Simplify double to number convertion.

Review URL: http://codereview.chromium.org/1694004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@4550 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -1761,41 +1761,6 @@ void Heap::SetNumberStringCache(Object* number, String* string) {
 }
 
 
-Object* Heap::SmiOrNumberFromDouble(double value,
-                                    bool new_object,
-                                    PretenureFlag pretenure) {
-  // We need to distinguish the minus zero value and this cannot be
-  // done after conversion to int. Doing this by comparing bit
-  // patterns is faster than using fpclassify() et al.
-  static const DoubleRepresentation plus_zero(0.0);
-  static const DoubleRepresentation minus_zero(-0.0);
-  static const DoubleRepresentation nan(OS::nan_value());
-  ASSERT(minus_zero_value() != NULL);
-  ASSERT(sizeof(plus_zero.value) == sizeof(plus_zero.bits));
-
-  DoubleRepresentation rep(value);
-  if (rep.bits == plus_zero.bits) return Smi::FromInt(0);  // not uncommon
-  if (rep.bits == minus_zero.bits) {
-    return new_object ? AllocateHeapNumber(-0.0, pretenure)
-                      : minus_zero_value();
-  }
-  if (rep.bits == nan.bits) {
-    return new_object
-        ? AllocateHeapNumber(OS::nan_value(), pretenure)
-        : nan_value();
-  }
-
-  // Try to represent the value as a tagged small integer.
-  int int_value = FastD2I(value);
-  if (value == FastI2D(int_value) && Smi::IsValid(int_value)) {
-    return Smi::FromInt(int_value);
-  }
-
-  // Materialize the value in the heap.
-  return AllocateHeapNumber(value, pretenure);
-}
-
-
 Object* Heap::NumberToString(Object* number, bool check_number_string_cache) {
   Counters::number_to_string_runtime.Increment();
   if (check_number_string_cache) {
@@ -1853,17 +1818,24 @@ Heap::RootListIndex Heap::RootIndexForExternalArrayType(
 }
 
 
-Object* Heap::NewNumberFromDouble(double value, PretenureFlag pretenure) {
-  return SmiOrNumberFromDouble(value,
-                               true /* number object must be new */,
-                               pretenure);
-}
-
-
 Object* Heap::NumberFromDouble(double value, PretenureFlag pretenure) {
-  return SmiOrNumberFromDouble(value,
-                               false /* use preallocated NaN, -0.0 */,
-                               pretenure);
+  // We need to distinguish the minus zero value and this cannot be
+  // done after conversion to int. Doing this by comparing bit
+  // patterns is faster than using fpclassify() et al.
+  static const DoubleRepresentation minus_zero(-0.0);
+
+  DoubleRepresentation rep(value);
+  if (rep.bits == minus_zero.bits) {
+    return AllocateHeapNumber(-0.0, pretenure);
+  }
+
+  int int_value = FastD2I(value);
+  if (value == int_value && Smi::IsValid(int_value)) {
+    return Smi::FromInt(int_value);
+  }
+
+  // Materialize the value in the heap.
+  return AllocateHeapNumber(value, pretenure);
 }
 
 

src/heap.h

@@ -527,13 +527,6 @@ class Heap : public AllStatic {
   // Please note this does not perform a garbage collection.
   static Object* AllocateArgumentsObject(Object* callee, int length);
 
-  // Converts a double into either a Smi or a HeapNumber object.
-  // Returns Failure::RetryAfterGC(requested_bytes, space) if the allocation
-  // failed.
-  // Please note this does not perform a garbage collection.
-  static Object* NewNumberFromDouble(double value,
-                                     PretenureFlag pretenure = NOT_TENURED);
-
   // Same as NewNumberFromDouble, but may return a preallocated/immutable
   // number object (e.g., minus_zero_value_, nan_value_)
   static Object* NumberFromDouble(double value,
@@ -1131,12 +1124,6 @@ class Heap : public AllStatic {
                                        GarbageCollector collector,
                                        GCTracer* tracer);
 
-  // Returns either a Smi or a Number object from 'value'. If 'new_object'
-  // is false, it may return a preallocated immutable object.
-  static Object* SmiOrNumberFromDouble(double value,
-                                       bool new_object,
-                                       PretenureFlag pretenure = NOT_TENURED);
-
   // Allocate an uninitialized object in map space.  The behavior is identical
   // to Heap::AllocateRaw(size_in_bytes, MAP_SPACE), except that (a) it doesn't
   // have to test the allocation space argument and (b) can reduce code size

src/runtime.cc

@@ -5412,7 +5412,7 @@ static Object* Runtime_NumberDiv(Arguments args) {
 
   CONVERT_DOUBLE_CHECKED(x, args[0]);
   CONVERT_DOUBLE_CHECKED(y, args[1]);
-  return Heap::NewNumberFromDouble(x / y);
+  return Heap::NumberFromDouble(x / y);
 }
 
 
@@ -5424,8 +5424,8 @@ static Object* Runtime_NumberMod(Arguments args) {
   CONVERT_DOUBLE_CHECKED(y, args[1]);
 
   x = modulo(x, y);
-  // NewNumberFromDouble may return a Smi instead of a Number object
-  return Heap::NewNumberFromDouble(x);
+  // NumberFromDouble may return a Smi instead of a Number object
+  return Heap::NumberFromDouble(x);
 }
 
 
@@ -6079,7 +6079,8 @@ static Object* Runtime_RoundNumber(Arguments args) {
 
   if (sign && value >= -0.5) return Heap::minus_zero_value();
 
-  return Heap::NumberFromDouble(floor(value + 0.5));
+  // Do not call NumberFromDouble() to avoid extra checks.
+  return Heap::AllocateHeapNumber(floor(value + 0.5));
 }