Ryujinx/ChocolArm64/Instructions/SoftFloat.cs

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using ChocolArm64.State;
using System;
using System.Diagnostics;
using System.Runtime.CompilerServices;
namespace ChocolArm64.Instructions
{
static class SoftFloat
{
static SoftFloat()
{
RecipEstimateTable = BuildRecipEstimateTable();
InvSqrtEstimateTable = BuildInvSqrtEstimateTable();
}
private static readonly byte[] RecipEstimateTable;
private static readonly byte[] InvSqrtEstimateTable;
private static byte[] BuildRecipEstimateTable()
{
byte[] table = new byte[256];
for (ulong index = 0; index < 256; index++)
{
ulong a = index | 0x100;
a = (a << 1) + 1;
ulong b = 0x80000 / a;
b = (b + 1) >> 1;
table[index] = (byte)(b & 0xFF);
}
return table;
}
private static byte[] BuildInvSqrtEstimateTable()
{
byte[] table = new byte[512];
for (ulong index = 128; index < 512; index++)
{
ulong a = index;
if (a < 256)
{
a = (a << 1) + 1;
}
else
{
a = (a | 1) << 1;
}
ulong b = 256;
while (a * (b + 1) * (b + 1) < (1ul << 28))
{
b++;
}
b = (b + 1) >> 1;
table[index] = (byte)(b & 0xFF);
}
return table;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float RecipEstimate(float x)
{
return (float)RecipEstimate((double)x);
}
public static double RecipEstimate(double x)
{
ulong xBits = (ulong)BitConverter.DoubleToInt64Bits(x);
ulong xSign = xBits & 0x8000000000000000;
ulong xExp = (xBits >> 52) & 0x7FF;
ulong scaled = xBits & ((1ul << 52) - 1);
if (xExp >= 2045)
{
if (xExp == 0x7ff && scaled != 0)
{
// NaN
return BitConverter.Int64BitsToDouble((long)(xBits | 0x0008000000000000));
}
// Infinity, or Out of range -> Zero
return BitConverter.Int64BitsToDouble((long)xSign);
}
if (xExp == 0)
{
if (scaled == 0)
{
// Zero -> Infinity
return BitConverter.Int64BitsToDouble((long)(xSign | 0x7FF0000000000000));
}
// Denormal
if ((scaled & (1ul << 51)) == 0)
{
xExp = ~0ul;
scaled <<= 2;
}
else
{
scaled <<= 1;
}
}
scaled >>= 44;
scaled &= 0xFF;
ulong resultExp = (2045 - xExp) & 0x7FF;
ulong estimate = (ulong)RecipEstimateTable[scaled];
ulong fraction = estimate << 44;
if (resultExp == 0)
{
fraction >>= 1;
fraction |= 1ul << 51;
}
else if (resultExp == 0x7FF)
{
resultExp = 0;
fraction >>= 2;
fraction |= 1ul << 50;
}
ulong result = xSign | (resultExp << 52) | fraction;
return BitConverter.Int64BitsToDouble((long)result);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float InvSqrtEstimate(float x)
{
return (float)InvSqrtEstimate((double)x);
}
public static double InvSqrtEstimate(double x)
{
ulong xBits = (ulong)BitConverter.DoubleToInt64Bits(x);
ulong xSign = xBits & 0x8000000000000000;
long xExp = (long)((xBits >> 52) & 0x7FF);
ulong scaled = xBits & ((1ul << 52) - 1);
