Ryujinx/ARMeilleure/Translation/RegisterUsage.cs
FICTURE7 36ec1bc6c0
Relax block ordering constraints (#1535)
* Relax block ordering constraints

Before `block.Next` had to follow `block.ListNext`, now it does not.
Instead `CodeGenerator` will now emit the necessary jump instructions
to ensure control flow.

This makes control flow and block order modifications easier. It also
eliminates some simple cases of redundant branches.

* Set PPTC version
2020-09-12 12:32:53 -03:00

416 lines
No EOL
14 KiB
C#

using ARMeilleure.IntermediateRepresentation;
using ARMeilleure.State;
using System;
using static ARMeilleure.IntermediateRepresentation.OperandHelper;
using static ARMeilleure.IntermediateRepresentation.OperationHelper;
namespace ARMeilleure.Translation
{
static class RegisterUsage
{
private const long CallerSavedIntRegistersMask = 0x7fL << 9;
private const long PStateNzcvFlagsMask = 0xfL << 60;
private const long FpStateNzcvFlagsMask = 0xfL << 60;
private const long CallerSavedVecRegistersMask = 0xffffL << 16;
private const int RegsCount = 32;
private const int RegsMask = RegsCount - 1;
private struct RegisterMask : IEquatable<RegisterMask>
{
public long IntMask { get; set; }
public long VecMask { get; set; }
public RegisterMask(long intMask, long vecMask)
{
IntMask = intMask;
VecMask = vecMask;
}
public static RegisterMask operator &(RegisterMask x, RegisterMask y)
{
return new RegisterMask(x.IntMask & y.IntMask, x.VecMask & y.VecMask);
}
public static RegisterMask operator |(RegisterMask x, RegisterMask y)
{
return new RegisterMask(x.IntMask | y.IntMask, x.VecMask | y.VecMask);
}
public static RegisterMask operator ~(RegisterMask x)
{
return new RegisterMask(~x.IntMask, ~x.VecMask);
}
public static bool operator ==(RegisterMask x, RegisterMask y)
{
return x.Equals(y);
}
public static bool operator !=(RegisterMask x, RegisterMask y)
{
return !x.Equals(y);
}
public override bool Equals(object obj)
{
return obj is RegisterMask regMask && Equals(regMask);
}
public bool Equals(RegisterMask other)
{
return IntMask == other.IntMask && VecMask == other.VecMask;
}
public override int GetHashCode()
{
return HashCode.Combine(IntMask, VecMask);
}
}
public static void RunPass(ControlFlowGraph cfg, ExecutionMode mode, bool isCompleteFunction)
{
// Compute local register inputs and outputs used inside blocks.
RegisterMask[] localInputs = new RegisterMask[cfg.Blocks.Count];
RegisterMask[] localOutputs = new RegisterMask[cfg.Blocks.Count];
for (BasicBlock block = cfg.Blocks.First; block != null; block = block.ListNext)
{
for (Node node = block.Operations.First; node != null; node = node.ListNext)
{
Operation operation = node as Operation;
for (int srcIndex = 0; srcIndex < operation.SourcesCount; srcIndex++)
{
Operand source = operation.GetSource(srcIndex);
if (source.Kind != OperandKind.Register)
{
continue;
}
Register register = source.GetRegister();
localInputs[block.Index] |= GetMask(register) & ~localOutputs[block.Index];
}
if (operation.Destination != null && operation.Destination.Kind == OperandKind.Register)
{
localOutputs[block.Index] |= GetMask(operation.Destination.GetRegister());
}
}
}
// Compute global register inputs and outputs used across blocks.
RegisterMask[] globalCmnOutputs = new RegisterMask[cfg.Blocks.Count];
RegisterMask[] globalInputs = new RegisterMask[cfg.Blocks.Count];
RegisterMask[] globalOutputs = new RegisterMask[cfg.Blocks.Count];
bool modified;
bool firstPass = true;
do
{
modified = false;
// Compute register outputs.
for (int index = cfg.PostOrderBlocks.Length - 1; index >= 0; index--)
