Reviewers: Lasse Reichstein, Mads Ager,
Message:
Lasse, Mads,
here comes promised more generic version of Array.concat.
Lasse, this patch should obsolete http://codereview.chromium.org/971001 if
submitted first
Description:
More generic version of Array.concat builtin.
Please review this at http://codereview.chromium.org/1036002
Affected files:
M src/builtins.cc
M src/v8-counters.h
Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index
4166b7121d269c5d38091cccf1b753425f306b00..38f23bdc55798eb14dca47252c61043d054b4e6f
100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -728,36 +728,29 @@ BUILTIN(ArraySplice) {
BUILTIN(ArrayConcat) {
- Counters::array_concat_builtin_total.Increment();
- if (args.length() != 2) {
- // Fast case only for concating two arrays.
- return CallJsBuiltin("ArrayConcat", args);
- }
- Counters::array_concat_builtin_two_args.Increment();
-
- Object* receiver_obj = *args.receiver();
- FixedArray* receiver_elms = NULL;
- Object* arg_obj = args[1];
- FixedArray* arg_elms = NULL;
- if (!IsJSArrayWithFastElements(receiver_obj, &receiver_elms)
- || !IsJSArrayWithFastElements(arg_obj, &arg_elms)
- || !ArrayPrototypeHasNoElements()) {
+ if (!ArrayPrototypeHasNoElements()) {
return CallJsBuiltin("ArrayConcat", args);
}
- JSArray* receiver_array = JSArray::cast(receiver_obj);
- ASSERT(receiver_array->HasFastElements());
- JSArray* arg_array = JSArray::cast(arg_obj);
- ASSERT(arg_array->HasFastElements());
-
- int receiver_len = Smi::cast(receiver_array->length())->value();
- int arg_len = Smi::cast(arg_array->length())->value();
- ASSERT(receiver_len <= (Smi::kMaxValue - arg_len));
+ // Iterate through all the arguments performing checks
+ // and calculating total length.
+ int n_arguments = args.length();
+ int result_len = 0;
+ for (int i = 0; i < n_arguments; i++) {
+ Object* arg = args[i];
+ FixedArray* elms = NULL;
+ if (!IsJSArrayWithFastElements(arg, &elms)) {
+ return CallJsBuiltin("ArrayConcat", args);
+ }
+ ASSERT(JSArray::cast(arg)->HasFastElements());
- int result_len = receiver_len + arg_len;
- if (result_len > FixedArray::kMaxSize) {
- return CallJsBuiltin("ArrayConcat", args);
+ int len = Smi::cast(JSArray::cast(arg)->length())->value();
+ result_len += len;
+ if (result_len > FixedArray::kMaxLength) {
+ return CallJsBuiltin("ArrayConcat", args);
+ }
}
+
if (result_len == 0) {
return AllocateEmptyJSArray();
}
@@ -773,8 +766,15 @@ BUILTIN(ArrayConcat) {
// Copy data.
AssertNoAllocation no_gc;
- CopyElements(&no_gc, result_elms, 0, receiver_elms, 0, receiver_len);
- CopyElements(&no_gc, result_elms, receiver_len, arg_elms, 0, arg_len);
+ int start_pos = 0;
+ for (int i = 0; i < n_arguments; i++) {
+ JSArray* array = JSArray::cast(args[i]);
+ FixedArray* elms = FixedArray::cast(array->elements());
+ int len = Smi::cast(array->length())->value();
+ CopyElements(&no_gc, result_elms, start_pos, elms, 0, len);
+ start_pos += len;
+ }
+ ASSERT(start_pos == result_len);
// Set the length and elements.
result_array->set_length(Smi::FromInt(result_len));
Index: src/v8-counters.h
diff --git a/src/v8-counters.h b/src/v8-counters.h
index
c1400ae4047f1b091c32d549a03499581cc740eb..b595cd4922c2739b6b537c68a33507891d97f955
100644
--- a/src/v8-counters.h
+++ b/src/v8-counters.h
@@ -151,8 +151,6 @@ namespace internal {
SC(constructed_objects_stub, V8.ConstructedObjectsStub) \
SC(array_function_runtime, V8.ArrayFunctionRuntime) \
SC(array_function_native, V8.ArrayFunctionNative) \
- SC(array_concat_builtin_total, V8.ArrayConcatTotal) \
- SC(array_concat_builtin_two_args, V8.ArrayConcatTwoArgs) \
SC(for_in, V8.ForIn) \
SC(enum_cache_hits, V8.EnumCacheHits) \
SC(enum_cache_misses, V8.EnumCacheMisses) \
--
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