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Revert "More generic version of Array.concat builtin."

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Review URL: http://codereview.chromium.org/1058003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4153 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
antonm@chromium.org 2010-03-17 09:13:39 +00:00
parent feefa06b35
commit c7e21cc31b
2 changed files with 28 additions and 31 deletions
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57
src/builtins.cc
View File

@ -728,34 +728,36 @@ BUILTIN(ArraySplice) {
BUILTIN(ArrayConcat) {
if (!ArrayPrototypeHasNoElements()) {
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()) {
return CallJsBuiltin("ArrayConcat", args);
}
// 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];
if (!arg->IsJSArray() || JSArray::cast(arg)->HasFastElements()) {
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 len = Smi::cast(JSArray::cast(arg)->length())->value();
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));
// We shouldn't overflow when adding another len.
const int kHalfOfMaxInt = 1 << (kBitsPerInt - 2);
STATIC_ASSERT(FixedArray::kMaxLength < kHalfOfMaxInt);
USE(kHalfOfMaxInt);
result_len += len;
ASSERT(result_len >= 0);
if (result_len > FixedArray::kMaxLength) {
return CallJsBuiltin("ArrayConcat", args);
}
int result_len = receiver_len + arg_len;
if (result_len > FixedArray::kMaxSize) {
return CallJsBuiltin("ArrayConcat", args);
}
if (result_len == 0) {
return AllocateEmptyJSArray();
}
@ -771,15 +773,8 @@ BUILTIN(ArrayConcat) {
// Copy data.
AssertNoAllocation no_gc;
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);
CopyElements(&no_gc, result_elms, 0, receiver_elms, 0, receiver_len);
CopyElements(&no_gc, result_elms, receiver_len, arg_elms, 0, arg_len);
// Set the length and elements.
result_array->set_length(Smi::FromInt(result_len));

2
src/v8-counters.h
View File

@ -151,6 +151,8 @@ 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) \