[es6] Further fixing of tail Calls.

1) Update profiling counters in Full codegen.
2) Call Runtime::kTraceTailCall when tracing is on

test/mjsunit/es6/tail-call-simple.js is disabled for now, because Turbofan does not fully support TCO yet.

BUG=v8:4698
LOG=N

Review URL: https://codereview.chromium.org/1670133002

Cr-Commit-Position: refs/heads/master@{#33886}

src/full-codegen/arm/full-codegen-arm.cc

@@ -423,6 +423,30 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
+void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
+    bool is_tail_call) {
+  // Pretend that the exit is a backwards jump to the entry.
+  int weight = 1;
+  if (info_->ShouldSelfOptimize()) {
+    weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+  } else {
+    int distance = masm_->pc_offset();
+    weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
+  }
+  EmitProfilingCounterDecrement(weight);
+  Label ok;
+  __ b(pl, &ok);
+  // Don't need to save result register if we are going to do a tail call.
+  if (!is_tail_call) {
+    __ push(r0);
+  }
+  __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
+  if (!is_tail_call) {
+    __ pop(r0);
+  }
+  EmitProfilingCounterReset();
+  __ bind(&ok);
+}
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
@@ -436,24 +460,7 @@ void FullCodeGenerator::EmitReturnSequence() {
       __ push(r0);
       __ CallRuntime(Runtime::kTraceExit);
     }
-    // Pretend that the exit is a backwards jump to the entry.
-    int weight = 1;
-    if (info_->ShouldSelfOptimize()) {
-      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
-    } else {
-      int distance = masm_->pc_offset();
-      weight = Min(kMaxBackEdgeWeight,
-                   Max(1, distance / kCodeSizeMultiplier));
-    }
-    EmitProfilingCounterDecrement(weight);
-    Label ok;
-    __ b(pl, &ok);
-    __ push(r0);
-    __ Call(isolate()->builtins()->InterruptCheck(),
-            RelocInfo::CODE_TARGET);
-    __ pop(r0);
-    EmitProfilingCounterReset();
-    __ bind(&ok);
+    EmitProfilingCounterHandlingForReturnSequence(false);
 
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
@@ -2754,6 +2761,14 @@ void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
 
   PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
   SetCallPosition(expr);
+  if (expr->tail_call_mode() == TailCallMode::kAllow) {
+    if (FLAG_trace) {
+      __ CallRuntime(Runtime::kTraceTailCall);
+    }
+    // Update profiling counters before the tail call since we will
+    // not return to this function.
+    EmitProfilingCounterHandlingForReturnSequence(true);
+  }
   Handle<Code> ic =
       CodeFactory::CallIC(isolate(), arg_count, mode, expr->tail_call_mode())
           .code();

src/full-codegen/arm64/full-codegen-arm64.cc

@@ -414,6 +414,30 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
+void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
+    bool is_tail_call) {
+  // Pretend that the exit is a backwards jump to the entry.
+  int weight = 1;
+  if (info_->ShouldSelfOptimize()) {
+    weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+  } else {
+    int distance = masm_->pc_offset() + kCodeSizeMultiplier / 2;
+    weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
+  }
+  EmitProfilingCounterDecrement(weight);
+  Label ok;
+  __ B(pl, &ok);
+  // Don't need to save result register if we are going to do a tail call.
+  if (!is_tail_call) {
+    __ Push(x0);
+  }
+  __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
+  if (!is_tail_call) {
+    __ Pop(x0);
+  }
+  EmitProfilingCounterReset();
+  __ Bind(&ok);
+}
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
@@ -430,24 +454,7 @@ void FullCodeGenerator::EmitReturnSequence() {
       __ CallRuntime(Runtime::kTraceExit);
       DCHECK(x0.Is(result_register()));
     }
-    // Pretend that the exit is a backwards jump to the entry.
-    int weight = 1;
-    if (info_->ShouldSelfOptimize()) {
-      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
-    } else {
-      int distance = masm_->pc_offset() + kCodeSizeMultiplier / 2;
-      weight = Min(kMaxBackEdgeWeight,
-                   Max(1, distance / kCodeSizeMultiplier));
-    }
-    EmitProfilingCounterDecrement(weight);
-    Label ok;
-    __ B(pl, &ok);
-    __ Push(x0);
-    __ Call(isolate()->builtins()->InterruptCheck(),
-            RelocInfo::CODE_TARGET);
-    __ Pop(x0);
-    EmitProfilingCounterReset();
-    __ Bind(&ok);
+    EmitProfilingCounterHandlingForReturnSequence(false);
 
