From 2df16ded9ba06a874b58132cc2c78175631a3b8d Mon Sep 17 00:00:00 2001
From: gdkchan <gab.dark.100@gmail.com>
Date: Sat, 15 Oct 2022 20:20:16 -0300
Subject: [PATCH] Improve shader BRX instruction code generation (#3759)
* Improve shader BRX instruction code generation
* Shader cache version bump, add some comments and asserts
---
.../Shader/DiskCache/DiskCacheHostStorage.cs | 2 +-
Ryujinx.Graphics.Shader/Decoders/Decoder.cs | 13 ++-
.../Instructions/InstEmitFlowControl.cs | 82 ++++++++++++++++---
.../Translation/EmitterContext.cs | 65 +++++++++++++--
.../Translation/Translator.cs | 2 +-
5 files changed, 140 insertions(+), 24 deletions(-)
diff --git a/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheHostStorage.cs b/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheHostStorage.cs
index edb05cc074..2168c18591 100644
--- a/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheHostStorage.cs
+++ b/Ryujinx.Graphics.Gpu/Shader/DiskCache/DiskCacheHostStorage.cs
@@ -22,7 +22,7 @@ namespace Ryujinx.Graphics.Gpu.Shader.DiskCache
private const ushort FileFormatVersionMajor = 1;
private const ushort FileFormatVersionMinor = 2;
private const uint FileFormatVersionPacked = ((uint)FileFormatVersionMajor << 16) | FileFormatVersionMinor;
- private const uint CodeGenVersion = 3732;
+ private const uint CodeGenVersion = 3759;
private const string SharedTocFileName = "shared.toc";
private const string SharedDataFileName = "shared.data";
diff --git a/Ryujinx.Graphics.Shader/Decoders/Decoder.cs b/Ryujinx.Graphics.Shader/Decoders/Decoder.cs
index 1c329b593b..9dafb089f7 100644
--- a/Ryujinx.Graphics.Shader/Decoders/Decoder.cs
+++ b/Ryujinx.Graphics.Shader/Decoders/Decoder.cs
@@ -377,6 +377,8 @@ namespace Ryujinx.Graphics.Shader.Decoders
if (lastOp.Name == InstName.Brx && block.Successors.Count == (hasNext ? 1 : 0))
{
+ HashSet<ulong> visited = new HashSet<ulong>();
+
InstBrx opBrx = new InstBrx(lastOp.RawOpCode);
ulong baseOffset = lastOp.GetAbsoluteAddress();
@@ -392,9 +394,14 @@ namespace Ryujinx.Graphics.Shader.Decoders
for (int i = 0; i < cbOffsetsCount; i++)
{
uint targetOffset = config.ConstantBuffer1Read(cbBaseOffset + i * 4);
- Block target = getBlock(baseOffset + targetOffset);
- target.Predecessors.Add(block);
- block.Successors.Add(target);
+ ulong targetAddress = baseOffset + targetOffset;
+
+ if (visited.Add(targetAddress))
+ {
+ Block target = getBlock(targetAddress);
+ target.Predecessors.Add(block);
+ block.Successors.Add(target);
+ }
}
}
}
diff --git a/Ryujinx.Graphics.Shader/Instructions/InstEmitFlowControl.cs b/Ryujinx.Graphics.Shader/Instructions/InstEmitFlowControl.cs
index aee52c517c..f1dd279c87 100644
--- a/Ryujinx.Graphics.Shader/Instructions/InstEmitFlowControl.cs
+++ b/Ryujinx.Graphics.Shader/Instructions/InstEmitFlowControl.cs
@@ -41,24 +41,82 @@ namespace Ryujinx.Graphics.Shader.Instructions
Operand address = context.IAdd(Register(op.SrcA, RegisterType.Gpr), Const(offset));
- // Sorting the target addresses in descending order improves the code,
- // since it will always check the most distant targets first, then the
- // near ones. This can be easily transformed into if/else statements.
- var sortedTargets = context.CurrBlock.Successors.Skip(startIndex).OrderByDescending(x => x.Address);
+ var targets = context.CurrBlock.Successors.Skip(startIndex);
- Block lastTarget = sortedTargets.LastOrDefault();
+ bool allTargetsSinglePred = true;
+ int total = context.CurrBlock.Successors.Count - startIndex;
+ int count = 0;
- foreach (Block possibleTarget in sortedTargets)
+ foreach (var target in targets.OrderBy(x => x.Address))
{
- Operand label = context.GetLabel(possibleTarget.Address);
-
- if (possibleTarget != lastTarget)
+ if (++count < total && (target.Predecessors.Count > 1 || target.Address <= context.CurrBlock.Address))
{
- context.BranchIfTrue(label, context.ICompareEqual(address, Const((int)possibleTarget.Address)));
+ allTargetsSinglePred = false;
+ break;
}
- else
+ }
+
+ if (allTargetsSinglePred)
+ {
+ // Chain blocks, each target block will check if the BRX target address
+ // matches its own address, if not, it jumps to the next target which will do the same check,
+ // until it reaches the last possible target, which executed unconditionally.
+ // We can only do this if the BRX block is the only predecessor of all target blocks.
+ // Additionally, this is not supported for blocks located before the current block,
+ // since it will be too late to insert a label, but this is something that can be improved
+ // in the future if necessary.
