SSE2 truncating double-to-i.

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index eeb84128d76bdf5f0ef2d12294de9adf2d47f8f1..e196bd035c63f85ac9a228f9f5f0ce2d69a079da 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -66,6 +66,7 @@ namespace internal {
 
 const double DoubleConstant::min_int = kMinInt;
 const double DoubleConstant::one_half = 0.5;
+const double DoubleConstant::minus_zero = -0.0;
 const double DoubleConstant::negative_infinity = -V8_INFINITY;
 
 
@@ -724,6 +725,12 @@ ExternalReference ExternalReference::address_of_one_half() {
 }
 
 
+ExternalReference ExternalReference::address_of_minus_zero() {
+  return ExternalReference(reinterpret_cast<void*>(
+      const_cast<double*>(&DoubleConstant::minus_zero)));
+}
+
+
 ExternalReference ExternalReference::address_of_negative_infinity() {
   return ExternalReference(reinterpret_cast<void*>(
       const_cast<double*>(&DoubleConstant::negative_infinity)));