First version of typr propagation in the new IR.

First version of type propagation in the new IR.

This CL introduces typed constants and values to the IR.  As a demonstration, the types are used to eagerly statically evaluate identical(a, b) to false, if a and b have different types.

R=kmillikin@google.com

Committed: https://code.google.com/p/dart/source/detail?r=42315

[karlklose, 2014-12-12 09:59:43]

karlklose@google.com changed reviewers:
+ kmillikin@google.com

[Kevin Millikin (Google), 2014-12-12 11:00:23]

LGTM with || replaced by && as noted below.

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
File pkg/compiler/lib/src/cps_ir/constant_propagation.dart (right):

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:60: a.isInMask(b,
classWorld) ||
Typo: || should be &&.

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:116: // and the constant
status of each expression.
'constant status' ==> 'abstract value'?

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:868: return new
_AbstractValue.nonConst(typeSystem.join(this.type, that.type));
If we drop the optimization to avoid joining dynamic and dynamic, we can use
this second code for the both dynamic case as well.

I think that would be better: easier to see that it's computing the same join
for constants, and easier to see what the difference is if we add the
optimization back in.

[karlklose, 2014-12-12 11:43:48]

Thank you, Kevin.

Comments addressed in patch set 3, renamed the file in patch set 4.

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
File pkg/compiler/lib/src/cps_ir/constant_propagation.dart (right):

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:60: a.isInMask(b,
classWorld) ||
Obsolete, removed the method from the TypeSystem interface.

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:116: // and the constant
status of each expression.
On 2014/12/12 11:00:23, kmillikin wrote:
> 'constant status' ==> 'abstract value'?

Done.

https://codereview.chromium.org/800433003/diff/20001/pkg/compiler/lib/src/cps...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:868: return new
_AbstractValue.nonConst(typeSystem.join(this.type, that.type));
On 2014/12/12 11:00:23, kmillikin wrote:
> If we drop the optimization to avoid joining dynamic and dynamic, we can use
> this second code for the both dynamic case as well.
> 
> I think that would be better: easier to see that it's computing the same join
> for constants, and easier to see what the difference is if we add the
> optimization back in.

Done.

[karlklose, 2014-12-12 12:14:27]

Committed patchset #4 (id:60001) manually as 42315 (presubmit successful).