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ryujinx-final/Ryujinx.Graphics.Shader/StructuredIr/StructuredProgramContext.cs
gdkchan d512ce122c
Initial tessellation shader support (#2534)
* Initial tessellation shader support

* Nits

* Re-arrange built-in table

* This is not needed anymore

* PR feedback
2021-10-18 18:38:04 -03:00

318 lines
No EOL
10 KiB
C#

using Ryujinx.Graphics.Shader.IntermediateRepresentation;
using Ryujinx.Graphics.Shader.Translation;
using System.Collections.Generic;
using System.Linq;
using static Ryujinx.Graphics.Shader.StructuredIr.AstHelper;
namespace Ryujinx.Graphics.Shader.StructuredIr
{
class StructuredProgramContext
{
private HashSet<BasicBlock> _loopTails;
private Stack<(AstBlock Block, int CurrEndIndex, int LoopEndIndex)> _blockStack;
private Dictionary<Operand, AstOperand> _localsMap;
private Dictionary<int, AstAssignment> _gotoTempAsgs;
private List<GotoStatement> _gotos;
private AstBlock _currBlock;
private int _currEndIndex;
private int _loopEndIndex;
public StructuredFunction CurrentFunction { get; private set; }
public StructuredProgramInfo Info { get; }
public ShaderConfig Config { get; }
public StructuredProgramContext(ShaderConfig config)
{
Info = new StructuredProgramInfo();
Config = config;
}
public void EnterFunction(
int blocksCount,
string name,
VariableType returnType,
VariableType[] inArguments,
VariableType[] outArguments)
{
_loopTails = new HashSet<BasicBlock>();
_blockStack = new Stack<(AstBlock, int, int)>();
_localsMap = new Dictionary<Operand, AstOperand>();
_gotoTempAsgs = new Dictionary<int, AstAssignment>();
_gotos = new List<GotoStatement>();
_currBlock = new AstBlock(AstBlockType.Main);
_currEndIndex = blocksCount;
_loopEndIndex = blocksCount;
CurrentFunction = new StructuredFunction(_currBlock, name, returnType, inArguments, outArguments);
}
public void LeaveFunction()
{
Info.Functions.Add(CurrentFunction);
}
public void EnterBlock(BasicBlock block)
{
while (_currEndIndex == block.Index)
{
(_currBlock, _currEndIndex, _loopEndIndex) = _blockStack.Pop();
}
if (_gotoTempAsgs.TryGetValue(block.Index, out AstAssignment gotoTempAsg))
{
AddGotoTempReset(block, gotoTempAsg);
}
LookForDoWhileStatements(block);
}
public void LeaveBlock(BasicBlock block, Operation branchOp)
{
LookForIfStatements(block, branchOp);
}
private void LookForDoWhileStatements(BasicBlock block)
{
// Check if we have any predecessor whose index is greater than the
// current block, this indicates a loop.
bool done = false;
foreach (BasicBlock predecessor in block.Predecessors.OrderByDescending(x => x.Index))
{
// If not a loop, break.
if (predecessor.Index < block.Index)
{
break;
}
// Check if we can create a do-while loop here (only possible if the loop end
// falls inside the current scope), if not add a goto instead.
if (predecessor.Index < _currEndIndex && !done)
{
// Create do-while loop block. We must avoid inserting a goto at the end
// of the loop later, when the tail block is processed. So we add the predecessor
// to a list of loop tails to prevent it from being processed later.
Operation branchOp = (Operation)predecessor.GetLastOp();
NewBlock(AstBlockType.DoWhile, branchOp, predecessor.Index + 1);
_loopTails.Add(predecessor);
done = true;
}
else
{
// Failed to create loop. Since this block is the loop head, we reset the
// goto condition variable here. The variable is always reset on the jump
// target, and this block is the jump target for some loop.
AddGotoTempReset(block, GetGotoTempAsg(block.Index));
break;
}
}
}
private void LookForIfStatements(BasicBlock block, Operation branchOp)
{
if (block.Branch == null)
{
return;
}
// We can only enclose the "if" when the branch lands before
// the end of the current block. If the current enclosing block
// is not a loop, then we can also do so if the branch lands
// right at the end of the current block. When it is a loop,
