Changeset 286251 in webkit for trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

Timestamp:

Nov 29, 2021, 12:04:08 PM (3 years ago)

Author:

[email protected]

Message:

[JSC] Public Class Field initialization is slow
​https://bugs.webkit.org/show_bug.cgi?id=232479

Reviewed by Alexey Shvayka.

JSTests:

• microbenchmarks/class-fields-classic-constructor-assignments.js: Added.

(Classic_Constructor_Assignments):
(bench):

• microbenchmarks/class-fields-private-fields.js: Added.

(ES2022_Private_Fields):
(bench):

• microbenchmarks/class-fields-public-fields.js: Added.

(ES2022_Public_Fields):
(bench):

• stress/class-fields-getter-override.js: Added.

(shouldThrow):
(defineCGetter.):
(B):
(define0Getter.):
(define0Getter):
(D):

• stress/custom-get-set-proto-chain-put.js:

(let.object.of.getObjects):

• stress/freeze-and-seal-should-prevent-extensions.js:
• stress/object-assign-fast-path.js:
• stress/ordinary-set-exceptions.js:

(shouldThrow):

• stress/put-non-reified-static-function-or-custom.js:
• wasm/js-api/test_basic_api.js:

(const.c.in.constructorProperties.switch):

Source/JavaScriptCore:

Class public field implementation did not have optimization for initializing class fields: using
runtime call to initialize fields instead of IC. This patch leverages put_by_id / put_by_val with
direct flag so that we can enable IC.

Currently, we are not changing original putDirect semantics since it is out of this patch's scope.
We will look into it and probably changing it in a separate patch, but not in this patch.

ToT Patched

class-fields-classic-constructor-assignments

17.1491+-2.6327 15.0906+-0.6795 might be 1.1364x faster

class-fields-public-fields 409.4328+-8.3140 ^{20.2752+-2.0835} definitely 20.1938x faster
class-fields-private-fields 27.2621+-1.3858 25.1810+-3.9873 might be 1.0826x faster

• bytecompiler/NodesCodegen.cpp:

(JSC::DefineFieldNode::emitBytecode):

• runtime/CommonSlowPaths.h:

(JSC::CommonSlowPaths::putDirectWithReify):

• runtime/JSObject.cpp:

(JSC::JSObject::putDirectCustomAccessor):
(JSC::JSObject::putDirectNonIndexAccessor):

• runtime/JSObject.h:

(JSC::JSObject::putDirect):
(JSC::JSObject::putDirectRespectingExtensibility):

• runtime/JSObjectInlines.h:

(JSC::JSObject::putInlineFast):
(JSC::JSObject::putDirectInternal):
(JSC::JSObject::putOwnDataProperty):
(JSC::JSObject::putOwnDataPropertyMayBeIndex):

Source/WTF:

• wtf/text/ASCIILiteral.h:

File:

• trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp (modified) (3 diffs)

trunk/Source/JavaScriptCore/bytecompiler/NodesCodegen.cpp

@@ -5040 +5040 @@
     switch (m_type) {
     case DefineFieldNode::Type::Name: {
-        // FIXME: Improve performance of public class fields
-        // https://bugs.webkit.org/show_bug.cgi?id=198330
-        RefPtr<RegisterID> propertyName = generator.emitLoad(nullptr, *m_ident);
-        generator.emitCallDefineProperty(generator.thisRegister(), propertyName.get(), value.get(), nullptr, nullptr, BytecodeGenerator::PropertyConfigurable | BytecodeGenerator::PropertyWritable | BytecodeGenerator::PropertyEnumerable, m_position);
+        StrictModeScope strictModeScope(generator);
+        if (auto index = parseIndex(*m_ident)) {
+            RefPtr<RegisterID> propertyName = generator.emitLoad(nullptr, jsNumber(index.value()));
+            generator.emitDirectPutByVal(generator.thisRegister(), propertyName.get(), value.get());
+        } else
+            generator.emitDirectPutById(generator.thisRegister(), *m_ident, value.get());
         break;
     }
@@ -5058 +5060 @@
     }
     case DefineFieldNode::Type::ComputedName: {
-        // FIXME: Improve performance of public class fields
-        // https://bugs.webkit.org/show_bug.cgi?id=198330
-
         // For ComputedNames, the expression has already been evaluated earlier during evaluation of a ClassExprNode.
         // Here, `m_ident` refers to private symbol ID in a class lexical scope, containing the value already converted to an Expression.
@@ -5073 +5072 @@
             generator.emitSetFunctionName(value.get(), privateName.get());
         generator.emitProfileType(privateName.get(), var, m_position, m_position + m_ident->length());
-        generator.emitCallDefineProperty(generator.thisRegister(), privateName.get(), value.get(), nullptr, nullptr, BytecodeGenerator::PropertyConfigurable | BytecodeGenerator::PropertyWritable | BytecodeGenerator::PropertyEnumerable, m_position);
+        {
+            StrictModeScope strictModeScope(generator);
+            generator.emitDirectPutByVal(generator.thisRegister(), privateName.get(), value.get());
+        }
         break;
     }