Move solution and projects to src

1 files changed, 0 insertions, 1101 deletions

diff --git a/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs b/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs
deleted file mode 100644
index d80157af..00000000
--- a/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs
+++ /dev/null
@@ -1,1101 +0,0 @@
-using ARMeilleure.Common;
-using ARMeilleure.IntermediateRepresentation;
-using ARMeilleure.Translation;
-using System;
-using System.Collections.Generic;
-using System.Diagnostics;
-using System.Linq;
-using System.Numerics;
-
-namespace ARMeilleure.CodeGen.RegisterAllocators
-{
-    // Based on:
-    // "Linear Scan Register Allocation for the Java(tm) HotSpot Client Compiler".
-    // http://www.christianwimmer.at/Publications/Wimmer04a/Wimmer04a.pdf
-    class LinearScanAllocator : IRegisterAllocator
-    {
-        private const int InstructionGap     = 2;
-        private const int InstructionGapMask = InstructionGap - 1;
-
-        private HashSet<int> _blockEdges;
-        private LiveRange[] _blockRanges;
-        private BitMap[] _blockLiveIn;
-
-        private List<LiveInterval> _intervals;
-        private LiveInterval[] _parentIntervals;
-
-        private List<(IntrusiveList<Operation>, Operation)> _operationNodes;
-        private int _operationsCount;
-
-        private class AllocationContext
-        {
-            public RegisterMasks Masks { get; }
-
-            public StackAllocator StackAlloc { get; }
-
-            public BitMap Active   { get; }
-            public BitMap Inactive { get; }
-
-            public int IntUsedRegisters { get; set; }
-            public int VecUsedRegisters { get; set; }
-
-            private readonly int[] _intFreePositions;
-            private readonly int[] _vecFreePositions;
-            private readonly int _intFreePositionsCount;
-            private readonly int _vecFreePositionsCount;
-
-            public AllocationContext(StackAllocator stackAlloc, RegisterMasks masks, int intervalsCount)
-            {
-                StackAlloc = stackAlloc;
-                Masks      = masks;
-
-                Active   = new BitMap(Allocators.Default, intervalsCount);
-                Inactive = new BitMap(Allocators.Default, intervalsCount);
-
-                PopulateFreePositions(RegisterType.Integer, out _intFreePositions, out _intFreePositionsCount);
-                PopulateFreePositions(RegisterType.Vector, out _vecFreePositions, out _vecFreePositionsCount);
-
-                void PopulateFreePositions(RegisterType type, out int[] positions, out int count)
-                {
-                    positions = new int[masks.RegistersCount];
-                    count = BitOperations.PopCount((uint)masks.GetAvailableRegisters(type));
-
-                    int mask = masks.GetAvailableRegisters(type);
-
-                    for (int i = 0; i < positions.Length; i++)
-                    {
-                        if ((mask & (1 << i)) != 0)
-                        {
-                            positions[i] = int.MaxValue;
-                        }
-                    }
-                }
-            }
-
-            public void GetFreePositions(RegisterType type, in Span<int> positions, out int count)
-            {
-                if (type == RegisterType.Integer)
-                {
-                    _intFreePositions.CopyTo(positions);
-
-                    count = _intFreePositionsCount;
-                }
-                else
-                {
-                    Debug.Assert(type == RegisterType.Vector);
-
-                    _vecFreePositions.CopyTo(positions);
-
-                    count = _vecFreePositionsCount;
-                }
-            }
-
-            public void MoveActiveToInactive(int bit)
-            {
-                Move(Active, Inactive, bit);
-            }
-
-            public void MoveInactiveToActive(int bit)
-            {
-                Move(Inactive, Active, bit);
-            }
-
-            private static void Move(BitMap source, BitMap dest, int bit)
-            {
-                source.Clear(bit);
-
-                dest.Set(bit);
-            }
-        }
-
-        public AllocationResult RunPass(
-            ControlFlowGraph cfg,
-            StackAllocator stackAlloc,
-            RegisterMasks regMasks)
-        {
-            NumberLocals(cfg, regMasks.RegistersCount);
-
-            var context = new AllocationContext(stackAlloc, regMasks, _intervals.Count);
-
-            BuildIntervals(cfg, context);
-
-            for (int index = 0; index < _intervals.Count; index++)
-            {
-                LiveInterval current = _intervals[index];
-
-                if (current.IsEmpty)
-                {
-                    continue;
-                }
-
-                if (current.IsFixed)
-                {
-                    context.Active.Set(index);
-
-                    if (current.IsFixedAndUsed)
