More accurate impl of FMINNM/FMAXNM, add vector variants (#296)

* More accurate impl of FMINNM/FMAXNM, add vector variants

* Optimize for the 0 case when op1 != op2

* Address PR feedback

3 files changed, 307 insertions, 147 deletions

diff --git a/ChocolArm64/Instruction/AInstEmitSimdArithmetic.cs b/ChocolArm64/Instruction/AInstEmitSimdArithmetic.cs
index 6772fe83..559811d9 100644
--- a/ChocolArm64/Instruction/AInstEmitSimdArithmetic.cs
+++ b/ChocolArm64/Instruction/AInstEmitSimdArithmetic.cs
@@ -335,98 +335,66 @@ namespace ChocolArm64.Instruction
 
         public static void Fmax_S(AILEmitterCtx Context)
         {
-            AOpCodeSimd Op = (AOpCodeSimd)Context.CurrOp;
-
             EmitScalarBinaryOpF(Context, () =>
             {
-                if (Op.Size == 0)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.MaxF));
-                }
-                else if (Op.Size == 1)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.Max));
-                }
-                else
-                {
-                    throw new InvalidOperationException();
-                }
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.Max));
             });
         }
 
         public static void Fmax_V(AILEmitterCtx Context)
         {
-            AOpCodeSimd Op = (AOpCodeSimd)Context.CurrOp;
+            EmitVectorBinaryOpF(Context, () =>
+            {
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.Max));
+            });
+        }
 
+        public static void Fmaxnm_S(AILEmitterCtx Context)
+        {
+            EmitScalarBinaryOpF(Context, () =>
+            {
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.MaxNum));
+            });
+        }
+
+        public static void Fmaxnm_V(AILEmitterCtx Context)
+        {
             EmitVectorBinaryOpF(Context, () =>
             {
-                if (Op.Size == 0)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.MaxF));
-                }
-                else if (Op.Size == 1)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.Max));
-                }
-                else
-                {
-                    throw new InvalidOperationException();
-                }
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.MaxNum));
             });
         }
 
         public static void Fmin_S(AILEmitterCtx Context)
         {
-            AOpCodeSimd Op = (AOpCodeSimd)Context.CurrOp;
-
             EmitScalarBinaryOpF(Context, () =>
             {
-                if (Op.Size == 0)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.MinF));
-                }
-                else if (Op.Size == 1)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.Min));
-                }
-                else
-                {
-                    throw new InvalidOperationException();
-                }
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.Min));
             });
         }
 
         public static void Fmin_V(AILEmitterCtx Context)
         {
-            AOpCodeSimd Op = (AOpCodeSimd)Context.CurrOp;
-
-            int SizeF = Op.Size & 1;
-
             EmitVectorBinaryOpF(Context, () =>
             {
-                if (SizeF == 0)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.MinF));
-                }
-                else if (SizeF == 1)
-                {
-                    AVectorHelper.EmitCall(Context, nameof(AVectorHelper.Min));
-                }
-                else
-                {
-                    throw new InvalidOperationException();
-                }
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.Min));
             });
         }
 
-        public static void Fmaxnm_S(AILEmitterCtx Context)
+        public static void Fminnm_S(AILEmitterCtx Context)
         {
-            Fmax_S(Context);
+            EmitScalarBinaryOpF(Context, () =>
+            {
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.MinNum));
+            });
         }
 
-        public static void Fminnm_S(AILEmitterCtx Context)
+        public static void Fminnm_V(AILEmitterCtx Context)
         {
-            Fmin_S(Context);
+            EmitVectorBinaryOpF(Context, () =>
+            {
+                EmitBinarySoftFloatCall(Context, nameof(ASoftFloat.MinNum));
+            });
         }
 
         public static void Fmla_Se(AILEmitterCtx Context)
diff --git a/ChocolArm64/Instruction/ASoftFloat.cs b/ChocolArm64/Instruction/ASoftFloat.cs
index 27f4f7fb..8afa4002 100644
--- a/ChocolArm64/Instruction/ASoftFloat.cs
+++ b/ChocolArm64/Instruction/ASoftFloat.cs
@@ -79,7 +79,7 @@ namespace ChocolArm64.Instruction
                 if (scaled == 0)
                 {
                     // Zero -> Infinity
-                    return BitConverter.Int64BitsToDouble((long)(x_sign | 0x7ff0000000000000));
+                    return BitConverter.Int64BitsToDouble((long)(x_sign | 0x7FF0000000000000));
                 }
 
