Changeset 52231 in webkit for trunk/JavaScriptCore/interpreter/Interpreter.cpp

Timestamp:

Dec 16, 2009, 7:50:37 PM (15 years ago)

Author:

[email protected]

Message:

Fixed <rdar://problem/7355025> Interpreter::privateExecute macro generates
bloated code

Reviewed by Oliver Hunt.

This patch cuts Interpreter stack use by about a third.

• bytecode/Opcode.h: Changed Opcode to const void* to work with the

const static initiliazation we want to do in Interpreter::privateExecute.

• interpreter/Interpreter.cpp:

(JSC::Interpreter::Interpreter): Moved hashtable initialization here to
avoid polluting Interpreter::privateExecute's stack, and changed it from a
series of add() calls to one add() call in a loop, to cut down on code size.

(JSC::Interpreter::privateExecute): Changed a series of label computations
to a copy of a compile-time constant array to cut down on code size.

File:

• trunk/JavaScriptCore/interpreter/Interpreter.cpp (modified) (2 diffs)

trunk/JavaScriptCore/interpreter/Interpreter.cpp

@@ -322 +322 @@
     , m_reentryDepth(0)
 {
+#if HAVE(COMPUTED_GOTO)
     privateExecute(InitializeAndReturn, 0, 0, 0);
+
+    for (int i = 0; i < numOpcodeIDs; ++i)
+        m_opcodeIDTable.add(m_opcodeTable[i], static_cast<OpcodeID>(i));
+#endif // HAVE(COMPUTED_GOTO)
+
 #if ENABLE(OPCODE_SAMPLING)
     enableSampler();
@@ -1082 +1088 @@
     // One-time initialization of our address tables. We have to put this code
     // here because our labels are only in scope inside this function.
-    if (flag == InitializeAndReturn) {
+    if (UNLIKELY(flag == InitializeAndReturn)) {
         #if HAVE(COMPUTED_GOTO)
-            #define ADD_BYTECODE(id, length) m_opcodeTable[id] = &&id;
-                FOR_EACH_OPCODE_ID(ADD_BYTECODE);
-            #undef ADD_BYTECODE
-
-            #define ADD_OPCODE_ID(id, length) m_opcodeIDTable.add(&&id, id);
-                FOR_EACH_OPCODE_ID(ADD_OPCODE_ID);
-            #undef ADD_OPCODE_ID
-            ASSERT(m_opcodeIDTable.size() == numOpcodeIDs);
+            #define LIST_OPCODE_LABEL(id, length) &&id,
+                static Opcode labels[] = { FOR_EACH_OPCODE_ID(LIST_OPCODE_LABEL) };
+                for (size_t i = 0; i < sizeof(labels) / sizeof(Opcode); ++i)
+                    m_opcodeTable[i] = labels[i];
+            #undef LIST_OPCODE_LABEL
         #endif // HAVE(COMPUTED_GOTO)
         return JSValue();