+/* from http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm */
+/* yes we are loosing precision by doing tos with floats instead of doubles
+ but it seems more stable this way. */
+
+static int AlmostEqual2sComplement (float A, float B, int maxUlps)
+{
+
+ int aInt = *(int*)&A;
+ int bInt = *(int*)&B;
+ int intDiff;
+ /* Make sure maxUlps is non-negative and small enough that the
+ default NAN won't compare as equal to anything. */
+
+ /* assert(maxUlps > 0 && maxUlps < 4 * 1024 * 1024); */
+
+ /* Make aInt lexicographically ordered as a twos-complement int */
+
+ if (aInt < 0)
+ aInt = 0x80000000l - aInt;
+
+ /* Make bInt lexicographically ordered as a twos-complement int */
+
+ if (bInt < 0)
+ bInt = 0x80000000l - bInt;
+
+ intDiff = abs(aInt - bInt);
+
+ if (intDiff <= maxUlps)
+ return 1;
+
+ return 0;
+}
+