From 6647c6f50230897ea426c875d635c11c4c45e0f7 Mon Sep 17 00:00:00 2001
From: lilinus <linus.hamlin@outlook.com>
Date: Thu, 25 Apr 2024 11:17:14 +0200
Subject: [PATCH 1/4] Simplify some CompareTo methods

---
 .../src/System/DateTimeOffset.cs              | 18 ++----
 .../System.Private.CoreLib/src/System/Guid.cs | 61 +------------------
 .../System/Runtime/InteropServices/NFloat.cs  | 14 +----
 3 files changed, 7 insertions(+), 86 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs b/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs
index 77f1153181f67..fce89e9b41da4 100644
--- a/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs
@@ -571,26 +571,16 @@ public static int Compare(DateTimeOffset first, DateTimeOffset second) =>
         int IComparable.CompareTo(object? obj)
         {
             if (obj == null) return 1;
-            if (!(obj is DateTimeOffset))
+            if (obj is not DateTimeOffset other)
             {
                 throw new ArgumentException(SR.Arg_MustBeDateTimeOffset);
             }
 
-            DateTime objUtc = ((DateTimeOffset)obj).UtcDateTime;
-            DateTime utc = UtcDateTime;
-            if (utc > objUtc) return 1;
-            if (utc < objUtc) return -1;
-            return 0;
+            return CompareTo(other);
         }
 
-        public int CompareTo(DateTimeOffset other)
-        {
-            DateTime otherUtc = other.UtcDateTime;
-            DateTime utc = UtcDateTime;
-            if (utc > otherUtc) return 1;
-            if (utc < otherUtc) return -1;
-            return 0;
-        }
+        public int CompareTo(DateTimeOffset other) =>
+            UtcDateTime.CompareTo(other.UtcDateTime);
 
         // Checks if this DateTimeOffset is equal to a given object. Returns
         // true if the given object is a boxed DateTimeOffset and its value
diff --git a/src/libraries/System.Private.CoreLib/src/System/Guid.cs b/src/libraries/System.Private.CoreLib/src/System/Guid.cs
index 911fb9f7184a3..7ce5edfc3fbb8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Guid.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Guid.cs
@@ -958,68 +958,11 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (!(value is Guid))
+            if (value is not Guid other)
             {
                 throw new ArgumentException(SR.Arg_MustBeGuid, nameof(value));
             }
-            Guid g = (Guid)value;
-
-            if (g._a != _a)
-            {
-                return GetResult((uint)_a, (uint)g._a);
-            }
-
-            if (g._b != _b)
-            {
-                return GetResult((uint)_b, (uint)g._b);
-            }
-
-            if (g._c != _c)
-            {
-                return GetResult((uint)_c, (uint)g._c);
-            }
-
-            if (g._d != _d)
-            {
-                return GetResult(_d, g._d);
-            }
-
-            if (g._e != _e)
-            {
-                return GetResult(_e, g._e);
-            }
-
-            if (g._f != _f)
-            {
-                return GetResult(_f, g._f);
-            }
-
-            if (g._g != _g)
-            {
-                return GetResult(_g, g._g);
-            }
-
-            if (g._h != _h)
-            {
-                return GetResult(_h, g._h);
-            }
-
-            if (g._i != _i)
-            {
-                return GetResult(_i, g._i);
-            }
-
-            if (g._j != _j)
-            {
-                return GetResult(_j, g._j);
-            }
-
-            if (g._k != _k)
-            {
-                return GetResult(_k, g._k);
-            }
-
-            return 0;
+            return CompareTo(other);
         }
 
         public int CompareTo(Guid value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
index 37c39bbc029a2..273a8a3d31f6b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/NFloat.cs
@@ -780,19 +780,7 @@ public int CompareTo(object? obj)
         {
             if (obj is NFloat other)
             {
-                if (_value < other._value) return -1;
-                if (_value > other._value) return 1;
-                if (_value == other._value) return 0;
-
-                // At least one of the values is NaN.
-                if (NativeType.IsNaN(_value))
-                {
-                    return NativeType.IsNaN(other._value) ? 0 : -1;
-                }
-                else
-                {
-                    return 1;
-                }
+                return CompareTo(other);
             }
             else if (obj is null)
             {

From 5dab47d411871a4eb0be77968046cc528ae04f76 Mon Sep 17 00:00:00 2001
From: lilinus <linus.hamlin@outlook.com>
Date: Thu, 25 Apr 2024 11:21:52 +0200
Subject: [PATCH 2/4] Simplify some more CompareTo methods

