Changeset 36972 in webkit for trunk/JavaScriptCore/VM/Machine.cpp

Timestamp:

Sep 26, 2008, 3:40:26 PM (17 years ago)

Author:

[email protected]

Message:

2008-09-26 Geoffrey Garen <​[email protected]>

Reviewed by Maciej Stachowiak.

Removed dynamic check for whether the callee needs an activation object.
Replaced with callee code to create the activation object.

0.5% speedup on SunSpider.
No change on v8 benchmark. (Might be a speedup, but it's in range of the
variance.)

0.7% speedup on v8 benchmark in bytecode.
1.3% speedup on empty call benchmark in bytecode.

• VM/CTI.cpp: (JSC::CTI::privateCompileMainPass): Added support for op_init_activation, the new opcode that specifies that the callee's initialization should create an activation object. (JSC::CTI::privateCompile): Removed previous code that did a similar thing in an ad-hoc way.

• VM/CodeBlock.cpp: (JSC::CodeBlock::dump): Added a case for dumping op_init_activation.

• VM/CodeGenerator.cpp: (JSC::CodeGenerator::generate): Added fixup code to change op_init to op_init_activation if necessary. (With a better parser, we would know which to use from the beginning.)

• VM/Instruction.h: (JSC::Instruction::Instruction): (WTF::): Faster traits for the instruction vector. An earlier version of this patch relied on inserting at the beginning of the vector, and depended on this change for speed.

• VM/Machine.cpp: (JSC::Machine::execute): Removed clients of setScopeChain, the old abstraction for dynamically checking for whether an activation object needed to be created. (JSC::Machine::privateExecute): ditto

(JSC::Machine::cti_op_push_activation): Renamed this function from
cti_vm_updateScopeChain, and made it faster by removing the call to
setScopeChain.

• VM/Machine.h:

• VM/Opcode.h: Declared op_init_activation.

File:

• trunk/JavaScriptCore/VM/Machine.cpp (modified) (5 diffs)

trunk/JavaScriptCore/VM/Machine.cpp

@@ -980 +980 @@
     JSValue* result = CTI::execute(newCodeBlock->ctiCode, &newExec, &m_registerFile, r, scopeChain, newCodeBlock, exception);
 #else
-    setScopeChain(&newExec, scopeChain, scopeChainForCall(exec, functionBodyNode, newCodeBlock, scopeChain, r));
+    setScopeChain(&newExec, scopeChain, scopeChain);
     JSValue* result = privateExecute(Normal, &newExec, &m_registerFile, r, scopeChain, newCodeBlock, exception);
 #endif
@@ -3299 +3299 @@
 
             codeBlock = newCodeBlock;
-            setScopeChain(exec, scopeChain, scopeChainForCall(exec, functionBodyNode, codeBlock, callDataScopeChain, r));
+            setScopeChain(exec, scopeChain, callDataScopeChain);
             vPC = codeBlock->instructions.begin();
 
@@ -3390 +3390 @@
         NEXT_OPCODE;
     }
+    BEGIN_OPCODE(op_init_activation) {
+        size_t i = 0;
+
+        for (size_t count = codeBlock->numVars; i < count; ++i)
+            r[i] = jsUndefined();
+
+        for (size_t count = codeBlock->constantRegisters.size(), j = 0; j < count; ++i, ++j)
+            r[i] = codeBlock->constantRegisters[j];
+
+        JSActivation* activation = new (exec) JSActivation(exec, static_cast<FunctionBodyNode*>(codeBlock->ownerNode), r);
+        r[RegisterFile::OptionalCalleeActivation] = activation;
+        setScopeChain(exec, scopeChain, scopeChain->copy()->push(activation));
+
+        ++vPC;
+        NEXT_OPCODE;
+    }
     BEGIN_OPCODE(op_construct) {
         /* construct dst(r) constr(r) constrProto(r) firstArg(r) argCount(n) registerOffset(n)
@@ -3448 +3464 @@
 
             codeBlock = newCodeBlock;
-            setScopeChain(exec, scopeChain, scopeChainForCall(exec, functionBodyNode, codeBlock, callDataScopeChain, r));
+            setScopeChain(exec, scopeChain, callDataScopeChain);
             vPC = codeBlock->instructions.begin();
 
@@ -4471 +4487 @@
 }
 
-void Machine::cti_vm_updateScopeChain(CTI_ARGS)
+void Machine::cti_op_push_activation(CTI_ARGS)
 {
     ExecState* exec = ARG_exec;
     CodeBlock* codeBlock = ARG_codeBlock;
     ScopeChainNode* scopeChain = ARG_scopeChain;
-
-    exec->machine()->setScopeChain(exec, scopeChain, scopeChainForCall(exec, static_cast<FunctionBodyNode*>(codeBlock->ownerNode), codeBlock, scopeChain, ARG_r));
-
+    Register* r = ARG_r;
+
+    JSActivation* activation = new (exec) JSActivation(exec, static_cast<FunctionBodyNode*>(codeBlock->ownerNode), r);
+    r[RegisterFile::OptionalCalleeActivation] = activation;
+
+    setScopeChain(exec, scopeChain, scopeChain->copy()->push(activation));
     ARG_setScopeChain(scopeChain);
 }