Reviewers: Mads Ager,
Description:
Provide special case for f.bind(obj).
Function returned for generic case is extremely slow, does an allocation
per-call and is not Crankshaft friendly.
Please review this at http://codereview.chromium.org/6413018/
SVN Base: https://v8.googlecode.com/svn/branches/bleeding_edge
Affected files:
M src/v8natives.js
Index: src/v8natives.js
diff --git a/src/v8natives.js b/src/v8natives.js
index
04444697d817a035c709ffcf9a044fb91bf3d81c..c502c2422065dfd3fd6ab31608d917ab240e0dc4
100644
--- a/src/v8natives.js
+++ b/src/v8natives.js
@@ -1141,26 +1141,30 @@ function FunctionBind(this_arg) { // Length is 1.
}
}
var fn = this;
- var result = function() {
- // Combine the args we got from the bind call with the args
- // given as argument to the invocation.
- var argc = %_ArgumentsLength();
- var args = new $Array(argc + argc_bound);
- // Add bound arguments.
- for (var i = 0; i < argc_bound; i++) {
- args[i] = bound_args[i];
- }
- // Add arguments from call.
- for (var i = 0; i < argc; i++) {
- args[argc_bound + i] = %_Arguments(i);
- }
- // If this is a construct call we use a special runtime method
- // to generate the actual object using the bound function.
- if (%_IsConstructCall()) {
- return %NewObjectFromBound(fn, args);
- }
- return fn.apply(this_arg, args);
- };
+ if (argc_bound == 0) {
+ var result = function() { return fn.apply(this_arg, arguments); };
+ } else {
+ var result = function() {
+ // Combine the args we got from the bind call with the args
+ // given as argument to the invocation.
+ var argc = %_ArgumentsLength();
+ var args = new $Array(argc + argc_bound);
+ // Add bound arguments.
+ for (var i = 0; i < argc_bound; i++) {
+ args[i] = bound_args[i];
+ }
+ // Add arguments from call.
+ for (var i = 0; i < argc; i++) {
+ args[argc_bound + i] = %_Arguments(i);
+ }
+ // If this is a construct call we use a special runtime method
+ // to generate the actual object using the bound function.
+ if (%_IsConstructCall()) {
+ return %NewObjectFromBound(fn, args);
+ }
+ return fn.apply(this_arg, args);
+ };
+ }
// We already have caller and arguments properties on functions,
// which are non-configurable. It therefore makes no sence to
--
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