JavaScriptCore-1218.tar.gz

[apple/javascriptcore.git] / bytecode / PolymorphicAccessStructureList.h

diff --git a/bytecode/PolymorphicAccessStructureList.h b/bytecode/PolymorphicAccessStructureList.h
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+/*
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef PolymorphicAccessStructureList_h
+#define PolymorphicAccessStructureList_h
+
+#include "JITStubRoutine.h"
+#include "Structure.h"
+#include "StructureChain.h"
+#include <wtf/Platform.h>
+
+#define POLYMORPHIC_LIST_CACHE_SIZE 8
+
+namespace JSC {
+
+// *Sigh*, If the JIT is enabled we need to track the stubRountine (of type CodeLocationLabel),
+// If the JIT is not in use we don't actually need the variable (that said, if the JIT is not in use we don't
+// curently actually use PolymorphicAccessStructureLists, which we should).  Anyway, this seems like the best
+// solution for now - will need to something smarter if/when we actually want mixed-mode operation.
+
+#if ENABLE(JIT)
+// Structure used by op_get_by_id_self_list and op_get_by_id_proto_list instruction to hold data off the main opcode stream.
+struct PolymorphicAccessStructureList {
+    WTF_MAKE_FAST_ALLOCATED;
+public:
+    struct PolymorphicStubInfo {
+        bool isChain;
+        bool isDirect;
+        RefPtr<JITStubRoutine> stubRoutine;
+        WriteBarrier<Structure> base;
+        union {
+            WriteBarrierBase<Structure> proto;
+            WriteBarrierBase<StructureChain> chain;
+        } u;
+
+        PolymorphicStubInfo()
+        {
+            u.proto.clear();
+        }
+
+        void set(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> _stubRoutine, Structure* _base, bool isDirect)
+        {
+            stubRoutine = _stubRoutine;
+            base.set(vm, owner, _base);
+            u.proto.clear();
+            isChain = false;
+            this->isDirect = isDirect;
+        }
+            
+        void set(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> _stubRoutine, Structure* _base, Structure* _proto, bool isDirect)
+        {
+            stubRoutine = _stubRoutine;
+            base.set(vm, owner, _base);
+            u.proto.set(vm, owner, _proto);
+            isChain = false;
+            this->isDirect = isDirect;
+        }
+            
+        void set(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> _stubRoutine, Structure* _base, StructureChain* _chain, bool isDirect)
+        {
+            stubRoutine = _stubRoutine;
+            base.set(vm, owner, _base);
+            u.chain.set(vm, owner, _chain);
+            isChain = true;
+            this->isDirect = isDirect;
+        }
+    } list[POLYMORPHIC_LIST_CACHE_SIZE];
+        
+    PolymorphicAccessStructureList()
+    {
+    }
+        
+    PolymorphicAccessStructureList(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> stubRoutine, Structure* firstBase, bool isDirect)
+    {
+        list[0].set(vm, owner, stubRoutine, firstBase, isDirect);
+    }
+
+    PolymorphicAccessStructureList(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> stubRoutine, Structure* firstBase, Structure* firstProto, bool isDirect)
+    {
+        list[0].set(vm, owner, stubRoutine, firstBase, firstProto, isDirect);
+    }
+
+    PolymorphicAccessStructureList(VM& vm, JSCell* owner, PassRefPtr<JITStubRoutine> stubRoutine, Structure* firstBase, StructureChain* firstChain, bool isDirect)
+    {
+        list[0].set(vm, owner, stubRoutine, firstBase, firstChain, isDirect);
+    }
+
+    bool visitWeak(int count)
+    {
+        for (int i = 0; i < count; ++i) {
+            PolymorphicStubInfo& info = list[i];
+            if (!info.base) {
+                // We're being marked during initialisation of an entry
+                ASSERT(!info.u.proto);
+                continue;
+            }
+                
+            if (!Heap::isMarked(info.base.get()))
+                return false;
+            if (info.u.proto && !info.isChain
+                && !Heap::isMarked(info.u.proto.get()))
+                return false;
+            if (info.u.chain && info.isChain
+                && !Heap::isMarked(info.u.chain.get()))
+                return false;
+        }
+            
+        return true;
+    }
+};
+
+#endif // ENABLE(JIT)
+
+} // namespace JSC
+
+#endif // PolymorphicAccessStructureList_h
+