// this is not valid as the loop condition would be evaluated,
// and it could erroneously jump back to the start of the loop.
bool inRange =
block.Branch.Index < _currEndIndex ||
(block.Branch.Index == _currEndIndex && block.Branch.Index < _loopEndIndex);
bool isLoop = block.Branch.Index <= block.Index;
if (inRange && !isLoop)
{
NewBlock(AstBlockType.If, branchOp, block.Branch.Index);
}
else if (!_loopTails.Contains(block))
{
AstAssignment gotoTempAsg = GetGotoTempAsg(block.Branch.Index);
// We use DoWhile type here, as the condition should be true for
// unconditional branches, or it should jump if the condition is true otherwise.
IAstNode cond = GetBranchCond(AstBlockType.DoWhile, branchOp);
AddNode(Assign(gotoTempAsg.Destination, cond));
AstOperation branch = new AstOperation(branchOp.Inst);
AddNode(branch);
GotoStatement gotoStmt = new GotoStatement(branch, gotoTempAsg, isLoop);
_gotos.Add(gotoStmt);
}
}
private AstAssignment GetGotoTempAsg(int index)
{
if (_gotoTempAsgs.TryGetValue(index, out AstAssignment gotoTempAsg))
{
return gotoTempAsg;
}
AstOperand gotoTemp = NewTemp(VariableType.Bool);
gotoTempAsg = Assign(gotoTemp, Const(IrConsts.False));
_gotoTempAsgs.Add(index, gotoTempAsg);
return gotoTempAsg;
}
private void AddGotoTempReset(BasicBlock block, AstAssignment gotoTempAsg)
{
// If it was already added, we don't need to add it again.
if (gotoTempAsg.Parent != null)
{
return;
}
AddNode(gotoTempAsg);
// For block 0, we don't need to add the extra "reset" at the beginning,
// because it is already the first node to be executed on the shader,
// so it is reset to false by the "local" assignment anyway.
if (block.Index != 0)
{
CurrentFunction.MainBlock.AddFirst(Assign(gotoTempAsg.Destination, Const(IrConsts.False)));
}
}
private void NewBlock(AstBlockType type, Operation branchOp, int endIndex)
{
NewBlock(type, GetBranchCond(type, branchOp), endIndex);
}
private void NewBlock(AstBlockType type, IAstNode cond, int endIndex)
{
AstBlock childBlock = new AstBlock(type, cond);
AddNode(childBlock);
_blockStack.Push((_currBlock, _currEndIndex, _loopEndIndex));
_currBlock = childBlock;
_currEndIndex = endIndex;
if (type == AstBlockType.DoWhile)
{
_loopEndIndex = endIndex;
}
}
private IAstNode GetBranchCond(AstBlockType type, Operation branchOp)
{
IAstNode cond;
if (branchOp.Inst == Instruction.Branch)
{
// If the branch is not conditional, the condition is a constant.
// For if it's false (always jump over, if block never executed).
// For loops it's always true (always loop).
cond = Const(type == AstBlockType.If ? IrConsts.False : IrConsts.True);
}
else
{
cond = GetOperandUse(branchOp.GetSource(0));
Instruction invInst = type == AstBlockType.If
? Instruction.BranchIfTrue
: Instruction.BranchIfFalse;
if (branchOp.Inst == invInst)
{
cond = new AstOperation(Instruction.LogicalNot, cond);
}
}
return cond;
}
public void AddNode(IAstNode node)
{
_currBlock.Add(node);
}
public GotoStatement[] GetGotos()
{
return _gotos.ToArray();
}
private AstOperand NewTemp(VariableType type)
{
AstOperand newTemp = Local(type);
CurrentFunction.Locals.Add(newTemp);
return newTemp;
}
public AstOperand GetOperandDef(Operand operand)
{
return GetOperand(operand);
}
public AstOperand GetOperandUse(Operand operand)
{
// If this flag is set, we're reading from an output attribute instead.
if (operand.Type.IsAttribute() && (operand.Value & AttributeConsts.LoadOutputMask) != 0)
{
return GetOperandDef(operand);
}
return GetOperand(operand);
}
private AstOperand GetOperand(Operand operand)
{
if (operand == null)
{
return null;
}
if (operand.Type != OperandType.LocalVariable)
{
return new AstOperand(operand);
}
if (!_localsMap.TryGetValue(operand, out AstOperand astOperand))
{
astOperand = new AstOperand(operand);
_localsMap.Add(operand, astOperand);
CurrentFunction.Locals.Add(astOperand);
}
return astOperand;
}
}
}