Changeset 38688 in webkit for trunk/JavaScriptCore/jit/JIT.cpp

Timestamp:

Nov 21, 2008, 7:34:43 PM (17 years ago)

Author:

[email protected]

Message:

2008-11-21 Gavin Barraclough <​[email protected]>

Reviewed by Oliver Hunt.

Add (really) polymorphic caching for get by id self.
Very similar to caching of prototype accesses, described below.

Oh, also, probably shouldn't have been leaking those structure list objects.

4% preogression on deltablue.

• bytecode/CodeBlock.cpp: (JSC::CodeBlock::dump): (JSC::CodeBlock::derefStructures): (JSC::PrototypeStructureList::derefStructures):
• bytecode/Instruction.h:
• bytecode/Opcode.h:
• interpreter/Interpreter.cpp: (JSC::Interpreter::privateExecute): (JSC::Interpreter::cti_op_get_by_id_self_fail):
• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): (JSC::JIT::privateCompileGetByIdSelfList): (JSC::JIT::patchGetByIdSelf):
• jit/JIT.h: (JSC::JIT::compileGetByIdSelfList):

File:

• trunk/JavaScriptCore/jit/JIT.cpp (modified) (3 diffs)

trunk/JavaScriptCore/jit/JIT.cpp

@@ -2360 +2360 @@
         case op_get_by_id_proto_list:
         case op_get_by_id_self:
+        case op_get_by_id_self_list:
         case op_get_string_length:
         case op_put_by_id_generic:
@@ -3231 +3232 @@
 
 #if USE(CTI_REPATCH_PIC)
-void JIT::privateCompileGetByIdProtoList(StructureStubInfo* stubInfo, PrototypeStructureList* prototypeStructures, int currentIndex, Structure* structure, Structure* prototypeStructure, size_t cachedOffset, CallFrame* callFrame)
+void JIT::privateCompileGetByIdSelfList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* polymorphicStructures, int currentIndex, Structure* structure, size_t cachedOffset)
+{
+    JmpSrc failureCase = checkStructure(X86::eax, structure);
+    __ movl_mr(FIELD_OFFSET(JSObject, m_propertyStorage), X86::eax, X86::eax);
+    __ movl_mr(cachedOffset * sizeof(JSValue*), X86::eax, X86::eax);
+    JmpSrc success = __ jmp();
+
+    void* code = __ executableCopy();
+    ASSERT(code);
+
+    // Use the repatch information to link the failure cases back to the original slow case routine.
+    void* lastProtoBegin = polymorphicStructures->list[currentIndex - 1].stubRoutine;
+    if (!lastProtoBegin)
+        lastProtoBegin = reinterpret_cast<char*>(stubInfo->callReturnLocation) - repatchOffsetGetByIdSlowCaseCall;
+
+    X86Assembler::link(code, failureCase, lastProtoBegin);
+
+    // On success return back to the hot patch code, at a point it will perform the store to dest for us.
+    intptr_t successDest = reinterpret_cast<intptr_t>(stubInfo->hotPathBegin) + repatchOffsetGetByIdPropertyMapOffset;
+    X86Assembler::link(code, success, reinterpret_cast<void*>(successDest));
+
+    structure->ref();
+    polymorphicStructures->list[currentIndex].set(structure, 0, cachedOffset, 0/*code*/);
+
+    // Finally repatch the jump to slow case back in the hot path to jump here instead.
+    intptr_t jmpLocation = reinterpret_cast<intptr_t>(stubInfo->hotPathBegin) + repatchOffsetGetByIdBranchToSlowCase;
+    X86Assembler::repatchBranchOffset(jmpLocation, code);
+}
+
+void JIT::privateCompileGetByIdProtoList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* prototypeStructures, int currentIndex, Structure* structure, Structure* prototypeStructure, size_t cachedOffset, CallFrame* callFrame)
 {
     // The prototype object definitely exists (if this stub exists the CodeBlock is referencing a Structure that is
@@ -3667 +3697 @@
     // We don't want to repatch more than once - in future go to cti_op_get_by_id_generic.
     // Should probably go to Interpreter::cti_op_get_by_id_fail, but that doesn't do anything interesting right now.
-    ctiRepatchCallByReturnAddress(returnAddress, reinterpret_cast<void*>(Interpreter::cti_op_get_by_id_generic));
+    ctiRepatchCallByReturnAddress(returnAddress, reinterpret_cast<void*>(Interpreter::cti_op_get_by_id_self_fail));
 
     // Repatch the offset into the propoerty map to load from, then repatch the Structure to look for.