Remove the forward-bailout stack from the non-optimizing compiler.

This was pretty heavyweight.  It was kept in just for a few corner cases
that assumed it was there.  We can work around them by making sure that the
expression in a reified test context is always really the expression that
was visited in that context; and by inspecting the context manually and
consing up a pair of extra AST IDs for the unusual case of unary not in a
value AST context.

R=fschneider@chromium.org
BUG=
TEST=

Review URL: http://codereview.chromium.org/8386037

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9863 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/ast.h

@@ -1288,8 +1288,17 @@ class UnaryOperation: public Expression {
                  Token::Value op,
                  Expression* expression,
                  int pos)
-      : Expression(isolate), op_(op), expression_(expression), pos_(pos) {
+      : Expression(isolate),
+        op_(op),
+        expression_(expression),
+        pos_(pos),
+        materialize_true_id_(AstNode::kNoNumber),
+        materialize_false_id_(AstNode::kNoNumber) {
     ASSERT(Token::IsUnaryOp(op));
+    if (op == Token::NOT) {
+      materialize_true_id_ = GetNextId(isolate);
+      materialize_false_id_ = GetNextId(isolate);
+    }
   }
 
   DECLARE_NODE_TYPE(UnaryOperation)
@@ -1302,10 +1311,18 @@ class UnaryOperation: public Expression {
   Expression* expression() const { return expression_; }
   virtual int position() const { return pos_; }
 
+  int MaterializeTrueId() { return materialize_true_id_; }
+  int MaterializeFalseId() { return materialize_false_id_; }
+
  private:
   Token::Value op_;
   Expression* expression_;
   int pos_;
+
+  // For unary not (Token::NOT), the AST ids where true and false will
+  // actually be materialized, respectively.
+  int materialize_true_id_;
+  int materialize_false_id_;
 };
 
 

src/full-codegen.cc

@@ -416,7 +416,7 @@ void FullCodeGenerator::StackValueContext::Plug(Register reg) const {
 void FullCodeGenerator::TestContext::Plug(Register reg) const {
   // For simplicity we always test the accumulator register.
   __ Move(result_register(), reg);
-  codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
+  codegen()->PrepareForBailoutBeforeSplit(condition(), false, NULL, NULL);
   codegen()->DoTest(this);
 }
 
@@ -438,7 +438,7 @@ void FullCodeGenerator::StackValueContext::PlugTOS() const {
 void FullCodeGenerator::TestContext::PlugTOS() const {
   // For simplicity we always test the accumulator register.
   __ pop(result_register());
-  codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
+  codegen()->PrepareForBailoutBeforeSplit(condition(), false, NULL, NULL);
   codegen()->DoTest(this);
 }
 
@@ -652,14 +652,13 @@ FullCodeGenerator::InlineFunctionGenerator
 }
 
 
-void FullCodeGenerator::EmitInlineRuntimeCall(CallRuntime* node) {
-  ZoneList<Expression*>* args = node->arguments();
-  const Runtime::Function* function = node->function();
+void FullCodeGenerator::EmitInlineRuntimeCall(CallRuntime* expr) {
+  const Runtime::Function* function = expr->function();
   ASSERT(function != NULL);
   ASSERT(function->intrinsic_type == Runtime::INLINE);
   InlineFunctionGenerator generator =
       FindInlineFunctionGenerator(function->function_id);
-  ((*this).*(generator))(args);
+  ((*this).*(generator))(expr);
 }
 
 
@@ -676,11 +675,25 @@ void FullCodeGenerator::VisitBinaryOperation(BinaryOperation* expr) {
 }
 
