Changeset 95742 in webkit

Timestamp:

Sep 22, 2011 11:51:02 AM (13 years ago)

Author:

oliver@apple.com

Message:

Implement get_scoped_var in the DFG
​https://bugs.webkit.org/show_bug.cgi?id=68640

Reviewed by Gavin Barraclough.

Naive implementation of get_scoped_var in the DFG. Essentially this
is the bare minimum required to get correct behaviour, so there's no
load/store coalescing or type profiling involved, even though these
would be wins. No impact on SunSpider or V8.

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::parseBlock):

• dfg/DFGCapabilities.h:

(JSC::DFG::canCompileOpcode):

• dfg/DFGNode.h:

(JSC::DFG::Node::hasVarNumber):
(JSC::DFG::Node::hasScopeChainDepth):
(JSC::DFG::Node::scopeChainDepth):

• dfg/DFGPropagator.cpp:

(JSC::DFG::Propagator::propagateNodePredictions):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compile):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• dfg/DFGByteCodeParser.cpp (modified) (1 diff)
• dfg/DFGCapabilities.h (modified) (1 diff)
• dfg/DFGNode.h (modified) (3 diffs)
• dfg/DFGPropagator.cpp (modified) (1 diff)
• dfg/DFGSpeculativeJIT.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-09-22  Oliver Hunt  <oliver@apple.com>
+
+        Implement get_scoped_var in the DFG
+        https://bugs.webkit.org/show_bug.cgi?id=68640
+
+        Reviewed by Gavin Barraclough.
+
+        Naive implementation of get_scoped_var in the DFG.  Essentially this
+        is the bare minimum required to get correct behaviour, so there's no
+        load/store coalescing or type profiling involved, even though these
+        would be wins.  No impact on SunSpider or V8.
+
+        * dfg/DFGByteCodeParser.cpp:
+        (JSC::DFG::ByteCodeParser::parseBlock):
+        * dfg/DFGCapabilities.h:
+        (JSC::DFG::canCompileOpcode):
+        * dfg/DFGNode.h:
+        (JSC::DFG::Node::hasVarNumber):
+        (JSC::DFG::Node::hasScopeChainDepth):
+        (JSC::DFG::Node::scopeChainDepth):
+        * dfg/DFGPropagator.cpp:
+        (JSC::DFG::Propagator::propagateNodePredictions):
+        * dfg/DFGSpeculativeJIT.cpp:
+        (JSC::DFG::SpeculativeJIT::compile):
+
 2011-09-22  Adam Roben  <aroben@apple.com>
 

trunk/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp

@@ -1082 +1082 @@
             continue;
         }
-
+        case op_get_scoped_var: {
+            int dst = currentInstruction[1].u.operand;
+            int slot = currentInstruction[2].u.operand;
+            int depth = currentInstruction[3].u.operand;
+            NodeIndex getScopedVar = addToGraph(GetScopedVar, OpInfo(slot), OpInfo(depth));
+            set(dst, getScopedVar);
+            NEXT_OPCODE(op_get_scoped_var);
+        }
         case op_get_by_id: {
             NodeIndex base = get(currentInstruction[2].u.operand);

trunk/Source/JavaScriptCore/dfg/DFGCapabilities.h

@@ -83 +83 @@
     case op_put_by_val:
     case op_method_check:
+    case op_get_scoped_var:
     case op_get_by_id:
     case op_put_by_id:

trunk/Source/JavaScriptCore/dfg/DFGNode.h

@@ -269 +269 @@
     macro(GetMethod, NodeResultJS | NodeMustGenerate) \
     macro(CheckMethod, NodeResultJS | NodeMustGenerate) \
+    macro(GetScopedVar, NodeResultJS | NodeMustGenerate) \
     macro(GetGlobalVar, NodeResultJS | NodeMustGenerate) \
     macro(PutGlobalVar, NodeMustGenerate | NodeClobbersWorld) \
@@ -538 +539 @@
     bool hasVarNumber()
     {
-        return op == GetGlobalVar || op == PutGlobalVar;
+        return op == GetGlobalVar || op == PutGlobalVar || op == GetScopedVar;
     }
 
@@ -545 +546 @@
         ASSERT(hasVarNumber());
         return m_opInfo;
+    }
+
+    bool hasScopeChainDepth()
+    {
+        return op == GetScopedVar;
+    }
+    
+    unsigned scopeChainDepth()
+    {
+        ASSERT(hasScopeChainDepth());
+        return m_opInfo2;
     }
 

trunk/Source/JavaScriptCore/dfg/DFGPropagator.cpp

@@ -561 +561 @@
         case ResolveBase:
         case ResolveBaseStrictPut:
+        case GetScopedVar:
             break;
             

trunk/Source/JavaScriptCore/dfg/DFGSpeculativeJIT.cpp

@@ -1626 +1626 @@
         break;
     }
-
+    case GetScopedVar: {
+        GPRTemporary result(this);
+        GPRReg resultGPR = result.gpr();
+
+        m_jit.loadPtr(JITCompiler::addressFor(static_cast<VirtualRegister>(RegisterFile::ScopeChain)), resultGPR);
+        bool checkTopLevel = m_jit.codeBlock()->codeType() == FunctionCode && m_jit.codeBlock()->needsFullScopeChain();
+        int skip = node.scopeChainDepth();
+        ASSERT(skip || !checkTopLevel);
+        if (checkTopLevel && skip--) {
+            JITCompiler::Jump activationNotCreated;
+            if (checkTopLevel)
+                activationNotCreated = m_jit.branchTestPtr(JITCompiler::Zero, JITCompiler::addressFor(static_cast<VirtualRegister>(m_jit.codeBlock()->activationRegister())));
+            m_jit.loadPtr(JITCompiler::Address(resultGPR, OBJECT_OFFSETOF(ScopeChainNode, next)), resultGPR);
+            activationNotCreated.link(&m_jit);
+        }
+        while (skip--)
+            m_jit.loadPtr(JITCompiler::Address(resultGPR, OBJECT_OFFSETOF(ScopeChainNode, next)), resultGPR);
+        
+        m_jit.loadPtr(JITCompiler::Address(resultGPR, OBJECT_OFFSETOF(ScopeChainNode, object)), resultGPR);
+        m_jit.loadPtr(JITCompiler::Address(resultGPR, JSVariableObject::offsetOfRegisters()), resultGPR);
+        m_jit.loadPtr(JITCompiler::Address(resultGPR, node.varNumber() * sizeof(Register)), resultGPR);
+        jsValueResult(resultGPR, m_compileIndex);
+        break;
+    }
     case GetById: {
         SpeculateCellOperand base(this, node.child1());