diff options
Diffstat (limited to 'src/ARMeilleure/Instructions/InstEmitAluHelper.cs')
| -rw-r--r-- | src/ARMeilleure/Instructions/InstEmitAluHelper.cs | 613 |
1 files changed, 613 insertions, 0 deletions
diff --git a/src/ARMeilleure/Instructions/InstEmitAluHelper.cs b/src/ARMeilleure/Instructions/InstEmitAluHelper.cs new file mode 100644 index 00000000..994878ad --- /dev/null +++ b/src/ARMeilleure/Instructions/InstEmitAluHelper.cs @@ -0,0 +1,613 @@ +using ARMeilleure.Decoders; +using ARMeilleure.IntermediateRepresentation; +using ARMeilleure.State; +using ARMeilleure.Translation; +using System; +using System.Diagnostics; + +using static ARMeilleure.Instructions.InstEmitHelper; +using static ARMeilleure.IntermediateRepresentation.Operand.Factory; + +namespace ARMeilleure.Instructions +{ + static class InstEmitAluHelper + { + public static bool ShouldSetFlags(ArmEmitterContext context) + { + IOpCode32HasSetFlags op = (IOpCode32HasSetFlags)context.CurrOp; + + if (op.SetFlags == null) + { + return !context.IsInIfThenBlock; + } + + return op.SetFlags.Value; + } + + public static void EmitNZFlagsCheck(ArmEmitterContext context, Operand d) + { + SetFlag(context, PState.NFlag, context.ICompareLess (d, Const(d.Type, 0))); + SetFlag(context, PState.ZFlag, context.ICompareEqual(d, Const(d.Type, 0))); + } + + public static void EmitAdcsCCheck(ArmEmitterContext context, Operand n, Operand d) + { + // C = (Rd == Rn && CIn) || Rd < Rn + Operand cIn = GetFlag(PState.CFlag); + + Operand cOut = context.BitwiseAnd(context.ICompareEqual(d, n), cIn); + + cOut = context.BitwiseOr(cOut, context.ICompareLessUI(d, n)); + + SetFlag(context, PState.CFlag, cOut); + } + + public static void EmitAddsCCheck(ArmEmitterContext context, Operand n, Operand d) + { + // C = Rd < Rn + SetFlag(context, PState.CFlag, context.ICompareLessUI(d, n)); + } + + public static void EmitAddsVCheck(ArmEmitterContext context, Operand n, Operand m, Operand d) + { + // V = (Rd ^ Rn) & ~(Rn ^ Rm) < 0 + Operand vOut = context.BitwiseExclusiveOr(d, n); + + vOut = context.BitwiseAnd(vOut, context.BitwiseNot(context.BitwiseExclusiveOr(n, m))); + + vOut = context.ICompareLess(vOut, Const(vOut.Type, 0)); + + SetFlag(context, PState.VFlag, vOut); + } + + public static void EmitSbcsCCheck(ArmEmitterContext context, Operand n, Operand m) + { + // C = (Rn == Rm && CIn) || Rn > Rm + Operand cIn = GetFlag(PState.CFlag); + + Operand cOut = context.BitwiseAnd(context.ICompareEqual(n, m), cIn); + + cOut = context.BitwiseOr(cOut, context.ICompareGreaterUI(n, m)); + + SetFlag(context, PState.CFlag, cOut); + } + + public static void EmitSubsCCheck(ArmEmitterContext context, Operand n, Operand m) + { + // C = Rn >= Rm + SetFlag(context, PState.CFlag, context.ICompareGreaterOrEqualUI(n, m)); + } + + public static void EmitSubsVCheck(ArmEmitterContext context, Operand n, Operand m, Operand d) + { + // V = (Rd ^ Rn) & (Rn ^ Rm) < 0 + Operand vOut = context.BitwiseExclusiveOr(d, n); + + vOut = context.BitwiseAnd(vOut, context.BitwiseExclusiveOr(n, m)); + + vOut = context.ICompareLess(vOut, Const(vOut.Type, 0)); + + SetFlag(context, PState.VFlag, vOut); + } + + public static Operand EmitReverseBits32Op(ArmEmitterContext