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Introduce basic type feedback for for-in statements to avoid deopts.

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R=fschneider@chromium.org

Review URL: https://chromiumcodereview.appspot.com/9571001

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10901 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This commit is contained in:
vegorov@chromium.org 2012-03-02 11:33:33 +00:00
parent 774e3f4575
commit ff6ebf7dff
7 changed files with 51 additions and 3 deletions
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10
src/arm/full-codegen-arm.cc
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@ -1004,6 +1004,16 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
// We got a fixed array in register r0. Iterate through that.
Label non_proxy;
__ bind(&fixed_array);
Handle<JSGlobalPropertyCell> cell =
isolate()->factory()->NewJSGlobalPropertyCell(
Handle<Object>(
Smi::FromInt(TypeFeedbackCells::kForInFastCaseMarker)));
RecordTypeFeedbackCell(stmt->PrepareId(), cell);
__ LoadHeapObject(r1, cell);
__ mov(r2, Operand(Smi::FromInt(TypeFeedbackCells::kForInSlowCaseMarker)));
__ str(r2, FieldMemOperand(r1, JSGlobalPropertyCell::kValueOffset));
__ mov(r1, Operand(Smi::FromInt(1))); // Smi indicates slow check
__ ldr(r2, MemOperand(sp, 0 * kPointerSize)); // Get enumerated object
STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);

4
src/hydrogen.cc
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@ -3274,6 +3274,10 @@ void HGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
return Bailout("ForInStatement optimization is disabled");
}
if (!oracle()->IsForInFastCase(stmt)) {
return Bailout("ForInStatement is not fast case");
}
if (!stmt->each()->IsVariableProxy() ||
!stmt->each()->AsVariableProxy()->var()->IsStackLocal()) {
return Bailout("ForInStatement with non-local each variable");

10
src/ia32/full-codegen-ia32.cc
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@ -1033,6 +1033,16 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
// We got a fixed array in register eax. Iterate through that.
Label non_proxy;
__ bind(&fixed_array);
Handle<JSGlobalPropertyCell> cell =
isolate()->factory()->NewJSGlobalPropertyCell(
Handle<Object>(
Smi::FromInt(TypeFeedbackCells::kForInFastCaseMarker)));
RecordTypeFeedbackCell(stmt->PrepareId(), cell);
__ LoadHeapObject(ebx, cell);
__ mov(FieldOperand(ebx, JSGlobalPropertyCell::kValueOffset),
Immediate(Smi::FromInt(TypeFeedbackCells::kForInSlowCaseMarker)));
__ mov(ebx, Immediate(Smi::FromInt(1))); // Smi indicates slow check
__ mov(ecx, Operand(esp, 0 * kPointerSize)); // Get enumerated object
STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);

3
src/objects.h
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@ -4063,6 +4063,9 @@ class TypeFeedbackCells: public FixedArray {
// Casting.
static inline TypeFeedbackCells* cast(Object* obj);
static const int kForInFastCaseMarker = 0;
static const int kForInSlowCaseMarker = 1;
};

12
src/type-info.cc
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@ -154,6 +154,13 @@ bool TypeFeedbackOracle::CallNewIsMonomorphic(CallNew* expr) {
}
bool TypeFeedbackOracle::IsForInFastCase(ForInStatement* stmt) {
Handle<Object> value = GetInfo(stmt->PrepareId());
return value->IsSmi() &&
Smi::cast(*value)->value() == TypeFeedbackCells::kForInFastCaseMarker;
}
Handle<Map> TypeFeedbackOracle::LoadMonomorphicReceiverType(Property* expr) {
ASSERT(LoadIsMonomorphicNormal(expr));
Handle<Object> map_or_code = GetInfo(expr->id());
@ -659,9 +666,10 @@ void TypeFeedbackOracle::ProcessTypeFeedbackCells(Handle<Code> code) {
for (int i = 0; i < cache->CellCount(); i++) {
unsigned ast_id = cache->AstId(i)->value();
Object* value = cache->Cell(i)->value();
if (value->IsJSFunction() &&
if (value->IsSmi() ||
(value->IsJSFunction() &&
!CanRetainOtherContext(JSFunction::cast(value),
*global_context_)) {
*global_context_))) {
SetInfo(ast_id, value);
}
}

3
src/type-info.h
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@ -228,6 +228,7 @@ class Expression;
class Property;
class SmallMapList;
class UnaryOperation;
class ForInStatement;
class TypeFeedbackOracle BASE_EMBEDDED {
@ -243,6 +244,8 @@ class TypeFeedbackOracle BASE_EMBEDDED {
bool CallIsMonomorphic(Call* expr);
bool CallNewIsMonomorphic(CallNew* expr);
bool IsForInFastCase(ForInStatement* expr);
Handle<Map> LoadMonomorphicReceiverType(Property* expr);
Handle<Map> StoreMonomorphicReceiverType(Expression* expr);

10
src/x64/full-codegen-x64.cc
View File

@ -969,6 +969,16 @@ void FullCodeGenerator::VisitForInStatement(ForInStatement* stmt) {
// We got a fixed array in register rax. Iterate through that.
Label non_proxy;
__ bind(&fixed_array);
Handle<JSGlobalPropertyCell> cell =
isolate()->factory()->NewJSGlobalPropertyCell(
Handle<Object>(
Smi::FromInt(TypeFeedbackCells::kForInFastCaseMarker)));
RecordTypeFeedbackCell(stmt->PrepareId(), cell);
__ LoadHeapObject(rbx, cell);
__ Move(FieldOperand(rbx, JSGlobalPropertyCell::kValueOffset),
Smi::FromInt(TypeFeedbackCells::kForInSlowCaseMarker));
__ Move(rbx, Smi::FromInt(1)); // Smi indicates slow check
__ movq(rcx, Operand(rsp, 0 * kPointerSize)); // Get enumerated object
STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);