-                    {
-                        if (current.Register.Type == RegisterType.Integer)
-                        {
-                            context.IntUsedRegisters |= 1 << current.Register.Index;
-                        }
-                        else /* if (interval.Register.Type == RegisterType.Vector) */
-                        {
-                            context.VecUsedRegisters |= 1 << current.Register.Index;
-                        }
-                    }
-
-                    continue;
-                }
-
-                AllocateInterval(context, current, index, regMasks.RegistersCount);
-            }
-
-            for (int index = regMasks.RegistersCount * 2; index < _intervals.Count; index++)
-            {
-                if (!_intervals[index].IsSpilled)
-                {
-                    ReplaceLocalWithRegister(_intervals[index]);
-                }
-            }
-
-            InsertSplitCopies();
-            InsertSplitCopiesAtEdges(cfg);
-
-            return new AllocationResult(context.IntUsedRegisters, context.VecUsedRegisters, context.StackAlloc.TotalSize);
-        }
-
-        private void AllocateInterval(AllocationContext context, LiveInterval current, int cIndex, int registersCount)
-        {
-            // Check active intervals that already ended.
-            foreach (int iIndex in context.Active)
-            {
-                LiveInterval interval = _intervals[iIndex];
-
-                interval.Forward(current.GetStart());
-
-                if (interval.GetEnd() < current.GetStart())
-                {
-                    context.Active.Clear(iIndex);
-                }
-                else if (!interval.Overlaps(current.GetStart()))
-                {
-                    context.MoveActiveToInactive(iIndex);
-                }
-            }
-
-            // Check inactive intervals that already ended or were reactivated.
-            foreach (int iIndex in context.Inactive)
-            {
-                LiveInterval interval = _intervals[iIndex];
-
-                interval.Forward(current.GetStart());
-
-                if (interval.GetEnd() < current.GetStart())
-                {
-                    context.Inactive.Clear(iIndex);
-                }
-                else if (interval.Overlaps(current.GetStart()))
-                {
-                    context.MoveInactiveToActive(iIndex);
-                }
-            }
-
-            if (!TryAllocateRegWithoutSpill(context, current, cIndex, registersCount))
-            {
-                AllocateRegWithSpill(context, current, cIndex, registersCount);
-            }
-        }
-
-        private bool TryAllocateRegWithoutSpill(AllocationContext context, LiveInterval current, int cIndex, int registersCount)
-        {
-            RegisterType regType = current.Local.Type.ToRegisterType();
-
-            Span<int> freePositions = stackalloc int[registersCount];
-
-            context.GetFreePositions(regType, freePositions, out int freePositionsCount);
-
-            foreach (int iIndex in context.Active)
-            {
-                LiveInterval interval = _intervals[iIndex];
-                Register reg = interval.Register;
-
-                if (reg.Type == regType)
-                {
-                    freePositions[reg.Index] = 0;
-                    freePositionsCount--;
-                }
-            }
-
-            // If all registers are already active, return early. No point in inspecting the inactive set to look for
-            // holes.
-            if (freePositionsCount == 0)
-            {
-                return false;
-            }
-
-            foreach (int iIndex in context.Inactive)
-            {
-                LiveInterval interval = _intervals[iIndex];
-                Register reg = interval.Register;
-
-                ref int freePosition = ref freePositions[reg.Index];
-
-                if (reg.Type == regType && freePosition != 0)
-                {
-                    int overlapPosition = interval.GetOverlapPosition(current);
-
-                    if (overlapPosition != LiveInterval.NotFound && freePosition > overlapPosition)
-                    {
-                        freePosition = overlapPosition;
-                    }
-                }
-            }
-
-            int selectedReg = GetHighestValueIndex(freePositions);
-            int selectedNextUse = freePositions[selectedReg];
-
-            // Intervals starts and ends at odd positions, unless they span an entire
-            // block, in this case they will have ranges at a even position.
-            // When a interval is loaded from the stack to a register, we can only
-            // do the split at a odd position, because otherwise the split interval
-            // that is inserted on the list to be processed may clobber a register
-            // used by the instruction at the same position as the split.
