Add a value range analysis phase to remove bounds checks.

lib/compiler/implementation/js_backend/constant_system_javascript.dart

Index: lib/compiler/implementation/js_backend/constant_system_javascript.dart
===================================================================
--- lib/compiler/implementation/js_backend/constant_system_javascript.dart	(revision 12781)
+++ lib/compiler/implementation/js_backend/constant_system_javascript.dart	(working copy)
@@ -42,6 +42,8 @@
     }
     return result;
   }
+
+  apply(left, right) => dartBitOperation.apply(left, right);

[Søren Gjesse, 2012/09/26 09:08:24]

Why do you not need to implement JavaScript semantics here?

[ngeoffray, 2012/09/26 09:33:26]

Because apply is semantic agnostic. It just calls the dart operator on left and
right.

 }
 
 class JavaScriptShiftRightOperation extends JavaScriptBinaryBitOperation {
@@ -87,6 +89,7 @@
     }
     return dartNegateOperation.fold(constant);
   }
+  apply(value) => -value;
 }
 
 class JavaScriptBinaryArithmeticOperation implements BinaryOperation {
@@ -102,6 +105,8 @@
     if (result == null) return result;
     return JAVA_SCRIPT_CONSTANT_SYSTEM.convertToJavaScriptConstant(result);
   }
+
+  apply(left, right) => dartArithmeticOperation.apply(left, right);
 }
 
 class JavaScriptIdentityOperation implements BinaryOperation {