context, Operand op) + { + Debug.Assert(op.Type == OperandType.I32); + + Operand val = context.BitwiseOr(context.ShiftRightUI(context.BitwiseAnd(op, Const(0xaaaaaaaau)), Const(1)), + context.ShiftLeft(context.BitwiseAnd(op, Const(0x55555555u)), Const(1))); + + val = context.BitwiseOr(context.ShiftRightUI(context.BitwiseAnd(val, Const(0xccccccccu)), Const(2)), + context.ShiftLeft(context.BitwiseAnd(val, Const(0x33333333u)), Const(2))); + val = context.BitwiseOr(context.ShiftRightUI(context.BitwiseAnd(val, Const(0xf0f0f0f0u)), Const(4)), + context.ShiftLeft(context.BitwiseAnd(val, Const(0x0f0f0f0fu)), Const(4))); + val = context.BitwiseOr(context.ShiftRightUI(context.BitwiseAnd(val, Const(0xff00ff00u)), Const(8)), + context.ShiftLeft(context.BitwiseAnd(val, Const(0x00ff00ffu)), Const(8))); + + return context.BitwiseOr(context.ShiftRightUI(val, Const(16)), context.ShiftLeft(val, Const(16))); + } + + public static Operand EmitReverseBytes16_64Op(ArmEmitterContext context, Operand op) + { + Debug.Assert(op.Type == OperandType.I64); + + return context.BitwiseOr(context.ShiftRightUI(context.BitwiseAnd(op, Const(0xff00ff00ff00ff00ul)), Const(8)), + context.ShiftLeft(context.BitwiseAnd(op, Const(0x00ff00ff00ff00fful)), Const(8))); + } + + public static Operand EmitReverseBytes16_32Op(ArmEmitterContext context, Operand op) + { + Debug.Assert(op.Type == OperandType.I32); + + Operand val = EmitReverseBytes16_64Op(context, context.ZeroExtend32(OperandType.I64, op)); + + return context.ConvertI64ToI32(val); + } + + private static void EmitAluWritePc(ArmEmitterContext context, Operand value) + { + Debug.Assert(value.Type == OperandType.I32); + + if (((OpCode32)context.CurrOp).IsThumb) + { + bool isReturn = IsA32Return(context); + if (!isReturn) + { + context.StoreToContext(); + } + + InstEmitFlowHelper.EmitVirtualJump(context, value, isReturn); + } + else + { + EmitBxWritePc(context, value); + } + } + + public static void EmitGenericAluStoreA32(ArmEmitterContext context, int rd, bool setFlags, Operand value) + { + Debug.Assert(value.Type == OperandType.I32); + + if (rd == RegisterAlias.Aarch32Pc && setFlags) + { + if (setFlags) + { + // TODO: Load SPSR etc. + + EmitBxWritePc(context, value); + } + else + { + EmitAluWritePc(context, value); + } + } + else + { + SetIntA32(context, rd, value); + } + } + + public static Operand GetAluN(ArmEmitterContext context) + { + if (context.CurrOp is IOpCodeAlu op) + { + if (op.DataOp == DataOp.Logical || op is IOpCodeAluRs) + { + return GetIntOrZR(context, op.Rn); + } + else + { + return GetIntOrSP(context, op.Rn); + } + } + else if (context.CurrOp is IOpCode32Alu op32) + { + return GetIntA32(context, op32.Rn); + } + else + { + throw InvalidOpCodeType(context.CurrOp); + } + } + + public static Operand GetAluM(ArmEmitterContext context, bool setCarry = true) + { + switch (context.CurrOp) + { + // ARM32. + case IOpCode32AluImm op: + { + if (ShouldSetFlags(context) && op.IsRotated && setCarry) + { + SetFlag(context, PState.CFlag, Const((uint)op.Immediate >> 31)); + } + + return Const(op.Immediate); + } + + case IOpCode32AluImm16 op: return Const(op.Immediate); + + case IOpCode32AluRsImm op: return GetMShiftedByImmediate(context, op, setCarry); + case