 
+void FullCodeGenerator::VisitInDuplicateContext(Expression* expr) {
+  if (context()->IsEffect()) {
+    VisitForEffect(expr);
+  } else if (context()->IsAccumulatorValue()) {
+    VisitForAccumulatorValue(expr);
+  } else if (context()->IsStackValue()) {
+    VisitForStackValue(expr);
+  } else if (context()->IsTest()) {
+    const TestContext* test = TestContext::cast(context());
+    VisitForControl(expr, test->true_label(), test->false_label(),
+                    test->fall_through());
+  }
+}
+
+
 void FullCodeGenerator::VisitComma(BinaryOperation* expr) {
   Comment cmnt(masm_, "[ Comma");
   VisitForEffect(expr->left());
-  if (context()->IsTest()) ForwardBailoutToChild(expr);
-  VisitInCurrentContext(expr->right());
+  VisitInDuplicateContext(expr->right());
 }
 
 
@@ -702,7 +715,6 @@ void FullCodeGenerator::VisitLogicalExpression(BinaryOperation* expr) {
     }
     PrepareForBailoutForId(right_id, NO_REGISTERS);
     __ bind(&eval_right);
-    ForwardBailoutToChild(expr);
 
   } else if (context()->IsAccumulatorValue()) {
     VisitForAccumulatorValue(left);
@@ -710,7 +722,6 @@ void FullCodeGenerator::VisitLogicalExpression(BinaryOperation* expr) {
     // case we need it.
     __ push(result_register());
     Label discard, restore;
-    PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
     if (is_logical_and) {
       DoTest(left, &discard, &restore, &restore);
     } else {
@@ -729,7 +740,6 @@ void FullCodeGenerator::VisitLogicalExpression(BinaryOperation* expr) {
     // case we need it.
     __ push(result_register());
     Label discard;
-    PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
     if (is_logical_and) {
       DoTest(left, &discard, &done, &discard);
     } else {
@@ -751,7 +761,7 @@ void FullCodeGenerator::VisitLogicalExpression(BinaryOperation* expr) {
     __ bind(&eval_right);
   }
 
-  VisitInCurrentContext(right);
+  VisitInDuplicateContext(right);
   __ bind(&done);
 }
 
@@ -778,34 +788,6 @@ void FullCodeGenerator::VisitArithmeticExpression(BinaryOperation* expr) {
 }
 
 
-void FullCodeGenerator::ForwardBailoutToChild(Expression* expr) {
-  if (!info_->HasDeoptimizationSupport()) return;
-  ASSERT(context()->IsTest());
-  ASSERT(expr == forward_bailout_stack_->expr());
-  forward_bailout_pending_ = forward_bailout_stack_;
-}
-
-
-void FullCodeGenerator::VisitInCurrentContext(Expression* expr) {
-  if (context()->IsTest()) {
-    ForwardBailoutStack stack(expr, forward_bailout_pending_);
-    ForwardBailoutStack* saved = forward_bailout_stack_;
-    forward_bailout_pending_ = NULL;
-    forward_bailout_stack_ = &stack;
-    Visit(expr);
-    forward_bailout_stack_ = saved;
-  } else {
-    ASSERT(forward_bailout_pending_ == NULL);
-    Visit(expr);
-    State state = context()->IsAccumulatorValue() ? TOS_REG : NO_REGISTERS;
-    PrepareForBailout(expr, state);
-    // Forwarding bailouts to children is a one shot operation. It should have
-    // been processed at this point.
-    ASSERT(forward_bailout_pending_ == NULL);
-  }
-}
-
-
 void FullCodeGenerator::VisitBlock(Block* stmt) {
   Comment cmnt(masm_, "[ Block");
   NestedBlock nested_block(this, stmt);
@@ -1247,16 +1229,15 @@ void FullCodeGenerator::VisitConditional(Conditional* expr) {
                     for_test->false_label(),
                     NULL);
   } else {
-    VisitInCurrentContext(expr->then_expression());
+    VisitInDuplicateContext(expr->then_expression());
     __ jmp(&done);
   }
 