                 // Denormal
@@ -94,7 +94,7 @@ namespace ChocolArm64.Instruction
             if (x_sign != 0)
             {
                 // Negative -> NaN
-                return BitConverter.Int64BitsToDouble((long)0x7ff8000000000000);
+                return BitConverter.Int64BitsToDouble((long)0x7FF8000000000000);
             }
 
             if (x_exp == 0x7ff && scaled == 0)
@@ -153,7 +153,7 @@ namespace ChocolArm64.Instruction
                 if (scaled == 0)
                 {
                     // Zero -> Infinity
-                    return BitConverter.Int64BitsToDouble((long)(x_sign | 0x7ff0000000000000));
+                    return BitConverter.Int64BitsToDouble((long)(x_sign | 0x7FF0000000000000));
                 }
 
                 // Denormal
@@ -208,8 +208,8 @@ namespace ChocolArm64.Instruction
             ulong op1_other = op1_bits & 0x7FFFFFFFFFFFFFFF;
             ulong op2_other = op2_bits & 0x7FFFFFFFFFFFFFFF;
 
-            bool inf1 = op1_other == 0x7ff0000000000000;
-            bool inf2 = op2_other == 0x7ff0000000000000;
+            bool inf1 = op1_other == 0x7FF0000000000000;
+            bool inf2 = op2_other == 0x7FF0000000000000;
             bool zero1 = op1_other == 0;
             bool zero2 = op2_other == 0;
 
@@ -220,7 +220,7 @@ namespace ChocolArm64.Instruction
             else if (inf1 || inf2)
             {
                 // Infinity
-                return BitConverter.Int64BitsToDouble((long)(0x7ff0000000000000 | (op1_sign ^ op2_sign)));
+                return BitConverter.Int64BitsToDouble((long)(0x7FF0000000000000 | (op1_sign ^ op2_sign)));
             }
 
