Write barrier for storing a code entry, and usage in CompileLazy builtin.

src/arm64/macro-assembler-arm64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #if V8_TARGET_ARCH_ARM64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 3800 matching lines @@
   Ldrsw(scratch1, UntagSmiFieldMemOperand(scratch2, kDetailsOffset));
   DCHECK_EQ(DATA, 0);
   TestAndBranchIfAnySet(scratch1, PropertyDetails::TypeField::kMask, miss);
 
   // Get the value at the masked, scaled index and return.
   const int kValueOffset =
       SeededNumberDictionary::kElementsStartOffset + kPointerSize;
   Ldr(result, FieldMemOperand(scratch2, kValueOffset));
 }
 
+void MacroAssembler::RecordWriteCodeEntryField(Register js_function,
+                                               Register code_entry,
+                                               Register scratch) {
+  const int offset = JSFunction::kCodeEntryOffset;
+
+  // Since a code entry (value) is always in old space, we don't need to update
+  // remembered set. If incremental marking is off, there is nothing for us to
+  // do.
+  if (!FLAG_incremental_marking) return;
+
+  DCHECK(js_function.is(x1));
+  DCHECK(code_entry.is(x7));
+  DCHECK(scratch.is(x5));
+  AssertNotSmi(js_function);
+
+  if (emit_debug_code()) {
+    UseScratchRegisterScope temps(this);
+    Register temp = temps.AcquireX();
+    Add(scratch, js_function, offset - kHeapObjectTag);
+    Ldr(temp, MemOperand(scratch));
+    Cmp(temp, code_entry);
+    Check(eq, kWrongAddressOrValuePassedToRecordWrite);
+  }
+
+  // First, check if a write barrier is even needed. The tests below
+  // catch stores of Smis and stores into young gen.
+  Label done;
+
+  CheckPageFlagClear(code_entry, scratch,
+                     MemoryChunk::kPointersToHereAreInterestingMask, &done);
+  CheckPageFlagClear(js_function, scratch,
+                     MemoryChunk::kPointersFromHereAreInterestingMask, &done);
+
+  const Register dst = scratch;
+  Add(dst, js_function, offset - kHeapObjectTag);
+
+  // Save caller-saved registers.Both input registers (x1 and x7) are caller
+  // saved, so there is no need to push them.
+  PushCPURegList(kCallerSaved);
+
+  int argument_count = 3;
+
+  Mov(x0, js_function);
+  Mov(x1, dst);
+  Mov(x2, ExternalReference::isolate_address(isolate()));
+
+  {
+    AllowExternalCallThatCantCauseGC scope(this);
+    CallCFunction(
+        ExternalReference::incremental_marking_record_write_code_entry_function(
+            isolate()),
+        argument_count);
+  }
+
+  // Restore caller-saved registers.
+  PopCPURegList(kCallerSaved);
+
+  Bind(&done);
+}
 
 void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
                                          Register address,
                                          Register scratch1,
                                          SaveFPRegsMode fp_mode,
                                          RememberedSetFinalAction and_then) {
   DCHECK(!AreAliased(object, address, scratch1));
   Label done, store_buffer_overflow;
   if (emit_debug_code()) {
     Label ok;
@@ skipping 1063 matching lines @@
 }
 
 
 #undef __
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_ARM64