if (xExp == 0x7FF && scaled != 0)
{
// NaN
return BitConverter.Int64BitsToDouble((long)(xBits | 0x0008000000000000));
}
if (xExp == 0)
{
if (scaled == 0)
{
// Zero -> Infinity
return BitConverter.Int64BitsToDouble((long)(xSign | 0x7FF0000000000000));
}
// Denormal
while ((scaled & (1 << 51)) == 0)
{
scaled <<= 1;
xExp--;
}
scaled <<= 1;
}
if (xSign != 0)
{
// Negative -> NaN
return BitConverter.Int64BitsToDouble((long)0x7FF8000000000000);
}
if (xExp == 0x7ff && scaled == 0)
{
// Infinity -> Zero
return BitConverter.Int64BitsToDouble((long)xSign);
}
if (((ulong)xExp & 1) == 1)
{
scaled >>= 45;
scaled &= 0xFF;
scaled |= 0x80;
}
else
{
scaled >>= 44;
scaled &= 0xFF;
scaled |= 0x100;
}
ulong resultExp = ((ulong)(3068 - xExp) / 2) & 0x7FF;
ulong estimate = (ulong)InvSqrtEstimateTable[scaled];
ulong fraction = estimate << 44;
ulong result = xSign | (resultExp << 52) | fraction;
return BitConverter.Int64BitsToDouble((long)result);
}
}
static class SoftFloat16_32
{
public static float FPConvert(ushort valueBits, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat16_32.FPConvert: state.Fpcr = 0x{state.Fpcr:X8}");
double real = valueBits.FPUnpackCv(out FpType type, out bool sign, state);
float result;
if (type == FpType.SNaN || type == FpType.QNaN)
{
if (state.GetFpcrFlag(Fpcr.Dn))
{
result = FPDefaultNaN();
}
else
{
result = FPConvertNaN(valueBits);
}
if (type == FpType.SNaN)
{
FPProcessException(FpExc.InvalidOp, state);
}
}
else if (type == FpType.Infinity)
{
result = FPInfinity(sign);
}
else if (type == FpType.Zero)
{
result = FPZero(sign);
}
else
{
result = FPRoundCv(real, state);
}
return result;
}
private static float FPDefaultNaN()
{
return -float.NaN;
}
private static float FPInfinity(bool sign)
{
return sign ? float.NegativeInfinity : float.PositiveInfinity;
}
private static float FPZero(bool sign)
{
return sign ? -0f : +0f;
}
private static float FPMaxNormal(bool sign)
{
return sign ? float.MinValue : float.MaxValue;
}
private static double FPUnpackCv(
this ushort valueBits,
out FpType type,
out bool sign,
CpuThreadState state)
{
sign = (~(uint)valueBits & 0x8000u) == 0u;
uint exp16 = ((uint)valueBits & 0x7C00u) >> 10;
uint frac16 = (uint)valueBits & 0x03FFu;
double real;
if (exp16 == 0u)
{
if (frac16 == 0u)
{
type = FpType.Zero;
real = 0d;
}
else
{
type = FpType.Nonzero; // Subnormal.
real = Math.Pow(2d, -14) * ((double)frac16 * Math.Pow(2d, -10));
}
}
else if (exp16 == 0x1Fu && !state.GetFpcrFlag(Fpcr.Ahp))
{
if (frac16 == 0u)
{
type = FpType.Infinity;
real = Math.Pow(2d, 1000);
}
else
{
type = (~frac16 & 0x0200u) == 0u ? FpType.QNaN : FpType.SNaN;
real = 0d;
}
}
else
{
type = FpType.Nonzero; // Normal.
