[es6] Add a flag to the Isolate that defines whether ES2015 tail call...

[es6] Add a flag to the Isolate that defines whether ES2015 tail call elimination is enabled or not.

Thus DevTools will be able to disable tail call elimination dynamically upon user's choice.

BUG=v8:4698
LOG=N

Review URL: https://codereview.chromium.org/1837513002

Cr-Commit-Position: refs/heads/master@{#35098}

src/arm/builtins-arm.cc

@@ -1933,6 +1933,16 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ mov(scratch1, Operand(is_tail_call_elimination_enabled));
+  __ ldrb(scratch1, MemOperand(scratch1));
+  __ cmp(scratch1, Operand(0));
+  __ b(eq, &done);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -1976,6 +1986,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
+  __ bind(&done);
 }
 }  // namespace
 

src/arm64/builtins-arm64.cc

@@ -1977,6 +1977,16 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ Mov(scratch1, Operand(is_tail_call_elimination_enabled));
+  __ Ldrb(scratch1, MemOperand(scratch1));
+  __ Cmp(scratch1, Operand(0));
+  __ B(eq, &done);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -2017,6 +2027,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
+  __ bind(&done);
 }
 }  // namespace
 

src/assembler.cc

@@ -1632,6 +1632,10 @@ ExternalReference ExternalReference::cpu_features() {
   return ExternalReference(&CpuFeatures::supported_);
 }
 
+ExternalReference ExternalReference::is_tail_call_elimination_enabled_address(
+    Isolate* isolate) {
+  return ExternalReference(isolate->is_tail_call_elimination_enabled_address());
+}
 
 ExternalReference ExternalReference::debug_is_active_address(
     Isolate* isolate) {

src/assembler.h

@@ -1029,6 +1029,9 @@ class ExternalReference BASE_EMBEDDED {
 
   static ExternalReference cpu_features();
 
+  static ExternalReference is_tail_call_elimination_enabled_address(
+      Isolate* isolate);
+
   static ExternalReference debug_is_active_address(Isolate* isolate);
   static ExternalReference debug_after_break_target_address(Isolate* isolate);
 

src/external-reference-table.cc

@@ -172,6 +172,9 @@ ExternalReferenceTable::ExternalReferenceTable(Isolate* isolate) {
       "Isolate::virtual_slot_register()");
   Add(ExternalReference::runtime_function_table_address(isolate).address(),
       "Runtime::runtime_function_table_address()");
+  Add(ExternalReference::is_tail_call_elimination_enabled_address(isolate)
+          .address(),
+      "Isolate::is_tail_call_elimination_enabled_address()");
 
   // Debug addresses
   Add(ExternalReference::debug_after_break_target_address(isolate).address(),

src/ia32/builtins-ia32.cc

@@ -1886,6 +1886,16 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ movzx_b(scratch1,
+             Operand::StaticVariable(is_tail_call_elimination_enabled));
+  __ cmp(scratch1, Immediate(0));
+  __ j(equal, &done, Label::kNear);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -1926,6 +1936,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3, ReturnAddressState::kOnStack, 0);
+  __ bind(&done);
 }
 }  // namespace
 

src/isolate.cc

@@ -1826,6 +1826,7 @@ Isolate::Isolate(bool enable_serializer)
       serializer_enabled_(enable_serializer),
       has_fatal_error_(false),
       initialized_from_snapshot_(false),
+      is_tail_call_elimination_enabled_(true),
       cpu_profiler_(NULL),
       heap_profiler_(NULL),
       function_entry_hook_(NULL),

src/isolate.h

@@ -1089,6 +1089,16 @@ class Isolate {
   int GetNextUniqueSharedFunctionInfoId() { return next_unique_sfi_id_++; }
 #endif
 