IOpCode32AluRsReg op: return GetMShiftedByReg(context, op, setCarry); + + case IOpCode32AluReg op: return GetIntA32(context, op.Rm); + + // ARM64. + case IOpCodeAluImm op: + { + if (op.GetOperandType() == OperandType.I32) + { + return Const((int)op.Immediate); + } + else + { + return Const(op.Immediate); + } + } + + case IOpCodeAluRs op: + { + Operand value = GetIntOrZR(context, op.Rm); + + switch (op.ShiftType) + { + case ShiftType.Lsl: value = context.ShiftLeft (value, Const(op.Shift)); break; + case ShiftType.Lsr: value = context.ShiftRightUI(value, Const(op.Shift)); break; + case ShiftType.Asr: value = context.ShiftRightSI(value, Const(op.Shift)); break; + case ShiftType.Ror: value = context.RotateRight (value, Const(op.Shift)); break; + } + + return value; + } + + case IOpCodeAluRx op: + { + Operand value = GetExtendedM(context, op.Rm, op.IntType); + + value = context.ShiftLeft(value, Const(op.Shift)); + + return value; + } + + default: throw InvalidOpCodeType(context.CurrOp); + } + } + + private static Exception InvalidOpCodeType(OpCode opCode) + { + return new InvalidOperationException($"Invalid OpCode type \"{opCode?.GetType().Name ?? "null"}\"."); + } + + // ARM32 helpers. + public static Operand GetMShiftedByImmediate(ArmEmitterContext context, IOpCode32AluRsImm op, bool setCarry) + { + Operand m = GetIntA32(context, op.Rm); + + int shift = op.Immediate; + + if (shift == 0) + { + switch (op.ShiftType) + { + case ShiftType.Lsr: shift = 32; break; + case ShiftType.Asr: shift = 32; break; + case ShiftType.Ror: shift = 1; break; + } + } + + if (shift != 0) + { + setCarry &= ShouldSetFlags(context); + + switch (op.ShiftType) + { + case ShiftType.Lsl: m = GetLslC(context, m, setCarry, shift); break; + case ShiftType.Lsr: m = GetLsrC(context, m, setCarry, shift); break; + case ShiftType.Asr: m = GetAsrC(context, m, setCarry, shift); break; + case ShiftType.Ror: + if (op.Immediate != 0) + { + m = GetRorC(context, m, setCarry, shift); + } + else + { + m = GetRrxC(context, m, setCarry); + } + break; + } + } + + return m; + } + + public static int DecodeImmShift(ShiftType shiftType, int shift) + { + if (shift == 0) + { + switch (shiftType) + { + case ShiftType.Lsr: shift = 32; break; + case ShiftType.Asr: shift = 32; break; + case ShiftType.Ror: shift = 1; break; + } + } + + return shift; + } + + public static Operand GetMShiftedByReg(ArmEmitterContext context, IOpCode32AluRsReg op, bool setCarry) + { + Operand m = GetIntA32(context, op.Rm); + Operand s = context.ZeroExtend8(OperandType.I32, GetIntA32(context, op.Rs)); + Operand shiftIsZero = context.ICompareEqual(s, Const(0)); + + Operand zeroResult = m; + Operand shiftResult = m; + + setCarry &= ShouldSetFlags(context); + + switch (op.ShiftType) + { + case ShiftType.Lsl: shiftResult = EmitLslC(context, m, setCarry, s, shiftIsZero); break; + case ShiftType.Lsr: shiftResult = EmitLsrC(context, m, setCarry, s, shiftIsZero); break; + case ShiftType.Asr: shiftResult = EmitAsrC(context, m, setCarry, s, shiftIsZero); break; + case ShiftType.Ror: shiftResult = EmitRorC(context, m, setCarry, s, shiftIsZero); break; + } + + return context.ConditionalSelect(shiftIsZero, zeroResult, shiftResult); + } + + public