-            // The problem only happens when a interval ends exactly at this instruction,
-            // because otherwise they would interfere, and the register wouldn't be selected.
-            // When the interval is aligned and the above happens, there's no problem as
-            // the instruction that is actually with the last use is the one
-            // before that position.
-            selectedNextUse &= ~InstructionGapMask;
-
-            if (selectedNextUse <= current.GetStart())
-            {
-                return false;
-            }
-            else if (selectedNextUse < current.GetEnd())
-            {
-                LiveInterval splitChild = current.Split(selectedNextUse);
-
-                if (splitChild.UsesCount != 0)
-                {
-                    Debug.Assert(splitChild.GetStart() > current.GetStart(), "Split interval has an invalid start position.");
-
-                    InsertInterval(splitChild, registersCount);
-                }
-                else
-                {
-                    Spill(context, splitChild);
-                }
-            }
-
-            current.Register = new Register(selectedReg, regType);
-
-            if (regType == RegisterType.Integer)
-            {
-                context.IntUsedRegisters |= 1 << selectedReg;
-            }
-            else /* if (regType == RegisterType.Vector) */
-            {
-                context.VecUsedRegisters |= 1 << selectedReg;
-            }
-
-            context.Active.Set(cIndex);
-
-            return true;
-        }
-
-        private void AllocateRegWithSpill(AllocationContext context, LiveInterval current, int cIndex, int registersCount)
-        {
-            RegisterType regType = current.Local.Type.ToRegisterType();
-
-            Span<int> usePositions = stackalloc int[registersCount];
-            Span<int> blockedPositions = stackalloc int[registersCount];
-
-            context.GetFreePositions(regType, usePositions, out _);
-            context.GetFreePositions(regType, blockedPositions, out _);
-
-            foreach (int iIndex in context.Active)
-            {
-                LiveInterval interval = _intervals[iIndex];
-                Register reg = interval.Register;
-
-                if (reg.Type == regType)
-                {
-                    ref int usePosition = ref usePositions[reg.Index];
-                    ref int blockedPosition = ref blockedPositions[reg.Index];
-
-                    if (interval.IsFixed)
-                    {
-                        usePosition = 0;
-                        blockedPosition = 0;
-                    }
-                    else
-                    {
-                        int nextUse = interval.NextUseAfter(current.GetStart());
-
-                        if (nextUse != LiveInterval.NotFound && usePosition > nextUse)
-                        {
-                            usePosition = nextUse;
-                        }
-                    }
-                }
-            }
-
-            foreach (int iIndex in context.Inactive)
-            {
-                LiveInterval interval = _intervals[iIndex];
-                Register reg = interval.Register;
-
-                if (reg.Type == regType)
-                {
-                    ref int usePosition = ref usePositions[reg.Index];
-                    ref int blockedPosition = ref blockedPositions[reg.Index];
-
-                    if (interval.IsFixed)
-                    {
-                        int overlapPosition = interval.GetOverlapPosition(current);
-
-                        if (overlapPosition != LiveInterval.NotFound)
-                        {
-                            blockedPosition = Math.Min(blockedPosition, overlapPosition);
-                            usePosition = Math.Min(usePosition, overlapPosition);
-                        }
-                    }
-                    else if (interval.Overlaps(current))
-                    {
-                        int nextUse = interval.NextUseAfter(current.GetStart());
-
-                        if (nextUse != LiveInterval.NotFound && usePosition > nextUse)
-                        {
-                            usePosition = nextUse;
-                        }
-                    }
-                }
-            }
-
-            int selectedReg = GetHighestValueIndex(usePositions);
-            int currentFirstUse = current.FirstUse();
-
-            Debug.Assert(currentFirstUse >= 0, "Current interval has no uses.");
-
-            if (usePositions[selectedReg] < currentFirstUse)
-            {
-                // All intervals on inactive and active are being used before current,
-                // so spill the current interval.
-                Debug.Assert(currentFirstUse > current.GetStart(), "Trying to spill a interval currently being used.");
-
-                LiveInterval splitChild = current.Split(currentFirstUse);
-
-                Debug.Assert(splitChild.GetStart() > current.GetStart(), "Split interval has an invalid start position.");
-
-                InsertInterval(splitChild, registersCount);
-
-                Spill(context, current);
-            }
-            else if (blockedPositions[selectedReg] > current.GetEnd())
-            {
-                // Spill made the register available for the entire current lifetime,
-                // so we only need to split the intervals using the selected register.
