Changeset 44412 in webkit for trunk/JavaScriptCore/jit/JITPropertyAccess.cpp

Timestamp:

Jun 4, 2009, 4:00:58 AM (16 years ago)

Author:

[email protected]

Message:

2009-06-04 Gavin Barraclough <​[email protected]>

Reviewed by Oliver Hunt.

Wrap the code that plants pushes/pops planted by JIT in explanatorily named
methods; move property storage reallocation into a standard stub function.

~No performance impact (possible <1% progression on x86-64, likely just noise).

• jit/JIT.cpp: (JSC::JIT::privateCompile): (JSC::JIT::privateCompileCTIMachineTrampolines):

Wrap calls to push/pop.

• jit/JIT.h:

Declare the new wrapper methods.

• jit/JITInlineMethods.h: (JSC::JIT::preverveReturnAddressAfterCall): (JSC::JIT::restoreReturnAddressBeforeReturn):

Define the new wrapper methods.

• jit/JITOpcodes.cpp: (JSC::JIT::emit_op_end): (JSC::JIT::emit_op_ret):

Wrap calls to push/pop.

• jit/JITPropertyAccess.cpp: (JSC::JIT::privateCompilePutByIdTransition):

Move property storage reallocation into a standard stub function.

• jit/JITStubs.cpp: (JSC::JITStubs::DEFINE_STUB_FUNCTION):
• jit/JITStubs.h: (JSC::JITStubs::):

File:

• trunk/JavaScriptCore/jit/JITPropertyAccess.cpp (modified) (4 diffs)

trunk/JavaScriptCore/jit/JITPropertyAccess.cpp

@@ -424 +424 @@
 }
 
-static JSObject* resizePropertyStorage(JSObject* baseObject, int32_t oldSize, int32_t newSize)
-{
-    baseObject->allocatePropertyStorage(oldSize, newSize);
-    return baseObject;
-}
-
-static inline bool transitionWillNeedStorageRealloc(Structure* oldStructure, Structure* newStructure)
-{
-    return oldStructure->propertyStorageCapacity() != newStructure->propertyStorageCapacity();
-}
-
 void JIT::privateCompilePutByIdTransition(StructureStubInfo* stubInfo, Structure* oldStructure, Structure* newStructure, size_t cachedOffset, StructureChain* chain, ProcessorReturnAddress returnAddress)
 {
@@ -443 +432 @@
     JumpList successCases;
 
-    //  ecx = baseObject
+    // ecx = baseObject
     loadPtr(Address(regT0, FIELD_OFFSET(JSCell, m_structure)), regT2);
     // proto(ecx) = baseObject->structure()->prototype()
@@ -468 +457 @@
 
     // emit a call only if storage realloc is needed
-    bool willNeedStorageRealloc = transitionWillNeedStorageRealloc(oldStructure, newStructure);
+    bool willNeedStorageRealloc = oldStructure->propertyStorageCapacity() != newStructure->propertyStorageCapacity();
     if (willNeedStorageRealloc) {
-        pop(X86::ebx);
-#if PLATFORM(X86_64)
-        // Setup arguments in edi, esi, edx.  Since baseObject is in regT0,
-        // regT0 had better not be any of these registers.
-        ASSERT(regT0 != X86::edx);
-        ASSERT(regT0 != X86::esi);
-        ASSERT(regT0 != X86::edi);
-        move(Imm32(newStructure->propertyStorageCapacity()), X86::edx);
-        move(Imm32(oldStructure->propertyStorageCapacity()), X86::esi);
-        move(regT0, X86::edi);
-        callTarget = call();
-#else
-        push(Imm32(newStructure->propertyStorageCapacity()));
-        push(Imm32(oldStructure->propertyStorageCapacity()));
-        push(regT0);
-        callTarget = call();
-        addPtr(Imm32(3 * sizeof(void*)), X86::esp);
-#endif
-        emitGetJITStubArg(3, regT1);
-        push(X86::ebx);
+        // This trampoline was called to like a JIT stub; before we can can call again we need to
+        // remove the return address from the stack, to prevent the stack from becoming misaligned.
+        preverveReturnAddressAfterCall(regT3);
+ 
+        JITStubCall stubCall(this, JITStubs::cti_op_put_by_id_transition_realloc);
+        stubCall.addArgument(regT0);
+        stubCall.addArgument(Imm32(oldStructure->propertyStorageCapacity()));
+        stubCall.addArgument(Imm32(newStructure->propertyStorageCapacity()));
+        stubCall.addArgument(regT1); // This argument is not used in the stub; we set it up on the stack so that it can be restored, below.
+        stubCall.call(regT0);
+        emitGetJITStubArg(4, regT1);
+
+        restoreReturnAddressBeforeReturn(regT3);
     }
 
@@ -512 +494 @@
     patchBuffer.link(failureCall, JITStubs::cti_op_put_by_id_fail);
 
-    if (willNeedStorageRealloc)
-        patchBuffer.link(callTarget, resizePropertyStorage);
+    if (willNeedStorageRealloc) {
+        ASSERT(m_calls.size() == 1);
+        patchBuffer.link(m_calls[0].from, JITStubs::cti_op_put_by_id_transition_realloc);
+    }
     
     CodeLocationLabel entryLabel = patchBuffer.finalizeCodeAddendum();