Changeset 58986 in webkit for trunk/JavaScriptCore/bytecode/CodeBlock.cpp

Timestamp:

May 7, 2010, 5:05:00 PM (15 years ago)

Author:

[email protected]

Message:

2010-05-07 Oliver Hunt <​[email protected]>

Reviewed by Geoffrey Garen.

Optimize access to the global object from a function that uses eval
​https://bugs.webkit.org/show_bug.cgi?id=38644

Add op_resolve_global_dynamic, a variant of op_resolve_global that
checks each node in the scope chain for dynamically inserted properties
and falls back to the normal resolve logic in that case.

• JavaScriptCore.exp:
• bytecode/CodeBlock.cpp: (JSC::isGlobalResolve): (JSC::CodeBlock::printStructures): (JSC::CodeBlock::dump): (JSC::CodeBlock::derefStructures):
• bytecode/Opcode.h:
• bytecompiler/BytecodeGenerator.cpp: (JSC::BytecodeGenerator::findScopedProperty):

Now take an additional reference parameter to used to indicate that
there were nodes that may gain dynamic properties

(JSC::BytecodeGenerator::emitResolve):
(JSC::BytecodeGenerator::emitResolveBase):
(JSC::BytecodeGenerator::emitResolveWithBase):

deal with additional argument to findScopedProperty

• bytecompiler/BytecodeGenerator.h:
• bytecompiler/NodesCodegen.cpp: (JSC::FunctionCallResolveNode::emitBytecode): (JSC::PostfixResolveNode::emitBytecode): (JSC::PrefixResolveNode::emitBytecode): (JSC::ReadModifyResolveNode::emitBytecode): (JSC::AssignResolveNode::emitBytecode):

These functions use findScopedProperty directly in order to
optimise lookup. They cannot trivially handle any degree of
dynamism in the lookup so we just give up in such case.

• interpreter/Interpreter.cpp: (JSC::Interpreter::resolveGlobalDynamic): (JSC::Interpreter::execute): (JSC::Interpreter::privateExecute):
• interpreter/Interpreter.h:
• jit/JIT.cpp: (JSC::JIT::privateCompileMainPass): (JSC::JIT::privateCompileSlowCases):
• jit/JIT.h:
• jit/JITOpcodes.cpp: (JSC::JIT::emit_op_resolve_global): (JSC::JIT::emit_op_resolve_global_dynamic): (JSC::JIT::emitSlow_op_resolve_global): (JSC::JIT::emitSlow_op_resolve_global_dynamic):

Happily resolve_global_dynamic can share the slow case!

• jit/JITStubs.h: (JSC::):
• runtime/JSActivation.cpp: (JSC::JSActivation::isDynamicScope):
• runtime/JSActivation.h:
• runtime/JSGlobalObject.cpp: (JSC::JSGlobalObject::isDynamicScope):
• runtime/JSGlobalObject.h:
• runtime/JSStaticScopeObject.cpp: (JSC::JSStaticScopeObject::isDynamicScope):
• runtime/JSStaticScopeObject.h:
• runtime/JSVariableObject.h:

File:

• trunk/JavaScriptCore/bytecode/CodeBlock.cpp (modified) (4 diffs)

trunk/JavaScriptCore/bytecode/CodeBlock.cpp

@@ -162 +162 @@
 static bool isGlobalResolve(OpcodeID opcodeID)
 {
-    return opcodeID == op_resolve_global;
+    return opcodeID == op_resolve_global || opcodeID == op_resolve_global_dynamic;
 }
 
@@ -299 +299 @@
         return;
     }
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global_dynamic)) {
+        printStructure("resolve_global_dynamic", vPC, 4);
+        return;
+    }
 
     // These m_instructions doesn't ref Structures.
@@ -665 +669 @@
             printf("[%4d] resolve_global\t %s, %s, %s\n", location, registerName(exec, r0).data(), valueToSourceString(exec, scope).ascii(), idName(id0, m_identifiers[id0]).data());
             it += 2;
+            break;
+        }
+        case op_resolve_global_dynamic: {
+            int r0 = (++it)->u.operand;
+            JSValue scope = JSValue((++it)->u.jsCell);
+            int id0 = (++it)->u.operand;
+            int depth = it[2].u.operand;
+            printf("[%4d] resolve_global_dynamic\t %s, %s, %s, %d\n", location, registerName(exec, r0).data(), valueToSourceString(exec, scope).ascii(), idName(id0, m_identifiers[id0]).data(), depth);
+            it += 3;
             break;
         }
@@ -1394 +1407 @@
         return;
     }
-    if (vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global)) {
+    if (vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global) || vPC[0].u.opcode == interpreter->getOpcode(op_resolve_global_dynamic)) {
         if(vPC[4].u.structure)
             vPC[4].u.structure->deref();