Changeset 55002 in webkit for trunk/JavaScriptCore/interpreter

Timestamp:

Feb 18, 2010, 10:23:25 PM (15 years ago)

Author:

[email protected]

Message:

2010-02-18 Oliver Hunt <​[email protected]>

Reviewed by Gavin Barraclough.

Improve interpreter getter performance
​https://bugs.webkit.org/show_bug.cgi?id=35138

Improve the performance of getter dispatch by making it possible
for the interpreter to cache the GetterSetter object lookup.

To do this we simply need to make PropertySlot aware of getters
as a potentially cacheable property, and record the base and this
objects for a getter access. This allows us to use more-or-less
identical code to that used by the normal get_by_id caching, with
the dispatch being the only actual difference.

I'm holding off of implementing this in the JIT until I do some
cleanup to try and making coding in the JIT not be as horrible
as it is currently.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump): (JSC::CodeBlock::derefStructures): (JSC::CodeBlock::refStructures):
• bytecode/Opcode.h:
• interpreter/Interpreter.cpp: (JSC::Interpreter::resolveGlobal): (JSC::Interpreter::tryCacheGetByID): (JSC::Interpreter::privateExecute):
• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass):
• jit/JITStubs.cpp: (JSC::JITThunks::tryCacheGetByID): (JSC::DEFINE_STUB_FUNCTION):
• runtime/JSObject.cpp: (JSC::JSObject::fillGetterPropertySlot):
• runtime/PropertySlot.cpp: (JSC::PropertySlot::functionGetter):
• runtime/PropertySlot.h: (JSC::PropertySlot::isGetter): (JSC::PropertySlot::isCacheable): (JSC::PropertySlot::isCacheableValue): (JSC::PropertySlot::setValueSlot): (JSC::PropertySlot::setGetterSlot): (JSC::PropertySlot::setCacheableGetterSlot): (JSC::PropertySlot::clearOffset): (JSC::PropertySlot::thisValue):

File:

• trunk/JavaScriptCore/interpreter/Interpreter.cpp (modified) (9 diffs)

trunk/JavaScriptCore/interpreter/Interpreter.cpp

@@ -41 +41 @@
 #include "EvalCodeCache.h"
 #include "ExceptionHelpers.h"
+#include "GetterSetter.h"
 #include "GlobalEvalFunction.h"
 #include "JSActivation.h"
@@ -170 +171 @@
     if (globalObject->getPropertySlot(callFrame, ident, slot)) {
         JSValue result = slot.getValue(callFrame, ident);
-        if (slot.isCacheable() && !globalObject->structure()->isUncacheableDictionary() && slot.slotBase() == globalObject) {
+        if (slot.isCacheableValue() && !globalObject->structure()->isUncacheableDictionary() && slot.slotBase() == globalObject) {
             if (vPC[4].u.structure)
                 vPC[4].u.structure->deref();
@@ -1030 +1031 @@
 
     if (slot.slotBase() == baseValue) {
-        vPC[0] = getOpcode(op_get_by_id_self);
+        vPC[0] = slot.isGetter() ? getOpcode(op_get_by_id_getter_self) : getOpcode(op_get_by_id_self);
         vPC[5] = slot.cachedOffset();
 
@@ -1057 +1058 @@
         ASSERT(!baseObject->structure()->isUncacheableDictionary());
 
-        vPC[0] = getOpcode(op_get_by_id_proto);
+        vPC[0] = slot.isGetter() ? getOpcode(op_get_by_id_getter_proto) : getOpcode(op_get_by_id_proto);
         vPC[5] = baseObject->structure();
         vPC[6] = offset;
@@ -1072 +1073 @@
     }
 
