[crankshaft] Loads and stores to typed arrays have to reference the backing store holder

src/crankshaft/x64/lithium-x64.cc

Index: src/crankshaft/x64/lithium-x64.cc
diff --git a/src/crankshaft/x64/lithium-x64.cc b/src/crankshaft/x64/lithium-x64.cc
index e7532cd804b4f58c00292c964859ae90ffb7d2a7..1bf1acd766d1c38e4f6c8acbdbb3344da0ea7f7c 100644
--- a/src/crankshaft/x64/lithium-x64.cc
+++ b/src/crankshaft/x64/lithium-x64.cc
@@ -2190,7 +2190,7 @@ LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
 
   if (!instr->is_fixed_typed_array()) {
     LOperand* obj = UseRegisterAtStart(instr->elements());
-    result = DefineAsRegister(new(zone()) LLoadKeyed(obj, key));
+    result = DefineAsRegister(new (zone()) LLoadKeyed(obj, key, nullptr));
   } else {
     DCHECK(
         (instr->representation().IsInteger32() &&
@@ -2198,7 +2198,9 @@ LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
         (instr->representation().IsDouble() &&
          (IsDoubleOrFloatElementsKind(elements_kind))));
     LOperand* backing_store = UseRegister(instr->elements());
-    result = DefineAsRegister(new(zone()) LLoadKeyed(backing_store, key));
+    LOperand* backing_store_owner = UseAny(instr->backing_store_owner());

[Benedikt Meurer, 2015/12/07 05:02:03]

I think UseAny in this case will prevent aliasing of backing_store_owner and
result, which means you need at least 4 free registers for this instruction,
even tho 3 would suffice. But given that we are sort of sloppy about the
constraints in this case anyway (i.e. UseRegister always on instr->elements())
it's probably fine to say UseAny here.

+    result = DefineAsRegister(
+        new (zone()) LLoadKeyed(backing_store, key, backing_store_owner));
   }
 
   bool needs_environment;
@@ -2270,7 +2272,7 @@ LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
       }
     }
 
-    return new(zone()) LStoreKeyed(object, key, val);
+    return new (zone()) LStoreKeyed(object, key, val, nullptr);
   }
 
   DCHECK(
@@ -2294,7 +2296,8 @@ LInstruction* LChunkBuilder::DoStoreKeyed(HStoreKeyed* instr) {
         : UseRegisterOrConstantAtStart(instr->key());
   }
   LOperand* backing_store = UseRegister(instr->elements());
-  return new(zone()) LStoreKeyed(backing_store, key, val);
+  LOperand* backing_store_owner = UseAny(instr->backing_store_owner());

[Benedikt Meurer, 2015/12/07 05:02:03]

Hm, I'm not sure if UseAny is the ideal choice here; but my knowledge about the
lithium allocator is close to zero at this point, so it's probably OK even tho
not 100% ideal.

+  return new (zone()) LStoreKeyed(backing_store, key, val, backing_store_owner);
 }