MIPS: Always require exact maps.

Port r14768 (5dec309f)

BUG=

Review URL: https://codereview.chromium.org/15948003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14784 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -2763,9 +2763,7 @@ void LCodeGen::DoLoadNamedFieldPolymorphic(LLoadNamedFieldPolymorphic* instr) {
     bool last = (i == map_count - 1);
     Handle<Map> map = instr->hydrogen()->types()->at(i);
     Label check_passed;
-    __ CompareMapAndBranch(
-        object_map, map, &check_passed,
-        eq, &check_passed, ALLOW_ELEMENT_TRANSITION_MAPS);
+    __ CompareMapAndBranch(object_map, map, &check_passed, eq, &check_passed);
     if (last && !need_generic) {
       DeoptimizeIf(al, instr->environment());
       __ bind(&check_passed);
@@ -5010,10 +5008,9 @@ void LCodeGen::DoCheckFunction(LCheckFunction* instr) {
 
 void LCodeGen::DoCheckMapCommon(Register map_reg,
                                 Handle<Map> map,
-                                CompareMapMode mode,
                                 LEnvironment* env) {
   Label success;
-  __ CompareMapAndBranch(map_reg, map, &success, eq, &success, mode);
+  __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
   DeoptimizeIf(al, env);
   __ bind(&success);
 }
@@ -5029,11 +5026,10 @@ void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
   __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
   for (int i = 0; i < map_set->length() - 1; i++) {
     Handle<Map> map = map_set->at(i);
-    __ CompareMapAndBranch(
-        map_reg, map, &success, eq, &success, REQUIRE_EXACT_MAP);
+    __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
   }
   Handle<Map> map = map_set->last();
-  DoCheckMapCommon(map_reg, map, REQUIRE_EXACT_MAP, instr->environment());
+  DoCheckMapCommon(map_reg, map, instr->environment());
   __ bind(&success);
 }
 
@@ -5105,10 +5101,7 @@ void LCodeGen::DoCheckPrototypeMaps(LCheckPrototypeMaps* instr) {
     for (int i = 0; i < prototypes->length(); i++) {
       __ LoadHeapObject(prototype_reg, prototypes->at(i));
       __ lw(map_reg, FieldMemOperand(prototype_reg, HeapObject::kMapOffset));
-      DoCheckMapCommon(map_reg,
-                       maps->at(i),
-                       ALLOW_ELEMENT_TRANSITION_MAPS,
-                       instr->environment());
+      DoCheckMapCommon(map_reg, maps->at(i), instr->environment());
     }
   }
 }

src/mips/lithium-codegen-mips.h

@@ -155,8 +155,7 @@ class LCodeGen BASE_EMBEDDED {
   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                        Label* map_check);
 
-  void DoCheckMapCommon(Register map_reg, Handle<Map> map,
-                        CompareMapMode mode, LEnvironment* env);
+  void DoCheckMapCommon(Register map_reg, Handle<Map> map, LEnvironment* env);
 
   // Parallel move support.
   void DoParallelMove(LParallelMove* move);

src/mips/macro-assembler-mips.cc

@@ -3464,10 +3464,9 @@ void MacroAssembler::CompareMapAndBranch(Register obj,
                                          Handle<Map> map,
                                          Label* early_success,
                                          Condition cond,
-                                         Label* branch_to,
-                                         CompareMapMode mode) {
+                                         Label* branch_to) {
   lw(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
-  CompareMapAndBranch(scratch, map, early_success, cond, branch_to, mode);
+  CompareMapAndBranch(scratch, map, early_success, cond, branch_to);
 }
 
 
@@ -3475,25 +3474,8 @@ void MacroAssembler::CompareMapAndBranch(Register obj_map,
                                          Handle<Map> map,
                                          Label* early_success,
                                          Condition cond,
-                                         Label* branch_to,
-                                         CompareMapMode mode) {
-  Operand right = Operand(map);
-  if (mode == ALLOW_ELEMENT_TRANSITION_MAPS) {
-    ElementsKind kind = map->elements_kind();
-    if (IsFastElementsKind(kind)) {
-      bool packed = IsFastPackedElementsKind(kind);
-      Map* current_map = *map;
-      while (CanTransitionToMoreGeneralFastElementsKind(kind, packed)) {
-        kind = GetNextMoreGeneralFastElementsKind(kind, packed);
-        current_map = current_map->LookupElementsTransitionMap(kind);
-        if (!current_map) break;
-        Branch(early_success, eq, obj_map, right);
-        right = Operand(Handle<Map>(current_map));
-      }
-    }
-  }
-
-  Branch(branch_to, cond, obj_map, right);
+                                         Label* branch_to) {
+  Branch(branch_to, cond, obj_map, Operand(map));
 }
 