     SetReturnPosition(literal());
     const Register& current_sp = __ StackPointer();
@@ -2556,7 +2563,14 @@ void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
 
   PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
   SetCallPosition(expr);
-
+  if (expr->tail_call_mode() == TailCallMode::kAllow) {
+    if (FLAG_trace) {
+      __ CallRuntime(Runtime::kTraceTailCall);
+    }
+    // Update profiling counters before the tail call since we will
+    // not return to this function.
+    EmitProfilingCounterHandlingForReturnSequence(true);
+  }
   Handle<Code> ic =
       CodeFactory::CallIC(isolate(), arg_count, mode, expr->tail_call_mode())
           .code();

src/full-codegen/full-codegen.h

@@ -505,6 +505,7 @@ class FullCodeGenerator: public AstVisitor {
 
   // Platform-specific return sequence
   void EmitReturnSequence();
+  void EmitProfilingCounterHandlingForReturnSequence(bool is_tail_call);
 
   // Platform-specific code sequences for calls
   void EmitCall(Call* expr, ConvertReceiverMode = ConvertReceiverMode::kAny);

src/full-codegen/ia32/full-codegen-ia32.cc

@@ -386,6 +386,30 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
+void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
+    bool is_tail_call) {
+  // Pretend that the exit is a backwards jump to the entry.
+  int weight = 1;
+  if (info_->ShouldSelfOptimize()) {
+    weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+  } else {
+    int distance = masm_->pc_offset();
+    weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
+  }
+  EmitProfilingCounterDecrement(weight);
+  Label ok;
+  __ j(positive, &ok, Label::kNear);
+  // Don't need to save result register if we are going to do a tail call.
+  if (!is_tail_call) {
+    __ push(eax);
+  }
+  __ call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
+  if (!is_tail_call) {
+    __ pop(eax);
+  }
+  EmitProfilingCounterReset();
+  __ bind(&ok);
+}
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
@@ -398,24 +422,7 @@ void FullCodeGenerator::EmitReturnSequence() {
       __ push(eax);
       __ CallRuntime(Runtime::kTraceExit);
     }
-    // Pretend that the exit is a backwards jump to the entry.
-    int weight = 1;
-    if (info_->ShouldSelfOptimize()) {
-      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
-    } else {
-      int distance = masm_->pc_offset();
-      weight = Min(kMaxBackEdgeWeight,
-                   Max(1, distance / kCodeSizeMultiplier));
-    }
-    EmitProfilingCounterDecrement(weight);
-    Label ok;
-    __ j(positive, &ok, Label::kNear);
-    __ push(eax);
-    __ call(isolate()->builtins()->InterruptCheck(),
-            RelocInfo::CODE_TARGET);
-    __ pop(eax);
-    EmitProfilingCounterReset();
-    __ bind(&ok);
+    EmitProfilingCounterHandlingForReturnSequence(false);
 
     SetReturnPosition(literal());
     __ leave();
@@ -2639,6 +2646,14 @@ void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
 
   PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
   SetCallPosition(expr);
+  if (expr->tail_call_mode() == TailCallMode::kAllow) {
+    if (FLAG_trace) {
+      __ CallRuntime(Runtime::kTraceTailCall);
+    }
+    // Update profiling counters before the tail call since we will
+    // not return to this function.
+    EmitProfilingCounterHandlingForReturnSequence(true);
+  }
   Handle<Code> ic =
       CodeFactory::CallIC(isolate(), arg_count, mode, expr->tail_call_mode())
           .code();

src/full-codegen/mips/full-codegen-mips.cc

@@ -414,6 +414,30 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
+void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
+    bool is_tail_call) {
+  // Pretend that the exit is a backwards jump to the entry.
+  int weight = 1;
+  if (info_->ShouldSelfOptimize()) {
+    weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+  } else {
+    int distance = masm_->pc_offset();
+    weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
+  }
+  EmitProfilingCounterDecrement(weight);
+  Label ok;
+  __ Branch(&ok, ge, a3, Operand(zero_reg));
+  // Don't need to save result register if we are going to do a tail call.
+  if (!is_tail_call) {
+    __ push(v0);
+  }
+  __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
+  if (!is_tail_call) {
+    __ pop(v0);
+  }
+  EmitProfilingCounterReset();
+  __ bind(&ok);
+}
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
@@ -427,24 +451,7 @@ void FullCodeGenerator::EmitReturnSequence() {
       __ push(v0);
       __ CallRuntime(Runtime::kTraceExit);
     }
-    // Pretend that the exit is a backwards jump to the entry.
-    int weight = 1;
-    if (info_->ShouldSelfOptimize()) {
-      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
-    } else {
-      int distance = masm_->pc_offset();
-      weight = Min(kMaxBackEdgeWeight,
-                   Max(1, distance / kCodeSizeMultiplier));
-    }
-    EmitProfilingCounterDecrement(weight);
-    Label ok;
-    __ Branch(&ok, ge, a3, Operand(zero_reg));
-    __ push(v0);
-    __ Call(isolate()->builtins()->InterruptCheck(),
-            RelocInfo::CODE_TARGET);
-    __ pop(v0);
-    EmitProfilingCounterReset();
-    __ bind(&ok);
+    EmitProfilingCounterHandlingForReturnSequence(false);
 
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
@@ -2741,6 +2748,14 @@ void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
   PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
   // Record source position of the IC call.
   SetCallPosition(expr);
+  if (expr->tail_call_mode() == TailCallMode::kAllow) {
+    if (FLAG_trace) {
+      __ CallRuntime(Runtime::kTraceTailCall);
+    }
+    // Update profiling counters before the tail call since we will
+    // not return to this function.
+    EmitProfilingCounterHandlingForReturnSequence(true);
+  }
   Handle<Code> ic =
       CodeFactory::CallIC(isolate(), arg_count, mode, expr->tail_call_mode())
           .code();

src/full-codegen/mips64/full-codegen-mips64.cc

@@ -414,6 +414,30 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
+void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
+    bool is_tail_call) {
+  // Pretend that the exit is a backwards jump to the entry.
+  int weight = 1;
+  if (info_->ShouldSelfOptimize()) {
+    weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+  } else {
+    int distance = masm_->pc_offset();
+    weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
+  }
+  EmitProfilingCounterDecrement(weight);
+  Label ok;
+  __ Branch(&ok, ge, a3, Operand(zero_reg));
+  // Don't need to save result register if we are going to do a tail call.
+  if (!is_tail_call) {
+    __ push(v0);
+  }
+  __ Call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
+  if (!is_tail_call) {
+    __ pop(v0);
+  }
+  EmitProfilingCounterReset();
+  __ bind(&ok);
+}
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
@@ -427,24 +451,7 @@ void FullCodeGenerator::EmitReturnSequence() {
       __ push(v0);
       __ CallRuntime(Runtime::kTraceExit);
     }
-    // Pretend that the exit is a backwards jump to the entry.
-    int weight = 1;
-    if (info_->ShouldSelfOptimize()) {
-      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
-    } else {
-      int distance = masm_->pc_offset();
-      weight = Min(kMaxBackEdgeWeight,
-                   Max(1, distance / kCodeSizeMultiplier));
-    }
-    EmitProfilingCounterDecrement(weight);
-    Label ok;
-    __ Branch(&ok, ge, a3, Operand(zero_reg));
-    __ push(v0);
-    __ Call(isolate()->builtins()->InterruptCheck(),
-            RelocInfo::CODE_TARGET);
-    __ pop(v0);
-    EmitProfilingCounterReset();
-    __ bind(&ok);
+    EmitProfilingCounterHandlingForReturnSequence(false);
 
