js_runtime tweaks for better code

js_runtime tweaks for better code

1. Help type inference infer constant maps have a .length that is a non-null subtype of int. On some programs this means dynamic.length can be inferred as non-null int.

2. Make arity dispatch interceptor free by comparing constants-first (via a switch statement).

R=sigmund@google.com

Committed: https://github.com/dart-lang/sdk/commit/d2c403704c5cd13779a00eee22894158a50fdc59

[sra1, 2015-12-19 02:29:40]

Description was changed from

==========
js_runtime tweaks for better code

1. Help type inference infer constant maps have an int length.
2. Make arity dispatch interceptor free by.
==========

to

==========
js_runtime tweaks for better code

1. Help type inference infer constant maps have a .length that is a non-null
subtype of int. On some programs this means dynamic.length can be inferred as
non-null int.

2. Make arity dispatch interceptor free by comparing constants-first (via a
switch statement).
==========

[sra1, 2015-12-19 02:29:40]

sra@google.com changed reviewers:
+ sigmund@google.com

[sra1, 2015-12-19 02:30:42]

Shaves about 1k off swarm unminified.

[sra1, 2015-12-19 02:52:50]

Patchset #1 (id:1) has been deleted

[Siggi Cherem (dart-lang), 2015-12-21 18:30:39]

lgtm

[sra1, 2015-12-21 21:30:35]

Description was changed from

==========
js_runtime tweaks for better code

1. Help type inference infer constant maps have a .length that is a non-null
subtype of int. On some programs this means dynamic.length can be inferred as
non-null int.

2. Make arity dispatch interceptor free by comparing constants-first (via a
switch statement).
==========

to

==========
js_runtime tweaks for better code

1. Help type inference infer constant maps have a .length that is a non-null
subtype of int. On some programs this means dynamic.length can be inferred as
non-null int.

2. Make arity dispatch interceptor free by comparing constants-first (via a
switch statement).

R=sigmund@google.com

Committed:
https://github.com/dart-lang/sdk/commit/d2c403704c5cd13779a00eee22894158a50fdc59
==========

[sra1, 2015-12-21 21:30:38]

Committed patchset #1 (id:20001) manually as
d2c403704c5cd13779a00eee22894158a50fdc59 (presubmit successful).