+  // Support for dynamically disabling tail call elimination.
+  Address is_tail_call_elimination_enabled_address() {
+    return reinterpret_cast<Address>(&is_tail_call_elimination_enabled_);
+  }
+  bool is_tail_call_elimination_enabled() const {
+    return is_tail_call_elimination_enabled_;
+  }
+  void set_tail_call_elimination_enabled(bool enabled) {
+    is_tail_call_elimination_enabled_ = enabled;
+  }
 
   void AddDetachedContext(Handle<Context> context);
   void CheckDetachedContextsAfterGC();
@@ -1277,6 +1287,9 @@ class Isolate {
   // True if this isolate was initialized from a snapshot.
   bool initialized_from_snapshot_;
 
+  // True if ES2015 tail call elimination feature is enabled.
+  bool is_tail_call_elimination_enabled_;
+
   // Time stamp at initialization.
   double time_millis_at_init_;
 

src/mips/builtins-mips.cc

@@ -1957,6 +1957,15 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ li(at, Operand(is_tail_call_elimination_enabled));
+  __ lb(scratch1, MemOperand(at));
+  __ Branch(&done, eq, scratch1, Operand(zero_reg));
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -2000,6 +2009,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
+  __ bind(&done);
 }
 }  // namespace
 

src/mips64/builtins-mips64.cc

@@ -1948,6 +1948,15 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ li(at, Operand(is_tail_call_elimination_enabled));
+  __ lb(scratch1, MemOperand(at));
+  __ Branch(&done, eq, scratch1, Operand(zero_reg));
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -1990,6 +1999,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
+  __ bind(&done);
 }
 }  // namespace
 

src/ppc/builtins-ppc.cc

@@ -1987,6 +1987,16 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ mov(scratch1, Operand(is_tail_call_elimination_enabled));
+  __ lbz(scratch1, MemOperand(scratch1));
+  __ cmpi(scratch1, Operand::Zero());
+  __ beq(&done);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -2034,6 +2044,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
+  __ bind(&done);
 }
 }  // namespace
 

src/s390/builtins-s390.cc

@@ -1949,6 +1949,16 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is active.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ mov(scratch1, Operand(is_tail_call_elimination_enabled));
+  __ LoadlB(scratch1, MemOperand(scratch1));
+  __ CmpP(scratch1, Operand::Zero());
+  __ beq(&done);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -1995,6 +2005,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3);
+  __ bind(&done);
 }
 }  // namespace
 

src/x64/builtins-x64.cc

@@ -2052,6 +2052,15 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is active.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ Move(kScratchRegister, is_tail_call_elimination_enabled);
+  __ cmpb(Operand(kScratchRegister, 0), Immediate(0));
+  __ j(equal, &done);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -2091,6 +2100,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3, ReturnAddressState::kOnStack);
+  __ bind(&done);
 }
 }  // namespace
 

src/x87/builtins-x87.cc

@@ -1912,6 +1912,16 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   DCHECK(!AreAliased(args_reg, scratch1, scratch2, scratch3));
   Comment cmnt(masm, "[ PrepareForTailCall");
 
+  // Prepare for tail call only if ES2015 tail call elimination is enabled.
+  Label done;
+  ExternalReference is_tail_call_elimination_enabled =
+      ExternalReference::is_tail_call_elimination_enabled_address(
+          masm->isolate());
+  __ movzx_b(scratch1,
+             Operand::StaticVariable(is_tail_call_elimination_enabled));
+  __ cmp(scratch1, Immediate(0));
+  __ j(equal, &done, Label::kNear);
+
   // Drop possible interpreter handler/stub frame.
   {
     Label no_interpreter_frame;
@@ -1952,6 +1962,7 @@ void PrepareForTailCall(MacroAssembler* masm, Register args_reg,
   ParameterCount callee_args_count(args_reg);
   __ PrepareForTailCall(callee_args_count, caller_args_count_reg, scratch2,
                         scratch3, ReturnAddressState::kOnStack, 0);
+  __ bind(&done);
 }
 }  // namespace