Ryujinx/Ryujinx.Graphics.Shader/Translation/Optimizations/Optimizer.cs
gdkchan 4523a73f75
Propagate Shader phi nodes with the same source value from all blocks (#3457)
* Propagate Shader phi nodes with the same source value from all incoming blocks

* Shader cache version bump
2022-07-12 00:36:58 +02:00

377 lines
No EOL
12 KiB
C#

using Ryujinx.Graphics.Shader.IntermediateRepresentation;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
namespace Ryujinx.Graphics.Shader.Translation.Optimizations
{
static class Optimizer
{
public static void RunPass(BasicBlock[] blocks, ShaderConfig config)
{
RunOptimizationPasses(blocks);
// Those passes are looking for specific patterns and only needs to run once.
for (int blkIndex = 0; blkIndex < blocks.Length; blkIndex++)
{
GlobalToStorage.RunPass(blocks[blkIndex], config);
BindlessToIndexed.RunPass(blocks[blkIndex], config);
BindlessElimination.RunPass(blocks[blkIndex], config);
}
// Run optimizations one last time to remove any code that is now optimizable after above passes.
RunOptimizationPasses(blocks);
}
private static void RunOptimizationPasses(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 (node.Value is PhiNode phi && !isUnused)
{
isUnused = PropagatePhi(phi);
}
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)) ||
(operation.Inst == Instruction.ShuffleXor && MatchDdxOrDdy(operation)))
{
if (DestHasNoUses(operation))
{
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 PropagatePhi(PhiNode phi)
{
// If all phi sources are the same, we can propagate it and remove the phi.
Operand firstSrc = phi.GetSource(0);
for (int index = 1; index < phi.SourcesCount; index++)
{
if (!IsSameOperand(firstSrc, phi.GetSource(index)))
{
return false;
}
}
// All sources are equal, we can propagate the value.
Operand dest = phi.Dest;
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, firstSrc);
}
}
}
return true;
}
private static bool IsSameOperand(Operand x, Operand y)
{
if (x.Type != y.Type || x.Value != y.Value)
{
return false;
}
return x.Type == OperandType.Attribute ||
x.Type == OperandType.AttributePerPatch ||
x.Type == OperandType.Constant ||
x.Type == OperandType.ConstantBuffer;
}
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.Index == 1 ? src1 : src0);
modified = true;
}
}
return modified;
}
public static bool MatchDdxOrDdy(Operation operation)
{
// It's assumed that "operation.Inst" is ShuffleXor,
// that should be checked before calling this method.
Debug.Assert(operation.Inst == Instruction.ShuffleXor);
bool modified = false;
Operand src2 = operation.GetSource(1);
Operand src3 = operation.GetSource(2);
if (src2.Type != OperandType.Constant || (src2.Value != 1 && src2.Value != 2))
{
return false;
}
if (src3.Type != OperandType.Constant || src3.Value != 0x1c03)
{
return false;
}
bool isDdy = src2.Value == 2;
bool isDdx = !isDdy;
// We can replace any use by a FSWZADD with DDX/DDY, when
// the following conditions are true:
// - The mask should be 0b10100101 for DDY, or 0b10011001 for DDX.
// - The first source operand must be the shuffle output.
// - The second source operand must be the shuffle first source operand.
INode[] uses = operation.Dest.UseOps.ToArray();
foreach (INode use in uses)
{
if (!(use is Operation test))
{
continue;
}
if (!(use is Operation useOp) || useOp.Inst != Instruction.SwizzleAdd)
{
continue;
}
Operand fswzaddSrc1 = useOp.GetSource(0);
Operand fswzaddSrc2 = useOp.GetSource(1);
Operand fswzaddSrc3 = useOp.GetSource(2);
if (fswzaddSrc1 != operation.Dest)
{
continue;
}
if (fswzaddSrc2 != operation.GetSource(0))
{
continue;
}
if (fswzaddSrc3.Type != OperandType.Constant)
{
continue;
}
int mask = fswzaddSrc3.Value;
if ((isDdx && mask != 0b10011001) ||
(isDdy && mask != 0b10100101))
{
continue;
}
useOp.TurnInto(isDdx ? Instruction.Ddx : Instruction.Ddy, fswzaddSrc2);
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)
{
Debug.Assert(src.AsgOp != null);
nodes.Enqueue(src.AsgOp);
}
}
}
}
private static bool IsUnused(INode node)
{
return !HasSideEffects(node) && DestIsLocalVar(node) && DestHasNoUses(node);
}
private static bool HasSideEffects(INode node)
{
if (node is Operation operation)
{
switch (operation.Inst & Instruction.Mask)
{
case Instruction.AtomicAdd:
case Instruction.AtomicAnd:
case Instruction.AtomicCompareAndSwap:
case Instruction.AtomicMaxS32:
case Instruction.AtomicMaxU32:
case Instruction.AtomicMinS32:
case Instruction.AtomicMinU32:
case Instruction.AtomicOr:
case Instruction.AtomicSwap:
case Instruction.AtomicXor:
case Instruction.Call:
case Instruction.ImageAtomic:
return true;
}
}
return false;
}
private static bool DestIsLocalVar(INode node)
{
if (node.DestsCount == 0)
{
return false;
}
for (int index = 0; index < node.DestsCount; index++)
{
Operand dest = node.GetDest(index);
if (dest != null && dest.Type != OperandType.LocalVariable)
{
return false;
}
}
return true;
}
private static bool DestHasNoUses(INode node)
{
for (int index = 0; index < node.DestsCount; index++)
{
Operand dest = node.GetDest(index);
if (dest != null && dest.UseOps.Count != 0)
{
return false;
}
}
return true;
}
}
}