real = Math.Pow(2d, (int)exp16 - 15) * (1d + (double)frac16 * Math.Pow(2d, -10));
}
return sign ? -real : real;
}
private static float FPRoundCv(double real, CpuThreadState state)
{
const int minimumExp = -126;
const int e = 8;
const int f = 23;
bool sign;
double mantissa;
if (real < 0d)
{
sign = true;
mantissa = -real;
}
else
{
sign = false;
mantissa = real;
}
int exponent = 0;
while (mantissa < 1d)
{
mantissa *= 2d;
exponent--;
}
while (mantissa >= 2d)
{
mantissa /= 2d;
exponent++;
}
if (state.GetFpcrFlag(Fpcr.Fz) && exponent < minimumExp)
{
state.SetFpsrFlag(Fpsr.Ufc);
return FPZero(sign);
}
uint biasedExp = (uint)Math.Max(exponent - minimumExp + 1, 0);
if (biasedExp == 0u)
{
mantissa /= Math.Pow(2d, minimumExp - exponent);
}
uint intMant = (uint)Math.Floor(mantissa * Math.Pow(2d, f));
double error = mantissa * Math.Pow(2d, f) - (double)intMant;
if (biasedExp == 0u && (error != 0d || state.GetFpcrFlag(Fpcr.Ufe)))
{
FPProcessException(FpExc.Underflow, state);
}
bool overflowToInf;
bool roundUp;
switch (state.FPRoundingMode())
{
default:
case RoundMode.ToNearest:
roundUp = (error > 0.5d || (error == 0.5d && (intMant & 1u) == 1u));
overflowToInf = true;
break;
case RoundMode.TowardsPlusInfinity:
roundUp = (error != 0d && !sign);
overflowToInf = !sign;
break;
case RoundMode.TowardsMinusInfinity:
roundUp = (error != 0d && sign);
overflowToInf = sign;
break;
case RoundMode.TowardsZero:
roundUp = false;
overflowToInf = false;
break;
}
if (roundUp)
{
intMant++;
if (intMant == (uint)Math.Pow(2d, f))
{
biasedExp = 1u;
}
if (intMant == (uint)Math.Pow(2d, f + 1))
{
biasedExp++;
intMant >>= 1;
}
}
float result;
if (biasedExp >= (uint)Math.Pow(2d, e) - 1u)
{
result = overflowToInf ? FPInfinity(sign) : FPMaxNormal(sign);
FPProcessException(FpExc.Overflow, state);
error = 1d;
}
else
{
result = BitConverter.Int32BitsToSingle(
(int)((sign ? 1u : 0u) << 31 | (biasedExp & 0xFFu) << 23 | (intMant & 0x007FFFFFu)));
}
if (error != 0d)
{
FPProcessException(FpExc.Inexact, state);
}
return result;
}
private static float FPConvertNaN(ushort valueBits)
{
return BitConverter.Int32BitsToSingle(
(int)(((uint)valueBits & 0x8000u) << 16 | 0x7FC00000u | ((uint)valueBits & 0x01FFu) << 13));
}
private static void FPProcessException(FpExc exc, CpuThreadState state)
{
int enable = (int)exc + 8;
if ((state.Fpcr & (1 << enable)) != 0)
{
throw new NotImplementedException("Floating-point trap handling.");
}
else
{
state.Fpsr |= 1 << (int)exc;
}
}
}
static class SoftFloat32_16
{
public static ushort FPConvert(float value, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32_16.FPConvert: state.Fpcr = 0x{state.Fpcr:X8}");
double real = value.FPUnpackCv(out FpType type, out bool sign, out uint valueBits, state);
bool altHp = state.GetFpcrFlag(Fpcr.Ahp);
ushort resultBits;
if (type == FpType.SNaN || type == FpType.QNaN)
{
if (altHp)
{
resultBits = FPZero(sign);
}
else if (state.GetFpcrFlag(Fpcr.Dn))
{
resultBits = FPDefaultNaN();
}
else
{
resultBits = FPConvertNaN(valueBits);
}
if (type == FpType.SNaN || altHp)
{
FPProcessException(FpExc.InvalidOp, state);
}
}
else if (type == FpType.Infinity)
{
if (altHp)
{
resultBits = (ushort)((sign ? 1u : 0u) << 15 | 0x7FFFu);
FPProcessException(FpExc.InvalidOp, state);
}
else
{
resultBits = FPInfinity(sign);
}
}
else if (type == FpType.Zero)
{
resultBits = FPZero(sign);
}
else
{
resultBits = FPRoundCv(real, state);
}
return resultBits;
}
private static ushort FPDefaultNaN()
{
return (ushort)0x7E00u;
}
private static ushort FPInfinity(bool sign)
{
return sign ? (ushort)0xFC00u : (ushort)0x7C00u;
}
private static ushort FPZero(bool sign)
{
return sign ? (ushort)0x8000u : (ushort)0x0000u;
}
private static ushort FPMaxNormal(bool sign)
{
return sign ? (ushort)0xFBFFu : (ushort)0x7BFFu;
}
private static double FPUnpackCv(
this float value,
out FpType type,
out bool sign,
out uint valueBits,
CpuThreadState state)
{
valueBits = (uint)BitConverter.SingleToInt32Bits(value);
sign = (~valueBits & 0x80000000u) == 0u;
uint exp32 = (valueBits & 0x7F800000u) >> 23;
uint frac32 = valueBits & 0x007FFFFFu;
double real;
if (exp32 == 0u)
{
if (frac32 == 0u || state.GetFpcrFlag(Fpcr.Fz))
{
type = FpType.Zero;
real = 0d;
if (frac32 != 0u)
{
FPProcessException(FpExc.InputDenorm, state);
}
}
else
{
type = FpType.Nonzero; // Subnormal.
