Author: [EMAIL PROTECTED]
Date: Mon Oct 27 07:36:08 2008
New Revision: 608
Modified:
branches/bleeding_edge/src/ic-arm.cc
branches/bleeding_edge/src/ic.cc
branches/bleeding_edge/src/objects-inl.h
branches/bleeding_edge/src/objects.h
branches/bleeding_edge/src/stub-cache-ia32.cc
Log:
Allow inline caching for getting the length of string wrapper objects.
Review URL: http://codereview.chromium.org/8620
Modified: branches/bleeding_edge/src/ic-arm.cc
==============================================================================
--- branches/bleeding_edge/src/ic-arm.cc (original)
+++ branches/bleeding_edge/src/ic-arm.cc Mon Oct 27 07:36:08 2008
@@ -157,6 +157,28 @@
}
+// Generate code to check if an object is a string. If the object is
+// a string, the map's instance type is left in the scratch1 register.
+static void GenerateStringCheck(MacroAssembler* masm,
+ Register receiver,
+ Register scratch1,
+ Register scratch2,
+ Label* smi,
+ Label* non_string_object) {
+ // Check that the receiver isn't a smi.
+ __ tst(receiver, Operand(kSmiTagMask));
+ __ b(eq, smi);
+
+ // Check that the object is a string.
+ __ ldr(scratch1, FieldMemOperand(receiver, HeapObject::kMapOffset));
+ __ ldrb(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
+ __ and_(scratch2, scratch1, Operand(kIsNotStringMask));
+ // The cast is to resolve the overload for the argument of 0x0.
+ __ cmp(scratch2, Operand(static_cast<int32_t>(kStringTag)));
+ __ b(ne, non_string_object);
+}
+
+
void LoadIC::GenerateStringLength(MacroAssembler* masm) {
// ----------- S t a t e -------------
// -- r2 : name
@@ -164,29 +186,32 @@
// -- [sp] : receiver
// -----------------------------------
- Label miss;
+ Label miss, load_length, check_wrapper;
__ ldr(r0, MemOperand(sp, 0));
- // Check that the receiver isn't a smi.
- __ tst(r0, Operand(kSmiTagMask));
- __ b(eq, &miss);
-
- // Check that the object is a string.
- __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
- __ ldrb(r1, FieldMemOperand(r1, Map::kInstanceTypeOffset));
- __ and_(r3, r1, Operand(kIsNotStringMask));
- // The cast is to resolve the overload for the argument of 0x0.
- __ cmp(r3, Operand(static_cast<int32_t>(kStringTag)));
- __ b(ne, &miss);
+ // Check if the object is a string.
+ GenerateStringCheck(masm, r0, r1, r3, &miss, &check_wrapper);
+ // Load length directly from the string.
+ __ bind(&load_length);
__ and_(r1, r1, Operand(kStringSizeMask));
__ add(r1, r1, Operand(String::kHashShift));
- // Load length directly from the string.
__ ldr(r0, FieldMemOperand(r0, String::kLengthOffset));
__ mov(r0, Operand(r0, LSR, r1));
__ mov(r0, Operand(r0, LSL, kSmiTagSize));
__ Ret();
+
+ // Check if the object is a JSValue wrapper.
+ __ bind(&check_wrapper);
+ __ cmp(r0, Operand(JS_VALUE_TYPE));
+ __ b(ne, &miss);
+
+ // Check if the wrapped value is a string and load the length
+ // directly if it is.
+ __ ldr(r0, FieldMemOperand(r0, JSValue::kValueOffset));
+ GenerateStringCheck(masm, r0, r1, r3, &miss, &miss);
+ __ b(&load_length);
// Cache miss: Jump to runtime.
__ bind(&miss);
Modified: branches/bleeding_edge/src/ic.cc
==============================================================================
--- branches/bleeding_edge/src/ic.cc (original)
+++ branches/bleeding_edge/src/ic.cc Mon Oct 27 07:36:08 2008
@@ -453,8 +453,17 @@
}
if (FLAG_use_ic) {
- // Use specialized code for getting the length of strings.
- if (object->IsString() && name->Equals(Heap::length_symbol())) {
+ // Use specialized code for getting the length of strings and
+ // string wrapper objects. The length property of string wrapper
+ // objects is read-only and therefore always returns the length of
+ // the underlying string value. See ECMA-262 15.5.5.1.