-                current.Register = new Register(selectedReg, regType);
-
-                SplitAndSpillOverlappingIntervals(context, current, registersCount);
-
-                context.Active.Set(cIndex);
-            }
-            else
-            {
-                // There are conflicts even after spill due to the use of fixed registers
-                // that can't be spilled, so we need to also split current at the point of
-                // the first fixed register use.
-                current.Register = new Register(selectedReg, regType);
-
-                int splitPosition = blockedPositions[selectedReg] & ~InstructionGapMask;
-
-                Debug.Assert(splitPosition > current.GetStart(), "Trying to split a interval at a invalid position.");
-
-                LiveInterval splitChild = current.Split(splitPosition);
-
-                if (splitChild.UsesCount != 0)
-                {
-                    Debug.Assert(splitChild.GetStart() > current.GetStart(), "Split interval has an invalid start position.");
-
-                    InsertInterval(splitChild, registersCount);
-                }
-                else
-                {
-                    Spill(context, splitChild);
-                }
-
-                SplitAndSpillOverlappingIntervals(context, current, registersCount);
-
-                context.Active.Set(cIndex);
-            }
-        }
-
-        private static int GetHighestValueIndex(Span<int> span)
-        {
-            int highest = int.MinValue;
-
-            int selected = 0;
-
-            for (int index = 0; index < span.Length; index++)
-            {
-                int current = span[index];
-
-                if (highest < current)
-                {
-                    highest  = current;
-                    selected = index;
-
-                    if (current == int.MaxValue)
-                    {
-                        break;
-                    }
-                }
-            }
-
-            return selected;
-        }
-
-        private void SplitAndSpillOverlappingIntervals(AllocationContext context, LiveInterval current, int registersCount)
-        {
-            foreach (int iIndex in context.Active)
-            {
-                LiveInterval interval = _intervals[iIndex];
-
-                if (!interval.IsFixed && interval.Register == current.Register)
-                {
-                    SplitAndSpillOverlappingInterval(context, current, interval, registersCount);
-
-                    context.Active.Clear(iIndex);
-                }
-            }
-
-            foreach (int iIndex in context.Inactive)
-            {
-                LiveInterval interval = _intervals[iIndex];
-
-                if (!interval.IsFixed && interval.Register == current.Register && interval.Overlaps(current))
-                {
-                    SplitAndSpillOverlappingInterval(context, current, interval, registersCount);
-
-                    context.Inactive.Clear(iIndex);
-                }
-            }
-        }
-
-        private void SplitAndSpillOverlappingInterval(
-            AllocationContext context,
-            LiveInterval      current,
-            LiveInterval      interval,
-            int               registersCount)
-        {
-            // If there's a next use after the start of the current interval,
-            // we need to split the spilled interval twice, and re-insert it
-            // on the "pending" list to ensure that it will get a new register
-            // on that use position.
-            int nextUse = interval.NextUseAfter(current.GetStart());
-
-            LiveInterval splitChild;
-
-            if (interval.GetStart() < current.GetStart())
-            {
-                splitChild = interval.Split(current.GetStart());
-            }
-            else
-            {
-                splitChild = interval;
-            }
-
-            if (nextUse != -1)
-            {
-                Debug.Assert(nextUse > current.GetStart(), "Trying to spill a interval currently being used.");
-
-                if (nextUse > splitChild.GetStart())
-                {
-                    LiveInterval right = splitChild.Split(nextUse);
-
-                    Spill(context, splitChild);
-
-                    splitChild = right;
-                }
-
-                InsertInterval(splitChild, registersCount);
-            }
-            else
-            {
-                Spill(context, splitChild);
-            }
-        }
-
-        private void InsertInterval(LiveInterval interval, int registersCount)
-        {
-            Debug.Assert(interval.UsesCount != 0, "Trying to insert a interval without uses.");
-            Debug.Assert(!interval.IsEmpty,       "Trying to insert a empty interval.");
-            Debug.Assert(!interval.IsSpilled,     "Trying to insert a spilled interval.");
-
-            int startIndex = registersCount * 2;
-
-            int insertIndex = _intervals.BinarySearch(startIndex, _intervals.Count - startIndex, interval, null);
-
-            if (insertIndex < 0)
-            {
-                insertIndex = ~insertIndex;
-            }
-
-            _intervals.Insert(insertIndex, interval);
-        }
-
-        private void Spill(AllocationContext context, LiveInterval interval)
-        {
-            Debug.Assert(!interval.IsFixed,       "Trying to spill a fixed interval.");
-            Debug.Assert(interval.UsesCount == 0, "Trying to spill a interval with uses.");
-
-            // We first check if any of the siblings were spilled, if so we can reuse
-            // the stack offset. Otherwise, we allocate a new space on the stack.