real = Math.Pow(2d, -126) * ((double)frac32 * Math.Pow(2d, -23));
}
}
else if (exp32 == 0xFFu)
{
if (frac32 == 0u)
{
type = FpType.Infinity;
real = Math.Pow(2d, 1000);
}
else
{
type = (~frac32 & 0x00400000u) == 0u ? FpType.QNaN : FpType.SNaN;
real = 0d;
}
}
else
{
type = FpType.Nonzero; // Normal.
real = Math.Pow(2d, (int)exp32 - 127) * (1d + (double)frac32 * Math.Pow(2d, -23));
}
return sign ? -real : real;
}
private static ushort FPRoundCv(double real, CpuThreadState state)
{
const int minimumExp = -14;
const int e = 5;
const int f = 10;
bool sign;
double mantissa;
if (real < 0d)
{
sign = true;
mantissa = -real;
}
else
{
sign = false;
mantissa = real;
}
int exponent = 0;
while (mantissa < 1d)
{
mantissa *= 2d;
exponent--;
}
while (mantissa >= 2d)
{
mantissa /= 2d;
exponent++;
}
uint biasedExp = (uint)Math.Max(exponent - minimumExp + 1, 0);
if (biasedExp == 0u)
{
mantissa /= Math.Pow(2d, minimumExp - exponent);
}
uint intMant = (uint)Math.Floor(mantissa * Math.Pow(2d, f));
double error = mantissa * Math.Pow(2d, f) - (double)intMant;
if (biasedExp == 0u && (error != 0d || state.GetFpcrFlag(Fpcr.Ufe)))
{
FPProcessException(FpExc.Underflow, state);
}
bool overflowToInf;
bool roundUp;
switch (state.FPRoundingMode())
{
default:
case RoundMode.ToNearest:
roundUp = (error > 0.5d || (error == 0.5d && (intMant & 1u) == 1u));
overflowToInf = true;
break;
case RoundMode.TowardsPlusInfinity:
roundUp = (error != 0d && !sign);
overflowToInf = !sign;
break;
case RoundMode.TowardsMinusInfinity:
roundUp = (error != 0d && sign);
overflowToInf = sign;
break;
case RoundMode.TowardsZero:
roundUp = false;
overflowToInf = false;
break;
}
if (roundUp)
{
intMant++;
if (intMant == (uint)Math.Pow(2d, f))
{
biasedExp = 1u;
}
if (intMant == (uint)Math.Pow(2d, f + 1))
{
biasedExp++;
intMant >>= 1;
}
}
ushort resultBits;
if (!state.GetFpcrFlag(Fpcr.Ahp))
{
if (biasedExp >= (uint)Math.Pow(2d, e) - 1u)
{
resultBits = overflowToInf ? FPInfinity(sign) : FPMaxNormal(sign);
FPProcessException(FpExc.Overflow, state);
error = 1d;
}
else
{
resultBits = (ushort)((sign ? 1u : 0u) << 15 | (biasedExp & 0x1Fu) << 10 | (intMant & 0x03FFu));
}
}
else
{
if (biasedExp >= (uint)Math.Pow(2d, e))
{
resultBits = (ushort)((sign ? 1u : 0u) << 15 | 0x7FFFu);
FPProcessException(FpExc.InvalidOp, state);
error = 0d;
}
else
{
resultBits = (ushort)((sign ? 1u : 0u) << 15 | (biasedExp & 0x1Fu) << 10 | (intMant & 0x03FFu));
}
}
if (error != 0d)
{
FPProcessException(FpExc.Inexact, state);
}
return resultBits;
}
private static ushort FPConvertNaN(uint valueBits)
{
return (ushort)((valueBits & 0x80000000u) >> 16 | 0x7E00u | (valueBits & 0x003FE000u) >> 13);
}
private static void FPProcessException(FpExc exc, CpuThreadState state)
{
int enable = (int)exc + 8;
if ((state.Fpcr & (1 << enable)) != 0)
{
throw new NotImplementedException("Floating-point trap handling.");
}
else
{
state.Fpsr |= 1 << (int)exc;
}
}
}
static class SoftFloat32
{
public static float FPAdd(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPAdd: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if (inf1 && inf2 && sign1 == !sign2)
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if ((inf1 && !sign1) || (inf2 && !sign2))
{
result = FPInfinity(false);
}
else if ((inf1 && sign1) || (inf2 && sign2))
{
result = FPInfinity(true);
}
else if (zero1 && zero2 && sign1 == sign2)
{
result = FPZero(sign1);
}
else
{
result = value1 + value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