static void EmitIfHelper(ArmEmitterContext context, Operand boolValue, Action action, bool expected = true) + { + Debug.Assert(boolValue.Type == OperandType.I32); + + Operand endLabel = Label(); + + if (expected) + { + context.BranchIfFalse(endLabel, boolValue); + } + else + { + context.BranchIfTrue(endLabel, boolValue); + } + + action(); + + context.MarkLabel(endLabel); + } + + public static Operand EmitLslC(ArmEmitterContext context, Operand m, bool setCarry, Operand shift, Operand shiftIsZero) + { + Debug.Assert(m.Type == OperandType.I32 && shift.Type == OperandType.I32 && shiftIsZero.Type == OperandType.I32); + + Operand shiftLarge = context.ICompareGreaterOrEqual(shift, Const(32)); + Operand result = context.ShiftLeft(m, shift); + if (setCarry) + { + EmitIfHelper(context, shiftIsZero, () => + { + Operand cOut = context.ShiftRightUI(m, context.Subtract(Const(32), shift)); + + cOut = context.BitwiseAnd(cOut, Const(1)); + cOut = context.ConditionalSelect(context.ICompareGreater(shift, Const(32)), Const(0), cOut); + + SetFlag(context, PState.CFlag, cOut); + }, false); + } + + return context.ConditionalSelect(shiftLarge, Const(0), result); + } + + public static Operand GetLslC(ArmEmitterContext context, Operand m, bool setCarry, int shift) + { + Debug.Assert(m.Type == OperandType.I32); + + if ((uint)shift > 32) + { + return GetShiftByMoreThan32(context, setCarry); + } + else if (shift == 32) + { + if (setCarry) + { + SetCarryMLsb(context, m); + } + + return Const(0); + } + else + { + if (setCarry) + { + Operand cOut = context.ShiftRightUI(m, Const(32 - shift)); + + cOut = context.BitwiseAnd(cOut, Const(1)); + + SetFlag(context, PState.CFlag, cOut); + } + + return context.ShiftLeft(m, Const(shift)); + } + } + + public static Operand EmitLsrC(ArmEmitterContext context, Operand m, bool setCarry, Operand shift, Operand shiftIsZero) + { + Debug.Assert(m.Type == OperandType.I32 && shift.Type == OperandType.I32 && shiftIsZero.Type == OperandType.I32); + + Operand shiftLarge = context.ICompareGreaterOrEqual(shift, Const(32)); + Operand result = context.ShiftRightUI(m, shift); + if (setCarry) + { + EmitIfHelper(context, shiftIsZero, () => + { + Operand cOut = context.ShiftRightUI(m, context.Subtract(shift, Const(1))); + + cOut = context.BitwiseAnd(cOut, Const(1)); + cOut = context.ConditionalSelect(context.ICompareGreater(shift, Const(32)), Const(0), cOut); + + SetFlag(context, PState.CFlag, cOut); + }, false); + } + + return context.ConditionalSelect(shiftLarge, Const(0), result); + } + + public static Operand GetLsrC(ArmEmitterContext context, Operand m, bool setCarry, int shift) + { + Debug.Assert(m.Type == OperandType.I32); + + if ((uint)shift > 32) + { + return GetShiftByMoreThan32(context, setCarry); + } + else if (shift == 32) + { + if (setCarry) + { + SetCarryMMsb(context, m); + } + + return Const(0); + } + else + { + if (setCarry) + { + SetCarryMShrOut(context, m, shift); + } + + return context.ShiftRightUI(m, Const(shift)); + } + } + + private static Operand GetShiftByMoreThan32(ArmEmitterContext context, bool setCarry) + { + if (setCarry) + { + SetFlag(context, PState.CFlag, Const(0)); + } + + return Const(0); + } + + public static