dbertoni 00/12/01 13:36:01
Modified: c/src/PlatformSupport DoubleSupport.cpp DoubleSupport.hpp
Log:
Special support code for positive and negative infinity.
Revision Changes Path
1.17 +26 -10 xml-xalan/c/src/PlatformSupport/DoubleSupport.cpp
Index: DoubleSupport.cpp
===================================================================
RCS file: /home/cvs/xml-xalan/c/src/PlatformSupport/DoubleSupport.cpp,v
retrieving revision 1.16
retrieving revision 1.17
diff -u -r1.16 -r1.17
--- DoubleSupport.cpp 2000/11/29 21:48:34 1.16
+++ DoubleSupport.cpp 2000/12/01 21:36:00 1.17
@@ -70,6 +70,8 @@
const double DoubleSupport::s_NaN = sqrt(-2.01);
const double DoubleSupport::s_positiveInfinity = HUGE_VAL;
const double DoubleSupport::s_negativeInfinity =
-DoubleSupport::s_positiveInfinity;
+const double DoubleSupport::s_positiveZero = 0.0;
+const double DoubleSupport::s_negativeZero = -DoubleSupport::s_positiveZero;
@@ -84,7 +86,27 @@
s_NaNFirstDWORD + 1;
+const unsigned long* DoubleSupport::s_positiveZeroFirstDWORD =
+#if defined(XALAN_OLD_STYLE_CASTS)
+ (const unsigned long*)&s_positiveZero;
+#else
+ reinterpret_cast<const unsigned
long*>(&s_positiveZero);
+#endif
+
+const unsigned long* DoubleSupport::s_positiveZeroSecondDWORD =
s_positiveZeroFirstDWORD + 1;
+
+
+const unsigned long* DoubleSupport::s_negativeZeroFirstDWORD =
+#if defined(XALAN_OLD_STYLE_CASTS)
+ (const unsigned long*)&s_negativeZero;
+#else
+ reinterpret_cast<const unsigned
long*>(&s_negativeZero);
+#endif
+
+const unsigned long* DoubleSupport::s_negativeZeroSecondDWORD =
s_negativeZeroFirstDWORD + 1;
+
+
bool
DoubleSupport::equal(
double theLHS,
@@ -107,14 +129,7 @@
double theLHS,
double theRHS)
{
- if (isNaN(theLHS) == true || isNaN(theRHS) == true)
- {
- return true;
- }
- else
- {
- return theLHS != theRHS;
- }
+ return !equal(theLHS, theRHS);
}
@@ -276,14 +291,15 @@
// This is NaN...
return DoubleSupport::getNaN();
}
- else if (theLHS > 0.0L)
+ else if (theLHS > 0.0L &&
+ isPositiveZero(theRHS) == true)
{
// This is positive infinity...
return DoubleSupport::getPositiveInfinity();
}
else
{
- // This is positive infinity...
+ // This is negative infinity...
return DoubleSupport::getNegativeInfinity();
}
}
1.9 +56 -0 xml-xalan/c/src/PlatformSupport/DoubleSupport.hpp
Index: DoubleSupport.hpp
===================================================================
RCS file: /home/cvs/xml-xalan/c/src/PlatformSupport/DoubleSupport.hpp,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -r1.8 -r1.9
--- DoubleSupport.hpp 2000/10/02 16:28:10 1.8
+++ DoubleSupport.hpp 2000/12/01 21:36:00 1.9
@@ -130,6 +130,54 @@
return !isNaN(theNumber) && theNumber == s_negativeInfinity;
}
+ /**
+ * Determine if target is positive 0.
+ *
+ * @param theNumber target number
+ * @return true if target represents the value for positive 0.
+ */
+ static bool
+ isPositiveZero(double theNumber)
+ {
+ // Compare the two DWORDs of the double as unsigned longs.
+ const unsigned long* const theFirstDWORD =
+#if defined(XALAN_OLD_STYLE_CASTS)
+ (const unsigned long*)&theNumber;
+#else
+ reinterpret_cast<const unsigned long*>(&theNumber);
+#endif
+
+ const unsigned long* const theSecondDWORD =
+ theFirstDWORD + 1;
+
+ return *theFirstDWORD == *s_positiveZeroFirstDWORD &&
+ *theSecondDWORD == *s_positiveZeroSecondDWORD;
+ }
+
+ /**
+ * Determine if target is negative 0
+ *
+ * @param theNumber target number
+ * @return true if target represents the value for negative 0
+ */
+ static bool
+ isNegativeZero(double theNumber)
+ {
+ // Compare the two DWORDs of the double as unsigned longs.
+ const unsigned long* const theFirstDWORD =
+#if defined(XALAN_OLD_STYLE_CASTS)
+ (const unsigned long*)&theNumber;
+#else
+ reinterpret_cast<const unsigned long*>(&theNumber);
+#endif
+
+ const unsigned long* const theSecondDWORD =
+ theFirstDWORD + 1;
+
+ return *theFirstDWORD == *s_negativeZeroFirstDWORD &&
+ *theSecondDWORD == *s_negativeZeroSecondDWORD;
+ }
+
// These can be used to initialize values, but should not
// be used to do equality comparisons, as == may fail on
// some platforms.
@@ -514,9 +562,17 @@
static const double s_NaN;
static const double s_positiveInfinity;
static const double s_negativeInfinity;
+ static const double s_positiveZero;
+ static const double s_negativeZero;
static const unsigned long* s_NaNFirstDWORD;
static const unsigned long* s_NaNSecondDWORD;
+
+ static const unsigned long* s_positiveZeroFirstDWORD;
+ static const unsigned long* s_positiveZeroSecondDWORD;
+
+ static const unsigned long* s_negativeZeroFirstDWORD;
+ static const unsigned long* s_negativeZeroSecondDWORD;
};
