Ryujinx/Ryujinx.Graphics.Shader/Instructions/InstEmitFlowControl.cs
gdkchan 2df16ded9b
Improve shader BRX instruction code generation (#3759)
* Improve shader BRX instruction code generation

* Shader cache version bump, add some comments and asserts
2022-10-15 23:20:16 +00:00

338 lines
11 KiB
C#

using Ryujinx.Graphics.Shader.Decoders;
using Ryujinx.Graphics.Shader.IntermediateRepresentation;
using Ryujinx.Graphics.Shader.Translation;
using System.Collections.Generic;
using System.Linq;
using static Ryujinx.Graphics.Shader.Instructions.InstEmitHelper;
using static Ryujinx.Graphics.Shader.IntermediateRepresentation.OperandHelper;
namespace Ryujinx.Graphics.Shader.Instructions
{
static partial class InstEmit
{
public static void Bra(EmitterContext context)
{
InstBra op = context.GetOp<InstBra>();
EmitBranch(context, context.CurrBlock.Successors[^1].Address);
}
public static void Brk(EmitterContext context)
{
InstBrk op = context.GetOp<InstBrk>();
EmitBrkContSync(context);
}
public static void Brx(EmitterContext context)
{
InstBrx op = context.GetOp<InstBrx>();
InstOp currOp = context.CurrOp;
int startIndex = context.CurrBlock.HasNext() ? 1 : 0;
if (context.CurrBlock.Successors.Count <= startIndex)
{
context.Config.GpuAccessor.Log($"Failed to find targets for BRX instruction at 0x{currOp.Address:X}.");
return;
}
int offset = (int)currOp.GetAbsoluteAddress();
Operand address = context.IAdd(Register(op.SrcA, RegisterType.Gpr), Const(offset));
var targets = context.CurrBlock.Successors.Skip(startIndex);
bool allTargetsSinglePred = true;
int total = context.CurrBlock.Successors.Count - startIndex;
int count = 0;
foreach (var target in targets.OrderBy(x => x.Address))
{
if (++count < total && (target.Predecessors.Count > 1 || target.Address <= context.CurrBlock.Address))
{
allTargetsSinglePred = false;
break;
}
}
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)
{
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);
}
}
}
}
public static void Cal(EmitterContext context)
{
InstCal op = context.GetOp<InstCal>();
DecodedFunction function = context.Program.GetFunctionByAddress(context.CurrOp.GetAbsoluteAddress());
if (function.IsCompilerGenerated)
{
switch (function.Type)
{
case FunctionType.BuiltInFSIBegin:
context.FSIBegin();
break;
case FunctionType.BuiltInFSIEnd:
context.FSIEnd();
break;
}
}
else
{
context.Call(function.Id, false);
}
}
public static void Cont(EmitterContext context)
{
InstCont op = context.GetOp<InstCont>();
EmitBrkContSync(context);
}
public static void Exit(EmitterContext context)
{
InstExit op = context.GetOp<InstExit>();
if (context.IsNonMain)
{
context.Config.GpuAccessor.Log("Invalid exit on non-main function.");
return;
}
if (op.Ccc == Ccc.T)
{
context.Return();
}
else
{
Operand cond = GetCondition(context, op.Ccc, IrConsts.False);
// If the condition is always false, we don't need to do anything.
if (cond.Type != OperandType.Constant || cond.Value != IrConsts.False)
{
Operand lblSkip = Label();
context.BranchIfFalse(lblSkip, cond);
context.Return();
context.MarkLabel(lblSkip);
}
}
}
public static void Kil(EmitterContext context)
{
InstKil op = context.GetOp<InstKil>();
context.Discard();
}
public static void Pbk(EmitterContext context)
{
InstPbk op = context.GetOp<InstPbk>();
EmitPbkPcntSsy(context);
}
public static void Pcnt(EmitterContext context)
{
InstPcnt op = context.GetOp<InstPcnt>();
EmitPbkPcntSsy(context);
}
public static void Ret(EmitterContext context)
{
InstRet op = context.GetOp<InstRet>();
if (context.IsNonMain)
{
context.Return();
}
else
{
context.Config.GpuAccessor.Log("Invalid return on main function.");
}
}
public static void Ssy(EmitterContext context)
{
InstSsy op = context.GetOp<InstSsy>();
EmitPbkPcntSsy(context);
}
public static void Sync(EmitterContext context)
{
InstSync op = context.GetOp<InstSync>();
EmitBrkContSync(context);
}
private static void EmitPbkPcntSsy(EmitterContext context)
{
var consumers = context.CurrBlock.PushOpCodes.First(x => x.Op.Address == context.CurrOp.Address).Consumers;
foreach (KeyValuePair<Block, Operand> kv in consumers)
{
Block consumerBlock = kv.Key;
Operand local = kv.Value;
int id = consumerBlock.SyncTargets[context.CurrOp.Address].PushOpId;
context.Copy(local, Const(id));
}
}
private static void EmitBrkContSync(EmitterContext context)
{
var targets = context.CurrBlock.SyncTargets;
if (targets.Count == 1)
{
// If we have only one target, then the SSY/PBK is basically
// a branch, we can produce better codegen for this case.
EmitBranch(context, targets.Values.First().PushOpInfo.Op.GetAbsoluteAddress());
}
else
{
// TODO: Support CC here aswell (condition).
foreach (SyncTarget target in targets.Values)
{
PushOpInfo pushOpInfo = target.PushOpInfo;
Operand label = context.GetLabel(pushOpInfo.Op.GetAbsoluteAddress());
Operand local = pushOpInfo.Consumers[context.CurrBlock];
context.BranchIfTrue(label, context.ICompareEqual(local, Const(target.PushOpId)));
}
}
}
private static void EmitBranch(EmitterContext context, ulong address)
{
InstOp op = context.CurrOp;
InstConditional opCond = new InstConditional(op.RawOpCode);
// If we're branching to the next instruction, then the branch
// is useless and we can ignore it.
if (address == op.Address + 8)
{
return;
}
Operand label = context.GetLabel(address);
Operand pred = Register(opCond.Pred, RegisterType.Predicate);
if (opCond.Ccc != Ccc.T)
{
Operand cond = GetCondition(context, opCond.Ccc);
if (opCond.Pred == RegisterConsts.PredicateTrueIndex)
{
pred = cond;
}
else if (opCond.PredInv)
{
pred = context.BitwiseAnd(context.BitwiseNot(pred), cond);
}
else
{
pred = context.BitwiseAnd(pred, cond);
}
context.BranchIfTrue(label, pred);
}
else if (opCond.Pred == RegisterConsts.PredicateTrueIndex)
{
context.Branch(label);
}
else if (opCond.PredInv)
{
context.BranchIfFalse(label, pred);
}
else
{
context.BranchIfTrue(label, pred);
}
}
private static Operand GetCondition(EmitterContext context, Ccc cond, int defaultCond = IrConsts.True)
{
// TODO: More condition codes, figure out how they work.
switch (cond)
{
case Ccc.Eq:
case Ccc.Equ:
return GetZF();
case Ccc.Ne:
case Ccc.Neu:
return context.BitwiseNot(GetZF());
}
return Const(defaultCond);
}
}
}