 
@@ -3501,13 +3483,12 @@ void MacroAssembler::CheckMap(Register obj,
                               Register scratch,
                               Handle<Map> map,
                               Label* fail,
-                              SmiCheckType smi_check_type,
-                              CompareMapMode mode) {
+                              SmiCheckType smi_check_type) {
   if (smi_check_type == DO_SMI_CHECK) {
     JumpIfSmi(obj, fail);
   }
   Label success;
-  CompareMapAndBranch(obj, scratch, map, &success, ne, fail, mode);
+  CompareMapAndBranch(obj, scratch, map, &success, ne, fail);
   bind(&success);
 }
 

src/mips/macro-assembler-mips.h

@@ -1014,8 +1014,7 @@ class MacroAssembler: public Assembler {
                            Handle<Map> map,
                            Label* early_success,
                            Condition cond,
-                           Label* branch_to,
-                           CompareMapMode mode = REQUIRE_EXACT_MAP);
+                           Label* branch_to);
 
   // As above, but the map of the object is already loaded into the register
   // which is preserved by the code generated.
@@ -1023,8 +1022,7 @@ class MacroAssembler: public Assembler {
                            Handle<Map> map,
                            Label* early_success,
                            Condition cond,
-                           Label* branch_to,
-                           CompareMapMode mode = REQUIRE_EXACT_MAP);
+                           Label* branch_to);
 
   // Check if the map of an object is equal to a specified map and branch to
   // label if not. Skip the smi check if not required (object is known to be a
@@ -1034,8 +1032,7 @@ class MacroAssembler: public Assembler {
                 Register scratch,
                 Handle<Map> map,
                 Label* fail,
-                SmiCheckType smi_check_type,
-                CompareMapMode mode = REQUIRE_EXACT_MAP);
+                SmiCheckType smi_check_type);
 
 
   void CheckMap(Register obj,

src/mips/stub-cache-mips.cc

@@ -453,7 +453,7 @@ void StubCompiler::GenerateStoreTransition(MacroAssembler* masm,
 
   // Check that the map of the object hasn't changed.
   __ CheckMap(receiver_reg, scratch1, Handle<Map>(object->map()), miss_label,
-              DO_SMI_CHECK, REQUIRE_EXACT_MAP);
+              DO_SMI_CHECK);
 
   // Perform global security token check if needed.
   if (object->IsJSGlobalProxy()) {
@@ -662,7 +662,7 @@ void StubCompiler::GenerateStoreField(MacroAssembler* masm,
 
   // Check that the map of the object hasn't changed.
   __ CheckMap(receiver_reg, scratch1, Handle<Map>(object->map()), miss_label,
-              DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
+              DO_SMI_CHECK);
 
   // Perform global security token check if needed.
   if (object->IsJSGlobalProxy()) {
@@ -1261,8 +1261,7 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
       if (!current.is_identical_to(first) || check == CHECK_ALL_MAPS) {
         Handle<Map> current_map(current->map());
         // CheckMap implicitly loads the map of |reg| into |map_reg|.
-        __ CheckMap(reg, map_reg, current_map, miss, DONT_DO_SMI_CHECK,
-                    ALLOW_ELEMENT_TRANSITION_MAPS);
+        __ CheckMap(reg, map_reg, current_map, miss, DONT_DO_SMI_CHECK);
       } else {
         __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
       }
@@ -1298,7 +1297,7 @@ Register StubCompiler::CheckPrototypes(Handle<JSObject> object,
   if (!holder.is_identical_to(first) || check == CHECK_ALL_MAPS) {
     // Check the holder map.
     __ CheckMap(reg, scratch1, Handle<Map>(holder->map()), miss,
-                DONT_DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
+                DONT_DO_SMI_CHECK);
   }
 
   // Perform security check for access to the global object.
@@ -2861,7 +2860,7 @@ Handle<Code> StoreStubCompiler::CompileStoreInterceptor(
 
   // Check that the map of the object hasn't changed.
   __ CheckMap(receiver(), scratch1(), Handle<Map>(object->map()), &miss,
-              DO_SMI_CHECK, ALLOW_ELEMENT_TRANSITION_MAPS);
+              DO_SMI_CHECK);
 
   // Perform global security token check if needed.
   if (object->IsJSGlobalProxy()) {