MIPS: Skip the mapcheck on the global object since the global proxy and cell...

MIPS: Skip the mapcheck on the global object since the global proxy and cell are already checked (or the global object map for contextual global loads).

Port 6af7ca6b

BUG=

Review URL: https://codereview.chromium.org/957393002

Cr-Commit-Position: refs/heads/master@{#26909}

src/ic/mips/handler-compiler-mips.cc

@@ -463,15 +463,14 @@ Register PropertyHandlerCompiler::CheckPrototypes(
     } else {
       Register map_reg = scratch1;
       __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
-      if (depth != 1 || check == CHECK_ALL_MAPS) {
-        Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
-        __ GetWeakValue(scratch2, cell);
-        __ Branch(miss, ne, scratch2, Operand(map_reg));
-      }
 
       if (current_map->IsJSGlobalObjectMap()) {
         GenerateCheckPropertyCell(masm(), Handle<JSGlobalObject>::cast(current),
                                   name, scratch2, miss);
+      } else if (depth != 1 || check == CHECK_ALL_MAPS) {
+        Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
+        __ GetWeakValue(scratch2, cell);
+        __ Branch(miss, ne, scratch2, Operand(map_reg));
       }
 
       reg = holder_reg;  // From now on the object will be in holder_reg.
@@ -484,6 +483,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
     current_map = handle(current->map());
   }
 
+  DCHECK(!current_map->IsJSGlobalProxyMap());
+
   // Log the check depth.
   LOG(isolate(), IntEvent("check-maps-depth", depth + 1));
 

src/ic/mips64/handler-compiler-mips64.cc

@@ -464,15 +464,14 @@ Register PropertyHandlerCompiler::CheckPrototypes(
     } else {
       Register map_reg = scratch1;
       __ ld(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
-      if (depth != 1 || check == CHECK_ALL_MAPS) {
-        Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
-        __ GetWeakValue(scratch2, cell);
-        __ Branch(miss, ne, scratch2, Operand(map_reg));
-      }
 
       if (current_map->IsJSGlobalObjectMap()) {
         GenerateCheckPropertyCell(masm(), Handle<JSGlobalObject>::cast(current),
                                   name, scratch2, miss);
+      } else if (depth != 1 || check == CHECK_ALL_MAPS) {
+        Handle<WeakCell> cell = Map::WeakCellForMap(current_map);
+        __ GetWeakValue(scratch2, cell);
+        __ Branch(miss, ne, scratch2, Operand(map_reg));
       }
 
       reg = holder_reg;  // From now on the object will be in holder_reg.
@@ -485,6 +484,8 @@ Register PropertyHandlerCompiler::CheckPrototypes(
     current_map = handle(current->map());
   }
 
+  DCHECK(!current_map->IsJSGlobalProxyMap());
+
   // Log the check depth.
   LOG(isolate(), IntEvent("check-maps-depth", depth + 1));