use strictfp in test

src/test/java/com/dynatrace/hash4j/distinctcount/BigInt.java

@@ -82,7 +82,7 @@ public static BigInt ceil(double d) {
     return fromIntDouble(Math.ceil(d));
   }
 
-  private static BigInt fromIntDouble(double d) {
+  private static strictfp BigInt fromIntDouble(double d) {
     checkArgument(d < TWO_POW_PLUS_126_DOUBLE);
     if (d >= TWO_POW_PLUS_63_DOUBLE) {
       long high = (long) (d * TWO_POW_MINUS_63_DOUBLE);
@@ -93,7 +93,7 @@ private static BigInt fromIntDouble(double d) {
     }
   }
 
-  public double asDouble() {
+  public strictfp double asDouble() {
     return high * TWO_POW_PLUS_63_DOUBLE + low;
   }
 

src/test/java/com/dynatrace/hash4j/distinctcount/TestUtils.java

@@ -26,26 +26,27 @@ public final class TestUtils {
 
   private TestUtils() {}
 
-  public static long[] getDistinctCountValues(long min, long max, double relativeIncrement) {
+  public static strictfp long[] getDistinctCountValues(
+      long min, long max, double relativeIncrement) {
     List<Long> distinctCounts = new ArrayList<>();
-    for (long c = max;
-        c >= min;
-        c = Math.min(c - 1, (long) Math.ceil(c / (1. + relativeIncrement)))) {
+    final double factor = 1. / (1. + relativeIncrement);
+    for (long c = max; c >= min; c = Math.min(c - 1, (long) Math.ceil(c * factor))) {
       distinctCounts.add(c);
     }
     Collections.reverse(distinctCounts);
     return distinctCounts.stream().mapToLong(Long::valueOf).toArray();
   }
 
-  public static List<BigInt> getDistinctCountValues(double max, double relativeIncrement) {
+  public static strictfp List<BigInt> getDistinctCountValues(double max, double relativeIncrement) {
     checkArgument(max >= 1.);
     List<BigInt> distinctCounts = new ArrayList<>();
     BigInt c = BigInt.ceil(max);
+    final double factor = 1. / (1. + relativeIncrement);
     while (c.isPositive()) {
       distinctCounts.add(c.copy());
       double d = c.asDouble();
       c.decrement();
-      c.min(BigInt.ceil(d / (1. + relativeIncrement)));
+      c.min(BigInt.ceil(d * factor));
     }
     Collections.reverse(distinctCounts);
     return distinctCounts;