Initial work

Ryujinx.Graphics.Shader/Translation/Optimizations/Optimizer.cs

@@ -0,0 +1,177 @@
+using Ryujinx.Graphics.Shader.IntermediateRepresentation;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace Ryujinx.Graphics.Shader.Translation.Optimizations
+{
+    static class Optimizer
+    {
+        public static void Optimize(BasicBlock[] blocks, ShaderStage stage)
+        {
+            for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
+            {
+                GlobalToStorage.RunPass(blocks[blkIndex], stage);
+            }
+
+            bool modified;
+
+            do
+            {
+                modified = false;
+
+                for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
+                {
+                    BasicBlock block = blocks[blkIndex];
+
+                    LinkedListNode<INode> node = block.Operations.First;
+
+                    while (node != null)
+                    {
+                        LinkedListNode<INode> nextNode = node.Next;
+
+                        bool isUnused = IsUnused(node.Value);
+
+                        if (!(node.Value is Operation operation) || isUnused)
+                        {
+                            if (isUnused)
+                            {
+                                RemoveNode(block, node);
+
+                                modified = true;
+                            }
+
+                            node = nextNode;
+
+                            continue;
+                        }
+
+                        ConstantFolding.RunPass(operation);
+
+                        Simplification.RunPass(operation);
+
+                        if (DestIsLocalVar(operation))
+                        {
+                            if (operation.Inst == Instruction.Copy)
+                            {
+                                PropagateCopy(operation);
+
+                                RemoveNode(block, node);
+
+                                modified = true;
+                            }
+                            else if (operation.Inst == Instruction.PackHalf2x16 && PropagatePack(operation))
+                            {
+                                if (operation.Dest.UseOps.Count == 0)
+                                {
+                                    RemoveNode(block, node);
+                                }
+
+                                modified = true;
+                            }
+                        }
+
+                        node = nextNode;
+                    }
+
+                    if (BranchElimination.RunPass(block))
+                    {
+                        RemoveNode(block, block.Operations.Last);
+
+                        modified = true;
+                    }
+                }
+            }
+            while (modified);
+        }
+
+        private static void PropagateCopy(Operation copyOp)
+        {
+            // Propagate copy source operand to all uses of
+            // the destination operand.
+            Operand dest = copyOp.Dest;
+            Operand src  = copyOp.GetSource(0);
+
+            INode[] uses = dest.UseOps.ToArray();
+
+            foreach (INode useNode in uses)
+            {
+                for (int index = 0; index < useNode.SourcesCount; index++)
+                {
+                    if (useNode.GetSource(index) == dest)
+                    {
+                        useNode.SetSource(index, src);
+                    }
+                }
+            }
+        }
+
+        private static bool PropagatePack(Operation packOp)
+        {
+            // Propagate pack source operands to uses by unpack
+            // instruction. The source depends on the unpack instruction.
+            bool modified = false;
+
+            Operand dest = packOp.Dest;
+            Operand src0 = packOp.GetSource(0);
+            Operand src1 = packOp.GetSource(1);
+
+            INode[] uses = dest.UseOps.ToArray();
+
+            foreach (INode useNode in uses)
+            {
+                if (!(useNode is Operation operation) || operation.Inst != Instruction.UnpackHalf2x16)
+                {
+                    continue;
+                }
+
+                if (operation.GetSource(0) == dest)
+                {
+                    operation.TurnIntoCopy(operation.ComponentIndex == 1 ? src1 : src0);
+
+                    modified = true;
+                }
+            }
+
+            return modified;
+        }
+
+        private static void RemoveNode(BasicBlock block, LinkedListNode<INode> llNode)
+        {
+            // Remove a node from the nodes list, and also remove itself
+            // from all the use lists on the operands that this node uses.
+            block.Operations.Remove(llNode);
+
+            Queue<INode> nodes = new Queue<INode>();
+
+            nodes.Enqueue(llNode.Value);
+
+            while (nodes.TryDequeue(out INode node))
+            {
+                for (int index = 0; index < node.SourcesCount; index++)
+                {
+                    Operand src = node.GetSource(index);
+
+                    if (src.Type != OperandType.LocalVariable)
+                    {
+                        continue;
+                    }
+
+                    if (src.UseOps.Remove(node) && src.UseOps.Count == 0)
+                    {
+                        nodes.Enqueue(src.AsgOp);
+                    }
+                }
+            }
+        }
+
+        private static bool IsUnused(INode node)
+        {
+            return DestIsLocalVar(node) && node.Dest.UseOps.Count == 0;
+        }
+
+        private static bool DestIsLocalVar(INode node)
+        {
+            return node.Dest != null && node.Dest.Type == OperandType.LocalVariable;
+        }
+    }
+}