+ if ((object->IsString() || object->IsStringWrapper()) &&
+ name->Equals(Heap::length_symbol())) {
+ HandleScope scope;
+ // Get the string if we have a string wrapper object.
+ if (object->IsJSValue()) {
+ object = Handle<Object>(Handle<JSValue>::cast(object)->value());
+ }
#ifdef DEBUG
if (FLAG_trace_ic) PrintF("[LoadIC : +#length /string]\n");
#endif
Modified: branches/bleeding_edge/src/objects-inl.h
==============================================================================
--- branches/bleeding_edge/src/objects-inl.h (original)
+++ branches/bleeding_edge/src/objects-inl.h Mon Oct 27 07:36:08 2008
@@ -301,6 +301,11 @@
}
+bool Object::IsStringWrapper() {
+ return IsJSValue() && JSValue::cast(this)->value()->IsString();
+}
+
+
bool Object::IsProxy() {
return Object::IsHeapObject()
&& HeapObject::cast(this)->map()->instance_type() == PROXY_TYPE;
Modified: branches/bleeding_edge/src/objects.h
==============================================================================
--- branches/bleeding_edge/src/objects.h (original)
+++ branches/bleeding_edge/src/objects.h Mon Oct 27 07:36:08 2008
@@ -626,6 +626,7 @@
inline bool IsOddball();
inline bool IsSharedFunctionInfo();
inline bool IsJSValue();
+ inline bool IsStringWrapper();
inline bool IsProxy();
inline bool IsBoolean();
inline bool IsJSArray();
Modified: branches/bleeding_edge/src/stub-cache-ia32.cc
==============================================================================
--- branches/bleeding_edge/src/stub-cache-ia32.cc (original)
+++ branches/bleeding_edge/src/stub-cache-ia32.cc Mon Oct 27 07:36:08 2008
@@ -159,31 +159,55 @@
}
-void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
- Register receiver,
- Register scratch,
- Label* miss_label) {
- // Check that the receiver isn't a smi.
+// Generate code to check if an object is a string. If the object is
+// a string, the map's instance type is left in the scratch register.
+static void GenerateStringCheck(MacroAssembler* masm,
+ Register receiver,
+ Register scratch,
+ Label* smi,
+ Label* non_string_object) {
+ // Check that the object isn't a smi.
__ test(receiver, Immediate(kSmiTagMask));
- __ j(zero, miss_label, not_taken);
+ __ j(zero, smi, not_taken);
// Check that the object is a string.
__ mov(scratch, FieldOperand(receiver, HeapObject::kMapOffset));
__ movzx_b(scratch, FieldOperand(scratch, Map::kInstanceTypeOffset));
ASSERT(kNotStringTag != 0);
__ test(scratch, Immediate(kNotStringTag));
- __ j(not_zero, miss_label, not_taken);
+ __ j(not_zero, non_string_object, not_taken);
+}
- __ and_(scratch, kStringSizeMask);
+
+void StubCompiler::GenerateLoadStringLength(MacroAssembler* masm,
+ Register receiver,
+ Register scratch,
+ Label* miss) {
+ Label load_length, check_wrapper;
+
+ // Check if the object is a string.
+ GenerateStringCheck(masm, receiver, scratch, miss, &check_wrapper);
// Load length directly from the string.
+ __ bind(&load_length);
+ __ and_(scratch, kStringSizeMask);
__ mov(eax, FieldOperand(receiver, String::kLengthOffset));
-
// ecx is also the receiver.
__ lea(ecx, Operand(scratch, String::kLongLengthShift));
__ shr(eax); // ecx is implicit shift register.
__ shl(eax, kSmiTagSize);
__ ret(0);
+
+ // Check if the object is a JSValue wrapper.
+ __ bind(&check_wrapper);
+ __ cmp(receiver, JS_VALUE_TYPE);
+ __ j(not_equal, miss, not_taken);
+
+ // Check if the wrapped value is a string and load the length
+ // directly if it is.
+ __ mov(receiver, FieldOperand(receiver, JSValue::kValueOffset));
+ GenerateStringCheck(masm, receiver, scratch, miss, miss);
+ __ jmp(&load_length);
}
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