Ryujinx/Ryujinx.Graphics/Gal/Shader/ShaderOptExprProp.cs
gdkchan b9aa3966c0 Merge shader branch, adding support for GLSL decompilation, a macro
interpreter, and a rewrite of the GPU code.
2018-04-08 16:41:38 -03:00

266 lines
No EOL
8.3 KiB
C#

using System;
using System.Collections.Generic;
namespace Ryujinx.Graphics.Gal.Shader
{
static class ShaderOptExprProp
{
private struct UseSite
{
public object Parent;
public int OperIndex;
public UseSite(object Parent, int OperIndex)
{
this.Parent = Parent;
this.OperIndex = OperIndex;
}
}
private class RegUse
{
public ShaderIrAsg Asg { get; private set; }
public int AsgIndex { get; private set; }
private bool Propagate;
private List<UseSite> Sites;
public RegUse()
{
Sites = new List<UseSite>();
}
public void AddUseSite(UseSite Site)
{
Sites.Add(Site);
}
public bool TryPropagate()
{
//This happens when a untiliazied register is used,
//this usually indicates a decoding error, but may also
//be cased 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 || !Propagate)
{
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, bool Propagate)
{
this.Asg = Asg;
this.AsgIndex = AsgIndex;
this.Propagate = Propagate;
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 FindRegUses(List<(int, UseSite)> UseList, object Parent, ShaderIrNode Node, int OperIndex = 0)
{
if (Node is ShaderIrAsg Asg)
{
FindRegUses(UseList, Asg, Asg.Src);
}
else if (Node is ShaderIrCond Cond)
{
FindRegUses(UseList, Cond, Cond.Pred, 0);
FindRegUses(UseList, Cond, Cond.Child, 1);
}
else if (Node is ShaderIrOp Op)
{
FindRegUses(UseList, Op, Op.OperandA, 0);
FindRegUses(UseList, Op, Op.OperandB, 1);
FindRegUses(UseList, Op, Op.OperandC, 2);
}
else if (Node is ShaderIrOperGpr Gpr && Gpr.Index != ShaderIrOperGpr.ZRIndex)
{
UseList.Add((GetGprKey(Gpr.Index), new UseSite(Parent, OperIndex)));
}
else if (Node is ShaderIrOperPred Pred)
{
UseList.Add((GetPredKey(Pred.Index), new UseSite(Parent, OperIndex)));
}
}
void TryAddRegUseSite(ShaderIrNode Node)
{
List<(int, UseSite)> UseList = new List<(int, UseSite)>();
FindRegUses(UseList, null, Node);
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)>();
FindRegUses(UseList, Use.Asg, Use.Asg.Src);
foreach ((int Key, UseSite Site) in UseList)
{
if (GetUse(Key).AsgIndex >= Use.AsgIndex)
{
return false;
}
}
return Use.TryPropagate();
}
for (int Index = 0, AsgIndex = 0; Index < Nodes.Count; Index++, AsgIndex++)
{
ShaderIrNode Node = Nodes[Index];
bool IsConditional = Node is ShaderIrCond;
TryAddRegUseSite(Node);
while (Node is ShaderIrCond Cond)
{
Node = Cond.Child;
}
if (!(Node is ShaderIrAsg Asg))
{
continue;
}
RegUse Use = null;
if (Asg.Dst is ShaderIrOperGpr Gpr && Gpr.Index != ShaderIrOperGpr.ZRIndex)
{
Use = GetGprUse(Gpr.Index);
}
else if (Asg.Dst is ShaderIrOperPred Pred)
{
Use = GetPredUse(Pred.Index);
}
if (!IsConditional && TryPropagate(Use))
{
Nodes.Remove(Use.Asg);
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, AsgIndex, !IsConditional);
}
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))
{
Nodes.Remove(Use.Asg);
}
}
}
}
}