New shader translator implementation (#654)

* Start implementing a new shader translator

* Fix shift instructions and a typo

* Small refactoring on StructuredProgram, move RemovePhis method to a separate class

* Initial geometry shader support

* Implement TLD4

* Fix -- There's no negation on FMUL32I

* Add constant folding and algebraic simplification optimizations, nits

* Some leftovers from constant folding

* Avoid cast for constant assignments

* Add a branch elimination pass, and misc small fixes

* Remove redundant branches, add expression propagation and other improvements on the code

* Small leftovers -- add missing break and continue, remove unused properties, other improvements

* Add null check to handle empty block cases on block visitor

* Add HADD2 and HMUL2 half float shader instructions

* Optimize pack/unpack sequences, some fixes related to half float instructions

* Add TXQ, TLD, TLDS and TLD4S shader texture instructions, and some support for bindless textures, some refactoring on codegen

* Fix copy paste mistake that caused RZ to be ignored on the AST instruction

* Add workaround for conditional exit, and fix half float instruction with constant buffer

* Add missing 0.0 source for TLDS.LZ variants

* Simplify the switch for TLDS.LZ

* Texture instructions related fixes

* Implement the HFMA instruction, and some misc. fixes

* Enable constant folding on UnpackHalf2x16 instructions

* Refactor HFMA to use OpCode* for opcode decoding rather than on the helper methods

* Remove the old shader translator

* Remove ShaderDeclInfo and other unused things

* Add dual vertex shader support

* Add ShaderConfig, used to pass shader type and maximum cbuffer size

* Move and rename some instruction enums

* Move texture instructions into a separate file

* Move operand GetExpression and locals management to OperandManager

* Optimize opcode decoding using a simple list and binary search

* Add missing condition for do-while on goto elimination

* Misc. fixes on texture instructions

* Simplify TLDS switch

* Address PR feedback, and a nit

1 files changed, 172 insertions, 0 deletions

diff --git a/Ryujinx.Graphics/Shader/Translation/Optimizations/Optimizer.cs b/Ryujinx.Graphics/Shader/Translation/Optimizations/Optimizer.cs
new file mode 100644
index 00000000..88118e3a
--- /dev/null
+++ b/Ryujinx.Graphics/Shader/Translation/Optimizations/Optimizer.cs
@@ -0,0 +1,172 @@
+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)
+        {
+            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.Fold(operation);
+
+                        Simplification.Simplify(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.Eliminate(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;
+        }
+    }
+}
\ No newline at end of file