---
 src/libraries/System.Private.CoreLib/src/System/Byte.cs    | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/Char.cs    | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/Decimal.cs | 5 ++---
 src/libraries/System.Private.CoreLib/src/System/Int16.cs   | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/Int32.cs   | 6 +-----
 src/libraries/System.Private.CoreLib/src/System/Int64.cs   | 6 +-----
 src/libraries/System.Private.CoreLib/src/System/SByte.cs   | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/UInt16.cs  | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/UInt32.cs  | 6 +-----
 src/libraries/System.Private.CoreLib/src/System/UInt64.cs  | 6 +-----
 10 files changed, 16 insertions(+), 33 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Byte.cs b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
index 31a2bccf21bf8..140f1ec2844ad 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Byte.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
@@ -58,12 +58,12 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (!(value is byte))
+            if (value is not byte other)
             {
                 throw new ArgumentException(SR.Arg_MustBeByte);
             }
 
-            return m_value - (((byte)value).m_value);
+            return CompareTo(other);
         }
 
         public int CompareTo(byte value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Char.cs b/src/libraries/System.Private.CoreLib/src/System/Char.cs
index a44d61f61a2ae..257cf2167ad7e 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Char.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Char.cs
@@ -140,12 +140,12 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (!(value is char))
+            if (value is not char other)
             {
                 throw new ArgumentException(SR.Arg_MustBeChar);
             }
 
-            return m_value - ((char)value).m_value;
+            return CompareTo(other);
         }
 
         public int CompareTo(char value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Decimal.cs b/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
index f2d89445f834b..e794eb2ee582d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
@@ -420,11 +420,10 @@ public int CompareTo(object? value)
         {
             if (value == null)
                 return 1;
-            if (!(value is decimal))
+            if (value is not decimal other)
                 throw new ArgumentException(SR.Arg_MustBeDecimal);
 
-            decimal other = (decimal)value;
-            return DecCalc.VarDecCmp(in this, in other);
+            return CompareTo(other);
         }
 
         public int CompareTo(decimal value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int16.cs b/src/libraries/System.Private.CoreLib/src/System/Int16.cs
index af144fb860c92..cfc49aa946a6b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int16.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int16.cs
@@ -60,9 +60,9 @@ public int CompareTo(object? value)
                 return 1;
             }
 
-            if (value is short)
+            if (value is short other)
             {
-                return m_value - ((short)value).m_value;
+                return CompareTo(other);
             }
 
             throw new ArgumentException(SR.Arg_MustBeInt16);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int32.cs b/src/libraries/System.Private.CoreLib/src/System/Int32.cs
index 2f91c2c2a5970..dd3431600aade 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int32.cs
@@ -63,13 +63,9 @@ public int CompareTo(object? value)
                 return 1;
             }
 
-            // NOTE: Cannot use return (_value - value) as this causes a wrap
-            // around in cases where _value - value > MaxValue.
             if (value is int i)
             {
-                if (m_value < i) return -1;
-                if (m_value > i) return 1;
-                return 0;
+                return CompareTo(i);
             }
 
             throw new ArgumentException(SR.Arg_MustBeInt32);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int64.cs b/src/libraries/System.Private.CoreLib/src/System/Int64.cs
index ca170d8c903ed..a68b2964687e3 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int64.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int64.cs
@@ -60,13 +60,9 @@ public int CompareTo(object? value)
                 return 1;
             }
 
-            // Need to use compare because subtraction will wrap
-            // to positive for very large neg numbers, etc.
             if (value is long i)
             {
-                if (m_value < i) return -1;
-                if (m_value > i) return 1;
-                return 0;
+                return CompareTo(i);
             }
 
             throw new ArgumentException(SR.Arg_MustBeInt64);
diff --git a/src/libraries/System.Private.CoreLib/src/System/SByte.cs b/src/libraries/System.Private.CoreLib/src/System/SByte.cs
index fb4734d41b69f..dff18a50ec7b6 100644
--- a/src/libraries/System.Private.CoreLib/src/System/SByte.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/SByte.cs
@@ -62,11 +62,11 @@ public int CompareTo(object? obj)
             {
                 return 1;
             }
-            if (!(obj is sbyte))
+            if (obj is not sbyte other)
             {
                 throw new ArgumentException(SR.Arg_MustBeSByte);
             }
-            return m_value - ((sbyte)obj).m_value;
+            return CompareTo(other);
         }
 
         public int CompareTo(sbyte value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
index fcc863a6310a8..bdadbd9782e6d 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
@@ -56,9 +56,9 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (value is ushort)
+            if (value is ushort other)
             {
-                return (int)m_value - (int)(((ushort)value).m_value);
+                return CompareTo(other);
             }
             throw new ArgumentException(SR.Arg_MustBeUInt16);
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
index 8487630193ec5..782102b7c8065 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
@@ -57,13 +57,9 @@ public int CompareTo(object? value)
                 return 1;
             }
 