-            // This prevents stack-to-stack copies being necessary for a split interval.
-            if (!interval.TrySpillWithSiblingOffset())
-            {
-                interval.Spill(context.StackAlloc.Allocate(interval.Local.Type));
-            }
-        }
-
-        private void InsertSplitCopies()
-        {
-            Dictionary<int, CopyResolver> copyResolvers = new Dictionary<int, CopyResolver>();
-
-            CopyResolver GetCopyResolver(int position)
-            {
-                if (!copyResolvers.TryGetValue(position, out CopyResolver copyResolver))
-                {
-                    copyResolver = new CopyResolver();
-
-                    copyResolvers.Add(position, copyResolver);
-                }
-
-                return copyResolver;
-            }
-
-            foreach (LiveInterval interval in _intervals.Where(x => x.IsSplit))
-            {
-                LiveInterval previous = interval;
-
-                foreach (LiveInterval splitChild in interval.SplitChildren())
-                {
-                    int splitPosition = splitChild.GetStart();
-
-                    if (!_blockEdges.Contains(splitPosition) && previous.GetEnd() == splitPosition)
-                    {
-                        GetCopyResolver(splitPosition).AddSplit(previous, splitChild);
-                    }
-
-                    previous = splitChild;
-                }
-            }
-
-            foreach (KeyValuePair<int, CopyResolver> kv in copyResolvers)
-            {
-                CopyResolver copyResolver = kv.Value;
-
-                if (!copyResolver.HasCopy)
-                {
-                    continue;
-                }
-
-                int splitPosition = kv.Key;
-
-                (IntrusiveList<Operation> nodes, Operation node) = GetOperationNode(splitPosition);
-
-                Operation[] sequence = copyResolver.Sequence();
-
-                nodes.AddBefore(node, sequence[0]);
-
-                node = sequence[0];
-
-                for (int index = 1; index < sequence.Length; index++)
-                {
-                    nodes.AddAfter(node, sequence[index]);
-
-                    node = sequence[index];
-                }
-            }
-        }
-
-        private void InsertSplitCopiesAtEdges(ControlFlowGraph cfg)
-        {
-            int blocksCount = cfg.Blocks.Count;
-
-            bool IsSplitEdgeBlock(BasicBlock block)
-            {
-                return block.Index >= blocksCount;
-            }
-
-            // Reset iterators to beginning because GetSplitChild depends on the state of the iterator.
-            foreach (LiveInterval interval in _intervals)
-            {
-                interval.Reset();
-            }
-
-            for (BasicBlock block = cfg.Blocks.First; block != null; block = block.ListNext)
-            {
-                if (IsSplitEdgeBlock(block))
-                {
-                    continue;
-                }
-
-                bool hasSingleOrNoSuccessor = block.SuccessorsCount <= 1;
-
-                for (int i = 0; i < block.SuccessorsCount; i++)
-                {
-                    BasicBlock successor = block.GetSuccessor(i);
-
-                    int succIndex = successor.Index;
-
-                    // If the current node is a split node, then the actual successor node
-                    // (the successor before the split) should be right after it.
