1 files changed, 105 insertions, 0 deletions
diff --git a/src/ARMeilleure/CodeGen/X86/CodeGenContext.cs b/src/ARMeilleure/CodeGen/X86/CodeGenContext.cs
new file mode 100644
index 00000000..89948724
--- /dev/null
+++ b/src/ARMeilleure/CodeGen/X86/CodeGenContext.cs
@@ -0,0 +1,105 @@
+using ARMeilleure.CodeGen.RegisterAllocators;
+using ARMeilleure.IntermediateRepresentation;
+using Ryujinx.Common.Memory;
+using System.IO;
+using System.Numerics;
+
+namespace ARMeilleure.CodeGen.X86
+{
+    class CodeGenContext
+    {
+        private readonly Stream _stream;
+        private readonly Operand[] _blockLabels;
+
+        public int StreamOffset => (int)_stream.Length;
+
+        public AllocationResult AllocResult { get; }
+
+        public Assembler Assembler { get; }
+        public BasicBlock CurrBlock { get; private set; }
+
+        public int CallArgsRegionSize { get; }
+        public int XmmSaveRegionSize { get; }
+
+        public CodeGenContext(AllocationResult allocResult, int maxCallArgs, int blocksCount, bool relocatable)
+        {
+            _stream = MemoryStreamManager.Shared.GetStream();
+            _blockLabels = new Operand[blocksCount];
+
+            AllocResult = allocResult;
+            Assembler = new Assembler(_stream, relocatable);
+
+            CallArgsRegionSize = GetCallArgsRegionSize(allocResult, maxCallArgs, out int xmmSaveRegionSize);
+            XmmSaveRegionSize  = xmmSaveRegionSize;
+        }
+
+        private static int GetCallArgsRegionSize(AllocationResult allocResult, int maxCallArgs, out int xmmSaveRegionSize)
+        {
+            // We need to add 8 bytes to the total size, as the call to this function already pushed 8 bytes (the
+            // return address).
+            int intMask = CallingConvention.GetIntCalleeSavedRegisters() & allocResult.IntUsedRegisters;
+            int vecMask = CallingConvention.GetVecCalleeSavedRegisters() & allocResult.VecUsedRegisters;
+
+            xmmSaveRegionSize = BitOperations.PopCount((uint)vecMask) * 16;
+
+            int calleeSaveRegionSize = BitOperations.PopCount((uint)intMask) * 8 + xmmSaveRegionSize + 8;
+
+            int argsCount = maxCallArgs;
+
+            if (argsCount < 0)
+            {
+                // When the function has no calls, argsCount is -1. In this case, we don't need to allocate the shadow
+                // space.
+                argsCount = 0;
+            }
+            else if (argsCount < 4)
+            {
+                // The ABI mandates that the space for at least 4 arguments is reserved on the stack (this is called
+                // shadow space).
+                argsCount = 4;
+            }
+
+            // TODO: Align XMM save region to 16 bytes because unwinding on Windows requires it.
+            int frameSize = calleeSaveRegionSize + allocResult.SpillRegionSize;
+
+            // TODO: Instead of always multiplying by 16 (the largest possible size of a variable, since a V128 has 16
+            // bytes), we should calculate the exact size consumed by the arguments passed to the called functions on
+            // the stack.
+            int callArgsAndFrameSize = frameSize + argsCount * 16;
+
+            // Ensure that the Stack Pointer will be aligned to 16 bytes.
+            callArgsAndFrameSize = (callArgsAndFrameSize + 0xf) & ~0xf;
+
+            return callArgsAndFrameSize - frameSize;
+        }
+
+        public void EnterBlock(BasicBlock block)
+        {
+            Assembler.MarkLabel(GetLabel(block));
+
+            CurrBlock = block;
+        }
+
+        public void JumpTo(BasicBlock target)
+        {
+            Assembler.Jmp(GetLabel(target));
+        }
+
+        public void JumpTo(X86Condition condition, BasicBlock target)
+        {
+            Assembler.Jcc(condition, GetLabel(target));
+        }
+
+        private Operand GetLabel(BasicBlock block)
+        {
+            ref Operand label = ref _blockLabels[block.Index];
+
+            if (label == default)
+            {
+                label = Operand.Factory.Label();
+            }
+
+            return label;
+        }
+    }
+}
+\ No newline at end of file