             return 2.0 + op1 * op2;
@@ -261,5 +261,277 @@ namespace ChocolArm64.Instruction
             uint new_exp = (uint)((exponent + 127) & 0xFF) << 23;
             return BitConverter.Int32BitsToSingle((int)((x_sign << 31) | new_exp | (x_mantissa << 13)));
         }
+
+        public static float MaxNum(float op1, float op2)
+        {
+            uint op1_bits = (uint)BitConverter.SingleToInt32Bits(op1);
+            uint op2_bits = (uint)BitConverter.SingleToInt32Bits(op2);
+
+            if (IsQNaN(op1_bits) && !IsQNaN(op2_bits))
+            {
+                op1 = float.NegativeInfinity;
+            }
+            else if (!IsQNaN(op1_bits) && IsQNaN(op2_bits))
+            {
+                op2 = float.NegativeInfinity;
+            }
+
+            return Max(op1, op2);
+        }
+
+        public static double MaxNum(double op1, double op2)
+        {
+            ulong op1_bits = (ulong)BitConverter.DoubleToInt64Bits(op1);
+            ulong op2_bits = (ulong)BitConverter.DoubleToInt64Bits(op2);
+
+            if (IsQNaN(op1_bits) && !IsQNaN(op2_bits))
+            {
+                op1 = double.NegativeInfinity;
+            }
+            else if (!IsQNaN(op1_bits) && IsQNaN(op2_bits))
+            {
+                op2 = double.NegativeInfinity;
+            }
+
+            return Max(op1, op2);
+        }
+
+        public static float Max(float op1, float op2)
+        {
+            // Fast path
+            if (op1 > op2)
+            {
+                return op1;
+            }
+
+            if (op1 < op2 || (op1 == op2 && op2 != 0))
+            {
+                return op2;
+            }
+
+            uint op1_bits = (uint)BitConverter.SingleToInt32Bits(op1);
+            uint op2_bits = (uint)BitConverter.SingleToInt32Bits(op2);
+
+            // Handle NaN cases
+            if (ProcessNaNs(op1_bits, op2_bits, out uint op_bits))
+            {
+                return BitConverter.Int32BitsToSingle((int)op_bits);
+            }
+
+            // Return the most positive zero
+            if ((op1_bits & op2_bits) == 0x80000000u)
+            {
+                return BitConverter.Int32BitsToSingle(int.MinValue);
+            }
+
+            return 0;
+        }
+
+        public static double Max(double op1, double op2)
+        {
+            // Fast path
+            if (op1 > op2)
+            {
+                return op1;
+            }
+
+            if (op1 < op2 || (op1 == op2 && op2 != 0))
+            {
+                return op2;
+            }
+
+            ulong op1_bits = (ulong)BitConverter.DoubleToInt64Bits(op1);
+            ulong op2_bits = (ulong)BitConverter.DoubleToInt64Bits(op2);
+
+            // Handle NaN cases
+            if (ProcessNaNs(op1_bits, op2_bits, out ulong op_bits))
+            {
+                return BitConverter.Int64BitsToDouble((long)op_bits);
+            }
+
+            // Return the most positive zero
+            if ((op1_bits & op2_bits) == 0x8000000000000000ul)
+            {
+                return BitConverter.Int64BitsToDouble(long.MinValue);
+            }
+
+            return 0;
+        }
+
+        public static float MinNum(float op1, float op2)
+        {
+            uint op1_bits = (uint)BitConverter.SingleToInt32Bits(op1);
+            uint op2_bits = (uint)BitConverter.SingleToInt32Bits(op2);
+
+            if (IsQNaN(op1_bits) && !IsQNaN(op2_bits))
+            {
+                op1 = float.PositiveInfinity;
+            }
+            else if (!IsQNaN(op1_bits) && IsQNaN(op2_bits))
+            {
+                op2 = float.PositiveInfinity;
+            }
+
+            return Max(op1, op2);
+        }
+
+        public static double MinNum(double op1, double op2)
+        {
+            ulong op1_bits = (ulong)BitConverter.DoubleToInt64Bits(op1);
+            ulong op2_bits = (ulong)BitConverter.DoubleToInt64Bits(op2);
+
+            if (IsQNaN(op1_bits) && !IsQNaN(op2_bits))
+            {
+                op1 = double.PositiveInfinity;
+            }
+            else if (!IsQNaN(op1_bits) && IsQNaN(op2_bits))
+            {
+                op2 = double.PositiveInfinity;
+            }
+
+            return Min(op1, op2);
+        }
+
+        public static float Min(float op1, float op2)
+        {
+            // Fast path
+            if (op1 < op2)
+            {
+                return op1;
+            }
+
+            if (op1 > op2 || (op1 == op2 && op2 != 0))
+            {
+                return op2;
+            }
+
+            uint op1_bits = (uint)BitConverter.SingleToInt32Bits(op1);
+            uint op2_bits = (uint)BitConverter.SingleToInt32Bits(op2);
+
+            // Handle NaN cases
+            if (ProcessNaNs(op1_bits, op2_bits, out uint op_bits))
+            {
+                return BitConverter.Int32BitsToSingle((int)op_bits);
+            }
+
+            // Return the most negative zero
+            if ((op1_bits | op2_bits) == 0x80000000u)
+            {
+                return BitConverter.Int32BitsToSingle(int.MinValue);
+            }
+
+            return 0;
+        }
+
+        public static double Min(double op1, double op2)
+        {
+            // Fast path
+            if (op1 < op2)
+            {
+                return op1;
+            }
+
+            if (op1 > op2 || (op1 == op2 && op2 != 0))
+            {
+                return op2;
+            }
+
+            ulong op1_bits = (ulong)BitConverter.DoubleToInt64Bits(op1);
+            ulong op2_bits = (ulong)BitConverter.DoubleToInt64Bits(op2);
+
+            // Handle NaN cases
+            if (ProcessNaNs(op1_bits, op2_bits, out ulong op_bits))
+            {
+                return BitConverter.Int64BitsToDouble((long)op_bits);
+            }
+
+            // Return the most negative zero
+            if ((op1_bits | op2_bits) == 0x8000000000000000ul)
+            {
+                return BitConverter.Int64BitsToDouble(long.MinValue);
+            }
+
+            return 0;
+        }
+
+        private static bool ProcessNaNs(uint op1_bits, uint op2_bits, out uint op_bits)
+        {
+            if (IsSNaN(op1_bits))
+            {
+                op_bits = op1_bits | (1u << 22); // op1 is SNaN, return QNaN op1
+            }
+            else if (IsSNaN(op2_bits))
+            {
+                op_bits = op2_bits | (1u << 22); // op2 is SNaN, return QNaN op2
+            }
+            else if (IsQNaN(op1_bits))
+            {
+                op_bits = op1_bits; // op1 is QNaN, return QNaN op1
+            }
+            else if (IsQNaN(op2_bits))
+            {
+                op_bits = op2_bits; // op2 is QNaN, return QNaN op2
+            }
+            else
+            {
+                op_bits = 0;
+
+                return false;
+            }
+
+            return true;
+        }
+
+        private static bool ProcessNaNs(ulong op1_bits, ulong op2_bits, out ulong op_bits)
+        {
+            if (IsSNaN(op1_bits))
+            {
+                op_bits = op1_bits | (1ul << 51); // op1 is SNaN, return QNaN op1
+            }
+            else if (IsSNaN(op2_bits))
+            {
+                op_bits = op2_bits | (1ul << 51); // op2 is SNaN, return QNaN op2
+            }
+            else if (IsQNaN(op1_bits))
+            {
+                op_bits = op1_bits; // op1 is QNaN, return QNaN op1
+            }
+            else if (IsQNaN(op2_bits))
+            {
+                op_bits = op2_bits; // op2 is QNaN, return QNaN op2
+            }
+            else
+            {
+                op_bits = 0;
+
+                return false;
+            }
+
+            return true;
+        }
+
+        private static bool IsQNaN(uint op_bits)
+        {
+            return (op_bits & 0x007FFFFF) != 0 &&
+                   (op_bits & 0x7FC00000) == 0x7FC00000;
+        }
+
+        private static bool IsQNaN(ulong op_bits)
+        {
+            return (op_bits & 0x000FFFFFFFFFFFFF) != 0 &&
+                   (op_bits & 0x7FF8000000000000) == 0x7FF8000000000000;
+        }
+
+        private static bool IsSNaN(uint op_bits)
+        {
+            return (op_bits & 0x007FFFFF) != 0 &&
+                   (op_bits & 0x7FC00000) == 0x7F800000;
+        }
+
+        private static bool IsSNaN(ulong op_bits)
+        {
+            return (op_bits & 0x000FFFFFFFFFFFFF) != 0 &&
+                   (op_bits & 0x7FF8000000000000) == 0x7FF0000000000000;
+        }
     }
 }
\ No newline at end of file
diff --git a/ChocolArm64/Instruction/AVectorHelper.cs b/ChocolArm64/Instruction/AVectorHelper.cs
index a0f887b0..b2d53740 100644
--- a/ChocolArm64/Instruction/AVectorHelper.cs
+++ b/ChocolArm64/Instruction/AVectorHelper.cs
@@ -93,86 +93,6 @@ namespace ChocolArm64.Instruction
                    Value < ulong.MinValue ? ulong.MinValue : (ulong)Value;
         }
 