-                    if (IsSplitEdgeBlock(successor))
-                    {
-                        succIndex = successor.GetSuccessor(0).Index;
-                    }
-
-                    CopyResolver copyResolver = null;
-
-                    foreach (int iIndex in _blockLiveIn[succIndex])
-                    {
-                        LiveInterval interval = _parentIntervals[iIndex];
-
-                        if (!interval.IsSplit)
-                        {
-                            continue;
-                        }
-
-                        int lEnd   = _blockRanges[block.Index].End - 1;
-                        int rStart = _blockRanges[succIndex].Start;
-
-                        LiveInterval left  = interval.GetSplitChild(lEnd);
-                        LiveInterval right = interval.GetSplitChild(rStart);
-
-                        if (left != default && right != default && left != right)
-                        {
-                            if (copyResolver == null)
-                            {
-                                copyResolver = new CopyResolver();
-                            }
-
-                            copyResolver.AddSplit(left, right);
-                        }
-                    }
-
-                    if (copyResolver == null || !copyResolver.HasCopy)
-                    {
-                        continue;
-                    }
-
-                    Operation[] sequence = copyResolver.Sequence();
-
-                    if (hasSingleOrNoSuccessor)
-                    {
-                        foreach (Operation operation in sequence)
-                        {
-                            block.Append(operation);
-                        }
-                    }
-                    else if (successor.Predecessors.Count == 1)
-                    {
-                        successor.Operations.AddFirst(sequence[0]);
-
-                        Operation prependNode = sequence[0];
-
-                        for (int index = 1; index < sequence.Length; index++)
-                        {
-                            Operation operation = sequence[index];
-
-                            successor.Operations.AddAfter(prependNode, operation);
-
-                            prependNode = operation;
-                        }
-                    }
-                    else
-                    {
-                        // Split the critical edge.
-                        BasicBlock splitBlock = cfg.SplitEdge(block, successor);
-
-                        foreach (Operation operation in sequence)
-                        {
-                            splitBlock.Append(operation);
-                        }
-                    }
-                }
-            }
-        }
-
-        private void ReplaceLocalWithRegister(LiveInterval current)
-        {
-            Operand register = GetRegister(current);
-
-            foreach (int usePosition in current.UsePositions())
-            {
-                (_, Operation operation) = GetOperationNode(usePosition);
-
-                for (int index = 0; index < operation.SourcesCount; index++)
-                {
-                    Operand source = operation.GetSource(index);
-
-                    if (source == current.Local)
-                    {
-                        operation.SetSource(index, register);
-                    }
-                    else if (source.Kind == OperandKind.Memory)
-                    {
-                        MemoryOperand memOp = source.GetMemory();
-
-                        if (memOp.BaseAddress == current.Local)
-                        {
-                            memOp.BaseAddress = register;
-                        }
-
-                        if (memOp.Index == current.Local)
-                        {
-                            memOp.Index = register;
-                        }
-                    }
-                }
-
-                for (int index = 0; index < operation.DestinationsCount; index++)
-                {
-                    Operand dest = operation.GetDestination(index);
-
-                    if (dest == current.Local)
-                    {
-                        operation.SetDestination(index, register);
-                    }
-                }
-            }
-        }
-
-        private static Operand GetRegister(LiveInterval interval)
-        {
-            Debug.Assert(!interval.IsSpilled, "Spilled intervals are not allowed.");
-
-            return Operand.Factory.Register(
-                interval.Register.Index,
-                interval.Register.Type,
-                interval.Local.Type);
-        }
-
-        private (IntrusiveList<Operation>, Operation) GetOperationNode(int position)
-        {
-            return _operationNodes[position / InstructionGap];
-        }
-
-        private void NumberLocals(ControlFlowGraph cfg, int registersCount)
-        {
-            _operationNodes = new List<(IntrusiveList<Operation>, Operation)>();
-            _intervals = new List<LiveInterval>();
-
-            for (int index = 0; index < registersCount; index++)
-            {
-                _intervals.Add(new LiveInterval(new Register(index, RegisterType.Integer)));
-                _intervals.Add(new LiveInterval(new Register(index, RegisterType.Vector)));
-            }
-
-            // The "visited" state is stored in the MSB of the local's value.
-            const ulong VisitedMask = 1ul << 63;
-
-            bool IsVisited(Operand local)
-            {
-                return (local.GetValueUnsafe() & VisitedMask) != 0;
-            }
-
-            void SetVisited(Operand local)
-            {
-                local.GetValueUnsafe() |= VisitedMask;
-            }
-
-            _operationsCount = 0;
-
-            for (int index = cfg.PostOrderBlocks.Length - 1; index >= 0; index--)
-            {
-                BasicBlock block = cfg.PostOrderBlocks[index];
-
-                for (Operation node = block.Operations.First; node != default; node = node.ListNext)
-                {
-                    _operationNodes.Add((block.Operations, node));
-
-                    for (int i = 0; i < node.DestinationsCount; i++)
-                    {
-                        Operand dest = node.GetDestination(i);
-
-                        if (dest.Kind == OperandKind.LocalVariable && !IsVisited(dest))
-                        {
-                            dest.NumberLocal(_intervals.Count);
-
-                            _intervals.Add(new LiveInterval(dest));
-
-                            SetVisited(dest);
-                        }
-                    }
-                }
-
-                _operationsCount += block.Operations.Count * InstructionGap;
-
-                if (block.Operations.Count == 0)
-                {
-                    // Pretend we have a dummy instruction on the empty block.
