[api] Only support direct hidden prototypes for API call optimizations

There are only two users of hidden prototypes left and they both only have 1 level. This slightly simplifies the handcrafted code.

Bug: v8:5561
Change-Id: I674e72f1465ccbe75c0bb63f7eea3525830145cb
Reviewed-on: https://chromium-review.googlesource.com/512745Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45503}

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

@@ -199,9 +199,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -209,10 +207,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ ldr(holder, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ ldr(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ ldr(holder, FieldMemOperand(holder, HeapObject::kMapOffset));
-        __ ldr(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

src/ic/arm64/handler-compiler-arm64.cc

@@ -134,9 +134,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Mov(holder, receiver);
@@ -144,10 +142,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ Ldr(holder, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ Ldr(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ Ldr(holder, FieldMemOperand(holder, HeapObject::kMapOffset));
-        __ Ldr(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

src/ic/call-optimization.cc

@@ -20,10 +20,8 @@ CallOptimization::CallOptimization(Handle<Object> function) {
   }
 }
 
-
 Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
-    Handle<Map> object_map, HolderLookup* holder_lookup,
-    int* holder_depth_in_prototype_chain) const {
+    Handle<Map> object_map, HolderLookup* holder_lookup) const {
   DCHECK(is_simple_api_call());
   if (!object_map->IsJSObjectMap()) {
     *holder_lookup = kHolderNotFound;
@@ -34,15 +32,11 @@ Handle<JSObject> CallOptimization::LookupHolderOfExpectedType(
     *holder_lookup = kHolderIsReceiver;
     return Handle<JSObject>::null();
   }
-  for (int depth = 1; true; depth++) {
-    if (!object_map->has_hidden_prototype()) break;
+  if (object_map->has_hidden_prototype()) {
     Handle<JSObject> prototype(JSObject::cast(object_map->prototype()));
     object_map = handle(prototype->map());
     if (expected_receiver_type_->IsTemplateFor(*object_map)) {
       *holder_lookup = kHolderFound;
-      if (holder_depth_in_prototype_chain != NULL) {
-        *holder_depth_in_prototype_chain = depth;
-      }
       return prototype;
     }
   }

src/ic/call-optimization.h

@@ -38,8 +38,7 @@ class CallOptimization BASE_EMBEDDED {
 
   enum HolderLookup { kHolderNotFound, kHolderIsReceiver, kHolderFound };
   Handle<JSObject> LookupHolderOfExpectedType(
-      Handle<Map> receiver_map, HolderLookup* holder_lookup,
-      int* holder_depth_in_prototype_chain = NULL) const;
+      Handle<Map> receiver_map, HolderLookup* holder_lookup) const;
 
   // Check if the api holder is between the receiver and the holder.
   bool IsCompatibleReceiver(Handle<Object> receiver,

src/ic/ia32/handler-compiler-ia32.cc

@@ -139,9 +139,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -149,10 +147,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ mov(holder, FieldOperand(receiver, HeapObject::kMapOffset));
       __ mov(holder, FieldOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ mov(holder, FieldOperand(holder, HeapObject::kMapOffset));
-        __ mov(holder, FieldOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

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

@@ -189,9 +189,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -199,10 +197,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ lw(holder, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ lw(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ lw(holder, FieldMemOperand(holder, HeapObject::kMapOffset));
-        __ lw(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

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

@@ -188,9 +188,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -198,10 +196,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ Ld(holder, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ Ld(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ Ld(holder, FieldMemOperand(holder, HeapObject::kMapOffset));
-        __ Ld(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

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

@@ -194,9 +194,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -204,10 +202,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ LoadP(holder, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ LoadP(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ LoadP(holder, FieldMemOperand(holder, HeapObject::kMapOffset));
-        __ LoadP(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

src/ic/s390/handler-compiler-s390.cc

@@ -186,9 +186,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -196,10 +194,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ LoadP(holder, FieldMemOperand(receiver, HeapObject::kMapOffset));
       __ LoadP(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ LoadP(holder, FieldMemOperand(holder, HeapObject::kMapOffset));
-        __ LoadP(holder, FieldMemOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

src/ic/x64/handler-compiler-x64.cc

@@ -117,9 +117,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -127,10 +125,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ movp(holder, FieldOperand(receiver, HeapObject::kMapOffset));
       __ movp(holder, FieldOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ movp(holder, FieldOperand(holder, HeapObject::kMapOffset));
-        __ movp(holder, FieldOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();

src/ic/x87/handler-compiler-x87.cc

@@ -138,9 +138,7 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
 
   // Put holder in place.
   CallOptimization::HolderLookup holder_lookup;
-  int holder_depth = 0;
-  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup,
-                                          &holder_depth);
+  optimization.LookupHolderOfExpectedType(receiver_map, &holder_lookup);
   switch (holder_lookup) {
     case CallOptimization::kHolderIsReceiver:
       __ Move(holder, receiver);
@@ -148,10 +146,6 @@ void PropertyHandlerCompiler::GenerateApiAccessorCall(
     case CallOptimization::kHolderFound:
       __ mov(holder, FieldOperand(receiver, HeapObject::kMapOffset));
       __ mov(holder, FieldOperand(holder, Map::kPrototypeOffset));
-      for (int i = 1; i < holder_depth; i++) {
-        __ mov(holder, FieldOperand(holder, HeapObject::kMapOffset));
-        __ mov(holder, FieldOperand(holder, Map::kPrototypeOffset));
-      }
       break;
     case CallOptimization::kHolderNotFound:
       UNREACHABLE();