From 54501962f60b87d5ea0790302138c6db81cc2f23 Mon Sep 17 00:00:00 2001
From: jduncanator <1518948+jduncanator@users.noreply.github.com>
Date: Fri, 6 Mar 2020 11:09:49 +1100
Subject: [PATCH] Fix branch with CC and predicate, and a case of SYNC
propagation (#967)
---
Ryujinx.Graphics.Shader/Decoders/Decoder.cs | 25 +++++++++++++++++--
.../Instructions/InstEmitFlow.cs | 20 ++++++++++++---
2 files changed, 40 insertions(+), 5 deletions(-)
diff --git a/Ryujinx.Graphics.Shader/Decoders/Decoder.cs b/Ryujinx.Graphics.Shader/Decoders/Decoder.cs
index 8a502e3c6c..cda88302a4 100644
--- a/Ryujinx.Graphics.Shader/Decoders/Decoder.cs
+++ b/Ryujinx.Graphics.Shader/Decoders/Decoder.cs
@@ -390,7 +390,14 @@ namespace Ryujinx.Graphics.Shader.Decoders
void Push(PathBlockState pbs)
{
- if (pbs.Block == null || visited.Add(pbs.Block))
+ // When block is null, this means we are pushing a restore operation.
+ // Restore operations are used to undo the work done inside a block
+ // when we return from it, for example it pops addresses pushed by
+ // SSY/PBK instructions inside the block, and pushes addresses poped
+ // by SYNC/BRK.
+ // For blocks, if it's already visited, we just ignore to avoid going
+ // around in circles and getting stuck here.
+ if (pbs.Block == null || !visited.Contains(pbs.Block))
{
workQueue.Push(pbs);
}
@@ -409,6 +416,14 @@ namespace Ryujinx.Graphics.Shader.Decoders
Block current = pbs.Block;
+ // If the block was already processed, we just ignore it, otherwise
+ // we would push the same child blocks of an already processed block,
+ // and go around in circles until memory is exhausted.
+ if (!visited.Add(current))
+ {
+ continue;
+ }
+
int pushOpsCount = current.PushOpCodes.Count;
if (pushOpsCount != 0)
@@ -434,7 +449,9 @@ namespace Ryujinx.Graphics.Shader.Decoders
}
else if (current.GetLastOp() is OpCodeBranchIndir brIndir)
{
- foreach (Block possibleTarget in brIndir.PossibleTargets)
+ // By adding them in descending order (sorted by address), we process the blocks
+ // in order (of ascending address), since we work with a LIFO.
+ foreach (Block possibleTarget in brIndir.PossibleTargets.OrderByDescending(x => x.Address))
{
Push(new PathBlockState(possibleTarget));
}
@@ -453,6 +470,10 @@ namespace Ryujinx.Graphics.Shader.Decoders
}
else
{
+ // First we push the target address (this will be used to push the
+ // address back into the SSY/PBK stack when we return from that block),
+ // then we push the block itself into the work "queue" (well, it's a stack)
+ // for processing.
Push(new PathBlockState(targetAddress));
Push(new PathBlockState(blocks[targetAddress]));
}
diff --git a/Ryujinx.Graphics.Shader/Instructions/InstEmitFlow.cs b/Ryujinx.Graphics.Shader/Instructions/InstEmitFlow.cs
index 0b96d7518e..4b058a8446 100644
--- a/Ryujinx.Graphics.Shader/Instructions/InstEmitFlow.cs
+++ b/Ryujinx.Graphics.Shader/Instructions/InstEmitFlow.cs
@@ -145,10 +145,24 @@ namespace Ryujinx.Graphics.Shader.Instructions
if (op is OpCodeBranch opBranch && opBranch.Condition != Condition.Always)
{
- pred = context.BitwiseAnd(pred, GetCondition(context, opBranch.Condition));
- }
+ Operand cond = GetCondition(context, opBranch.Condition);
- if (op.Predicate.IsPT)
+ if (op.Predicate.IsPT)
+ {
+ pred = cond;
+ }
+ else if (op.InvertPredicate)
+ {
+ pred = context.BitwiseAnd(context.BitwiseNot(pred), cond);
+ }
+ else
+ {
+ pred = context.BitwiseAnd(pred, cond);
+ }
+
+ context.BranchIfTrue(label, pred);
+ }
+ else if (op.Predicate.IsPT)
{
context.Branch(label);
}