instruction for null checks.

Currently we only instantiate the instruction for the null
checks inserted for numeric operators.

The corresponding instruction also exists in the tree IR,
partly because there is no way to say "x.toString" with the
current instruction set.

BUG=
R=sra@google.com

Committed: https://github.com/dart-lang/sdk/commit/c5539316fbaca52eacb3cd2030aadd011cda032b

[asgerf, 2015-12-10 18:22:47]

Description was changed from

==========
dart2js cps: Add instruction for null checks.

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

to

==========
dart2js cps: Add instruction for null checks.

Currently we only instantiate the instruction for the null
checks inserted for numeric operators.

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

[asgerf, 2015-12-10 18:30:47]

Description was changed from

==========
dart2js cps: Add instruction for null checks.

Currently we only instantiate the instruction for the null
checks inserted for numeric operators.

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

to

==========
dart2js cps: Add instruction for null checks.

Currently we only instantiate the instruction for the null
checks inserted for numeric operators.

The corresponding instruction also exists in the tree IR,
partly because there is no way to say "x.toString" with the
current instruction set.

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

[asgerf, 2015-12-10 18:31:06]

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

[asgerf, 2015-12-10 18:32:19]

On 2015/12/10 18:31:07, asgerf wrote:

Sorry for the overlap with the bounds check CL btw.

[sra1, 2015-12-11 03:34:06]

lgtm

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
File pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart (right):

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart:1154: /// an integer.
Maybe say something about the index being valid

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
File pkg/compiler/lib/src/cps_ir/type_propagation.dart (right):

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
pkg/compiler/lib/src/cps_ir/type_propagation.dart:1098: // the guarded check is
better based on the type?
We should also consider generating something like

   if (typeof x != "number") return J.$lt(x, arg)

when x is broader than [null|num] but only num has $lt.

[asgerf, 2015-12-11 10:15:40]

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
File pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart (right):

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart:1154: /// an integer.
On 2015/12/11 03:34:06, sra1 wrote:
> Maybe say something about the index being valid

Done.

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
File pkg/compiler/lib/src/cps_ir/type_propagation.dart (right):

https://codereview.chromium.org/1507313006/diff/20001/pkg/compiler/lib/src/cp...
pkg/compiler/lib/src/cps_ir/type_propagation.dart:1098: // the guarded check is
better based on the type?
On 2015/12/11 03:34:06, sra1 wrote:
> We should also consider generating something like
> 
>    if (typeof x != "number") return J.$lt(x, arg)
> 
> when x is broader than [null|num] but only num has $lt.

I see.  NullCheck would certainly not be an appropriate instruction for that. 
Maybe what we need is a variant of TypeCast that throws a NoSuchMethodError.

[asgerf, 2015-12-11 13:18:03]

Description was changed from

==========
dart2js cps: Add instruction for null checks.

Currently we only instantiate the instruction for the null
checks inserted for numeric operators.

The corresponding instruction also exists in the tree IR,
partly because there is no way to say "x.toString" with the
current instruction set.

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

to

==========
dart2js cps: Add instruction for null checks.

Currently we only instantiate the instruction for the null
checks inserted for numeric operators.

The corresponding instruction also exists in the tree IR,
partly because there is no way to say "x.toString" with the
current instruction set.

BUG=
R=sra@google.com

Committed:
https://github.com/dart-lang/sdk/commit/c5539316fbaca52eacb3cd2030aadd011cda032b
==========

[asgerf, 2015-12-11 13:18:04]

Committed patchset #6 (id:100001) manually as
c5539316fbaca52eacb3cd2030aadd011cda032b (presubmit successful).