-    vPC[0] = getOpcode(op_get_by_id_chain);
+    vPC[0] = slot.isGetter() ? getOpcode(op_get_by_id_getter_chain) : getOpcode(op_get_by_id_chain);
     vPC[4] = structure;
     vPC[5] = structure->prototypeChain(callFrame);
@@ -2162 +2163 @@
         NEXT_INSTRUCTION();
     }
+#if HAVE(COMPUTED_GOTO)
+    goto *(&&skip_id_getter_proto);
+#endif
+    DEFINE_OPCODE(op_get_by_id_getter_proto) {
+        /* op_get_by_id_getter_proto dst(r) base(r) property(id) structure(sID) prototypeStructure(sID) offset(n) nop(n)
+         
+         Cached property access: Attempts to get a cached getter property from the
+         value base's prototype. If the cache misses, op_get_by_id_getter_proto
+         reverts to op_get_by_id.
+         */
+        int base = vPC[2].u.operand;
+        JSValue baseValue = callFrame->r(base).jsValue();
+        
+        if (LIKELY(baseValue.isCell())) {
+            JSCell* baseCell = asCell(baseValue);
+            Structure* structure = vPC[4].u.structure;
+            
+            if (LIKELY(baseCell->structure() == structure)) {
+                ASSERT(structure->prototypeForLookup(callFrame).isObject());
+                JSObject* protoObject = asObject(structure->prototypeForLookup(callFrame));
+                Structure* prototypeStructure = vPC[5].u.structure;
+                
+                if (LIKELY(protoObject->structure() == prototypeStructure)) {
+                    int dst = vPC[1].u.operand;
+                    int offset = vPC[6].u.operand;
+                    if (GetterSetter* getterSetter = asGetterSetter(protoObject->getDirectOffset(offset).asCell())) {
+                        JSObject* getter = getterSetter->getter();
+                        CallData callData;
+                        CallType callType = getter->getCallData(callData);
+                        JSValue result = call(callFrame, getter, callType, callData, asObject(baseCell), ArgList());
+                        CHECK_FOR_EXCEPTION();
+                        callFrame->r(dst) = result;
+                    } else
+                        callFrame->r(dst) = jsUndefined();
+                    vPC += OPCODE_LENGTH(op_get_by_id_getter_proto);
+                    NEXT_INSTRUCTION();
+                }
+            }
+        }
+        uncacheGetByID(callFrame->codeBlock(), vPC);
+        NEXT_INSTRUCTION();
+    }
+#if HAVE(COMPUTED_GOTO)
+    skip_id_getter_proto:
+#endif
     DEFINE_OPCODE(op_get_by_id_self_list) {
         // Polymorphic self access caching currently only supported when JITting.
@@ -2176 +2222 @@
         NEXT_INSTRUCTION();
     }
+    DEFINE_OPCODE(op_get_by_id_getter_self_list) {
+        // Polymorphic self access caching currently only supported when JITting.
+        ASSERT_NOT_REACHED();
+        // This case of the switch must not be empty, else (op_get_by_id_self_list == op_get_by_id_chain)!
+        vPC += OPCODE_LENGTH(op_get_by_id_self_list);
+        NEXT_INSTRUCTION();
+    }
+    DEFINE_OPCODE(op_get_by_id_getter_proto_list) {
+        // Polymorphic prototype access caching currently only supported when JITting.
+        ASSERT_NOT_REACHED();
+        // This case of the switch must not be empty, else (op_get_by_id_proto_list == op_get_by_id_chain)!
+        vPC += OPCODE_LENGTH(op_get_by_id_proto_list);
+        NEXT_INSTRUCTION();
+    }
     DEFINE_OPCODE(op_get_by_id_chain) {
         /* op_get_by_id_chain dst(r) base(r) property(id) structure(sID) structureChain(chain) count(n) offset(n)
@@ -2222 +2282 @@
         NEXT_INSTRUCTION();
     }
+#if HAVE(COMPUTED_GOTO)
+    goto *(&&skip_id_getter_self);
+#endif
+    DEFINE_OPCODE(op_get_by_id_getter_self) {
+        /* op_get_by_id_self dst(r) base(r) property(id) structure(sID) offset(n) nop(n) nop(n)
+         
+         Cached property access: Attempts to get a cached property from the
+         value base. If the cache misses, op_get_by_id_getter_self reverts to
+         op_get_by_id.
+         */
+        int base = vPC[2].u.operand;
+        JSValue baseValue = callFrame->r(base).jsValue();
+        
+        if (LIKELY(baseValue.isCell())) {
