Introduce ToNumber stub and use it in non-optimized code for to-number conversion.

This stub is used for increment/decrement operations and unary plus.
The resulting code is more compact and faster than calling a JS builtin.


Review URL: http://codereview.chromium.org/6350021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6527 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/code-stubs-arm.cc

@@ -55,6 +55,28 @@ static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm,
                                            Register rhs);
 
 
+void ToNumberStub::Generate(MacroAssembler* masm) {
+  // The ToNumber stub takes one argument in eax.
+  Label check_heap_number, call_builtin;
+  __ tst(r0, Operand(kSmiTagMask));
+  __ b(ne, &check_heap_number);
+  __ Ret();
+
+  __ bind(&check_heap_number);
+  __ ldr(r1, FieldMemOperand(r0, HeapObject::kMapOffset));
+  __ LoadRoot(ip, Heap::kHeapNumberMapRootIndex);
+  __ cmp(r1, ip);
+  __ b(ne, &call_builtin);
+  __ Ret();
+
+  __ bind(&call_builtin);
+  __ pop(r2);  // Pop return address.
+  __ push(r0);
+  __ push(r2);  // Push return address.
+  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_JS);
+}
+
+
 void FastNewClosureStub::Generate(MacroAssembler* masm) {
   // Create a new closure from the given function info in new
   // space. Set the context to the current context in cp.

src/arm/full-codegen-arm.cc

@@ -3057,8 +3057,8 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
       Label no_conversion;
       __ tst(result_register(), Operand(kSmiTagMask));
       __ b(eq, &no_conversion);
-      __ push(r0);
-      __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_JS);
+      ToNumberStub convert_stub;
+      __ CallStub(&convert_stub);
       __ bind(&no_conversion);
       context()->Plug(result_register());
       break;
@@ -3177,8 +3177,8 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   // Call ToNumber only if operand is not a smi.
   Label no_conversion;
   __ JumpIfSmi(r0, &no_conversion);
-  __ push(r0);
-  __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_JS);
+  ToNumberStub convert_stub;
+  __ CallStub(&convert_stub);
   __ bind(&no_conversion);
 
   // Save result for postfix expressions.

src/code-stubs.h

@@ -59,6 +59,7 @@ namespace internal {
   V(GenericUnaryOp)                      \
   V(RevertToNumber)                      \
   V(ToBoolean)                           \
+  V(ToNumber)                            \
   V(CounterOp)                           \
   V(ArgumentsAccess)                     \
   V(RegExpExec)                          \
@@ -260,6 +261,19 @@ class StackCheckStub : public CodeStub {
 };
 
 
+class ToNumberStub: public CodeStub {
+ public:
+  ToNumberStub() { }
+
+  void Generate(MacroAssembler* masm);
+
+ private:
+  Major MajorKey() { return ToNumber; }
+  int MinorKey() { return 0; }
+  const char* GetName() { return "ToNumberStub"; }
+};
+
+
 class FastNewClosureStub : public CodeStub {
  public:
   void Generate(MacroAssembler* masm);

src/ia32/code-stubs-ia32.cc

@@ -38,6 +38,28 @@ namespace v8 {
 namespace internal {
 
 #define __ ACCESS_MASM(masm)
+
+void ToNumberStub::Generate(MacroAssembler* masm) {
+  // The ToNumber stub takes one argument in eax.
+  NearLabel check_heap_number, call_builtin;
+  __ test(eax, Immediate(kSmiTagMask));
+  __ j(not_zero, &check_heap_number);
+  __ ret(0);
+
+  __ bind(&check_heap_number);
+  __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
+  __ cmp(Operand(ebx), Immediate(Factory::heap_number_map()));
+  __ j(not_equal, &call_builtin);
+  __ ret(0);
+
+  __ bind(&call_builtin);
+  __ pop(ecx);  // Pop return address.
+  __ push(eax);
+  __ push(ecx);  // Push return address.
+  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_FUNCTION);
+}
+
+
 void FastNewClosureStub::Generate(MacroAssembler* masm) {
   // Create a new closure from the given function info in new
   // space. Set the context to the current context in esi.

src/ia32/full-codegen-ia32.cc

@@ -3747,8 +3747,8 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
       Label no_conversion;
       __ test(result_register(), Immediate(kSmiTagMask));
       __ j(zero, &no_conversion);
-      __ push(result_register());
-      __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION);
+      ToNumberStub convert_stub;
+      __ CallStub(&convert_stub);
       __ bind(&no_conversion);
       context()->Plug(result_register());
       break;
@@ -3868,8 +3868,8 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
     __ test(eax, Immediate(kSmiTagMask));
     __ j(zero, &no_conversion);
   }
-  __ push(eax);
-  __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION);
+  ToNumberStub convert_stub;
+  __ CallStub(&convert_stub);
   __ bind(&no_conversion);
 
   // Save result for postfix expressions.

src/x64/code-stubs-x64.cc

@@ -37,6 +37,28 @@ namespace v8 {
 namespace internal {
 
 #define __ ACCESS_MASM(masm)
+
+void ToNumberStub::Generate(MacroAssembler* masm) {
+  // The ToNumber stub takes one argument in eax.
+  NearLabel check_heap_number, call_builtin;
+  __ SmiTest(rax);
+  __ j(not_zero, &check_heap_number);
+  __ Ret();
+
+  __ bind(&check_heap_number);
+  __ Move(rbx, Factory::heap_number_map());
+  __ cmpq(rbx, FieldOperand(rax, HeapObject::kMapOffset));
+  __ j(not_equal, &call_builtin);
+  __ Ret();
+
+  __ bind(&call_builtin);
+  __ pop(rcx);  // Pop return address.
+  __ push(rax);
+  __ push(rcx);  // Push return address.
+  __ InvokeBuiltin(Builtins::TO_NUMBER, JUMP_FUNCTION);
+}
+
+
 void FastNewClosureStub::Generate(MacroAssembler* masm) {
   // Create a new closure from the given function info in new
   // space. Set the context to the current context in rsi.

src/x64/full-codegen-x64.cc

@@ -3063,8 +3063,8 @@ void FullCodeGenerator::VisitUnaryOperation(UnaryOperation* expr) {
       Label no_conversion;
       Condition is_smi = masm_->CheckSmi(result_register());
       __ j(is_smi, &no_conversion);
-      __ push(result_register());
-      __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION);
+      ToNumberStub convert_stub;
+      __ CallStub(&convert_stub);
       __ bind(&no_conversion);
       context()->Plug(result_register());
       break;
@@ -3180,8 +3180,8 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   Condition is_smi;
   is_smi = masm_->CheckSmi(rax);
   __ j(is_smi, &no_conversion);
-  __ push(rax);
-  __ InvokeBuiltin(Builtins::TO_NUMBER, CALL_FUNCTION);
+  ToNumberStub convert_stub;
+  __ CallStub(&convert_stub);
   __ bind(&no_conversion);
 
   // Save result for postfix expressions.