     // Make sure that the constant pool is not emitted inside of the return
     // sequence.
@@ -2747,6 +2754,14 @@ void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
   PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
   // Record source position of the IC call.
   SetCallPosition(expr);
+  if (expr->tail_call_mode() == TailCallMode::kAllow) {
+    if (FLAG_trace) {
+      __ CallRuntime(Runtime::kTraceTailCall);
+    }
+    // Update profiling counters before the tail call since we will
+    // not return to this function.
+    EmitProfilingCounterHandlingForReturnSequence(true);
+  }
   Handle<Code> ic =
       CodeFactory::CallIC(isolate(), arg_count, mode, expr->tail_call_mode())
           .code();

src/full-codegen/x64/full-codegen-x64.cc

@@ -389,6 +389,30 @@ void FullCodeGenerator::EmitBackEdgeBookkeeping(IterationStatement* stmt,
   PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
 }
 
+void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
+    bool is_tail_call) {
+  // Pretend that the exit is a backwards jump to the entry.
+  int weight = 1;
+  if (info_->ShouldSelfOptimize()) {
+    weight = FLAG_interrupt_budget / FLAG_self_opt_count;
+  } else {
+    int distance = masm_->pc_offset();
+    weight = Min(kMaxBackEdgeWeight, Max(1, distance / kCodeSizeMultiplier));
+  }
+  EmitProfilingCounterDecrement(weight);
+  Label ok;
+  __ j(positive, &ok, Label::kNear);
+  // Don't need to save result register if we are going to do a tail call.
+  if (!is_tail_call) {
+    __ Push(rax);
+  }
+  __ call(isolate()->builtins()->InterruptCheck(), RelocInfo::CODE_TARGET);
+  if (!is_tail_call) {
+    __ Pop(rax);
+  }
+  EmitProfilingCounterReset();
+  __ bind(&ok);
+}
 
 void FullCodeGenerator::EmitReturnSequence() {
   Comment cmnt(masm_, "[ Return sequence");
@@ -400,24 +424,7 @@ void FullCodeGenerator::EmitReturnSequence() {
       __ Push(rax);
       __ CallRuntime(Runtime::kTraceExit);
     }
-    // Pretend that the exit is a backwards jump to the entry.
-    int weight = 1;
-    if (info_->ShouldSelfOptimize()) {
-      weight = FLAG_interrupt_budget / FLAG_self_opt_count;
-    } else {
-      int distance = masm_->pc_offset();
-      weight = Min(kMaxBackEdgeWeight,
-                   Max(1, distance / kCodeSizeMultiplier));
-    }
-    EmitProfilingCounterDecrement(weight);
-    Label ok;
-    __ j(positive, &ok, Label::kNear);
-    __ Push(rax);
-    __ call(isolate()->builtins()->InterruptCheck(),
-            RelocInfo::CODE_TARGET);
-    __ Pop(rax);
-    EmitProfilingCounterReset();
-    __ bind(&ok);
+    EmitProfilingCounterHandlingForReturnSequence(false);
 
     SetReturnPosition(literal());
     __ leave();
@@ -2625,6 +2632,14 @@ void FullCodeGenerator::EmitCall(Call* expr, ConvertReceiverMode mode) {
 
   PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
   SetCallPosition(expr);
+  if (expr->tail_call_mode() == TailCallMode::kAllow) {
+    if (FLAG_trace) {
+      __ CallRuntime(Runtime::kTraceTailCall);
+    }
+    // Update profiling counters before the tail call since we will
+    // not return to this function.
+    EmitProfilingCounterHandlingForReturnSequence(true);
+  }
   Handle<Code> ic =
       CodeFactory::CallIC(isolate(), arg_count, mode, expr->tail_call_mode())
           .code();

src/runtime/runtime-test.cc

@@ -408,53 +408,54 @@ RUNTIME_FUNCTION(Runtime_DisassembleFunction) {
   return isolate->heap()->undefined_value();
 }
 