+
+ var sortedTargets = targets.OrderBy(x => x.Address);
+
+ Block currentTarget = null;
+ ulong firstTargetAddress = 0;
+
+ foreach (Block nextTarget in sortedTargets)
{
- context.Branch(label);
+ if (currentTarget != null)
+ {
+ if (currentTarget.Address != nextTarget.Address)
+ {
+ context.SetBrxTarget(currentTarget.Address, address, (int)currentTarget.Address, nextTarget.Address);
+ }
+ }
+ else
+ {
+ firstTargetAddress = nextTarget.Address;
+ }
+
+ currentTarget = nextTarget;
+ }
+
+ context.Branch(context.GetLabel(firstTargetAddress));
+ }
+ else
+ {
+ // Emit the branches sequentially.
+ // This generates slightly worse code, but should work for all cases.
+
+ var sortedTargets = targets.OrderByDescending(x => x.Address);
+ ulong lastTargetAddress = ulong.MaxValue;
+
+ count = 0;
+
+ foreach (Block target in sortedTargets)
+ {
+ Operand label = context.GetLabel(target.Address);
+
+ if (++count < total)
+ {
+ if (target.Address != lastTargetAddress)
+ {
+ context.BranchIfTrue(label, context.ICompareEqual(address, Const((int)target.Address)));
+ }
+
+ lastTargetAddress = target.Address;
+ }
+ else
+ {
+ context.Branch(label);
+ }
}
}
}
diff --git a/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs b/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs
index 3e50ce2fdf..ef5d7b96dd 100644
--- a/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs
+++ b/Ryujinx.Graphics.Shader/Translation/EmitterContext.cs
@@ -21,8 +21,33 @@ namespace Ryujinx.Graphics.Shader.Translation
public int OperationsCount => _operations.Count;
+ private struct BrxTarget
+ {
+ public readonly Operand Selector;
+ public readonly int ExpectedValue;
+ public readonly ulong NextTargetAddress;
+
+ public BrxTarget(Operand selector, int expectedValue, ulong nextTargetAddress)
+ {
+ Selector = selector;
+ ExpectedValue = expectedValue;
+ NextTargetAddress = nextTargetAddress;
+ }
+ }
+
+ private class BlockLabel
+ {
+ public readonly Operand Label;
+ public BrxTarget BrxTarget;
+
+ public BlockLabel(Operand label)
+ {
+ Label = label;
+ }
+ }
+
private readonly List<Operation> _operations;
- private readonly Dictionary<ulong, Operand> _labels;
+ private readonly Dictionary<ulong, BlockLabel> _labels;
public EmitterContext(DecodedProgram program, ShaderConfig config, bool isNonMain)
{
@@ -30,7 +55,7 @@ namespace Ryujinx.Graphics.Shader.Translation
Config = config;
IsNonMain = isNonMain;
_operations = new List<Operation>();
- _labels = new Dictionary<ulong, Operand>();
+ _labels = new Dictionary<ulong, BlockLabel>();
EmitStart();
}
@@ -158,14 +183,40 @@ namespace Ryujinx.Graphics.Shader.Translation
public Operand GetLabel(ulong address)
{
- if (!_labels.TryGetValue(address, out Operand label))
- {
- label = Label();
+ return EnsureBlockLabel(address).Label;
+ }
- _labels.Add(address, label);
+ public void SetBrxTarget(ulong address, Operand selector, int targetValue, ulong nextTargetAddress)
+ {
+ BlockLabel blockLabel = EnsureBlockLabel(address);
+ Debug.Assert(blockLabel.BrxTarget.Selector == null);
+ blockLabel.BrxTarget = new BrxTarget(selector, targetValue, nextTargetAddress);
+ }
+
+ public void EnterBlock(ulong address)
+ {
+ BlockLabel blockLabel = EnsureBlockLabel(address);
+
+ MarkLabel(blockLabel.Label);
+
+ BrxTarget brxTarget = blockLabel.BrxTarget;
+
+ if (brxTarget.Selector != null)
+ {
+ this.BranchIfFalse(GetLabel(brxTarget.NextTargetAddress), this.ICompareEqual(brxTarget.Selector, Const(brxTarget.ExpectedValue)));
+ }
+ }
+
+ private BlockLabel EnsureBlockLabel(ulong address)
+ {
+ if (!_labels.TryGetValue(address, out BlockLabel blockLabel))
+ {
+ blockLabel = new BlockLabel(Label());
+
+ _labels.Add(address, blockLabel);
}
- return label;
+ return blockLabel;
}
public void PrepareForVertexReturn()
diff --git a/Ryujinx.Graphics.Shader/Translation/Translator.cs b/Ryujinx.Graphics.Shader/Translation/Translator.cs
index 78fd9498ae..ff0de1bd0b 100644
--- a/Ryujinx.Graphics.Shader/Translation/Translator.cs
+++ b/Ryujinx.Graphics.Shader/Translation/Translator.cs
@@ -162,7 +162,7 @@ namespace Ryujinx.Graphics.Shader.Translation
{
context.CurrBlock = block;
- context.MarkLabel(context.GetLabel(block.Address));
+ context.EnterBlock(block.Address);
EmitOps(context, block);
}