[es6] Optimize TypedArray.subarray()

src/macros.py

Index: src/macros.py
diff --git a/src/macros.py b/src/macros.py
index 6ea6d1683b1bd0f552d416daff240c8efddf1ddd..9f6a698a844c019d7f063c2a32905aae55d250cc 100644
--- a/src/macros.py
+++ b/src/macros.py
@@ -157,6 +157,8 @@ macro TO_NAME(arg) = (%_ToName(arg));
 macro JSON_NUMBER_TO_STRING(arg) = ((%_IsSmi(%IS_VAR(arg)) || arg - arg == 0) ? %_NumberToString(arg) : "null");
 macro HAS_OWN_PROPERTY(arg, index) = (%_CallFunction(arg, index, ObjectHasOwnProperty));
 macro HAS_INDEX(array, index, is_array) = ((is_array && %_HasFastPackedElements(%IS_VAR(array))) ? (index < array.length) : (index in array));
+macro MAX_SIMPLE(argA, argB) = (argA < argB ? argB : argA);

[Michael Starzinger, 2015/10/07 18:49:07]

Please be aware that this macro will expand "MAX_SIMPLE(a + b, 0)" to "a + b < 0
? a + b : 0" which will evaluate the addition twice in the baseline compiler
(which is the only compiler where this macro makes any sense in the first
place).

If you wanted to guard against that, then the %IS_VAR marker would be the right
thing. But then you would need to adapt the use-sites accordingly. And I see
that this is now being used left and right in the builtin JavaScript files and
almost all use-sites are affected.

+macro MIN_SIMPLE(argA, argB) = (argA < argB ? argA : argB);
 
 # Private names.
 macro IS_PRIVATE(sym) = (%SymbolIsPrivate(sym));