Changeset 53391 in webkit for trunk/JavaScriptCore/bytecode

Timestamp:

Jan 17, 2010, 11:28:53 PM (15 years ago)

Author:

[email protected]

Message:

​https://bugs.webkit.org/show_bug.cgi?id=33731
Remove uses of PtrAndFlags from JIT data stuctures.

Reviewed by Oliver Hunt.

These break the OS X Leaks tool. Free up a bit in CallLinkInfo, and invalid
permutation of pointer states in MethodCallLinkInfo to represent the removed bits.

• bytecode/CodeBlock.h:

(JSC::CallLinkInfo::seenOnce):
(JSC::CallLinkInfo::setSeen):
(JSC::MethodCallLinkInfo::MethodCallLinkInfo):
(JSC::MethodCallLinkInfo::seenOnce):
(JSC::MethodCallLinkInfo::setSeen):

• jit/JIT.cpp:

(JSC::JIT::unlinkCall):

• jit/JITPropertyAccess.cpp:

(JSC::JIT::patchMethodCallProto):

• runtime/UString.h:

File:

• trunk/JavaScriptCore/bytecode/CodeBlock.h (modified) (4 diffs)

trunk/JavaScriptCore/bytecode/CodeBlock.h

@@ -111 +111 @@
         CodeLocationDataLabelPtr hotPathBegin;
         CodeLocationNearCall hotPathOther;
-        PtrAndFlags<CodeBlock, HasSeenShouldRepatch> ownerCodeBlock;
+        CodeBlock* ownerCodeBlock;
         CodeBlock* callee;
-        unsigned position;
+        unsigned position : 31;
+        unsigned hasSeenShouldRepatch : 1;
         
         void setUnlinked() { callee = 0; }
@@ -120 +121 @@
         bool seenOnce()
         {
-            return ownerCodeBlock.isFlagSet(hasSeenShouldRepatch);
+            return hasSeenShouldRepatch;
         }
 
         void setSeen()
         {
-            ownerCodeBlock.setFlag(hasSeenShouldRepatch);
-        }
-    };
+            hasSeenShouldRepatch = true;
+        }
+    };
+
+#define MethodCallLinkInfo_seenFlag ((Structure*)1)
 
     struct MethodCallLinkInfo {
         MethodCallLinkInfo()
             : cachedStructure(0)
+            , cachedPrototypeStructure(0)
         {
         }
@@ -137 +141 @@
         bool seenOnce()
         {
-            return cachedPrototypeStructure.isFlagSet(hasSeenShouldRepatch);
+            ASSERT(!cachedStructure);
+            return cachedPrototypeStructure;
         }
 
         void setSeen()
         {
-            cachedPrototypeStructure.setFlag(hasSeenShouldRepatch);
+            ASSERT(!cachedStructure && !cachedPrototypeStructure);
+            // We use the values of cachedStructure & cachedPrototypeStructure to indicate the
+            // current state.
+            //     - In the initial state, both are null.
+            //     - Once this transition has been taken once, cachedStructure is
+            //       null and cachedPrototypeStructure is set to a nun-null value.
+            //     - Once the call is linked both structures are set to non-null values.
+            cachedPrototypeStructure = MethodCallLinkInfo_seenFlag;
         }
 
@@ -148 +160 @@
         CodeLocationDataLabelPtr structureLabel;
         Structure* cachedStructure;
-        PtrAndFlags<Structure, HasSeenShouldRepatch> cachedPrototypeStructure;
+        Structure* cachedPrototypeStructure;
     };