MIPS: Migrate instance of deprecated maps in HCheckMaps.

Port r16057 (b73ae514)

Original commit message:
Currently only direct map checks are supported. Otherwise only polymorphic cases with a generic fallback behave properly, regular polymorphic cases still need to be adapted.

BUG=

Review URL: https://codereview.chromium.org/22254007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16062 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -5193,31 +5193,63 @@ void LCodeGen::DoCheckFunction(LCheckFunction* instr) {
 }
 
 
-void LCodeGen::DoCheckMapCommon(Register map_reg,
-                                Handle<Map> map,
-                                LEnvironment* env) {
-  Label success;
-  __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
-  DeoptimizeIf(al, env);
-  __ bind(&success);
+void LCodeGen::DoDeferredInstanceMigration(LCheckMaps* instr, Register object) {
+  {
+    PushSafepointRegistersScope scope(this, Safepoint::kWithRegisters);
+    __ push(object);
+    CallRuntimeFromDeferred(Runtime::kMigrateInstance, 1, instr);
+    __ StoreToSafepointRegisterSlot(v0, scratch0());
+  }
+  __ And(at, scratch0(), Operand(kSmiTagMask));
+  DeoptimizeIf(eq, instr->environment(), at, Operand(zero_reg));
 }
 
 
 void LCodeGen::DoCheckMaps(LCheckMaps* instr) {
+  class DeferredCheckMaps: public LDeferredCode {
+   public:
+    DeferredCheckMaps(LCodeGen* codegen, LCheckMaps* instr, Register object)
+        : LDeferredCode(codegen), instr_(instr), object_(object) {
+      SetExit(check_maps());
+    }
+    virtual void Generate() {
+      codegen()->DoDeferredInstanceMigration(instr_, object_);
+    }
+    Label* check_maps() { return &check_maps_; }
+    virtual LInstruction* instr() { return instr_; }
+   private:
+    LCheckMaps* instr_;
+    Label check_maps_;
+    Register object_;
+  };
+
   if (instr->hydrogen()->CanOmitMapChecks()) return;
   Register map_reg = scratch0();
   LOperand* input = instr->value();
   ASSERT(input->IsRegister());
   Register reg = ToRegister(input);
-  Label success;
   SmallMapList* map_set = instr->hydrogen()->map_set();
   __ lw(map_reg, FieldMemOperand(reg, HeapObject::kMapOffset));
+
+  DeferredCheckMaps* deferred = NULL;
+  if (instr->hydrogen()->has_migration_target()) {
+    deferred = new(zone()) DeferredCheckMaps(this, instr, reg);
+    __ bind(deferred->check_maps());
+  }
+
+  Label success;
   for (int i = 0; i < map_set->length() - 1; i++) {
     Handle<Map> map = map_set->at(i);
     __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
   }
   Handle<Map> map = map_set->last();
-  DoCheckMapCommon(map_reg, map, instr->environment());
+  __ CompareMapAndBranch(map_reg, map, &success, eq, &success);
+  if (instr->hydrogen()->has_migration_target()) {
+    __ Branch(deferred->entry());
+  } else {
+    DeoptimizeIf(al, instr->environment());
+  }
+
   __ bind(&success);
 }
 

src/mips/lithium-codegen-mips.h

@@ -153,7 +153,7 @@ class LCodeGen BASE_EMBEDDED {
   void DoDeferredInstanceOfKnownGlobal(LInstanceOfKnownGlobal* instr,
                                        Label* map_check);
 
-  void DoCheckMapCommon(Register map_reg, Handle<Map> map, LEnvironment* env);
+  void DoDeferredInstanceMigration(LCheckMaps* instr, Register object);
 
   // Parallel move support.
   void DoParallelMove(LParallelMove* move);

src/mips/lithium-mips.cc

@@ -1934,10 +1934,16 @@ LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
 
 LInstruction* LChunkBuilder::DoCheckMaps(HCheckMaps* instr) {
   LOperand* value = NULL;
-  if (!instr->CanOmitMapChecks()) value = UseRegisterAtStart(instr->value());
-  LInstruction* result = new(zone()) LCheckMaps(value);
-  if (instr->CanOmitMapChecks()) return result;
-  return AssignEnvironment(result);
+  if (!instr->CanOmitMapChecks()) {
+    value = UseRegisterAtStart(instr->value());
+    if (instr->has_migration_target()) info()->MarkAsDeferredCalling();
+  }
+  LCheckMaps* result = new(zone()) LCheckMaps(value);
+  if (!instr->CanOmitMapChecks()) {
+    AssignEnvironment(result);
+    if (instr->has_migration_target()) return AssignPointerMap(result);
+  }
+  return result;
 }