diff options
| author | gdkchan <gab.dark.100@gmail.com> | 2024-06-19 09:39:29 -0300 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-06-19 09:39:29 -0300 |
| commit | 0afa8f2c14f046b46ac5ba14c96f3a5ce523ba16 (patch) | |
| tree | 406a8cde8e662d045f4a0dbfc1d37876a623fa9e | |
| parent | d25a084858438dd1188113efb76548916c2da9de (diff) | |
JIT: Coalesce copies on LSRA with simple register preferencing (#6950)1.1.1336
* JIT: Coalesce copies on LSRA with simple register preferencing
* PPTC version bump
| -rw-r--r-- | src/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs | 39 | ||||
| -rw-r--r-- | src/ARMeilleure/CodeGen/RegisterAllocators/LiveInterval.cs | 21 | ||||
| -rw-r--r-- | src/ARMeilleure/Translation/PTC/Ptc.cs | 2 |
3 files changed, 56 insertions, 6 deletions
diff --git a/src/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs b/src/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs index f156e088..16feeb91 100644 --- a/src/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs +++ b/src/ARMeilleure/CodeGen/RegisterAllocators/LinearScanAllocator.cs @@ -251,7 +251,20 @@ namespace ARMeilleure.CodeGen.RegisterAllocators } } - int selectedReg = GetHighestValueIndex(freePositions); + // If this is a copy destination variable, we prefer the register used for the copy source. + // If the register is available, then the copy can be eliminated later as both source + // and destination will use the same register. + int selectedReg; + + if (current.TryGetCopySourceRegister(out int preferredReg) && freePositions[preferredReg] >= current.GetEnd()) + { + selectedReg = preferredReg; + } + else + { + selectedReg = GetHighestValueIndex(freePositions); + } + int selectedNextUse = freePositions[selectedReg]; // Intervals starts and ends at odd positions, unless they span an entire @@ -431,7 +444,7 @@ namespace ARMeilleure.CodeGen.RegisterAllocators } } - private static int GetHighestValueIndex(Span<int> span) + private static int GetHighestValueIndex(ReadOnlySpan<int> span) { int highest = int.MinValue; @@ -798,12 +811,12 @@ namespace ARMeilleure.CodeGen.RegisterAllocators // The "visited" state is stored in the MSB of the local's value. const ulong VisitedMask = 1ul << 63; - bool IsVisited(Operand local) + static bool IsVisited(Operand local) { return (local.GetValueUnsafe() & VisitedMask) != 0; } - void SetVisited(Operand local) + static void SetVisited(Operand local) { local.GetValueUnsafe() |= VisitedMask; } @@ -826,9 +839,25 @@ namespace ARMeilleure.CodeGen.RegisterAllocators { dest.NumberLocal(_intervals.Count); - _intervals.Add(new LiveInterval(dest)); + LiveInterval interval = new LiveInterval(dest); + _intervals.Add(interval); SetVisited(dest); + + // If this is a copy (or copy-like operation), set the copy source interval as well. + // This is used for register preferencing later on, which allows the copy to be eliminated + // in some cases. + if (node.Instruction == Instruction.Copy || node.Instruction == Instruction.ZeroExtend32) + { + Operand source = node.GetSource(0); + + if (source.Kind == OperandKind.LocalVariable && + source.GetLocalNumber() > 0 && + (node.Instruction == Instruction.Copy || source.Type == OperandType.I32)) + { + interval.SetCopySource(_intervals[source.GetLocalNumber()]); + } + } } } } diff --git a/src/ARMeilleure/CodeGen/RegisterAllocators/LiveInterval.cs b/src/ARMeilleure/CodeGen/RegisterAllocators/LiveInterval.cs index 333d3951..cfe1bc7c 100644 --- a/src/ARMeilleure/CodeGen/RegisterAllocators/LiveInterval.cs +++ b/src/ARMeilleure/CodeGen/RegisterAllocators/LiveInterval.cs @@ -19,6 +19,7 @@ namespace ARMeilleure.CodeGen.RegisterAllocators public LiveRange CurrRange; public LiveInterval Parent; + public LiveInterval CopySource; public UseList Uses; public LiveIntervalList Children; @@ -37,6 +38,7 @@ namespace ARMeilleure.CodeGen.RegisterAllocators private ref LiveRange CurrRange => ref _data->CurrRange; private ref LiveRange PrevRange => ref _data->PrevRange; private ref LiveInterval Parent => ref _data->Parent; + private ref LiveInterval CopySource => ref _data->CopySource; private ref UseList Uses => ref _data->Uses; private ref LiveIntervalList Children => ref _data->Children; @@ -78,6 +80,25 @@ namespace ARMeilleure.CodeGen.RegisterAllocators Register = register; } + public void SetCopySource(LiveInterval copySource) + { + CopySource = copySource; + } + + public bool TryGetCopySourceRegister(out int copySourceRegIndex) + { + if (CopySource._data != null) + { + copySourceRegIndex = CopySource.Register.Index; + + return true; + } + + copySourceRegIndex = 0; + + return false; + } + public void Reset() { PrevRange = default; diff --git a/src/ARMeilleure/Translation/PTC/Ptc.cs b/src/ARMeilleure/Translation/PTC/Ptc.cs index f56bdce1..c2eed7a5 100644 --- a/src/ARMeilleure/Translation/PTC/Ptc.cs +++ b/src/ARMeilleure/Translation/PTC/Ptc.cs @@ -29,7 +29,7 @@ namespace ARMeilleure.Translation.PTC private const string OuterHeaderMagicString = "PTCohd\0\0"; private const string InnerHeaderMagicString = "PTCihd\0\0"; - private const uint InternalVersion = 6634; //! To be incremented manually for each change to the ARMeilleure project. + private const uint InternalVersion = 6950; //! To be incremented manually for each change to the ARMeilleure project. private const string ActualDir = "0"; private const string BackupDir = "1"; |