Visit the Optimized Code Map on first call rather than closure creation.

src/arm64/builtins-arm64.cc

Index: src/arm64/builtins-arm64.cc
diff --git a/src/arm64/builtins-arm64.cc b/src/arm64/builtins-arm64.cc
index 4ed33a0072a6ae8628fce88646a1fe49bcae12c0..e790ba33049a7173d810de0bbc7a5a3ad7b772e8 100644
--- a/src/arm64/builtins-arm64.cc
+++ b/src/arm64/builtins-arm64.cc
@@ -1177,6 +1177,138 @@ void Builtins::Generate_InterpreterEnterBytecodeDispatch(MacroAssembler* masm) {
 
 
 void Builtins::Generate_CompileLazy(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- x0 : argument count (preserved for callee)
+  //  -- x3 : new target (preserved for callee)
+  //  -- x1 : target function (preserved for callee)
+  // -----------------------------------
+  // First lookup code, maybe we don't need to compile!
+  Label gotta_call_runtime;
+  Label maybe_call_runtime;
+  Label try_shared;
+  Label loop_top, loop_bottom;
+
+  Register closure = x1;
+  Register new_target = x3;
+  Register map = x13;
+  Register index = x2;
+  __ Ldr(map, FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
+  __ Ldr(map,
+         FieldMemOperand(map, SharedFunctionInfo::kOptimizedCodeMapOffset));
+  __ Ldrsw(index, UntagSmiFieldMemOperand(map, FixedArray::kLengthOffset));
+  __ Cmp(index, Operand(2));
+  __ B(lt, &gotta_call_runtime);
+
+  // Find literals.
+  // x3  : native context
+  // x2  : length / index
+  // x13 : optimized code map
+  // stack[0] : new target
+  // stack[4] : closure
+  Register native_context = x4;
+  __ Ldr(native_context, NativeContextMemOperand());
+
+  __ Bind(&loop_top);
+  Register temp = x5;
+  Register array_pointer = x6;
+
+  // Does the native context match?
+  __ Add(array_pointer, map, Operand(index, LSL, kPointerSizeLog2));
+  __ Ldr(temp, FieldMemOperand(array_pointer,
+                               SharedFunctionInfo::kOffsetToPreviousContext));
+  __ Ldr(temp, FieldMemOperand(temp, WeakCell::kValueOffset));
+  __ Cmp(temp, native_context);
+  __ B(ne, &loop_bottom);
+  // OSR id set to none?
+  __ Ldr(temp, FieldMemOperand(array_pointer,
+                               SharedFunctionInfo::kOffsetToPreviousOsrAstId));
+  const int bailout_id = BailoutId::None().ToInt();
+  __ Cmp(temp, Operand(Smi::FromInt(bailout_id)));
+  __ B(ne, &loop_bottom);
+  // Literals available?
+  __ Ldr(temp, FieldMemOperand(array_pointer,
+                               SharedFunctionInfo::kOffsetToPreviousLiterals));
+  __ Ldr(temp, FieldMemOperand(temp, WeakCell::kValueOffset));
+  __ JumpIfSmi(temp, &gotta_call_runtime);
+
+  // Save the literals in the closure.
+  __ Str(temp, FieldMemOperand(closure, JSFunction::kLiteralsOffset));
+  __ RecordWriteField(closure, JSFunction::kLiteralsOffset, temp, x7,
+                      kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+
+  // Code available?
+  Register entry = x7;
+  __ Ldr(entry,
+         FieldMemOperand(array_pointer,
+                         SharedFunctionInfo::kOffsetToPreviousCachedCode));
+  __ Ldr(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
+  __ JumpIfSmi(entry, &maybe_call_runtime);
+
+  // Found literals and code. Get them into the closure and return.
+  __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
+
+  Label install_optimized_code_and_tailcall;
+  __ Bind(&install_optimized_code_and_tailcall);
+  __ Str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
+  __ RecordWriteCodeEntryField(closure, entry, x5);
+
+  // Link the closure into the optimized function list.
+  // x7 : code entry
+  // x4 : native context
+  // x1 : closure
+  __ Ldr(x8,
+         ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
+  __ Str(x8, FieldMemOperand(closure, JSFunction::kNextFunctionLinkOffset));
+  __ RecordWriteField(closure, JSFunction::kNextFunctionLinkOffset, x8, x13,
+                      kLRHasNotBeenSaved, kDontSaveFPRegs, EMIT_REMEMBERED_SET,
+                      OMIT_SMI_CHECK);
+  const int function_list_offset =
+      Context::SlotOffset(Context::OPTIMIZED_FUNCTIONS_LIST);
+  __ Str(closure,
+         ContextMemOperand(native_context, Context::OPTIMIZED_FUNCTIONS_LIST));
+  __ Mov(x5, closure);
+  __ RecordWriteContextSlot(native_context, function_list_offset, x5, x13,
+                            kLRHasNotBeenSaved, kDontSaveFPRegs);
+  __ Jump(entry);
+
+  __ Bind(&loop_bottom);
+  __ Sub(index, index, Operand(SharedFunctionInfo::kEntryLength));
+  __ Cmp(index, Operand(1));
+  __ B(gt, &loop_top);
+
+  // We found neither literals nor code.
+  __ B(&gotta_call_runtime);
+
+  __ Bind(&maybe_call_runtime);
+
+  // Last possibility. Check the context free optimized code map entry.
+  __ Ldr(entry, FieldMemOperand(map, FixedArray::kHeaderSize +
+                                         SharedFunctionInfo::kSharedCodeIndex));
+  __ Ldr(entry, FieldMemOperand(entry, WeakCell::kValueOffset));
+  __ JumpIfSmi(entry, &try_shared);
+
+  // Store code entry in the closure.
+  __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ B(&install_optimized_code_and_tailcall);
+
+  __ Bind(&try_shared);
+  // Is the full code valid?
+  __ Ldr(entry,
+         FieldMemOperand(closure, JSFunction::kSharedFunctionInfoOffset));
+  __ Ldr(entry, FieldMemOperand(entry, SharedFunctionInfo::kCodeOffset));
+  __ Ldr(x5, FieldMemOperand(entry, Code::kFlagsOffset));
+  __ and_(x5, x5, Operand(Code::KindField::kMask));
+  __ Mov(x5, Operand(x5, LSR, Code::KindField::kShift));
+  __ Cmp(x5, Operand(Code::BUILTIN));
+  __ B(eq, &gotta_call_runtime);
+  // Yes, install the full code.
+  __ Add(entry, entry, Operand(Code::kHeaderSize - kHeapObjectTag));
+  __ Str(entry, FieldMemOperand(closure, JSFunction::kCodeEntryOffset));
+  __ RecordWriteCodeEntryField(closure, entry, x5);
+  __ Jump(entry);
+
+  __ Bind(&gotta_call_runtime);
   GenerateTailCallToReturnedCode(masm, Runtime::kCompileLazy);
 }