Imported WebKit commit 356d83016b090995d08ad568f2d2c243aa55e831 (http://svn.webkit.org/repository/webkit/trunk@126147)

New snapshot including various build fixes for newer Qt 5

1 files changed, 24 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp b/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp
index 9208cde1b..000e1a938 100644
--- a/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGArgumentsSimplificationPhase.cpp
@@ -317,6 +317,17 @@ public:
                     // PhantomArguments and OSR exit will still do the right things.
                     break;
                     
+                case CheckStructure:
+                case ForwardCheckStructure:
+                case StructureTransitionWatchpoint:
+                case ForwardStructureTransitionWatchpoint:
+                    // We don't care about these because if we get uses of the relevant
+                    // variable then we can safely get rid of these, too. This of course
+                    // relies on there not being any information transferred by the CFA
+                    // from a CheckStructure on one variable to the information about the
+                    // structures of another variable.
+                    break;
+                    
                 default:
                     observeBadArgumentsUses(node);
                     break;
@@ -471,6 +482,19 @@ public:
                     break;
                 }
                     
+                case CheckStructure:
+                case ForwardCheckStructure:
+                case StructureTransitionWatchpoint:
+                case ForwardStructureTransitionWatchpoint: {
+                    // We can just get rid of this node, if it references a phantom argument.
+                    if (!isOKToOptimize(m_graph[node.child1()]))
+                        break;
+                    m_graph.deref(node.child1());
+                    node.setOpAndDefaultFlags(Phantom);
+                    node.children.setChild1(Edge());
+                    break;
+                }
+                    
                 case GetByVal: {
                     if (!node.prediction()
                         || !m_graph[node.child1()].prediction()