Separate branch on strict compare into a new IL instruction.

Separate branch on strict compare into a new IL instruction.

This avoid unnecessary environment uses since the strict compare
can not deoptimize.

This is a first step in refactoring branch instructions so that we
can easily do explicit checks for specialized comparisons (smi, double).
Committed: https://code.google.com/p/dart/source/detail?r=11373

[Kevin Millikin (Google), 2012-08-24 12:37:26]

LGTM.

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
File runtime/vm/intermediate_language.h (right):

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language.h:1993: M(Return)                              
                                     \
Return, Throw, ReThrow, and Goto should also become control instructions.

That's not completely trivial, so let's do it separately.

[srdjan, 2012-08-24 18:55:39]

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
File runtime/vm/intermediate_language.h (right):

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language.h:3118: Token::Kind kind_;
const

[srdjan, 2012-08-24 21:35:05]

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
File runtime/vm/intermediate_language.h (right):

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language.h:3091: class StrictCompareAndBranchInstr :
public TemplateControlInstruction<2> {
You could use this to replace BranchInstr in
FlowGraphOptimizer::VisitBranch(BranchInstr* instr) .

[Florian Schneider, 2012-08-27 08:55:30]

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
File runtime/vm/intermediate_language.h (right):

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language.h:3091: class StrictCompareAndBranchInstr :
public TemplateControlInstruction<2> {
On 2012/08/24 21:35:05, srdjan wrote:
> You could use this to replace BranchInstr in
> FlowGraphOptimizer::VisitBranch(BranchInstr* instr) .

Currently it is not very convenient to replace branch instructions because of
updating the control flow graph. I'm doing it in the builder instead, since this
is an optimization that does not rely on type feedback and can therefore also be
done in the non-optimizing case.

https://chromiumcodereview.appspot.com/10867050/diff/1/runtime/vm/intermediat...
runtime/vm/intermediate_language.h:3118: Token::Kind kind_;
On 2012/08/24 18:55:39, srdjan wrote:
> const 

Done.