   PrepareForBailoutForId(expr->ElseId(), NO_REGISTERS);
   __ bind(&false_case);
-  if (context()->IsTest()) ForwardBailoutToChild(expr);
   SetExpressionPosition(expr->else_expression(),
                         expr->else_expression_position());
-  VisitInCurrentContext(expr->else_expression());
+  VisitInDuplicateContext(expr->else_expression());
   // If control flow falls through Visit, merge it with true case here.
   if (!context()->IsTest()) {
     __ bind(&done);
@@ -1314,7 +1295,7 @@ bool FullCodeGenerator::TryLiteralCompare(CompareOperation* expr) {
   Expression *sub_expr;
   Handle<String> check;
   if (expr->IsLiteralCompareTypeof(&sub_expr, &check)) {
-    EmitLiteralCompareTypeof(sub_expr, check);
+    EmitLiteralCompareTypeof(expr, sub_expr, check);
     return true;
   }
 

src/full-codegen.h

@@ -85,9 +85,7 @@ class FullCodeGenerator: public AstVisitor {
         loop_depth_(0),
         context_(NULL),
         bailout_entries_(0),
-        stack_checks_(2),  // There's always at least one.
-        forward_bailout_stack_(NULL),
-        forward_bailout_pending_(NULL) {
+        stack_checks_(2) {  // There's always at least one.
   }
 
   static bool MakeCode(CompilationInfo* info);
@@ -275,27 +273,8 @@ class FullCodeGenerator: public AstVisitor {
     }
   };
 
-  // The forward bailout stack keeps track of the expressions that can
-  // bail out to just before the control flow is split in a child
-  // node. The stack elements are linked together through the parent
-  // link when visiting expressions in test contexts after requesting
-  // bailout in child forwarding.
-  class ForwardBailoutStack BASE_EMBEDDED {
-   public:
-    ForwardBailoutStack(Expression* expr, ForwardBailoutStack* parent)
-        : expr_(expr), parent_(parent) { }
-
-    Expression* expr() const { return expr_; }
-    ForwardBailoutStack* parent() const { return parent_; }
-
-   private:
-    Expression* const expr_;
-    ForwardBailoutStack* const parent_;
-  };
-
   // Type of a member function that generates inline code for a native function.
-  typedef void (FullCodeGenerator::*InlineFunctionGenerator)
-      (ZoneList<Expression*>*);
+  typedef void (FullCodeGenerator::*InlineFunctionGenerator)(CallRuntime* expr);
 
   static const InlineFunctionGenerator kInlineFunctionGenerators[];
 
@@ -356,23 +335,22 @@ class FullCodeGenerator: public AstVisitor {
   // need the write barrier if location is CONTEXT.
   MemOperand VarOperand(Variable* var, Register scratch);
 
-  // Forward the bailout responsibility for the given expression to
-  // the next child visited (which must be in a test context).
-  void ForwardBailoutToChild(Expression* expr);
-
   void VisitForEffect(Expression* expr) {
     EffectContext context(this);
-    VisitInCurrentContext(expr);
+    Visit(expr);
+    PrepareForBailout(expr, NO_REGISTERS);
   }
 
   void VisitForAccumulatorValue(Expression* expr) {
     AccumulatorValueContext context(this);
-    VisitInCurrentContext(expr);
+    Visit(expr);
+    PrepareForBailout(expr, TOS_REG);
   }
 
   void VisitForStackValue(Expression* expr) {
     StackValueContext context(this);
-    VisitInCurrentContext(expr);
+    Visit(expr);
+    PrepareForBailout(expr, NO_REGISTERS);
   }
 
   void VisitForControl(Expression* expr,
@@ -380,9 +358,14 @@ class FullCodeGenerator: public AstVisitor {
                        Label* if_false,
                        Label* fall_through) {
     TestContext context(this, expr, if_true, if_false, fall_through);
-    VisitInCurrentContext(expr);
+    Visit(expr);
+    // For test contexts, we prepare for bailout before branching, not at
+    // the end of the entire expression.  This happens as part of visiting
+    // the expression.
   }
 
