Ryujinx/Ryujinx.Graphics/Gal/Shader/ShaderOptExprProp.cs

366 lines
No EOL
12 KiB
C#

using System;
using System.Collections.Generic;
namespace Ryujinx.Graphics.Gal.Shader
{
static class ShaderOptExprProp
{
private struct UseSite
{
public ShaderIrNode Parent { get; private set; }
public ShaderIrCond Cond { get; private set; }
public int UseIndex { get; private set; }
public int OperIndex { get; private set; }
public UseSite(
ShaderIrNode Parent,
ShaderIrCond Cond,
int UseIndex,
int OperIndex)
{
this.Parent = Parent;
this.Cond = Cond;
this.UseIndex = UseIndex;
this.OperIndex = OperIndex;
}
}
private class RegUse
{
public ShaderIrAsg Asg { get; private set; }
public int AsgIndex { get; private set; }
public int LastSiteIndex { get; private set; }
public ShaderIrCond Cond { get; private set; }
private List<UseSite> Sites;
public RegUse()
{
Sites = new List<UseSite>();
}
public void AddUseSite(UseSite Site)
{
if (LastSiteIndex < Site.UseIndex)
{
LastSiteIndex = Site.UseIndex;
}
Sites.Add(Site);
}
public bool TryPropagate()
{
//This happens when a untiliazied register is used,
//this usually indicates a decoding error, but may also
//be caused by bogus programs (?). In any case, we just
//keep the unitialized access and avoid trying to propagate
//the expression (since we can't propagate what doesn't yet exist).
if (Asg == null)
{
return false;
}
if (Cond != null)
{
//If the assignment is conditional, we can only propagate
//to the use sites that shares the same condition of the assignment.
foreach (UseSite Site in Sites)
{
if (!IsSameCondition(Cond, Site.Cond))
{
return false;
}
}
}
if (Sites.Count > 0)
{
foreach (UseSite Site in Sites)
{
if (Site.Parent is ShaderIrCond Cond)
{
switch (Site.OperIndex)
{
case 0: Cond.Pred = Asg.Src; break;
case 1: Cond.Child = Asg.Src; break;
default: throw new InvalidOperationException();
}
}
else if (Site.Parent is ShaderIrOp Op)
{
switch (Site.OperIndex)
{
case 0: Op.OperandA = Asg.Src; break;
case 1: Op.OperandB = Asg.Src; break;
case 2: Op.OperandC = Asg.Src; break;
default: throw new InvalidOperationException();
}
}
else if (Site.Parent is ShaderIrAsg SiteAsg)
{
SiteAsg.Src = Asg.Src;
}
else
{
throw new InvalidOperationException();
}
}
}
return true;
}
public void SetNewAsg(ShaderIrAsg Asg, int AsgIndex, ShaderIrCond Cond)
{
this.Asg = Asg;
this.AsgIndex = AsgIndex;
this.Cond = Cond;
LastSiteIndex = 0;
Sites.Clear();
}
}
public static void Optimize(List<ShaderIrNode> Nodes, GalShaderType ShaderType)
{
Dictionary<int, RegUse> Uses = new Dictionary<int, RegUse>();
RegUse GetUse(int Key)
{
RegUse Use;
if (!Uses.TryGetValue(Key, out Use))
{
Use = new RegUse();
Uses.Add(Key, Use);
}
return Use;
}
int GetGprKey(int GprIndex)
{
return GprIndex;
}
int GetPredKey(int PredIndex)
{
return PredIndex | 0x10000000;
}
RegUse GetGprUse(int GprIndex)
{
return GetUse(GetGprKey(GprIndex));
}
RegUse GetPredUse(int PredIndex)
{
return GetUse(GetPredKey(PredIndex));
}
void RemoveUse(RegUse Use)
{
if (!Nodes.Remove((ShaderIrNode)Use.Cond ?? Use.Asg))
{
throw new InvalidOperationException();
}
}
void FindRegUses(
List<(int, UseSite)> UseList,
ShaderIrNode Parent,
ShaderIrNode Node,
ShaderIrCond CondNode,
int UseIndex,
int OperIndex = 0)
{
if (Node is ShaderIrAsg Asg)
{
FindRegUses(UseList, Asg, Asg.Src, CondNode, UseIndex);
}
else if (Node is ShaderIrCond Cond)
{
FindRegUses(UseList, Cond, Cond.Pred, CondNode, UseIndex, 0);
FindRegUses(UseList, Cond, Cond.Child, CondNode, UseIndex, 1);
}