public static int FPCompare(float value1, float value2, bool signalNaNs, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPCompare: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out _, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out _, state);
int result;
if (type1 == FpType.SNaN || type1 == FpType.QNaN || type2 == FpType.SNaN || type2 == FpType.QNaN)
{
result = 0b0011;
if (type1 == FpType.SNaN || type2 == FpType.SNaN || signalNaNs)
{
FPProcessException(FpExc.InvalidOp, state);
}
}
else
{
if (value1 == value2)
{
result = 0b0110;
}
else if (value1 < value2)
{
result = 0b1000;
}
else
{
result = 0b0010;
}
}
return result;
}
public static float FPDiv(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPDiv: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && inf2) || (zero1 && zero2))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if (inf1 || zero2)
{
result = FPInfinity(sign1 ^ sign2);
if (!inf1)
{
FPProcessException(FpExc.DivideByZero, state);
}
}
else if (zero1 || inf2)
{
result = FPZero(sign1 ^ sign2);
}
else
{
result = value1 / value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
public static float FPMax(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMax: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
if (value1 > value2)
{
if (type1 == FpType.Infinity)
{
result = FPInfinity(sign1);
}
else if (type1 == FpType.Zero)
{
result = FPZero(sign1 && sign2);
}
else
{
result = value1;
}
}
else
{
if (type2 == FpType.Infinity)
{
result = FPInfinity(sign2);
}
else if (type2 == FpType.Zero)
{
result = FPZero(sign1 && sign2);
}
else
{
result = value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
}
return result;
}
public static float FPMaxNum(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMaxNum: state.Fpcr = 0x{state.Fpcr:X8}");
value1.FPUnpack(out FpType type1, out _, out _, state);
value2.FPUnpack(out FpType type2, out _, out _, state);
if (type1 == FpType.QNaN && type2 != FpType.QNaN)
{
value1 = FPInfinity(true);
}
else if (type1 != FpType.QNaN && type2 == FpType.QNaN)
{
value2 = FPInfinity(true);
}
return FPMax(value1, value2, state);
}
public static float FPMin(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMin: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
if (value1 < value2)
{
if (type1 == FpType.Infinity)
{
result = FPInfinity(sign1);
}
else if (type1 == FpType.Zero)
{
result = FPZero(sign1 || sign2);
}
else
{
result = value1;
}
}
else
{
if (type2 == FpType.Infinity)
{
result = FPInfinity(sign2);
}
else if (type2 == FpType.Zero)
{
result = FPZero(sign1 || sign2);
}
else
{
result = value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
}
return result;
}
public static float FPMinNum(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMinNum: state.Fpcr = 0x{state.Fpcr:X8}");
value1.FPUnpack(out FpType type1, out _, out _, state);
value2.FPUnpack(out FpType type2, out _, out _, state);
if (type1 == FpType.QNaN && type2 != FpType.QNaN)
{
value1 = FPInfinity(false);
}
else if (type1 != FpType.QNaN && type2 == FpType.QNaN)
{
value2 = FPInfinity(false);
}
return FPMin(value1, value2, state);
}
public static float FPMul(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMul: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else if (zero1 || zero2)
{
result = FPZero(sign1 ^ sign2);
}
else
{
result = value1 * value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
public static float FPMulAdd(
