1 files changed, 330 insertions, 0 deletions
diff --git a/Ryujinx.Graphics/Shader/Translation/Ssa.cs b/Ryujinx.Graphics/Shader/Translation/Ssa.cs
new file mode 100644
index 00000000..b612649c
--- /dev/null
+++ b/Ryujinx.Graphics/Shader/Translation/Ssa.cs
@@ -0,0 +1,330 @@
+using Ryujinx.Graphics.Shader.Decoders;
+using Ryujinx.Graphics.Shader.IntermediateRepresentation;
+using System.Collections.Generic;
+
+using static Ryujinx.Graphics.Shader.IntermediateRepresentation.OperandHelper;
+
+namespace Ryujinx.Graphics.Shader.Translation
+{
+    static class Ssa
+    {
+        private const int GprsAndPredsCount = RegisterConsts.GprsCount + RegisterConsts.PredsCount;
+
+        private class DefMap
+        {
+            private Dictionary<Register, Operand> _map;
+
+            private long[] _phiMasks;
+
+            public DefMap()
+            {
+                _map = new Dictionary<Register, Operand>();
+
+                _phiMasks = new long[(RegisterConsts.TotalCount + 63) / 64];
+            }
+
+            public bool TryAddOperand(Register reg, Operand operand)
+            {
+                return _map.TryAdd(reg, operand);
+            }
+
+            public bool TryGetOperand(Register reg, out Operand operand)
+            {
+                return _map.TryGetValue(reg, out operand);
+            }
+
+            public bool AddPhi(Register reg)
+            {
+                int key = GetKeyFromRegister(reg);
+
+                int index = key / 64;
+                int bit   = key & 63;
+
+                long mask = 1L << bit;
+
+                if ((_phiMasks[index] & mask) != 0)
+                {
+                    return false;
+                }
+
+                _phiMasks[index] |= mask;
+
+                return true;
+            }
+
+            public bool HasPhi(Register reg)
+            {
+                int key = GetKeyFromRegister(reg);
+
+                int index = key / 64;
+                int bit   = key & 63;
+
+                return (_phiMasks[index] & (1L << bit)) != 0;
+            }
+        }
+
+        private struct Definition
+        {
+            public BasicBlock Block { get; }
+            public Operand    Local { get; }
+
+            public Definition(BasicBlock block, Operand local)
+            {
+                Block = block;
+                Local = local;
+            }
+        }
+
+        public static void Rename(BasicBlock[] blocks)
+        {
+            DefMap[] globalDefs = new DefMap[blocks.Length];
+
+            for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
+            {
+                globalDefs[blkIndex] = new DefMap();
+            }
+
+            Queue<BasicBlock> dfPhiBlocks = new Queue<BasicBlock>();
+
+            //First pass, get all defs and locals uses.
+            for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
+            {
+                Operand[] localDefs = new Operand[RegisterConsts.TotalCount];
+
+                Operand RenameLocal(Operand operand)
+                {
+                    if (operand != null && operand.Type == OperandType.Register)
+                    {
+                        Operand local = localDefs[GetKeyFromRegister(operand.GetRegister())];
+
+                        operand = local ?? operand;
+                    }
+
+                    return operand;
+                }
+
+                BasicBlock block = blocks[blkIndex];
+
+                LinkedListNode<INode> node = block.Operations.First;
+
+                while (node != null)
+                {
+                    if (node.Value is Operation operation)
+                    {
+                        for (int index = 0; index < operation.SourcesCount; index++)
+                        {
+                            operation.SetSource(index, RenameLocal(operation.GetSource(index)));
+                        }
+
+                        if (operation.Dest != null && operation.Dest.Type == OperandType.Register)
+                        {
+                            Operand local = Local();
+
+                            localDefs[GetKeyFromRegister(operation.Dest.GetRegister())] = local;
+
+                            operation.Dest = local;
+                        }
+                    }
+
+                    node = node.Next;
+                }
+
+                for (int index = 0; index < RegisterConsts.TotalCount; index++)
+                {
+                    Operand local = localDefs[index];
+
+                    if (local == null)
+                    {
+                        continue;
+                    }
+
+                    Register reg = GetRegisterFromKey(index);
+
+                    globalDefs[block.Index].TryAddOperand(reg, local);
+
+                    dfPhiBlocks.Enqueue(block);
+
+                    while (dfPhiBlocks.TryDequeue(out BasicBlock dfPhiBlock))
+                    {
+                        foreach (BasicBlock domFrontier in dfPhiBlock.DominanceFrontiers)
+                        {
+                            if (globalDefs[domFrontier.Index].AddPhi(reg))
+                            {
+                                dfPhiBlocks.Enqueue(domFrontier);
+                            }
+                        }
+                    }
+                }
+            }
+
+            //Second pass, rename variables with definitions on different blocks.