+  void VisitInDuplicateContext(Expression* expr);
+
   void VisitDeclarations(ZoneList<Declaration*>* declarations);
   void DeclareGlobals(Handle<FixedArray> pairs);
   int DeclareGlobalsFlags();
@@ -394,7 +377,9 @@ class FullCodeGenerator: public AstVisitor {
 
   // Platform-specific code for comparing the type of a value with
   // a given literal string.
-  void EmitLiteralCompareTypeof(Expression* expr, Handle<String> check);
+  void EmitLiteralCompareTypeof(Expression* expr,
+                                Expression* sub_expr,
+                                Handle<String> check);
 
   // Platform-specific code for equality comparison with a nil-like value.
   void EmitLiteralCompareNil(CompareOperation* expr,
@@ -414,7 +399,7 @@ class FullCodeGenerator: public AstVisitor {
   // canonical JS true value so we will insert a (dead) test against true at
   // the actual bailout target from the optimized code. If not
   // should_normalize, the true and false labels are ignored.
-  void PrepareForBailoutBeforeSplit(State state,
+  void PrepareForBailoutBeforeSplit(Expression* expr,
                                     bool should_normalize,
                                     Label* if_true,
                                     Label* if_false);
@@ -449,7 +434,7 @@ class FullCodeGenerator: public AstVisitor {
   void EmitInlineRuntimeCall(CallRuntime* expr);
 
 #define EMIT_INLINE_RUNTIME_CALL(name, x, y) \
-  void Emit##name(ZoneList<Expression*>* arguments);
+  void Emit##name(CallRuntime* expr);
   INLINE_FUNCTION_LIST(EMIT_INLINE_RUNTIME_CALL)
   INLINE_RUNTIME_FUNCTION_LIST(EMIT_INLINE_RUNTIME_CALL)
 #undef EMIT_INLINE_RUNTIME_CALL
@@ -576,7 +561,6 @@ class FullCodeGenerator: public AstVisitor {
   void VisitComma(BinaryOperation* expr);
   void VisitLogicalExpression(BinaryOperation* expr);
   void VisitArithmeticExpression(BinaryOperation* expr);
-  void VisitInCurrentContext(Expression* expr);
 
   void VisitForTypeofValue(Expression* expr);
 
@@ -771,8 +755,6 @@ class FullCodeGenerator: public AstVisitor {
   const ExpressionContext* context_;
   ZoneList<BailoutEntry> bailout_entries_;
   ZoneList<BailoutEntry> stack_checks_;
-  ForwardBailoutStack* forward_bailout_stack_;
-  ForwardBailoutStack* forward_bailout_pending_;
 
   friend class NestedStatement;
 

src/hydrogen.cc

@@ -5379,7 +5379,7 @@ void HGraphBuilder::VisitNot(UnaryOperation* expr) {
                                 materialize_true));
 
   if (materialize_false->HasPredecessor()) {
-    materialize_false->SetJoinId(expr->expression()->id());
+    materialize_false->SetJoinId(expr->MaterializeFalseId());
     set_current_block(materialize_false);
     Push(graph()->GetConstantFalse());
   } else {
@@ -5387,7 +5387,7 @@ void HGraphBuilder::VisitNot(UnaryOperation* expr) {
   }
 
   if (materialize_true->HasPredecessor()) {
-    materialize_true->SetJoinId(expr->expression()->id());
+    materialize_true->SetJoinId(expr->MaterializeTrueId());
     set_current_block(materialize_true);
     Push(graph()->GetConstantTrue());
   } else {

src/mips/full-codegen-mips.cc

@@ -405,7 +405,7 @@ void FullCodeGenerator::StackValueContext::Plug(Variable* var) const {
 void FullCodeGenerator::TestContext::Plug(Variable* var) const {
   // For simplicity we always test the accumulator register.
   codegen()->GetVar(result_register(), var);
-  codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
+  codegen()->PrepareForBailoutBeforeSplit(false, NULL, NULL);
   codegen()->DoTest(this);
 }
 
