Revert r4591

src/fast-dtoa.cc

Index: src/fast-dtoa.cc
===================================================================
--- src/fast-dtoa.cc	(revision 4591)
+++ src/fast-dtoa.cc	(working copy)
@@ -314,7 +314,7 @@
 //  w's fractional part is therefore 0x567890abcdef.
 // Printing w's integral part is easy (simply print 0x1234 in decimal).
 // In order to print its fraction we repeatedly multiply the fraction by 10 and
-// get each digit. Example the first digit after the point would be computed by
+// get each digit. Example the first digit after the comma would be computed by
 //   (0x567890abcdef * 10) >> 48. -> 3
 // The whole thing becomes slightly more complicated because we want to stop
 // once we have enough digits. That is, once the digits inside the buffer
@@ -490,11 +490,18 @@
 
 bool FastDtoa(double v,
               Vector<char> buffer,
+              int* sign,
               int* length,
               int* point) {
-  ASSERT(v > 0);
+  ASSERT(v != 0);
   ASSERT(!Double(v).IsSpecial());
 
+  if (v < 0) {
+    v = -v;
+    *sign = 1;
+  } else {
+    *sign = 0;
+  }
   int decimal_exponent;
   bool result = grisu3(v, buffer, length, &decimal_exponent);
   *point = *length + decimal_exponent;