Avoid flushing the icache unnecessarily when updating target addresses in code.

src/arm64/assembler-arm64-inl.h

Index: src/arm64/assembler-arm64-inl.h
diff --git a/src/arm64/assembler-arm64-inl.h b/src/arm64/assembler-arm64-inl.h
index 98d8c1d01bb907ba1e768163f5ad87b7ba05b249..d7ebc0f5a757e028ee8d4b1a5b81868678f4d99d 100644
--- a/src/arm64/assembler-arm64-inl.h
+++ b/src/arm64/assembler-arm64-inl.h
@@ -17,15 +17,18 @@ namespace internal {
 bool CpuFeatures::SupportsCrankshaft() { return true; }
 
 
-void RelocInfo::apply(intptr_t delta) {
+void RelocInfo::apply(intptr_t delta, ICacheFlushMode icache_flush_mode) {
   UNIMPLEMENTED();
 }
 
 
-void RelocInfo::set_target_address(Address target, WriteBarrierMode mode) {
+void RelocInfo::set_target_address(Address target,
+                                   WriteBarrierMode write_barrier_mode,
+                                   ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || IsRuntimeEntry(rmode_));
-  Assembler::set_target_address_at(pc_, host_, target);
-  if (mode == UPDATE_WRITE_BARRIER && host() != NULL && IsCodeTarget(rmode_)) {
+  Assembler::set_target_address_at(pc_, host_, target, icache_flush_mode);
+  if (write_barrier_mode == UPDATE_WRITE_BARRIER && host() != NULL &&
+      IsCodeTarget(rmode_)) {
     Object* target_code = Code::GetCodeFromTargetAddress(target);
     host()->GetHeap()->incremental_marking()->RecordWriteIntoCode(
         host(), this, HeapObject::cast(target_code));
@@ -625,7 +628,8 @@ void Assembler::deserialization_set_special_target_at(
 
 void Assembler::set_target_address_at(Address pc,
                                       ConstantPoolArray* constant_pool,
-                                      Address target) {
+                                      Address target,
+                                      ICacheFlushMode icache_flush_mode) {
   Memory::Address_at(target_pointer_address_at(pc)) = target;
   // Intuitively, we would think it is necessary to always flush the
   // instruction cache after patching a target address in the code as follows:
@@ -640,9 +644,10 @@ void Assembler::set_target_address_at(Address pc,
 
 void Assembler::set_target_address_at(Address pc,
                                       Code* code,
-                                      Address target) {
+                                      Address target,
+                                      ICacheFlushMode icache_flush_mode) {
   ConstantPoolArray* constant_pool = code ? code->constant_pool() : NULL;
-  set_target_address_at(pc, constant_pool, target);
+  set_target_address_at(pc, constant_pool, target, icache_flush_mode);
 }
 
 
@@ -684,12 +689,15 @@ Handle<Object> RelocInfo::target_object_handle(Assembler* origin) {
 }
 
 
-void RelocInfo::set_target_object(Object* target, WriteBarrierMode mode) {
+void RelocInfo::set_target_object(Object* target,
+                                  WriteBarrierMode write_barrier_mode,
+                                  ICacheFlushMode icache_flush_mode) {
   ASSERT(IsCodeTarget(rmode_) || rmode_ == EMBEDDED_OBJECT);
   ASSERT(!target->IsConsString());
   Assembler::set_target_address_at(pc_, host_,
-                                   reinterpret_cast<Address>(target));
-  if (mode == UPDATE_WRITE_BARRIER &&
+                                   reinterpret_cast<Address>(target),
+                                   icache_flush_mode);
+  if (write_barrier_mode == UPDATE_WRITE_BARRIER &&
       host() != NULL &&
       target->IsHeapObject()) {
     host()->GetHeap()->incremental_marking()->RecordWrite(
@@ -711,9 +719,12 @@ Address RelocInfo::target_runtime_entry(Assembler* origin) {
 
 
 void RelocInfo::set_target_runtime_entry(Address target,
-                                         WriteBarrierMode mode) {
+                                         WriteBarrierMode write_barrier_mode,
+                                         ICacheFlushMode icache_flush_mode) {
   ASSERT(IsRuntimeEntry(rmode_));
-  if (target_address() != target) set_target_address(target, mode);
+  if (target_address() != target) {
+    set_target_address(target, write_barrier_mode, icache_flush_mode);
+  }
 }
 
 
@@ -730,7 +741,9 @@ Cell* RelocInfo::target_cell() {
 }
 
 
-void RelocInfo::set_target_cell(Cell* cell, WriteBarrierMode mode) {
+void RelocInfo::set_target_cell(Cell* cell,
+                                WriteBarrierMode write_barrier_mode,
+                                ICacheFlushMode icache_flush_mode) {
   UNIMPLEMENTED();
 }
 
@@ -753,7 +766,8 @@ Code* RelocInfo::code_age_stub() {
 }
 
 
-void RelocInfo::set_code_age_stub(Code* stub) {
+void RelocInfo::set_code_age_stub(Code* stub,
+                                  ICacheFlushMode icache_flush_mode) {
   ASSERT(rmode_ == RelocInfo::CODE_AGE_SEQUENCE);
   ASSERT(!Code::IsYoungSequence(stub->GetIsolate(), pc_));
   // Overwrite the stub entry point in the code age sequence. This is loaded as