+            for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
+            {
+                Operand[] localDefs = new Operand[RegisterConsts.TotalCount];
+
+                BasicBlock block = blocks[blkIndex];
+
+                Operand RenameGlobal(Operand operand)
+                {
+                    if (operand != null && operand.Type == OperandType.Register)
+                    {
+                        int key = GetKeyFromRegister(operand.GetRegister());
+
+                        Operand local = localDefs[key];
+
+                        if (local != null)
+                        {
+                            return local;
+                        }
+
+                        operand = FindDefinitionForCurr(globalDefs, block, operand.GetRegister());
+
+                        localDefs[key] = operand;
+                    }
+
+                    return operand;
+                }
+
+                LinkedListNode<INode> node = block.Operations.First;
+
+                while (node != null)
+                {
+                    if (node.Value is Operation operation)
+                    {
+                        for (int index = 0; index < operation.SourcesCount; index++)
+                        {
+                            operation.SetSource(index, RenameGlobal(operation.GetSource(index)));
+                        }
+                    }
+
+                    node = node.Next;
+                }
+            }
+        }
+
+        private static Operand FindDefinitionForCurr(DefMap[] globalDefs, BasicBlock current, Register reg)
+        {
+            if (globalDefs[current.Index].HasPhi(reg))
+            {
+                return InsertPhi(globalDefs, current, reg);
+            }
+
+            if (current != current.ImmediateDominator)
+            {
+                return FindDefinition(globalDefs, current.ImmediateDominator, reg).Local;
+            }
+
+            return Undef();
+        }
+
+        private static Definition FindDefinition(DefMap[] globalDefs, BasicBlock current, Register reg)
+        {
+            foreach (BasicBlock block in SelfAndImmediateDominators(current))
+            {
+                DefMap defMap = globalDefs[block.Index];
+
+                if (defMap.TryGetOperand(reg, out Operand lastDef))
+                {
+                    return new Definition(block, lastDef);
+                }
+
+                if (defMap.HasPhi(reg))
+                {
+                    return new Definition(block, InsertPhi(globalDefs, block, reg));
+                }
+            }
+
+            return new Definition(current, Undef());
+        }
+
+        private static IEnumerable<BasicBlock> SelfAndImmediateDominators(BasicBlock block)
+        {
+            while (block != block.ImmediateDominator)
+            {
+                yield return block;
+
+                block = block.ImmediateDominator;
+            }
+
+            yield return block;
+        }
+
+        private static Operand InsertPhi(DefMap[] globalDefs, BasicBlock block, Register reg)
+        {
+            //This block has a Phi that has not been materialized yet, but that
+            //would define a new version of the variable we're looking for. We need
+            //to materialize the Phi, add all the block/operand pairs into the Phi, and
+            //then use the definition from that Phi.
+            Operand local = Local();
+
+            PhiNode phi = new PhiNode(local);
+
+            AddPhi(block, phi);
+
+            globalDefs[block.Index].TryAddOperand(reg, local);
+
+            foreach (BasicBlock predecessor in block.Predecessors)
+            {
+                Definition def = FindDefinition(globalDefs, predecessor, reg);
+
+                phi.AddSource(def.Block, def.Local);
+            }
+
+            return local;
+        }
+
+        private static void AddPhi(BasicBlock block, PhiNode phi)
+        {
+            LinkedListNode<INode> node = block.Operations.First;
+
+            if (node != null)
+            {
+                while (node.Next?.Value is PhiNode)
+                {
+                    node = node.Next;
+                }
+            }
+
+            if (node?.Value is PhiNode)
+            {
+                block.Operations.AddAfter(node, phi);
+            }
+            else
+            {
+                block.Operations.AddFirst(phi);
+            }
+        }
+
+        private static int GetKeyFromRegister(Register reg)
+        {
+            if (reg.Type == RegisterType.Gpr)
+            {
+                return reg.Index;
+            }
+            else if (reg.Type == RegisterType.Predicate)
+            {
+                return RegisterConsts.GprsCount + reg.Index;
+            }
+            else /* if (reg.Type == RegisterType.Flag) */
+            {
+                return GprsAndPredsCount + reg.Index;
+            }
+        }
+
+        private static Register GetRegisterFromKey(int key)
+        {
+            if (key < RegisterConsts.GprsCount)
+            {
+                return new Register(key, RegisterType.Gpr);
+            }
+            else if (key < GprsAndPredsCount)
+            {
+                return new Register(key - RegisterConsts.GprsCount, RegisterType.Predicate);
+            }
+            else /* if (key < RegisterConsts.TotalCount) */
+            {
+                return new Register(key - GprsAndPredsCount, RegisterType.Flag);
+            }
+        }
+    }
+}
+\ No newline at end of file