-        public static double Max(double LHS, double RHS)
-        {
-            if (LHS == 0.0 && RHS == 0.0)
-            {
-                if (BitConverter.DoubleToInt64Bits(LHS) < 0 &&
-                    BitConverter.DoubleToInt64Bits(RHS) < 0)
-                    return -0.0;
-
-                return 0.0;
-            }
-
-            if (LHS > RHS)
-                return LHS;
-
-            if (double.IsNaN(LHS))
-                return LHS;
-
-            return RHS;
-        }
-
-        public static float MaxF(float LHS, float RHS)
-        {
-            if (LHS == 0.0 && RHS == 0.0)
-            {
-                if (BitConverter.SingleToInt32Bits(LHS) < 0 &&
-                    BitConverter.SingleToInt32Bits(RHS) < 0)
-                    return -0.0f;
-
-                return 0.0f;
-            }
-
-            if (LHS > RHS)
-                return LHS;
-
-            if (float.IsNaN(LHS))
-                return LHS;
-
-            return RHS;
-        }
-
-        public static double Min(double LHS, double RHS)
-        {
-            if (LHS == 0.0 && RHS == 0.0)
-            {
-                if (BitConverter.DoubleToInt64Bits(LHS) < 0 ||
-                    BitConverter.DoubleToInt64Bits(RHS) < 0)
-                    return -0.0;
-
-                return 0.0;
-            }
-
-            if (LHS < RHS)
-                return LHS;
-
-            if (double.IsNaN(LHS))
-                return LHS;
-
-            return RHS;
-        }
-
-        public static float MinF(float LHS, float RHS)
-        {
-            if (LHS == 0.0 && RHS == 0.0)
-            {
-                if (BitConverter.SingleToInt32Bits(LHS) < 0 ||
-                    BitConverter.SingleToInt32Bits(RHS) < 0)
-                    return -0.0f;
-
-                return 0.0f;
-            }
-
-            if (LHS < RHS)
-                return LHS;
-
-            if (float.IsNaN(LHS))
-                return LHS;
-
-            return RHS;
-        }
-
         public static double Round(double Value, int Fpcr)
         {
             switch ((ARoundMode)((Fpcr >> 22) & 3))