{
BasicBlock block = cfg.PostOrderBlocks[index];
if (block.Predecessors.Count != 0 && !HasContextLoad(block))
{
BasicBlock predecessor = block.Predecessors[0];
RegisterMask cmnOutputs = localOutputs[predecessor.Index] | globalCmnOutputs[predecessor.Index];
RegisterMask outputs = globalOutputs[predecessor.Index];
for (int pIndex = 1; pIndex < block.Predecessors.Count; pIndex++)
{
predecessor = block.Predecessors[pIndex];
cmnOutputs &= localOutputs[predecessor.Index] | globalCmnOutputs[predecessor.Index];
outputs |= globalOutputs[predecessor.Index];
}
globalInputs[block.Index] |= outputs & ~cmnOutputs;
if (!firstPass)
{
cmnOutputs &= globalCmnOutputs[block.Index];
}
if (Exchange(globalCmnOutputs, block.Index, cmnOutputs))
{
modified = true;
}
outputs |= localOutputs[block.Index];
if (Exchange(globalOutputs, block.Index, globalOutputs[block.Index] | outputs))
{
modified = true;
}
}
else if (Exchange(globalOutputs, block.Index, localOutputs[block.Index]))
{
modified = true;
}
}
// Compute register inputs.
for (int index = 0; index < cfg.PostOrderBlocks.Length; index++)
{
BasicBlock block = cfg.PostOrderBlocks[index];
RegisterMask inputs = localInputs[block.Index];
for (int i = 0; i < block.SuccessorCount; i++)
{
inputs |= globalInputs[block.GetSuccessor(i).Index];
}
inputs &= ~globalCmnOutputs[block.Index];
if (Exchange(globalInputs, block.Index, globalInputs[block.Index] | inputs))
{
modified = true;
}
}
firstPass = false;
}
while (modified);
// Insert load and store context instructions where needed.
for (BasicBlock block = cfg.Blocks.First; block != null; block = block.ListNext)
{
bool hasContextLoad = HasContextLoad(block);
if (hasContextLoad)
{
block.Operations.Remove(block.Operations.First);
}
// The only block without any predecessor should be the entry block.
// It always needs a context load as it is the first block to run.
if (block.Predecessors.Count == 0 || hasContextLoad)
{
LoadLocals(block, globalInputs[block.Index].VecMask, RegisterType.Vector, mode);
LoadLocals(block, globalInputs[block.Index].IntMask, RegisterType.Integer, mode);
}
bool hasContextStore = HasContextStore(block);
if (hasContextStore)
{
block.Operations.Remove(block.Operations.Last);
}
if (EndsWithReturn(block) || hasContextStore)
{
StoreLocals(block, globalOutputs[block.Index].IntMask, RegisterType.Integer, mode, isCompleteFunction);
StoreLocals(block, globalOutputs[block.Index].VecMask, RegisterType.Vector, mode, isCompleteFunction);
}
}
}
private static bool HasContextLoad(BasicBlock block)
{
return StartsWith(block, Instruction.LoadFromContext) && block.Operations.First.SourcesCount == 0;
}
private static bool HasContextStore(BasicBlock block)
{
return EndsWith(block, Instruction.StoreToContext) && block.GetLastOp().SourcesCount == 0;
}
private static bool StartsWith(BasicBlock block, Instruction inst)
{
if (block.Operations.Count == 0)
{
return false;
}
return block.Operations.First is Operation operation && operation.Instruction == inst;
}
private static bool EndsWith(BasicBlock block, Instruction inst)
{
if (block.Operations.Count == 0)
{
return false;
}
return block.Operations.Last is Operation operation && operation.Instruction == inst;
}
private static RegisterMask GetMask(Register register)
{
long intMask = 0;
long vecMask = 0;
switch (register.Type)
{
case RegisterType.Flag: intMask = (1L << RegsCount) << register.Index; break;
case RegisterType.Integer: intMask = 1L << register.Index; break;
case RegisterType.FpFlag: vecMask = (1L << RegsCount) << register.Index; break;