-            // Need to use compare because subtraction will wrap
-            // to positive for very large neg numbers, etc.
             if (value is uint i)
             {
-                if (m_value < i) return -1;
-                if (m_value > i) return 1;
-                return 0;
+                return CompareTo(i);
             }
 
             throw new ArgumentException(SR.Arg_MustBeUInt32);
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
index dc12c5c006a82..35992be8d1c8f 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
@@ -57,13 +57,9 @@ public int CompareTo(object? value)
                 return 1;
             }
 
-            // Need to use compare because subtraction will wrap
-            // to positive for very large neg numbers, etc.
             if (value is ulong i)
             {
-                if (m_value < i) return -1;
-                if (m_value > i) return 1;
-                return 0;
+                return CompareTo(i);
             }
 
             throw new ArgumentException(SR.Arg_MustBeUInt64);

From 73a141836025e3a8c7905ca1713601d30c5d87a0 Mon Sep 17 00:00:00 2001
From: lilinus <linus.hamlin@outlook.com>
Date: Thu, 25 Apr 2024 15:31:55 +0200
Subject: [PATCH 3/4] Revert "Simplify some more CompareTo methods"

This reverts commit 5dab47d411871a4eb0be77968046cc528ae04f76.
---
 src/libraries/System.Private.CoreLib/src/System/Byte.cs    | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/Char.cs    | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/Decimal.cs | 5 +++--
 src/libraries/System.Private.CoreLib/src/System/Int16.cs   | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/Int32.cs   | 6 +++++-
 src/libraries/System.Private.CoreLib/src/System/Int64.cs   | 6 +++++-
 src/libraries/System.Private.CoreLib/src/System/SByte.cs   | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/UInt16.cs  | 4 ++--
 src/libraries/System.Private.CoreLib/src/System/UInt32.cs  | 6 +++++-
 src/libraries/System.Private.CoreLib/src/System/UInt64.cs  | 6 +++++-
 10 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/Byte.cs b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
index 140f1ec2844ad..31a2bccf21bf8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Byte.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Byte.cs
@@ -58,12 +58,12 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (value is not byte other)
+            if (!(value is byte))
             {
                 throw new ArgumentException(SR.Arg_MustBeByte);
             }
 
-            return CompareTo(other);
+            return m_value - (((byte)value).m_value);
         }
 
         public int CompareTo(byte value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Char.cs b/src/libraries/System.Private.CoreLib/src/System/Char.cs
index 257cf2167ad7e..a44d61f61a2ae 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Char.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Char.cs
@@ -140,12 +140,12 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (value is not char other)
+            if (!(value is char))
             {
                 throw new ArgumentException(SR.Arg_MustBeChar);
             }
 
-            return CompareTo(other);
+            return m_value - ((char)value).m_value;
         }
 
         public int CompareTo(char value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Decimal.cs b/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
index e794eb2ee582d..f2d89445f834b 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Decimal.cs
@@ -420,10 +420,11 @@ public int CompareTo(object? value)
         {
             if (value == null)
                 return 1;
-            if (value is not decimal other)
+            if (!(value is decimal))
                 throw new ArgumentException(SR.Arg_MustBeDecimal);
 
-            return CompareTo(other);
+            decimal other = (decimal)value;
+            return DecCalc.VarDecCmp(in this, in other);
         }
 
         public int CompareTo(decimal value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int16.cs b/src/libraries/System.Private.CoreLib/src/System/Int16.cs
index cfc49aa946a6b..af144fb860c92 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int16.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int16.cs
@@ -60,9 +60,9 @@ public int CompareTo(object? value)
                 return 1;
             }
 
-            if (value is short other)
+            if (value is short)
             {
-                return CompareTo(other);
+                return m_value - ((short)value).m_value;
             }
 
             throw new ArgumentException(SR.Arg_MustBeInt16);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int32.cs b/src/libraries/System.Private.CoreLib/src/System/Int32.cs
index dd3431600aade..2f91c2c2a5970 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int32.cs
@@ -63,9 +63,13 @@ public int CompareTo(object? value)
                 return 1;
             }
 
