1 files changed, 232 insertions, 0 deletions
diff --git a/Spv.Generator/Instruction.cs b/Spv.Generator/Instruction.cs
new file mode 100644
index 00000000..92299404
--- /dev/null
+++ b/Spv.Generator/Instruction.cs
@@ -0,0 +1,232 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+
+namespace Spv.Generator
+{
+    public sealed class Instruction : Operand, IEquatable<Instruction>
+    {
+        public const uint InvalidId = uint.MaxValue;
+
+        public Specification.Op Opcode { get; private set; }
+        private Instruction _resultType;
+        private InstructionOperands _operands;
+
+        public uint Id { get; set; }
+
+        public Instruction() { }
+
+        public void Set(Specification.Op opcode, uint id = InvalidId, Instruction resultType = null)
+        {
+            Opcode = opcode;
+            Id = id;
+            _resultType = resultType;
+
+            _operands = new InstructionOperands();
+        }
+
+        public void SetId(uint id)
+        {
+            Id = id;
+        }
+
+        public OperandType Type => OperandType.Instruction;
+
+        public ushort GetTotalWordCount()
+        {
+            ushort result = WordCount;
+
+            if (Id != InvalidId)
+            {
+                result++;
+            }
+
+            if (_resultType != null)
+            {
+                result += _resultType.WordCount;
+            }
+
+            Span<Operand> operands = _operands.ToSpan();
+            for (int i = 0; i < operands.Length; i++)
+            {
+                result += operands[i].WordCount;
+            }
+
+            return result;
+        }
+
+        public ushort WordCount => 1;
+
+        public void AddOperand(Operand value)
+        {
+            Debug.Assert(value != null);
+            _operands.Add(value);
+        }
+
+        public void AddOperand(Operand[] value)
+        {
+            foreach (Operand instruction in value)
+            {
+                AddOperand(instruction);
+            }
+        }
+
+        public void AddOperand(LiteralInteger[] value)
+        {
+            foreach (LiteralInteger instruction in value)
+            {
+                AddOperand(instruction);
+            }
+        }
+
+        public void AddOperand(LiteralInteger value)
+        {
+            AddOperand((Operand)value);
+        }
+
+        public void AddOperand(Instruction[] value)
+        {
+            foreach (Instruction instruction in value)
+            {
+                AddOperand(instruction);
+            }
+        }
+
+        public void AddOperand(Instruction value)
+        {
+            AddOperand((Operand)value);
+        }
+
+        public void AddOperand(string value)
+        {
+            AddOperand(new LiteralString(value));
+        }
+
+        public void AddOperand<T>(T value) where T: Enum
+        {
+            AddOperand(LiteralInteger.CreateForEnum(value));
+        }
+
+        public void Write(BinaryWriter writer)
+        {
+            // Word 0
+            writer.Write((ushort)Opcode);
+            writer.Write(GetTotalWordCount());
+
+            _resultType?.WriteOperand(writer);
+
+            if (Id != InvalidId)
+            {
+                writer.Write(Id);
+            }
+
+            Span<Operand> operands = _operands.ToSpan();
+            for (int i = 0; i < operands.Length; i++)
+            {
+                operands[i].WriteOperand(writer);
+            }
+        }
+
+        public void WriteOperand(BinaryWriter writer)
+        {
+            Debug.Assert(Id != InvalidId);
+
+            if (Id == InvalidId)
+            {
+                string methodToCall;
+
+                if (Opcode == Specification.Op.OpVariable)
+                {
+                    methodToCall = "AddLocalVariable or AddGlobalVariable";
+                }
+                else if (Opcode == Specification.Op.OpLabel)
+                {
+                    methodToCall = "AddLabel";
+                }
+                else
+                {
+                    throw new InvalidOperationException("Internal error");
+                }
+
+                throw new InvalidOperationException($"Id wasn't bound to the module, please make sure to call {methodToCall}");
+            }
+
+            writer.Write(Id);
+        }
+
+        public override bool Equals(object obj)
+        {
+            return obj is Instruction instruction && Equals(instruction);
+        }
+
+        public bool Equals(Instruction cmpObj)
+        {
+            bool result = Type == cmpObj.Type && Id == cmpObj.Id;
+
+            if (result)
+            {
+                if (_resultType != null && cmpObj._resultType != null)
+                {
+                    result &= _resultType.Equals(cmpObj._resultType);
+                }
+                else if (_resultType != null || cmpObj._resultType != null)
+                {
+                    return false;
+                }
+            }
+
+            if (result)
+            {
+                result &= EqualsContent(cmpObj);
+            }
+
+            return result;
+        }
+
+        public bool EqualsContent(Instruction cmpObj)
+        {
+            Span<Operand> thisOperands = _operands.ToSpan();
+            Span<Operand> cmpOperands = cmpObj._operands.ToSpan();
+
+            if (thisOperands.Length != cmpOperands.Length)
+            {
+                return false;
+            }
+
+            for (int i = 0; i < thisOperands.Length; i++)
+            {
+                if (!thisOperands[i].Equals(cmpOperands[i]))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        public bool EqualsResultType(Instruction cmpObj)
+        {
+            return _resultType.Opcode == cmpObj._resultType.Opcode && _resultType.EqualsContent(cmpObj._resultType);
+        }
+
+        public int GetHashCodeContent()
+        {
+            return DeterministicHashCode.Combine<Operand>(_operands.ToSpan());
+        }
+
+        public int GetHashCodeResultType()
+        {
+            return DeterministicHashCode.Combine(_resultType.Opcode, _resultType.GetHashCodeContent());
+        }
+
+        public override int GetHashCode()
+        {
+            return DeterministicHashCode.Combine(Opcode, Id, _resultType, DeterministicHashCode.Combine<Operand>(_operands.ToSpan()));
+        }
+
+        public bool Equals(Operand obj)
+        {
+            return obj is Instruction instruction && Equals(instruction);
+        }
+    }
+}