Add CPS IR transformation to make the JavaScript backend specific semantics explicit in the tree.

Add CPS IR transformation to make the JavaScript backend specific semantics explicit in the tree.

Also implement transformation to insert boolean conversion.

R=kmillikin@google.com

Committed: https://code.google.com/p/dart/source/detail?r=41979

[Kevin Millikin (Google), 2014-11-25 14:27:23]

It looks like it's all there.  The constant propagator should be changed as
mentioned below.

LGTM with the change.

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
File pkg/compiler/lib/src/cps_ir/constant_propagation.dart (right):

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:610:
setReachable(node.left.definition);
I need to understand the code in this file a bit better.  But I think the safe
thing here is to have:

void visitIdentical(Identical node) {
  setValue(node, _ConstnessLattice.NonConst);
}

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
File pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart (right):

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart:457: Identical(Primitive a,
Primitive b)
I do prefer a ==> left and b ==> right in parameters.

[karlklose, 2014-11-25 14:38:46]

PTAL, I think we have to mark the definitions of the references as reachable.

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
File pkg/compiler/lib/src/cps_ir/constant_propagation.dart (right):

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
pkg/compiler/lib/src/cps_ir/constant_propagation.dart:610:
setReachable(node.left.definition);
I am not sure if it is okay to not set the parameters as reachable.

I added the call to mark the node itself as non-constant.

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
File pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart (right):

https://codereview.chromium.org/735253003/diff/1/pkg/compiler/lib/src/cps_ir/...
pkg/compiler/lib/src/cps_ir/cps_ir_nodes.dart:457: Identical(Primitive a,
Primitive b)
On 2014/11/25 14:27:23, kmillikin wrote:
> I do prefer a ==> left and b ==> right in parameters.

Done.

[karlklose, 2014-11-26 07:26:58]

Committed patchset #3 (id:40001) manually as 41979 (presubmit successful).