-                    _operationNodes.Add((default, default));
-
-                    _operationsCount += InstructionGap;
-                }
-            }
-
-            _parentIntervals = _intervals.ToArray();
-        }
-
-        private void BuildIntervals(ControlFlowGraph cfg, AllocationContext context)
-        {
-            _blockRanges = new LiveRange[cfg.Blocks.Count];
-
-            int mapSize = _intervals.Count;
-
-            BitMap[] blkLiveGen  = new BitMap[cfg.Blocks.Count];
-            BitMap[] blkLiveKill = new BitMap[cfg.Blocks.Count];
-
-            // Compute local live sets.
-            for (BasicBlock block = cfg.Blocks.First; block != null; block = block.ListNext)
-            {
-                BitMap liveGen  = new BitMap(Allocators.Default, mapSize);
-                BitMap liveKill = new BitMap(Allocators.Default, mapSize);
-
-                for (Operation node = block.Operations.First; node != default; node = node.ListNext)
-                {
-                    for (int i = 0; i < node.SourcesCount; i++)
-                    {
-                        VisitSource(node.GetSource(i));
-                    }
-
-                    for (int i = 0; i < node.DestinationsCount; i++)
-                    {
-                        VisitDestination(node.GetDestination(i));
-                    }
-
-                    void VisitSource(Operand source)
-                    {
-                        if (IsLocalOrRegister(source.Kind))
-                        {
-                            int id = GetOperandId(source);
-
-                            if (!liveKill.IsSet(id))
-                            {
-                                liveGen.Set(id);
-                            }
-                        }
-                        else if (source.Kind == OperandKind.Memory)
-                        {
-                            MemoryOperand memOp = source.GetMemory();
-
-                            if (memOp.BaseAddress != default)
-                            {
-                                VisitSource(memOp.BaseAddress);
-                            }
-
-                            if (memOp.Index != default)
-                            {
-                                VisitSource(memOp.Index);
-                            }
-                        }
-                    }
-
-                    void VisitDestination(Operand dest)
-                    {
-                        liveKill.Set(GetOperandId(dest));
-                    }
-                }
-
-                blkLiveGen [block.Index] = liveGen;
-                blkLiveKill[block.Index] = liveKill;
-            }
-
-            // Compute global live sets.
-            BitMap[] blkLiveIn  = new BitMap[cfg.Blocks.Count];
-            BitMap[] blkLiveOut = new BitMap[cfg.Blocks.Count];
-
-            for (int index = 0; index < cfg.Blocks.Count; index++)
-            {
-                blkLiveIn [index] = new BitMap(Allocators.Default, mapSize);
-                blkLiveOut[index] = new BitMap(Allocators.Default, mapSize);
-            }
-
-            bool modified;
-
-            do
-            {
-                modified = false;
-
-                for (int index = 0; index < cfg.PostOrderBlocks.Length; index++)
-                {
-                    BasicBlock block = cfg.PostOrderBlocks[index];
-
-                    BitMap liveOut = blkLiveOut[block.Index];
-
-                    for (int i = 0; i < block.SuccessorsCount; i++)
-                    {
-                        BasicBlock succ = block.GetSuccessor(i);
-
-                        modified |= liveOut.Set(blkLiveIn[succ.Index]);
-                    }
-
-                    BitMap liveIn = blkLiveIn[block.Index];
-
-                    liveIn.Set  (liveOut);
-                    liveIn.Clear(blkLiveKill[block.Index]);
-                    liveIn.Set  (blkLiveGen [block.Index]);
-                }
-            }
-            while (modified);
-
-            _blockLiveIn = blkLiveIn;
-
-            _blockEdges = new HashSet<int>();
-
-            // Compute lifetime intervals.
