Changeset 139540 in webkit

Timestamp:

Jan 11, 2013, 8:22:32 PM (12 years ago)

Author:

fpizlo@apple.com

Message:

If you use Phantom to force something to be live across an OSR exit, you should put it after the OSR exit
​https://bugs.webkit.org/show_bug.cgi?id=106724

Reviewed by Oliver Hunt.

In cases where we were getting it wrong, I think it was benign because we would either already have an
OSR exit prior to there, or the operand would be a constant. But still, it's good to get this right.

• dfg/DFGByteCodeParser.cpp:

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

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• dfg/DFGByteCodeParser.cpp (modified) (4 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2013-01-11  Filip Pizlo  <fpizlo@apple.com>
+
+        If you use Phantom to force something to be live across an OSR exit, you should put it after the OSR exit
+        https://bugs.webkit.org/show_bug.cgi?id=106724
+
+        Reviewed by Oliver Hunt.
+        
+        In cases where we were getting it wrong, I think it was benign because we would either already have an
+        OSR exit prior to there, or the operand would be a constant.  But still, it's good to get this right.
+
+        * dfg/DFGByteCodeParser.cpp:
+        (JSC::DFG::ByteCodeParser::parseBlock):
+
 2013-01-11  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp

@@ -3014 +3014 @@
 
             if (putToBase->m_isDynamic) {
-                addToGraph(Phantom, get(base));
                 addToGraph(PutById, OpInfo(identifier), get(base), get(value));
                 NEXT_OPCODE(op_put_to_base);
@@ -3021 +3020 @@
             switch (putToBase->m_kind) {
             case PutToBaseOperation::Uninitialised:
+                addToGraph(ForceOSRExit);
                 addToGraph(Phantom, get(base));
-                addToGraph(ForceOSRExit);
                 break;
 
@@ -3050 +3049 @@
             case PutToBaseOperation::GlobalPropertyPut: {
                 if (!putToBase->m_structure) {
+                    addToGraph(ForceOSRExit);
                     addToGraph(Phantom, get(base));
-                    addToGraph(ForceOSRExit);
                     NEXT_OPCODE(op_put_to_base);
                 }
@@ -3071 +3070 @@
             case PutToBaseOperation::Readonly:
             case PutToBaseOperation::Generic:
-                addToGraph(Phantom, get(base));
                 addToGraph(PutById, OpInfo(identifier), get(base), get(value));
             }