Introduce HObjectAccess, which is used by LoadNamedField and StoreNamedField to denote what parts

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 70e2395574747085a8a554cc0a84d00eecd81390..74419470e74cfbf0e46f98f34b1478333b6c1401 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -3653,4 +3653,39 @@ void HCheckFunction::Verify() {
 
 #endif
 

[danno, 2013/05/02 14:16:47]

nit: 2 lines

[titzer, 2013/05/03 09:18:41]

Done.

+void HObjectAccess::SetGVNFlags(HValue *instr, bool is_store) {
+  // set the appropriate GVN flags for a given load or store instruction
+  if (!is_store) {

[danno, 2013/05/02 14:16:47]

Why not just switch the else and then blocks so it's "if (is_store)"

[titzer, 2013/05/03 09:18:41]

Done.

+    instr->SetFlag(HValue::kUseGVN);    // try to GVN loads
+    instr->SetGVNFlag(kDependsOnMaps);  // but don't hoist above map changes
+  } else {
+    // track dominating allocations in order to eliminate write barriers
+    instr->SetGVNFlag(kDependsOnNewSpacePromotion);
+    instr->SetFlag(HValue::kTrackSideEffectDominators);
+  }
+
+  switch (portion_) {
+  case kArrayLengths:

[danno, 2013/05/02 14:16:47]

Weird indentation. Elsewhere in the code we use 2-char indents for cases, please
use that here, too.

[titzer, 2013/05/03 09:18:41]

Done.

+    instr->SetGVNFlag(
+        is_store ? kChangesArrayLengths : kDependsOnArrayLengths);
+    break;
+  case kInobject:
+    instr->SetGVNFlag(
+        is_store ? kChangesInobjectFields : kDependsOnInobjectFields);
+    break;
+  case kBackingStore:
+    instr->SetGVNFlag(
+        is_store ? kChangesBackingStoreFields : kDependsOnBackingStoreFields);
+    break;
+  case kElementsPointer:
+    instr->SetGVNFlag(
+        is_store ? kChangesElementsPointer : kDependsOnElementsPointer);
+    break;
+  case kMaps:
+    instr->SetGVNFlag(
+        is_store ? kChangesMaps : kDependsOnMaps);
+    break;
+  }
+}
+
 } }  // namespace v8::internal