-            int operationPos = _operationsCount;
-
-            for (int index = 0; index < cfg.PostOrderBlocks.Length; index++)
-            {
-                BasicBlock block = cfg.PostOrderBlocks[index];
-
-                // We handle empty blocks by pretending they have a dummy instruction,
-                // because otherwise the block would have the same start and end position,
-                // and this is not valid.
-                int instCount = Math.Max(block.Operations.Count, 1);
-
-                int blockStart = operationPos - instCount * InstructionGap;
-                int blockEnd   = operationPos;
-
-                _blockRanges[block.Index] = new LiveRange(blockStart, blockEnd);
-
-                _blockEdges.Add(blockStart);
-
-                BitMap liveOut = blkLiveOut[block.Index];
-
-                foreach (int id in liveOut)
-                {
-                    _intervals[id].AddRange(blockStart, blockEnd);
-                }
-
-                if (block.Operations.Count == 0)
-                {
-                    operationPos -= InstructionGap;
-
-                    continue;
-                }
-
-                for (Operation node = block.Operations.Last; node != default; node = node.ListPrevious)
-                {
-                    operationPos -= InstructionGap;
-
-                    for (int i = 0; i < node.DestinationsCount; i++)
-                    {
-                        VisitDestination(node.GetDestination(i));
-                    }
-
-                    for (int i = 0; i < node.SourcesCount; i++)
-                    {
-                        VisitSource(node.GetSource(i));
-                    }
-
-                    if (node.Instruction == Instruction.Call)
-                    {
-                        AddIntervalCallerSavedReg(context.Masks.IntCallerSavedRegisters, operationPos, RegisterType.Integer);
-                        AddIntervalCallerSavedReg(context.Masks.VecCallerSavedRegisters, operationPos, RegisterType.Vector);
-                    }
-
-                    void VisitSource(Operand source)
-                    {
-                        if (IsLocalOrRegister(source.Kind))
-                        {
-                            LiveInterval interval = _intervals[GetOperandId(source)];
-
-                            interval.AddRange(blockStart, operationPos + 1);
-                            interval.AddUsePosition(operationPos);
-                        }
-                        else if (source.Kind == OperandKind.Memory)
-                        {
-                            MemoryOperand memOp = source.GetMemory();
-
-                            if (memOp.BaseAddress != default)
-                            {
-                                VisitSource(memOp.BaseAddress);
-                            }
-
-                            if (memOp.Index != default)
-                            {
-                                VisitSource(memOp.Index);
-                            }
-                        }
-                    }
-
-                    void VisitDestination(Operand dest)
-                    {
-                        LiveInterval interval = _intervals[GetOperandId(dest)];
-
-                        if (interval.IsFixed)
-                        {
-                            interval.IsFixedAndUsed = true;
-                        }
-
-                        interval.SetStart(operationPos + 1);
-                        interval.AddUsePosition(operationPos + 1);
-                    }
-                }
-            }
-
-            foreach (LiveInterval interval in _parentIntervals)
-            {
-                interval.Reset();
-            }
-        }
-
-        private void AddIntervalCallerSavedReg(int mask, int operationPos, RegisterType regType)
-        {
-            while (mask != 0)
-            {
-                int regIndex = BitOperations.TrailingZeroCount(mask);
-
-                Register callerSavedReg = new Register(regIndex, regType);
-
-                LiveInterval interval = _intervals[GetRegisterId(callerSavedReg)];
-
-                interval.AddRange(operationPos + 1, operationPos + InstructionGap);
-
-                mask &= ~(1 << regIndex);
-            }
-        }
-
-        private static int GetOperandId(Operand operand)
-        {
-            if (operand.Kind == OperandKind.LocalVariable)
-            {
-                return operand.GetLocalNumber();
-            }
-            else if (operand.Kind == OperandKind.Register)
-            {
-                return GetRegisterId(operand.GetRegister());
-            }
-            else
-            {
-                throw new ArgumentException($"Invalid operand kind \"{operand.Kind}\".");
-            }
-        }
-
-        private static int GetRegisterId(Register register)
-        {
-            return (register.Index << 1) | (register.Type == RegisterType.Vector ? 1 : 0);
-        }
-
-        private static bool IsLocalOrRegister(OperandKind kind)
-        {
-            return kind == OperandKind.LocalVariable ||
-                   kind == OperandKind.Register;
-        }
-    }
-}
\ No newline at end of file