Changeset 179767 in webkit

Timestamp:

Feb 6, 2015, 3:37:39 PM (12 years ago)

Author:

fpizlo@apple.com

Message:

DFG SSA shouldn't have SetArgument nodes
​https://bugs.webkit.org/show_bug.cgi?id=141342

Reviewed by Mark Lam.

I was wondering why we kept the SetArgument around for captured
variables. It turns out we did so because we thought we had to, even
though we didn't have to. The node is meaningless in SSA.

• dfg/DFGSSAConversionPhase.cpp:

(JSC::DFG::SSAConversionPhase::run):

• ftl/FTLLowerDFGToLLVM.cpp:

(JSC::FTL::LowerDFGToLLVM::compileNode):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• dfg/DFGSSAConversionPhase.cpp (modified) (2 diffs)
• ftl/FTLLowerDFGToLLVM.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2015-02-06  Filip Pizlo  <fpizlo@apple.com>
+
+        DFG SSA shouldn't have SetArgument nodes
+        https://bugs.webkit.org/show_bug.cgi?id=141342
+
+        Reviewed by Mark Lam.
+
+        I was wondering why we kept the SetArgument around for captured
+        variables. It turns out we did so because we thought we had to, even
+        though we didn't have to. The node is meaningless in SSA.
+
+        * dfg/DFGSSAConversionPhase.cpp:
+        (JSC::DFG::SSAConversionPhase::run):
+        * ftl/FTLLowerDFGToLLVM.cpp:
+        (JSC::FTL::LowerDFGToLLVM::compileNode):
+
 2015-02-06  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/dfg/DFGSSAConversionPhase.cpp

@@ -199 +199 @@
         //     valueForOperand.
         //
-        //   - SetArgument is removed unless it's a captured variable. Note that GetArgument nodes
-        //     have already been inserted.
+        //   - SetArgument is removed. Note that GetArgument nodes have already been inserted.
         Operands<Node*> valueForOperand(OperandsLike, m_graph.block(0)->variablesAtHead);
         for (BasicBlock* block : m_graph.blocksInPreOrder()) {
@@ -335 +334 @@
                     
                 case SetArgument: {
-                    VariableAccessData* variable = node->variableAccessData();
-                    if (variable->isCaptured())
-                        break;
                     node->convertToPhantom();
                     break;

trunk/Source/JavaScriptCore/ftl/FTLLowerDFGToLLVM.cpp

@@ -736 +736 @@
 
         case PhantomLocal:
-        case SetArgument:
         case LoopHint:
         case VariableWatchpoint: