Lightning JIT test impl

src/Ryujinx.Cpu/LightningJit/Arm32/Target/Arm64/InstEmitFlow.cs

@@ -140,6 +140,9 @@ namespace Ryujinx.Cpu.LightningJit.Arm32.Target.Arm64
             bool isTail = false)
         {
             int tempRegister;
+            int tempGuestAddress = 0;
+
+            bool inlineLookup = guestAddress.Kind != OperandKind.Constant && funcTable != null && funcTable.Levels.Length == 2;
 
             if (guestAddress.Kind == OperandKind.Constant)
             {
@@ -153,6 +156,13 @@ namespace Ryujinx.Cpu.LightningJit.Arm32.Target.Arm64
             else
             {
                 asm.StrRiUn(guestAddress, Register(regAlloc.FixedContextRegister), NativeContextOffsets.DispatchAddressOffset);
+
+                if (inlineLookup)
+                {
+                    // Might be overwritten. Move the address to a temp register.
+                    tempGuestAddress = regAlloc.AllocateTempGprRegister();
+                    asm.Mov(Register(tempGuestAddress), guestAddress);
+                }
             }
 
             tempRegister = regAlloc.FixedContextRegister == 1 ? 2 : 1;
@@ -176,6 +186,47 @@ namespace Ryujinx.Cpu.LightningJit.Arm32.Target.Arm64
                 asm.Mov(rn, funcPtrLoc & ~0xfffUL);
                 asm.LdrRiUn(rn, rn, (int)(funcPtrLoc & 0xfffUL));
             }
+            else if (inlineLookup)
+            {
+                // Inline table lookup. Only enabled when the sparse function table is enabled with 2 levels.
+
+                Operand indexReg = Register(3);
+                guestAddress = Register(tempGuestAddress);
+
+                var level0 = funcTable.Levels[0];
+                asm.Ubfx(indexReg, guestAddress, level0.Index, level0.Length);
+                asm.Lsl(indexReg, indexReg, Const(3));
+
+                ulong tableBase = (ulong)funcTable.Base;
+
+                // Index into the table.
+                asm.Mov(rn, tableBase);
+                asm.Add(rn, rn, indexReg);
+
+                // Load the page address.
+                asm.LdrRiUn(rn, rn, 0);
+
+                var level1 = funcTable.Levels[1];
+                asm.Ubfx(indexReg, guestAddress, level1.Index, level1.Length);
+                asm.Lsl(indexReg, indexReg, Const(3));
+
+                // Is the page address zero? Make sure to use the fallback if it is.
+                asm.Tst(rn, rn);
+
+                // Index into the page.
+                asm.Add(rn, rn, indexReg);
+
+                // Reuse the index register for the fallback
+                ulong fallback = (ulong)funcTable.Fallback;
+                asm.Mov(indexReg, fallback);
+
+                asm.Csel(rn, indexReg, rn, ArmCondition.Eq);
+
+                // Load the final branch address
+                asm.LdrRiUn(rn, rn, 0);
+
+                regAlloc.FreeTempGprRegister(tempGuestAddress);
+            }
             else
             {
                 asm.Mov(rn, (ulong)funcPtr);
@@ -252,5 +303,10 @@ namespace Ryujinx.Cpu.LightningJit.Arm32.Target.Arm64
         {
             return new Operand(register, RegisterType.Integer, type);
         }
+
+        private static Operand Const(long value, OperandType type = OperandType.I64)
+        {
+            return new Operand(type, (ulong)value);
+        }
     }
 }

src/Ryujinx.Cpu/LightningJit/Arm64/Target/Arm64/InstEmitSystem.cs

@@ -305,6 +305,9 @@ namespace Ryujinx.Cpu.LightningJit.Arm64.Target.Arm64
             bool isTail = false)
         {
             int tempRegister;
+            int tempGuestAddress = 0;
+
+            bool inlineLookup = guestAddress.Kind != OperandKind.Constant && funcTable != null && funcTable.Levels.Length == 2;
 
             if (guestAddress.Kind == OperandKind.Constant)
             {
@@ -318,6 +321,13 @@ namespace Ryujinx.Cpu.LightningJit.Arm64.Target.Arm64
             else
             {
                 asm.StrRiUn(guestAddress, Register(regAlloc.FixedContextRegister), NativeContextOffsets.DispatchAddressOffset);
+
+                if (inlineLookup)
+                {
+                    // Might be overwritten. Move the address to a temp register.
+                    tempGuestAddress = regAlloc.AllocateTempGprRegister();
+                    asm.Mov(Register(tempGuestAddress), guestAddress);
+                }
             }
 
