Version 3.12.18

Forced using bit-pattern for signed zero double. (issue 2239)

Made sure double to int conversion is correct. (issue 2260)

Performance and stability improvements on all platforms.

git-svn-id: http://v8.googlecode.com/svn/trunk@12227 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
diff --git a/src/conversions.h b/src/conversions.h
index 70559c9..1fbb5f1 100644
--- a/src/conversions.h
+++ b/src/conversions.h
@@ -52,8 +52,13 @@
 }
 
 
-inline double SignedZero(bool negative) {
-  return negative ? -0.0 : 0.0;
+// The fast double-to-(unsigned-)int conversion routine does not guarantee
+// rounding towards zero.
+// For NaN and values outside the int range, return INT_MIN or INT_MAX.
+inline int FastD2IChecked(double x) {
+  if (!(x >= INT_MIN)) return INT_MIN;  // Negation to catch NaNs.
+  if (x > INT_MAX) return INT_MAX;
+  return static_cast<int>(x);
 }
 
 
@@ -62,8 +67,6 @@
 // The result is unspecified if x is infinite or NaN, or if the rounded
 // integer value is outside the range of type int.
 inline int FastD2I(double x) {
-  // The static_cast convertion from double to int used to be slow, but
-  // as new benchmarks show, now it is much faster than lrint().
   return static_cast<int>(x);
 }