Changeset 89954 in webkit

Timestamp:

Jun 28, 2011 1:21:37 PM (13 years ago)

Author:

oliver@apple.com

Message:

2011-06-28 Oliver Hunt <​oliver@apple.com>

Reviewed by Gavin Barraclough.

Make constant array optimisation less strict about what constitutes a constant
​https://bugs.webkit.org/show_bug.cgi?id=63554

Now allow string constants in array literals to actually be considered constant,
and so avoid codegen in array literals with strings in them.

• bytecode/CodeBlock.h: (JSC::CodeBlock::addConstantBuffer): (JSC::CodeBlock::constantBuffer):
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::addConstantBuffer): (JSC::BytecodeGenerator::addStringConstant): (JSC::BytecodeGenerator::emitNewArray):
• bytecompiler/BytecodeGenerator.h:
• interpreter/Interpreter.cpp: (JSC::Interpreter::privateExecute):
• jit/JITStubs.cpp: (JSC::DEFINE_STUB_FUNCTION):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• bytecode/CodeBlock.h (modified) (2 diffs)
• bytecompiler/BytecodeGenerator.cpp (modified) (3 diffs)
• bytecompiler/BytecodeGenerator.h (modified) (2 diffs)
• interpreter/Interpreter.cpp (modified) (1 diff)
• jit/JITStubs.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-06-28  Oliver Hunt  <oliver@apple.com>
+
+        Reviewed by Gavin Barraclough.
+
+        Make constant array optimisation less strict about what constitutes a constant
+        https://bugs.webkit.org/show_bug.cgi?id=63554
+
+        Now allow string constants in array literals to actually be considered constant,
+        and so avoid codegen in array literals with strings in them.
+
+        * bytecode/CodeBlock.h:
+        (JSC::CodeBlock::addConstantBuffer):
+        (JSC::CodeBlock::constantBuffer):
+        * bytecompiler/BytecodeGenerator.cpp:
+        (JSC::BytecodeGenerator::addConstantBuffer):
+        (JSC::BytecodeGenerator::addStringConstant):
+        (JSC::BytecodeGenerator::emitNewArray):
+        * bytecompiler/BytecodeGenerator.h:
+        * interpreter/Interpreter.cpp:
+        (JSC::Interpreter::privateExecute):
+        * jit/JITStubs.cpp:
+        (JSC::DEFINE_STUB_FUNCTION):
+
 2011-06-28  Gavin Barraclough  <barraclough@apple.com>
 

trunk/Source/JavaScriptCore/bytecode/CodeBlock.h

@@ -478 +478 @@
         RegExp* regexp(int index) const { ASSERT(m_rareData); return m_rareData->m_regexps[index].get(); }
 
-        unsigned addImmediateBuffer(unsigned length)
+        unsigned addConstantBuffer(unsigned length)
         {
             createRareDataIfNecessary();
-            unsigned size = m_rareData->m_immediateBuffers.size();
-            m_rareData->m_immediateBuffers.append(Vector<JSValue>(length));
+            unsigned size = m_rareData->m_constantBuffers.size();
+            m_rareData->m_constantBuffers.append(Vector<JSValue>(length));
             return size;
         }
 
-        JSValue* immediateBuffer(unsigned index)
+        JSValue* constantBuffer(unsigned index)
         {
             ASSERT(m_rareData);
-            return m_rareData->m_immediateBuffers[index].data();
+            return m_rareData->m_constantBuffers[index].data();
         }
 
@@ -596 +596 @@
 
             // Buffers used for large array literals
-            Vector<Vector<JSValue> > m_immediateBuffers;
+            Vector<Vector<JSValue> > m_constantBuffers;
             