             tempRegister = regAlloc.FixedContextRegister == 1 ? 2 : 1;
@@ -341,6 +351,47 @@ namespace Ryujinx.Cpu.LightningJit.Arm64.Target.Arm64
                 asm.Mov(rn, funcPtrLoc & ~0xfffUL);
                 asm.LdrRiUn(rn, rn, (int)(funcPtrLoc & 0xfffUL));
             }
+            else if (inlineLookup)
+            {
+                // Inline table lookup. Only enabled when the sparse function table is enabled with 2 levels.
+
+                Operand indexReg = Register(3);
+                guestAddress = Register(tempGuestAddress);
+
+                var level0 = funcTable.Levels[0];
+                asm.Ubfx(indexReg, guestAddress, level0.Index, level0.Length);
+                asm.Lsl(indexReg, indexReg, Const(3));
+
+                ulong tableBase = (ulong)funcTable.Base;
+
+                // Index into the table.
+                asm.Mov(rn, tableBase);
+                asm.Add(rn, rn, indexReg);
+
+                // Load the page address.
+                asm.LdrRiUn(rn, rn, 0);
+
+                var level1 = funcTable.Levels[1];
+                asm.Ubfx(indexReg, guestAddress, level1.Index, level1.Length);
+                asm.Lsl(indexReg, indexReg, Const(3));
+
+                // Is the page address zero? Make sure to use the fallback if it is.
+                asm.Tst(rn, rn);
+
+                // Index into the page.
+                asm.Add(rn, rn, indexReg);
+
+                // Reuse the index register for the fallback
+                ulong fallback = (ulong)funcTable.Fallback;
+                asm.Mov(indexReg, fallback);
+
+                asm.Csel(rn, indexReg, rn, ArmCondition.Eq);
+
+                // Load the final branch address
+                asm.LdrRiUn(rn, rn, 0);
+
+                regAlloc.FreeTempGprRegister(tempGuestAddress);
+            }
             else
             {
                 asm.Mov(rn, (ulong)funcPtr);
@@ -613,5 +664,10 @@ namespace Ryujinx.Cpu.LightningJit.Arm64.Target.Arm64
         {
             return new Operand(register, RegisterType.Integer, type);
         }
+
+        private static Operand Const(long value, OperandType type = OperandType.I64)
+        {
+            return new Operand(type, (ulong)value);
+        }
     }
 }

src/Ryujinx.Cpu/LightningJit/Translator.cs

@@ -16,6 +16,8 @@ namespace Ryujinx.Cpu.LightningJit
 {
     class Translator : IDisposable
     {
+        private const bool UseSparseTable = true;
+
         // Should be enabled on platforms that enforce W^X.
         private static bool IsNoWxPlatform => false;
 
@@ -38,6 +40,20 @@ namespace Ryujinx.Cpu.LightningJit
                 new( 1, 6),
             };
 
+        private static readonly AddressTable<ulong>.Level[] _levels64BitSparse =
+            new AddressTable<ulong>.Level[]
+            {
+                new(23, 16),
+                new( 2, 21),
+            };
+
+        private static readonly AddressTable<ulong>.Level[] _levels32BitSparse =
+            new AddressTable<ulong>.Level[]
+            {
+                new(22, 10),
+                new( 1, 21),
+            };
+
         private readonly ConcurrentQueue<KeyValuePair<ulong, TranslatedFunction>> _oldFuncs;
         private readonly NoWxCache _noWxCache;
         private bool _disposed;
@@ -62,8 +78,19 @@ namespace Ryujinx.Cpu.LightningJit
                 JitCache.Initialize(new JitMemoryAllocator(forJit: true));
             }
 
+            AddressTable<ulong>.Level[] levels;
+
+            if (UseSparseTable)
+            {
+                levels = for64Bits ? _levels64BitSparse : _levels32BitSparse;
+            }
+            else
+            {
+                levels = for64Bits ? _levels64Bit : _levels32Bit;
+            }
+
             Functions = new TranslatorCache<TranslatedFunction>();
-            FunctionTable = new AddressTable<ulong>(for64Bits ? _levels64Bit : _levels32Bit);
+            FunctionTable = new AddressTable<ulong>(levels);
             Stubs = new TranslatorStubs(FunctionTable, _noWxCache);
 
             FunctionTable.Fill = (ulong)Stubs.SlowDispatchStub;