commit 2faae0ed1b7ba5a8ce146e263ae12ece9ccc9ea1
author commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Mon Oct 07 22:08:53 2013 +0000
committer commit-queue@webkit.org <commit-queue@webkit.org@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Mon Oct 07 22:08:53 2013 +0000
tree de2ab0c2670eb6da7b18c316da81e6100bc85a4c
parent f293496b879c2d880e85e5641e7c6854b896f155

FTL: Optimize IsString(@2<String>) -> JSConst(true) + Phantom()
https://bugs.webkit.org/show_bug.cgi?id=122363

Patch by Nadav Rotem <nrotem@apple.com> on 2013-10-07
Reviewed by Filip Pizlo.

* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@157059 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/JavaScriptCore/dfg/DFGFixupPhase.cpp

diff --git a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
index 499f56f..59128d4 100644
--- a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
@@ -884,8 +884,17 @@
         case Int52ToValue:
             RELEASE_ASSERT_NOT_REACHED();
             break;
-        
-#if !ASSERT_DISABLED    
+
+        case IsString:
+            if (node->child1()->shouldSpeculateString()) {
+                m_insertionSet.insertNode(m_indexInBlock, SpecNone, Phantom, node->codeOrigin,
+                    Edge(node->child1().node(), StringUse));
+                m_graph.convertToConstant(node, jsBoolean(true));
+                observeUseKindOnNode<StringUse>(node);
+            }
+            break;
+
+#if !ASSERT_DISABLED
         // Have these no-op cases here to ensure that nobody forgets to add handlers for new opcodes.
         case SetArgument:
         case JSConstant:
@@ -912,7 +921,6 @@
         case IsUndefined:
         case IsBoolean:
         case IsNumber:
-        case IsString:
         case IsObject:
         case IsFunction:
         case CreateActivation: