Inline Array.prototype.forEach in TurboFan

src/builtins/x64/builtins-x64.cc

 // Copyright 2012 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_X64
 
 #include "src/code-factory.h"
 #include "src/codegen.h"
 #include "src/counters.h"
 #include "src/deoptimizer.h"
@@ skipping 1407 matching lines @@
 }
 
 void Builtins::Generate_NotifyStubFailure(MacroAssembler* masm) {
   Generate_NotifyStubFailureHelper(masm, kDontSaveFPRegs);
 }
 
 void Builtins::Generate_NotifyStubFailureSaveDoubles(MacroAssembler* masm) {
   Generate_NotifyStubFailureHelper(masm, kSaveFPRegs);
 }
 
+void Builtins::Generate_NotifyBuiltinContinuation(MacroAssembler* masm) {
+  // Enter an internal frame.
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+
+    // Preserve registers across notification, this is important for compiled
+    // stubs that tail call the runtime on deopts passing their parameters in
+    // registers.

[Jarin, 2017/05/24 06:41:22]

Improve comment? (We do not really tail call runtime from here...)

[danno, 2017/06/06 12:04:52]

Done.

+    __ Pushad();
+    __ CallRuntime(Runtime::kNotifyStubFailure, false);
+    __ Popad();
+    // Tear down internal frame.
+  }
+
+  __ DropUnderReturnAddress(1);  // Ignore state offset
+  __ ret(0);  // Return to IC Miss stub, continuation still on stack.

[Jarin, 2017/05/24 06:41:22]

Fix comment.

[danno, 2017/06/06 12:04:52]

Done.

+}
+
+namespace {
+void Generate_ContinueToBuiltinHelper(MacroAssembler* masm,
+                                      bool java_script_builtin,
+                                      bool with_result) {
+  const RegisterConfiguration* config(RegisterConfiguration::Turbofan());
+  int allocatable_register_count = config->num_allocatable_general_registers();
+  if (with_result) {
+    __ movq(Operand(rsp,
+                    config->num_allocatable_general_registers() * kPointerSize +
+                        TYPED_FRAME_SIZE(1)),
+            rax);

[Jarin, 2017/05/24 06:41:22]

Is this the bit that overwrites the hole inserted by the deoptimizer? Please add
a comment to that effect.

[danno, 2017/06/06 12:04:52]

Done.

+  }
+  for (int i = allocatable_register_count - 1; i >= 0; --i) {
+    int code = config->GetAllocatableGeneralCode(i);
+    __ popq(Register::from_code(code));
+    if (java_script_builtin && code == kJavaScriptCallArgCountRegister.code()) {
+      __ SmiToInteger32(Register::from_code(code), Register::from_code(code));
+    }
+  }
+  __ movq(rbp, Operand(rsp, 2 * kPointerSize));
+  __ popq(Operand(rsp, TYPED_FRAME_SIZE_FROM_SP(0)));
+  __ addq(rsp, Immediate(kPointerSize));
+  __ addq(Operand(rsp, 0), Immediate(Code::kHeaderSize - kHeapObjectTag));
+  __ Ret();
+}
+}  // namespace
+
+void Builtins::Generate_ContinueToCodeStubBuiltin(MacroAssembler* masm) {
+  Generate_ContinueToBuiltinHelper(masm, false, false);
+}
+
+void Builtins::Generate_ContinueToCodeStubBuiltinWithResult(
+    MacroAssembler* masm) {
+  Generate_ContinueToBuiltinHelper(masm, false, true);
+}
+
+void Builtins::Generate_ContinueToJavaScriptBuiltin(MacroAssembler* masm) {
+  Generate_ContinueToBuiltinHelper(masm, true, false);
+}
+
+void Builtins::Generate_ContinueToJavaScriptBuiltinWithResult(
+    MacroAssembler* masm) {
+  Generate_ContinueToBuiltinHelper(masm, true, true);
+}
+
 static void Generate_NotifyDeoptimizedHelper(MacroAssembler* masm,
                                              Deoptimizer::BailoutType type) {
   // Enter an internal frame.
   {
     FrameScope scope(masm, StackFrame::INTERNAL);
 
     // Pass the deoptimization type to the runtime system.
     __ Push(Smi::FromInt(static_cast<int>(type)));
 
     __ CallRuntime(Runtime::kNotifyDeoptimized);
@@ skipping 1797 matching lines @@
   // Now jump to the instructions of the returned code object.
   __ jmp(r11);
 }
 
 #undef __
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64