Fpvaluecompare (#131)

* fp comparison fix for negative, +0 -0
intel · Nov 7, 2024 · cdc8ca3 · cdc8ca3
1 parent 062ea0d
commit cdc8ca3
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Showing 2 changed files with 28 additions and 9 deletions.
diff --git a/lib/src/arithmetic/floating_point/floating_point_values/floating_point_value.dart b/lib/src/arithmetic/floating_point/floating_point_values/floating_point_value.dart
@@ -552,20 +552,18 @@ class FloatingPointValue implements Comparable<FloatingPointValue> {
         (mantissa.width != other.mantissa.width)) {
       throw Exception('FloatingPointValue widths must match for comparison');
     }
-    // } else {
+    final signCompare = sign.compareTo(other.sign);
     final expCompare = exponent.compareTo(other.exponent);
     final mantCompare = mantissa.compareTo(other.mantissa);
+    if ((signCompare != 0) && !(exponent.isZero && mantissa.isZero)) {
+      return signCompare;
+    }
     if (expCompare != 0) {
-      return expCompare;
+      return sign.isZero ? expCompare : -expCompare;
     } else if (mantCompare != 0) {
-      return mantCompare;
-    } else {
-      final signCompare = sign.compareTo(other.sign);
-      if ((signCompare != 0) && !(exponent.isZero && mantissa.isZero)) {
-        return signCompare;
-      }
-      return 0;
+      return sign.isZero ? mantCompare : -mantCompare;
     }
+    return 0;
   }
 
   /// Return the bias of this FP format

diff --git a/test/arithmetic/floating_point/floating_point_value_test.dart b/test/arithmetic/floating_point/floating_point_value_test.dart
@@ -292,4 +292,25 @@ void main() {
     final fp2 = FloatingPoint16Value.ofSpacedBinaryString(s);
     expect(fp, equals(fp2));
   });
+
+  test('Initializing derived type', () {
+    final fp = FloatingPoint16Value.ofInts(15, 0);
+    final s = fp.toString();
+    final fp2 = FloatingPoint16Value.ofSpacedBinaryString(s);
+    expect(fp, equals(fp2));
+  });
+  test('FPV Value comparison', () {
+    final fp = FloatingPointValue.ofSpacedBinaryString('1 0101 0101');
+    expect(fp.compareTo(FloatingPointValue.ofSpacedBinaryString('1 0101 0101')),
+        0);
+    expect(fp.compareTo(FloatingPointValue.ofSpacedBinaryString('1 0100 0101')),
+        lessThan(0));
+    expect(fp.compareTo(FloatingPointValue.ofSpacedBinaryString('1 0101 0100')),
+        lessThan(0));
+
+    final fp2 = FloatingPointValue.ofSpacedBinaryString('1 0000 0000');
+    expect(
+        fp2.compareTo(FloatingPointValue.ofSpacedBinaryString('0 0000 0000')),
+        equals(0));
+  });
 }