From cdc8ca342804a9733c1fe2b93ba9eb3a3d9467c9 Mon Sep 17 00:00:00 2001
From: Desmond Kirkpatrick <desmond.a.kirkpatrick@intel.com>
Date: Wed, 6 Nov 2024 18:55:07 -0800
Subject: [PATCH] Fpvaluecompare (#131)

* fp comparison fix for negative, +0 -0
---
 .../floating_point_value.dart                 | 16 +++++++-------
 .../floating_point_value_test.dart            | 21 +++++++++++++++++++
 2 files changed, 28 insertions(+), 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
index 83c8d9e1..825758b3 100644
--- 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
index e98aa25c..36933ce8 100644
--- 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));
+  });
 }