@@ -522,7 +522,7 @@ void FullCodeGenerator::TestContext::DropAndPlug(int count,
   // For simplicity we always test the accumulator register.
   __ Drop(count);
   __ Move(result_register(), reg);
-  codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
+  codegen()->PrepareForBailoutBeforeSplit(false, NULL, NULL);
   codegen()->DoTest(this);
 }
 
@@ -2413,7 +2413,7 @@ void FullCodeGenerator::EmitIsSmi(ZoneList<Expression*>* args) {
   context()->PrepareTest(&materialize_true, &materialize_false,
                          &if_true, &if_false, &fall_through);
 
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   __ And(t0, v0, Operand(kSmiTagMask));
   Split(eq, t0, Operand(zero_reg), if_true, if_false, fall_through);
 
@@ -2433,7 +2433,7 @@ void FullCodeGenerator::EmitIsNonNegativeSmi(ZoneList<Expression*>* args) {
   context()->PrepareTest(&materialize_true, &materialize_false,
                          &if_true, &if_false, &fall_through);
 
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   __ And(at, v0, Operand(kSmiTagMask | 0x80000000));
   Split(eq, at, Operand(zero_reg), if_true, if_false, fall_through);
 
@@ -2463,7 +2463,7 @@ void FullCodeGenerator::EmitIsObject(ZoneList<Expression*>* args) {
   __ Branch(if_false, ne, at, Operand(zero_reg));
   __ lbu(a1, FieldMemOperand(a2, Map::kInstanceTypeOffset));
   __ Branch(if_false, lt, a1, Operand(FIRST_NONCALLABLE_SPEC_OBJECT_TYPE));
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(le, a1, Operand(LAST_NONCALLABLE_SPEC_OBJECT_TYPE),
         if_true, if_false, fall_through);
 
@@ -2485,7 +2485,7 @@ void FullCodeGenerator::EmitIsSpecObject(ZoneList<Expression*>* args) {
 
   __ JumpIfSmi(v0, if_false);
   __ GetObjectType(v0, a1, a1);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(ge, a1, Operand(FIRST_SPEC_OBJECT_TYPE),
         if_true, if_false, fall_through);
 
@@ -2509,7 +2509,7 @@ void FullCodeGenerator::EmitIsUndetectableObject(ZoneList<Expression*>* args) {
   __ lw(a1, FieldMemOperand(v0, HeapObject::kMapOffset));
   __ lbu(a1, FieldMemOperand(a1, Map::kBitFieldOffset));
   __ And(at, a1, Operand(1 << Map::kIsUndetectable));
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(ne, at, Operand(zero_reg), if_true, if_false, fall_through);
 
   context()->Plug(if_true, if_false);
@@ -2594,7 +2594,7 @@ void FullCodeGenerator::EmitIsStringWrapperSafeForDefaultValueOf(
   __ sb(a2, FieldMemOperand(a1, Map::kBitField2Offset));
   __ jmp(if_true);
 
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   context()->Plug(if_true, if_false);
 }
 
@@ -2613,7 +2613,7 @@ void FullCodeGenerator::EmitIsFunction(ZoneList<Expression*>* args) {
 
   __ JumpIfSmi(v0, if_false);
   __ GetObjectType(v0, a1, a2);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   __ Branch(if_true, eq, a2, Operand(JS_FUNCTION_TYPE));
   __ Branch(if_false);
 
@@ -2635,7 +2635,7 @@ void FullCodeGenerator::EmitIsArray(ZoneList<Expression*>* args) {
 
   __ JumpIfSmi(v0, if_false);
   __ GetObjectType(v0, a1, a1);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(eq, a1, Operand(JS_ARRAY_TYPE),
         if_true, if_false, fall_through);
 