+            // NOTE: Cannot use return (_value - value) as this causes a wrap
+            // around in cases where _value - value > MaxValue.
             if (value is int i)
             {
-                return CompareTo(i);
+                if (m_value < i) return -1;
+                if (m_value > i) return 1;
+                return 0;
             }
 
             throw new ArgumentException(SR.Arg_MustBeInt32);
diff --git a/src/libraries/System.Private.CoreLib/src/System/Int64.cs b/src/libraries/System.Private.CoreLib/src/System/Int64.cs
index a68b2964687e3..ca170d8c903ed 100644
--- a/src/libraries/System.Private.CoreLib/src/System/Int64.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/Int64.cs
@@ -60,9 +60,13 @@ public int CompareTo(object? value)
                 return 1;
             }
 
+            // Need to use compare because subtraction will wrap
+            // to positive for very large neg numbers, etc.
             if (value is long i)
             {
-                return CompareTo(i);
+                if (m_value < i) return -1;
+                if (m_value > i) return 1;
+                return 0;
             }
 
             throw new ArgumentException(SR.Arg_MustBeInt64);
diff --git a/src/libraries/System.Private.CoreLib/src/System/SByte.cs b/src/libraries/System.Private.CoreLib/src/System/SByte.cs
index dff18a50ec7b6..fb4734d41b69f 100644
--- a/src/libraries/System.Private.CoreLib/src/System/SByte.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/SByte.cs
@@ -62,11 +62,11 @@ public int CompareTo(object? obj)
             {
                 return 1;
             }
-            if (obj is not sbyte other)
+            if (!(obj is sbyte))
             {
                 throw new ArgumentException(SR.Arg_MustBeSByte);
             }
-            return CompareTo(other);
+            return m_value - ((sbyte)obj).m_value;
         }
 
         public int CompareTo(sbyte value)
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
index bdadbd9782e6d..fcc863a6310a8 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt16.cs
@@ -56,9 +56,9 @@ public int CompareTo(object? value)
             {
                 return 1;
             }
-            if (value is ushort other)
+            if (value is ushort)
             {
-                return CompareTo(other);
+                return (int)m_value - (int)(((ushort)value).m_value);
             }
             throw new ArgumentException(SR.Arg_MustBeUInt16);
         }
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
index 782102b7c8065..8487630193ec5 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt32.cs
@@ -57,9 +57,13 @@ public int CompareTo(object? value)
                 return 1;
             }
 
+            // Need to use compare because subtraction will wrap
+            // to positive for very large neg numbers, etc.
             if (value is uint i)
             {
-                return CompareTo(i);
+                if (m_value < i) return -1;
+                if (m_value > i) return 1;
+                return 0;
             }
 
             throw new ArgumentException(SR.Arg_MustBeUInt32);
diff --git a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
index 35992be8d1c8f..dc12c5c006a82 100644
--- a/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/UInt64.cs
@@ -57,9 +57,13 @@ public int CompareTo(object? value)
                 return 1;
             }
 
+            // Need to use compare because subtraction will wrap
+            // to positive for very large neg numbers, etc.
             if (value is ulong i)
             {
-                return CompareTo(i);
+                if (m_value < i) return -1;
+                if (m_value > i) return 1;
+                return 0;
             }
 
             throw new ArgumentException(SR.Arg_MustBeUInt64);

From 957cb10be3a4eb939f2340b8632f252cf3e52839 Mon Sep 17 00:00:00 2001
From: lilinus <linus.hamlin@outlook.com>
Date: Wed, 8 May 2024 11:18:21 +0200
Subject: [PATCH 4/4] Use DateTime.CompareTo in DatetimeOffset

---
 .../System.Private.CoreLib/src/System/DateTimeOffset.cs       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs b/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs
index fce89e9b41da4..5baf1e5076b6e 100644
--- a/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/DateTimeOffset.cs
@@ -576,11 +576,11 @@ int IComparable.CompareTo(object? obj)
                 throw new ArgumentException(SR.Arg_MustBeDateTimeOffset);
             }
 
-            return CompareTo(other);
+            return DateTime.Compare(UtcDateTime, other.UtcDateTime);
         }
 
         public int CompareTo(DateTimeOffset other) =>
-            UtcDateTime.CompareTo(other.UtcDateTime);
+            DateTime.Compare(UtcDateTime, other.UtcDateTime);
 
         // Checks if this DateTimeOffset is equal to a given object. Returns
         // true if the given object is a boxed DateTimeOffset and its value