Separate HTypeConversion checked type from output type.

Separate HTypeConversion checked type from output type.

This mostly improves checked mode code.
By separating the types, we can propagate a more precise type.  Example:

   var a = ... ? 1 : 'hello';   // {int,String}
   ...
   int i = a;      // {Null,int) * {int,String} = {int}
   int j = i + 1;  // no receiver type check

R=ngeoffray@google.com

Committed: https://code.google.com/p/dart/source/detail?r=29176

[sra1, 2013-10-22 22:56:16]

This helps checked mode code size and performance.
Checked DeltaBliue is +50%, but still far behind unchecked.

https://codereview.chromium.org/36073002/diff/60001/sdk/lib/_internal/compile...
File sdk/lib/_internal/compiler/implementation/ssa/types_propagation.dart
(right):

https://codereview.chromium.org/36073002/diff/60001/sdk/lib/_internal/compile...
sdk/lib/_internal/compiler/implementation/ssa/types_propagation.dart:157: // We
only do an int check if the input is integer or null.
It would be nice to make checkedType final.

What I don't understand here is what does 'not enough' mean.
Why is the HTypeConversion originally created with the 'wrong' type?

[ngeoffray, 2013-10-24 06:50:55]

LGTM

https://codereview.chromium.org/36073002/diff/60001/sdk/lib/_internal/compile...
File sdk/lib/_internal/compiler/implementation/ssa/codegen.dart (right):

https://codereview.chromium.org/36073002/diff/60001/sdk/lib/_internal/compile...
sdk/lib/_internal/compiler/implementation/ssa/codegen.dart:2482: &&
(checkedType.isInteger() || checkedType.isIndexablePrimitive(compiler));
Line too long.

https://codereview.chromium.org/36073002/diff/60001/sdk/lib/_internal/compile...
File sdk/lib/_internal/compiler/implementation/ssa/types_propagation.dart
(right):

https://codereview.chromium.org/36073002/diff/60001/sdk/lib/_internal/compile...
sdk/lib/_internal/compiler/implementation/ssa/types_propagation.dart:157: // We
only do an int check if the input is integer or null.
On 2013/10/22 22:56:16, sra1 wrote:
> It would be nice to make checkedType final.
> 
> What I don't understand here is what does 'not enough' mean.
> Why is the HTypeConversion originally created with the 'wrong' type?

Not enough because the check we emit is (a | 0) === a, which does not cover all
our ints. Note that a checked mode HTypeConversion uses a helper that does the
right int check.

It is created with the 'wrong' type because at the creation point, we
unconditionally do it. This code here makes the conversion correct in case the
input is not int or null.

[sra1, 2013-10-24 15:59:37]

Committed patchset #3 manually as r29176 (presubmit successful).

[sra1, 2013-10-25 03:48:53]

https://chromiumcodereview.appspot.com/36073002/diff/60001/sdk/lib/_internal/...
File sdk/lib/_internal/compiler/implementation/ssa/codegen.dart (right):

https://chromiumcodereview.appspot.com/36073002/diff/60001/sdk/lib/_internal/...
sdk/lib/_internal/compiler/implementation/ssa/codegen.dart:2482: &&
(checkedType.isInteger() || checkedType.isIndexablePrimitive(compiler));
On 2013/10/24 06:50:55, ngeoffray wrote:
> Line too long.

Done.