@@ -2657,7 +2657,7 @@ void FullCodeGenerator::EmitIsRegExp(ZoneList<Expression*>* args) {
 
   __ JumpIfSmi(v0, if_false);
   __ GetObjectType(v0, a1, a1);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(eq, a1, Operand(JS_REGEXP_TYPE), if_true, if_false, fall_through);
 
   context()->Plug(if_true, if_false);
@@ -2687,7 +2687,7 @@ void FullCodeGenerator::EmitIsConstructCall(ZoneList<Expression*>* args) {
   // Check the marker in the calling frame.
   __ bind(&check_frame_marker);
   __ lw(a1, MemOperand(a2, StandardFrameConstants::kMarkerOffset));
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(eq, a1, Operand(Smi::FromInt(StackFrame::CONSTRUCT)),
         if_true, if_false, fall_through);
 
@@ -2710,7 +2710,7 @@ void FullCodeGenerator::EmitObjectEquals(ZoneList<Expression*>* args) {
                          &if_true, &if_false, &fall_through);
 
   __ pop(a1);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(eq, v0, Operand(a1), if_true, if_false, fall_through);
 
   context()->Plug(if_true, if_false);
@@ -3396,7 +3396,7 @@ void FullCodeGenerator::EmitHasCachedArrayIndex(ZoneList<Expression*>* args) {
   __ lw(a0, FieldMemOperand(v0, String::kHashFieldOffset));
   __ And(a0, a0, Operand(String::kContainsCachedArrayIndexMask));
 
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Split(eq, a0, Operand(zero_reg), if_true, if_false, fall_through);
 
   context()->Plug(if_true, if_false);
@@ -4048,7 +4048,7 @@ void FullCodeGenerator::EmitLiteralCompareTypeof(Expression* expr,
   { AccumulatorValueContext context(this);
     VisitForTypeofValue(expr);
   }
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
 
   if (check->Equals(isolate()->heap()->number_symbol())) {
     __ JumpIfSmi(v0, if_true);
@@ -4134,7 +4134,7 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
     case Token::IN:
       VisitForStackValue(expr->right());
       __ InvokeBuiltin(Builtins::IN, CALL_FUNCTION);
-      PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
+      PrepareForBailoutBeforeSplit(false, NULL, NULL);
       __ LoadRoot(t0, Heap::kTrueValueRootIndex);
       Split(eq, v0, Operand(t0), if_true, if_false, fall_through);
       break;
@@ -4143,7 +4143,7 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
       VisitForStackValue(expr->right());
       InstanceofStub stub(InstanceofStub::kNoFlags);
       __ CallStub(&stub);
-      PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+      PrepareForBailoutBeforeSplit(true, if_true, if_false);
       // The stub returns 0 for true.
       Split(eq, v0, Operand(zero_reg), if_true, if_false, fall_through);
       break;
@@ -4191,7 +4191,7 @@ void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
       Handle<Code> ic = CompareIC::GetUninitialized(op);
       __ Call(ic, RelocInfo::CODE_TARGET, expr->id());
       patch_site.EmitPatchInfo();
-      PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+      PrepareForBailoutBeforeSplit(true, if_true, if_false);
       Split(cc, v0, Operand(zero_reg), if_true, if_false, fall_through);
     }
   }
@@ -4213,7 +4213,7 @@ void FullCodeGenerator::EmitLiteralCompareNil(CompareOperation* expr,
                          &if_true, &if_false, &fall_through);
 
   VisitForAccumulatorValue(sub_expr);
-  PrepareForBailoutBeforeSplit(TOS_REG, true, if_true, if_false);
+  PrepareForBailoutBeforeSplit(true, if_true, if_false);
   Heap::RootListIndex nil_value = nil == kNullValue ?
       Heap::kNullValueRootIndex :
       Heap::kUndefinedValueRootIndex;