+namespace {
 
-static int StackSize(Isolate* isolate) {
+int StackSize(Isolate* isolate) {
   int n = 0;
   for (JavaScriptFrameIterator it(isolate); !it.done(); it.Advance()) n++;
   return n;
 }
 
-
-static void PrintTransition(Isolate* isolate, Object* result) {
-  // indentation
-  {
-    const int nmax = 80;
-    int n = StackSize(isolate);
-    if (n <= nmax)
-      PrintF("%4d:%*s", n, n, "");
-    else
-      PrintF("%4d:%*s", n, nmax, "...");
-  }
-
-  if (result == NULL) {
-    JavaScriptFrame::PrintTop(isolate, stdout, true, false);
-    PrintF(" {\n");
+void PrintIndentation(Isolate* isolate) {
+  const int nmax = 80;
+  int n = StackSize(isolate);
+  if (n <= nmax) {
+    PrintF("%4d:%*s", n, n, "");
   } else {
-    // function result
-    PrintF("} -> ");
-    result->ShortPrint();
-    PrintF("\n");
+    PrintF("%4d:%*s", n, nmax, "...");
   }
 }
 
+}  // namespace
 
 RUNTIME_FUNCTION(Runtime_TraceEnter) {
   SealHandleScope shs(isolate);
-  DCHECK(args.length() == 0);
-  PrintTransition(isolate, NULL);
+  DCHECK_EQ(0, args.length());
+  PrintIndentation(isolate);
+  JavaScriptFrame::PrintTop(isolate, stdout, true, false);
+  PrintF(" {\n");
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_TraceExit) {
   SealHandleScope shs(isolate);
-  DCHECK(args.length() == 1);
+  DCHECK_EQ(1, args.length());
   CONVERT_ARG_CHECKED(Object, obj, 0);
-  PrintTransition(isolate, obj);
+  PrintIndentation(isolate);
+  PrintF("} -> ");
+  obj->ShortPrint();
+  PrintF("\n");
   return obj;  // return TOS
 }
 
+RUNTIME_FUNCTION(Runtime_TraceTailCall) {
+  SealHandleScope shs(isolate);
+  DCHECK_EQ(0, args.length());
+  PrintIndentation(isolate);
+  PrintF("} -> tail call ->\n");
+  return isolate->heap()->undefined_value();
+}
 
 RUNTIME_FUNCTION(Runtime_HaveSameMap) {
   SealHandleScope shs(isolate);

src/runtime/runtime.h

@@ -919,7 +919,6 @@ namespace internal {
   F(SymbolRegistry, 0, 1)            \
   F(SymbolIsPrivate, 1, 1)
 
-
 #define FOR_EACH_INTRINSIC_TEST(F)            \
   F(DeoptimizeFunction, 1, 1)                 \
   F(DeoptimizeNow, 0, 1)                      \
@@ -947,6 +946,7 @@ namespace internal {
   F(DisassembleFunction, 1, 1)                \
   F(TraceEnter, 0, 1)                         \
   F(TraceExit, 1, 1)                          \
+  F(TraceTailCall, 0, 1)                      \
   F(HaveSameMap, 2, 1)                        \
   F(InNewSpace, 1, 1)                         \
   F(HasFastSmiElements, 1, 1)                 \
@@ -968,7 +968,6 @@ namespace internal {
   F(HasFixedFloat64Elements, 1, 1)            \
   F(HasFixedUint8ClampedElements, 1, 1)
 
