--- /dev/null
+/* Taken from
+ * http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm
+ *
+ * Code assumed to be in the public domain.
+ */
+
+#ifndef __libpbd__floating_h__
+#define __libpbd__floating_h__
+
+namespace PBD {
+
+union Float_t
+{
+ Float_t (float num = 0.0f) : f(num) {}
+
+ // Portable extraction of components.
+ bool negative() const { return (i >> 31) != 0; }
+ int32_t raw_mantissa() const { return i & ((1 << 23) - 1); }
+ int32_t raw_exponent() const { return (i >> 23) & 0xFF; }
+
+ int32_t i;
+ float f;
+};
+
+/* Note: ULPS = Units in the Last Place */
+
+static inline bool floateq (float a, float b, int max_ulps_diff)
+{
+ Float_t ua(a);
+ Float_t ub(b);
+
+ // Different signs means they do not match.
+ if (ua.negative() != ub.negative()) {
+ // Check for equality to make sure +0==-0
+ if (a == b) {
+ return true;
+ }
+ return false;
+ }
+
+ // Find the difference in ULPs.
+ int ulps_diff = abs (ua.i - ub.i);
+
+ if (ulps_diff <= max_ulps_diff) {
+ return true;
+ }
+
+ return false;
+}
+
+} /* namespace */
+
+#endif /* __libpbd__floating_h__ */