case RegisterType.Vector: vecMask = 1L << register.Index; break;
}
return new RegisterMask(intMask, vecMask);
}
private static bool Exchange(RegisterMask[] masks, int blkIndex, RegisterMask value)
{
RegisterMask oldValue = masks[blkIndex];
masks[blkIndex] = value;
return oldValue != value;
}
private static void LoadLocals(BasicBlock block, long inputs, RegisterType baseType, ExecutionMode mode)
{
Operand arg0 = Local(OperandType.I64);
for (int bit = 63; bit >= 0; bit--)
{
long mask = 1L << bit;
if ((inputs & mask) == 0)
{
continue;
}
Operand dest = GetRegFromBit(bit, baseType, mode);
long offset = NativeContext.GetRegisterOffset(dest.GetRegister());
Operand addr = Local(OperandType.I64);
Operation loadOp = Operation(Instruction.Load, dest, addr);
block.Operations.AddFirst(loadOp);
Operation calcOffsOp = Operation(Instruction.Add, addr, arg0, Const(offset));
block.Operations.AddFirst(calcOffsOp);
}
Operation loadArg0 = Operation(Instruction.LoadArgument, arg0, Const(0));
block.Operations.AddFirst(loadArg0);
}
private static void StoreLocals(BasicBlock block, long outputs, RegisterType baseType, ExecutionMode mode, bool isCompleteFunction)
{
if (Optimizations.AssumeStrictAbiCompliance && isCompleteFunction)
{
if (baseType == RegisterType.Integer || baseType == RegisterType.Flag)
{
outputs = ClearCallerSavedIntRegs(outputs);
}
else /* if (baseType == RegisterType.Vector || baseType == RegisterType.FpFlag) */
{
outputs = ClearCallerSavedVecRegs(outputs);
}
}
Operand arg0 = Local(OperandType.I64);
Operation loadArg0 = Operation(Instruction.LoadArgument, arg0, Const(0));
block.Append(loadArg0);
for (int bit = 0; bit < 64; bit++)
{
long mask = 1L << bit;
if ((outputs & mask) == 0)
{
continue;
}
Operand source = GetRegFromBit(bit, baseType, mode);
long offset = NativeContext.GetRegisterOffset(source.GetRegister());
Operand addr = Local(OperandType.I64);
Operation calcOffsOp = Operation(Instruction.Add, addr, arg0, Const(offset));
block.Append(calcOffsOp);
Operation storeOp = Operation(Instruction.Store, null, addr, source);
block.Append(storeOp);
}
}
private static Operand GetRegFromBit(int bit, RegisterType baseType, ExecutionMode mode)
{
if (bit < RegsCount)
{
return OperandHelper.Register(bit, baseType, GetOperandType(baseType, mode));
}
else if (baseType == RegisterType.Integer)
{
return OperandHelper.Register(bit & RegsMask, RegisterType.Flag, OperandType.I32);
}
else if (baseType == RegisterType.Vector)
{
return OperandHelper.Register(bit & RegsMask, RegisterType.FpFlag, OperandType.I32);
}
else
{
throw new ArgumentOutOfRangeException(nameof(bit));
}
}
private static OperandType GetOperandType(RegisterType type, ExecutionMode mode)
{
switch (type)
{
case RegisterType.Flag: return OperandType.I32;
case RegisterType.FpFlag: return OperandType.I32;
case RegisterType.Integer: return (mode == ExecutionMode.Aarch64) ? OperandType.I64 : OperandType.I32;
case RegisterType.Vector: return OperandType.V128;
}
throw new ArgumentException($"Invalid register type \"{type}\".");
}
private static bool EndsWithReturn(BasicBlock block)
{
if (!(block.GetLastOp() is Operation operation))
{
return false;
}
return operation.Instruction == Instruction.Return;
}
private static long ClearCallerSavedIntRegs(long mask)
{
// TODO: ARM32 support.
mask &= ~(CallerSavedIntRegistersMask | PStateNzcvFlagsMask);
return mask;
}
private static long ClearCallerSavedVecRegs(long mask)
{
// TODO: ARM32 support.
mask &= ~(CallerSavedVecRegistersMask | FpStateNzcvFlagsMask);
return mask;
}
}
}