+            JSCell* baseCell = asCell(baseValue);
+            Structure* structure = vPC[4].u.structure;
+            
+            if (LIKELY(baseCell->structure() == structure)) {
+                ASSERT(baseCell->isObject());
+                JSObject* baseObject = asObject(baseCell);
+                int dst = vPC[1].u.operand;
+                int offset = vPC[5].u.operand;
+
+                if (GetterSetter* getterSetter = asGetterSetter(baseObject->getDirectOffset(offset).asCell())) {
+                    JSObject* getter = getterSetter->getter();
+                    CallData callData;
+                    CallType callType = getter->getCallData(callData);
+                    JSValue result = call(callFrame, getter, callType, callData, baseObject, ArgList());
+                    CHECK_FOR_EXCEPTION();
+                    callFrame->r(dst) = result;
+                } else
+                    callFrame->r(dst) = jsUndefined();
+
+                vPC += OPCODE_LENGTH(op_get_by_id_getter_self);
+                NEXT_INSTRUCTION();
+            }
+        }
+        uncacheGetByID(callFrame->codeBlock(), vPC);
+        NEXT_INSTRUCTION();
+    }
+#if HAVE(COMPUTED_GOTO)
+    skip_id_getter_self:
+#endif
     DEFINE_OPCODE(op_get_by_id_generic) {
         /* op_get_by_id_generic dst(r) base(r) property(id) nop(sID) nop(n) nop(n) nop(n)
@@ -2242 +2345 @@
         NEXT_INSTRUCTION();
     }
+#if HAVE(COMPUTED_GOTO)
+    goto *(&&skip_id_getter_chain);
+#endif
+    DEFINE_OPCODE(op_get_by_id_getter_chain) {
+        /* op_get_by_id_getter_chain dst(r) base(r) property(id) structure(sID) structureChain(chain) count(n) offset(n)
+         
+         Cached property access: Attempts to get a cached property from the
+         value base's prototype chain. If the cache misses, op_get_by_id_getter_chain
+         reverts to op_get_by_id.
+         */
+        int base = vPC[2].u.operand;
+        JSValue baseValue = callFrame->r(base).jsValue();
+        
+        if (LIKELY(baseValue.isCell())) {
+            JSCell* baseCell = asCell(baseValue);
+            Structure* structure = vPC[4].u.structure;
+            
+            if (LIKELY(baseCell->structure() == structure)) {
+                RefPtr<Structure>* it = vPC[5].u.structureChain->head();
+                size_t count = vPC[6].u.operand;
+                RefPtr<Structure>* end = it + count;
+                
+                while (true) {
+                    JSObject* baseObject = asObject(baseCell->structure()->prototypeForLookup(callFrame));
+                    
+                    if (UNLIKELY(baseObject->structure() != (*it).get()))
+                        break;
+                    
+                    if (++it == end) {
+                        int dst = vPC[1].u.operand;
+                        int offset = vPC[7].u.operand;
+                        if (GetterSetter* getterSetter = asGetterSetter(baseObject->getDirectOffset(offset).asCell())) {
+                            JSObject* getter = getterSetter->getter();
+                            CallData callData;
+                            CallType callType = getter->getCallData(callData);
+                            JSValue result = call(callFrame, getter, callType, callData, asObject(baseCell), ArgList());
+                            CHECK_FOR_EXCEPTION();
+                            callFrame->r(dst) = result;
+                        } else
+                            callFrame->r(dst) = jsUndefined();
+                        vPC += OPCODE_LENGTH(op_get_by_id_getter_chain);
+                        NEXT_INSTRUCTION();
+                    }
+                    
+                    // Update baseCell, so that next time around the loop we'll pick up the prototype's prototype.
+                    baseCell = baseObject;
+                }
+            }
+        }
+        uncacheGetByID(callFrame->codeBlock(), vPC);
+        NEXT_INSTRUCTION();
+    }
+#if HAVE(COMPUTED_GOTO)
+    skip_id_getter_chain:
+#endif
     DEFINE_OPCODE(op_get_array_length) {
         /* op_get_array_length dst(r) base(r) property(id) nop(sID) nop(n) nop(n) nop(n)