else if (Node is ShaderIrOp Op)
{
FindRegUses(UseList, Op, Op.OperandA, CondNode, UseIndex, 0);
FindRegUses(UseList, Op, Op.OperandB, CondNode, UseIndex, 1);
FindRegUses(UseList, Op, Op.OperandC, CondNode, UseIndex, 2);
}
else if (Node is ShaderIrOperGpr Gpr && !Gpr.IsConst)
{
UseList.Add((GetGprKey(Gpr.Index), new UseSite(Parent, CondNode, UseIndex, OperIndex)));
}
else if (Node is ShaderIrOperPred Pred)
{
UseList.Add((GetPredKey(Pred.Index), new UseSite(Parent, CondNode, UseIndex, OperIndex)));
}
}
void TryAddRegUseSite(ShaderIrNode Node, ShaderIrCond CondNode, int UseIndex)
{
List<(int, UseSite)> UseList = new List<(int, UseSite)>();
FindRegUses(UseList, null, Node, CondNode, UseIndex);
foreach ((int Key, UseSite Site) in UseList)
{
GetUse(Key).AddUseSite(Site);
}
}
bool TryPropagate(RegUse Use)
{
//We can only propagate if the registers that the expression depends
//on weren't assigned after the original expression assignment
//to a register took place. We traverse the expression tree to find
//all registers being used, if any of those registers was assigned
//after the assignment to be propagated, then we can't propagate.
if (Use?.Asg == null)
{
return false;
}
List<(int, UseSite)> UseList = new List<(int, UseSite)>();
if (Use.Cond != null)
{
FindRegUses(UseList, null, Use.Cond, null, 0);
}
else
{
FindRegUses(UseList, Use.Asg, Use.Asg.Src, null, 0);
}
foreach ((int Key, UseSite Site) in UseList)
{
//TODO: Build an assignment list inside RegUse,
//and check if there is an assignment inside the
//range of Use.AsgIndex and Use.LastSiteIndex,
//and if that's the case, then we should return false.
//The current method is too conservative.
if (GetUse(Key).AsgIndex >= Use.AsgIndex)
{
return false;
}
}
return Use.TryPropagate();
}
for (int Index = 0, IterCount = 0; Index < Nodes.Count; Index++, IterCount++)
{
ShaderIrNode Node = Nodes[Index];
ShaderIrCond CondNode = null;
if (Node is ShaderIrCond)
{
CondNode = (ShaderIrCond)Node;
}
TryAddRegUseSite(Node, CondNode, IterCount);;
while (Node is ShaderIrCond Cond)
{
Node = Cond.Child;
}
if (!(Node is ShaderIrAsg Asg))
{
continue;
}
RegUse Use = null;
if (Asg.Dst is ShaderIrOperGpr Gpr && !Gpr.IsConst)
{
Use = GetGprUse(Gpr.Index);
}
else if (Asg.Dst is ShaderIrOperPred Pred)
{
Use = GetPredUse(Pred.Index);
}
bool CanRemoveAsg = CondNode == null;
CanRemoveAsg |= IsSameCondition(CondNode, Use?.Cond);
if (CanRemoveAsg && TryPropagate(Use))
{
RemoveUse(Use);
//Note: Only decrement if the removal was successful.
//RemoveUse throws when this is not the case so we should be good.
Index--;
}
//All nodes inside conditional nodes can't be propagated,
//as we don't even know if they will be executed to begin with.
Use?.SetNewAsg(Asg, IterCount, CondNode);
}
foreach (RegUse Use in Uses.Values)
{
//Gprs 0-3 are the color output on fragment shaders,
//so we can't remove the last assignments to those registers.
if (ShaderType == GalShaderType.Fragment)
{
if (Use.Asg?.Dst is ShaderIrOperGpr Gpr && Gpr.Index < 4)
{
continue;
}
}
if (TryPropagate(Use))
{
RemoveUse(Use);
}
}
}
private static bool IsSameCondition(ShaderIrCond CondA, ShaderIrCond CondB)
{
if (CondA == null || CondB == null)
{
return CondA == CondB;
}
if (CondA.Not != CondB.Not)
{
return false;
}
if (CondA.Pred is ShaderIrOperPred PredA)
{
if (!(CondB.Pred is ShaderIrOperPred PredB))
{
return false;
}
if (PredA.Index != PredB.Index)
{
return false;
}
}
else if (CondA.Pred != CondB.Pred)
{
return false;
}
return true;
}
}
}