Only flush SharedFunctionInfo optimized code cache when necessary

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index dfcb29b6027aafbdfab53181fecb10d5f52b542c..1d560fd03d74ef81d8f6621885ea621d9ed2e040 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9034,7 +9034,7 @@ void SharedFunctionInfo::InstallFromOptimizedCodeMap(JSFunction* function,
 void SharedFunctionInfo::ClearOptimizedCodeMap(const char* reason) {
   if (!optimized_code_map()->IsSmi()) {
     if (FLAG_trace_opt) {
-      PrintF("[clearing optimizing code map (%s) for ", reason);
+      PrintF("[clearing entire optimizing code map (%s) for ", reason);
       ShortPrint();
       PrintF("]\n");
     }
@@ -9043,6 +9043,47 @@ void SharedFunctionInfo::ClearOptimizedCodeMap(const char* reason) {
 }
 
 
+void SharedFunctionInfo::EvictFromOptimizedCodeMap(Code* optimized_code,
+                                                   const char* reason) {
+  if (optimized_code_map()->IsSmi()) return;
+
+  int i;
+  bool removed_entry = false;
+  FixedArray* code_map = FixedArray::cast(optimized_code_map());
+  for (i = 0; i < code_map->length(); i += kEntryLength) {
+    ASSERT(code_map->get(i)->IsNativeContext());
+    if (Code::cast(code_map->get(i + 1)) == optimized_code) {
+      if (FLAG_trace_opt) {
+        PrintF("[clearing optimizing code map (%s) for ", reason);
+        ShortPrint();
+        PrintF("]\n");
+      }
+      removed_entry = true;
+      break;
+    }
+  }
+  while (i < (code_map->length() - kEntryLength)) {
+    code_map->set(i, code_map->get(i + 1 + kEntryLength));

[Michael Starzinger, 2013/05/13 14:26:46]

The indices look suspiciously off in this loop!

[danno, 2013/05/13 15:23:10]

Done.

+    code_map->set(i + 1, code_map->get(i + 2 + kEntryLength));
+    code_map->set(i + 2, code_map->get(i + 3 + kEntryLength));
+    i += kEntryLength;
+  }
+  if (removed_entry) {
+    Heap* heap = GetHeap();
+    int new_length = code_map->length() - kEntryLength;
+    if (new_length == 0) {
+      ClearOptimizedCodeMap(reason);
+      return;
+    }
+    Address filler_start = reinterpret_cast<Address>(
+        code_map->GetFirstElementAddress() + new_length);
+    heap->CreateFillerObjectAt(filler_start,

[Michael Starzinger, 2013/05/13 14:26:46]

This will destroy live-bytes count if incremental marking is active. Please use
the RightTrimFixedArray helper instead to do the trimming.

[danno, 2013/05/13 15:23:10]

Done.

[danno, 2013/05/13 15:23:10]

Oh, this is much better! Thanks!
On 2013/05/13 14:26:46, Michael Starzinger wrote:

+                               kEntryLength * kPointerSize);
+    code_map->set_length(new_length);
+  }
+}
+
+
 bool JSFunction::CompileLazy(Handle<JSFunction> function,
                              ClearExceptionFlag flag) {
   bool result = true;