             // Jump Tables

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp

@@ -1509 +1509 @@
 }
 
-unsigned BytecodeGenerator::addImmediateBuffer(unsigned length)
-{
-    return m_codeBlock->addImmediateBuffer(length);
+unsigned BytecodeGenerator::addConstantBuffer(unsigned length)
+{
+    return m_codeBlock->addConstantBuffer(length);
+}
+
+JSString* BytecodeGenerator::addStringConstant(const Identifier& identifier)
+{
+    JSString*& stringInMap = m_stringMap.add(identifier.impl(), 0).first->second;
+    if (!stringInMap) {
+        stringInMap = jsString(globalData(), identifier.ustring());
+        addConstantValue(stringInMap);
+    }
+    return stringInMap;
 }
 
@@ -1519 +1529 @@
     unsigned checkLength = 0;
 #endif
-    bool hadNonNumber = false;
+    bool hadVariableExpression = false;
     if (length) {
         for (ElementNode* n = elements; n; n = n->next()) {
-            if (!n->value()->isNumber()) {
-                hadNonNumber = true;
+            if (!n->value()->isNumber() && !n->value()->isString()) {
+                hadVariableExpression = true;
                 break;
             }
@@ -1532 +1542 @@
 #endif
         }
-        if (!hadNonNumber) {
+        if (!hadVariableExpression) {
             ASSERT(length == checkLength);
-            unsigned immediateBufferIndex = addImmediateBuffer(length);
-            JSValue* immediateBuffer = m_codeBlock->immediateBuffer(immediateBufferIndex);
+            unsigned constantBufferIndex = addConstantBuffer(length);
+            JSValue* constantBuffer = m_codeBlock->constantBuffer(constantBufferIndex);
             unsigned index = 0;
-            for (ElementNode* n = elements; index < length; n = n->next())
-                immediateBuffer[index++] = jsNumber(static_cast<NumberNode*>(n->value())->value());
+            for (ElementNode* n = elements; index < length; n = n->next()) {
+                if (n->value()->isNumber())
+                    constantBuffer[index++] = jsNumber(static_cast<NumberNode*>(n->value())->value());
+                else {
+                    ASSERT(n->value()->isString());
+                    constantBuffer[index++] = addStringConstant(static_cast<StringNode*>(n->value())->value());
+                }
+            }
             emitOpcode(op_new_array_buffer);
             instructions().append(dst->index());
-            instructions().append(immediateBufferIndex);
+            instructions().append(constantBufferIndex);
             instructions().append(length);
             return dst;

trunk/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h

@@ -470 +470 @@
         unsigned addRegExp(RegExp*);
 
-        unsigned addImmediateBuffer(unsigned length);
+        unsigned addConstantBuffer(unsigned length);
         
         FunctionExecutable* makeFunction(ExecState* exec, FunctionBodyNode* body)
@@ -481 +481 @@
             return FunctionExecutable::create(globalData, body->ident(), body->source(), body->usesArguments(), body->parameters(), body->isStrictMode(), body->lineNo(), body->lastLine());
         }
+
+        JSString* addStringConstant(const Identifier&);
 
         void addLineInfo(unsigned lineNo)

trunk/Source/JavaScriptCore/interpreter/Interpreter.cpp

@@ -1607 +1607 @@
          Constructs a new Array instance using the original
          constructor, and puts the result in register dst.
-         The array be initialized with the values from immediateBuffer[index]
+         The array be initialized with the values from constantBuffer[index]
          */
         int dst = vPC[1].u.operand;
         int firstArg = vPC[2].u.operand;
         int argCount = vPC[3].u.operand;
-        ArgList args(codeBlock->immediateBuffer(firstArg), argCount);
+        ArgList args(codeBlock->constantBufferfirstArg), argCount);
         callFrame->uncheckedR(dst) = JSValue(constructArray(callFrame, args));
         

trunk/Source/JavaScriptCore/jit/JITStubs.cpp

@@ -2265 +2265 @@
     STUB_INIT_STACK_FRAME(stackFrame);
     
-    ArgList argList(stackFrame.callFrame->codeBlock()->immediateBuffer(stackFrame.args[0].int32()), stackFrame.args[1].int32());
+    ArgList argList(stackFrame.callFrame->codeBlock()->constantBuffer(stackFrame.args[0].int32()), stackFrame.args[1].int32());
     return constructArray(stackFrame.callFrame, argList);
 }