Operand EmitAsrC(ArmEmitterContext context, Operand m, bool setCarry, Operand shift, Operand shiftIsZero) + { + Debug.Assert(m.Type == OperandType.I32 && shift.Type == OperandType.I32 && shiftIsZero.Type == OperandType.I32); + + Operand l32Result; + Operand ge32Result; + + Operand less32 = context.ICompareLess(shift, Const(32)); + + ge32Result = context.ShiftRightSI(m, Const(31)); + + if (setCarry) + { + EmitIfHelper(context, context.BitwiseOr(less32, shiftIsZero), () => + { + SetCarryMLsb(context, ge32Result); + }, false); + } + + l32Result = context.ShiftRightSI(m, shift); + if (setCarry) + { + EmitIfHelper(context, context.BitwiseAnd(less32, context.BitwiseNot(shiftIsZero)), () => + { + Operand cOut = context.ShiftRightUI(m, context.Subtract(shift, Const(1))); + + cOut = context.BitwiseAnd(cOut, Const(1)); + + SetFlag(context, PState.CFlag, cOut); + }); + } + + return context.ConditionalSelect(less32, l32Result, ge32Result); + } + + public static Operand GetAsrC(ArmEmitterContext context, Operand m, bool setCarry, int shift) + { + Debug.Assert(m.Type == OperandType.I32); + + if ((uint)shift >= 32) + { + m = context.ShiftRightSI(m, Const(31)); + + if (setCarry) + { + SetCarryMLsb(context, m); + } + + return m; + } + else + { + if (setCarry) + { + SetCarryMShrOut(context, m, shift); + } + + return context.ShiftRightSI(m, Const(shift)); + } + } + + public static Operand EmitRorC(ArmEmitterContext context, Operand m, bool setCarry, Operand shift, Operand shiftIsZero) + { + Debug.Assert(m.Type == OperandType.I32 && shift.Type == OperandType.I32 && shiftIsZero.Type == OperandType.I32); + + shift = context.BitwiseAnd(shift, Const(0x1f)); + m = context.RotateRight(m, shift); + + if (setCarry) + { + EmitIfHelper(context, shiftIsZero, () => + { + SetCarryMMsb(context, m); + }, false); + } + + return m; + } + + public static Operand GetRorC(ArmEmitterContext context, Operand m, bool setCarry, int shift) + { + Debug.Assert(m.Type == OperandType.I32); + + shift &= 0x1f; + + m = context.RotateRight(m, Const(shift)); + + if (setCarry) + { + SetCarryMMsb(context, m); + } + + return m; + } + + public static Operand GetRrxC(ArmEmitterContext context, Operand m, bool setCarry) + { + Debug.Assert(m.Type == OperandType.I32); + + // Rotate right by 1 with carry. + Operand cIn = context.Copy(GetFlag(PState.CFlag)); + + if (setCarry) + { + SetCarryMLsb(context, m); + } + + m = context.ShiftRightUI(m, Const(1)); + + m = context.BitwiseOr(m, context.ShiftLeft(cIn, Const(31))); + + return m; + } + + private static void SetCarryMLsb(ArmEmitterContext context, Operand m) + { + Debug.Assert(m.Type == OperandType.I32); + + SetFlag(context, PState.CFlag, context.BitwiseAnd(m, Const(1))); + } + + private static void SetCarryMMsb(ArmEmitterContext context, Operand m) + { + Debug.Assert(m.Type == OperandType.I32); + + SetFlag(context, PState.CFlag, context.ShiftRightUI(m, Const(31))); + } + + private static void SetCarryMShrOut(ArmEmitterContext context, Operand m, int shift) + { + Debug.Assert(m.Type == OperandType.I32); + + Operand cOut = context.ShiftRightUI(m, Const(shift - 1)); + + cOut = context.BitwiseAnd(cOut, Const(1)); + + SetFlag(context, PState.CFlag, cOut); + } + } +} |