-
 #define FOR_EACH_INTRINSIC_TYPEDARRAY(F)     \
   F(ArrayBufferGetByteLength, 1, 1)          \
   F(ArrayBufferSliceImpl, 4, 1)              \

test/mjsunit/es6/tail-call-simple.js

@@ -15,6 +15,8 @@
     return f(n - 1);
   }
   assertThrows(()=>{ f(1e6) });
+  %OptimizeFunctionOnNextCall(f);
+  assertThrows(()=>{ f(1e6) });
 })();
 
 
@@ -30,6 +32,8 @@
     return f(n - 1);
   }
   assertEquals("foo", f(1e6));
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals("foo", f(1e6));
 })();
 
 
@@ -49,6 +53,9 @@
   }
   assertEquals("foo", f(1e6));
   assertEquals("bar", f(1e6 + 1));
+  %OptimizeFunctionOnNextCall(f);
+  assertEquals("foo", f(1e6));
+  assertEquals("bar", f(1e6 + 1));
 })();
 
 
@@ -61,9 +68,14 @@
     if (n <= 0) {
       return "foo";
     }
-    return f(n - 1);
+    return f_bound(n - 1);
   }
-  var f = f0.bind({});
+  var f_bound = f0.bind({});
+  function f(n) {
+    return f_bound(n);
+  }
+  assertEquals("foo", f(1e6));
+  %OptimizeFunctionOnNextCall(f);
   assertEquals("foo", f(1e6));
 })();
 
@@ -74,17 +86,22 @@
     if (n <= 0) {
       return "foo";
     }
-    return g(n - 1);
+    return g_bound(n - 1);
   }
   function g0(n){
     if (n <= 0) {
       return "bar";
     }
-    return f(n - 1);
+    return f_bound(n - 1);
   }
-  var f = f0.bind({});
-  var g = g0.bind({});
-
+  var f_bound = f0.bind({});
+  var g_bound = g0.bind({});
+  function f(n) {
+    return f_bound(n);
+  }
+  assertEquals("foo", f(1e6));
+  assertEquals("bar", f(1e6 + 1));
+  %OptimizeFunctionOnNextCall(f);
   assertEquals("foo", f(1e6));
   assertEquals("bar", f(1e6 + 1));
 })();

test/mjsunit/function-caller.js

@@ -47,7 +47,8 @@ f(null);
 eval('f(null)');
 
 // Check called from strict builtin functions.
-[null, null].sort(f);
+// [null, null].sort(f);  // Does not work because sort tail calls.
+[null].forEach(f, null);
 
 // Check called from sloppy builtin functions.
 "abel".replace(/b/g, function h() {

test/mjsunit/mjsunit.status

@@ -43,6 +43,9 @@
   # This test non-deterministically runs out of memory on Windows ia32.
   'regress/regress-crbug-160010': [SKIP],
 
+  # Issue 4698: not fully supported by Turbofan yet
+  'es6/tail-call-simple': [SKIP],
+
   # Issue 3389: deopt_every_n_garbage_collections is unsafe
   'regress/regress-2653': [SKIP],
 

test/mjsunit/strict-mode.js

@@ -1149,7 +1149,9 @@ function CheckArgumentsPillDescriptor(func, name) {
 
   function strict() {
     "use strict";
-    return return_my_caller();
+    // Returning result via local variable to avoid tail call optimization.
+    var res = return_my_caller();
+    return res;
   }
   assertSame(null, strict());
 
@@ -1163,7 +1165,9 @@ function CheckArgumentsPillDescriptor(func, name) {
 (function TestNonStrictFunctionCallerPill() {
   function strict(n) {
     "use strict";
-    return non_strict(n);
+    // Returning result via local variable to avoid tail call optimization.
+    var res = non_strict(n);
+    return res;
   }
 
   function recurse(n, then) {
@@ -1191,7 +1195,9 @@ function CheckArgumentsPillDescriptor(func, name) {
 (function TestNonStrictFunctionCallerDescriptorPill() {
   function strict(n) {
     "use strict";
-    return non_strict(n);
+    // Returning result via local variable to avoid tail call optimization.
+    var res = non_strict(n);
+    return res;
   }
 
   function recurse(n, then) {