float valueA,
float value1,
float value2,
CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMulAdd: state.Fpcr = 0x{state.Fpcr:X8}");
valueA = valueA.FPUnpack(out FpType typeA, out bool signA, out uint addend, state);
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
float result = FPProcessNaNs3(typeA, type1, type2, addend, op1, op2, out bool done, state);
if (typeA == FpType.QNaN && ((inf1 && zero2) || (zero1 && inf2)))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
if (!done)
{
bool infA = typeA == FpType.Infinity; bool zeroA = typeA == FpType.Zero;
bool signP = sign1 ^ sign2;
bool infP = inf1 || inf2;
bool zeroP = zero1 || zero2;
if ((inf1 && zero2) || (zero1 && inf2) || (infA && infP && signA != signP))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if ((infA && !signA) || (infP && !signP))
{
result = FPInfinity(false);
}
else if ((infA && signA) || (infP && signP))
{
result = FPInfinity(true);
}
else if (zeroA && zeroP && signA == signP)
{
result = FPZero(signA);
}
else
{
// TODO: When available, use: T MathF.FusedMultiplyAdd(T, T, T);
// https://github.com/dotnet/corefx/issues/31903
result = valueA + (value1 * value2);
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float FPMulSub(
float valueA,
float value1,
float value2,
CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMulSub: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPNeg();
return FPMulAdd(valueA, value1, value2, state);
}
public static float FPMulX(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPMulX: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPTwo(sign1 ^ sign2);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else if (zero1 || zero2)
{
result = FPZero(sign1 ^ sign2);
}
else
{
result = value1 * value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
public static float FPRecipStepFused(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRecipStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPNeg();
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPTwo(false);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else
{
// TODO: When available, use: T MathF.FusedMultiplyAdd(T, T, T);
// https://github.com/dotnet/corefx/issues/31903
result = 2f + (value1 * value2);
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
public static float FPRecpX(float value, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRecpX: state.Fpcr = 0x{state.Fpcr:X8}");
value.FPUnpack(out FpType type, out bool sign, out uint op, state);
float result;
if (type == FpType.SNaN || type == FpType.QNaN)
{
result = FPProcessNaN(type, op, state);
}
else
{
uint notExp = (~op >> 23) & 0xFFu;
uint maxExp = 0xFEu;
result = BitConverter.Int32BitsToSingle(
(int)((sign ? 1u : 0u) << 31 | (notExp == 0xFFu ? maxExp : notExp) << 23));
}
return result;
}
public static float FPRSqrtStepFused(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRSqrtStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPNeg();
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPOnePointFive(false);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else
{
// TODO: When available, use: T MathF.FusedMultiplyAdd(T, T, T);
// https://github.com/dotnet/corefx/issues/31903
result = (3f + (value1 * value2)) / 2f;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
public static float FPSqrt(float value, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPSqrt: state.Fpcr = 0x{state.Fpcr:X8}");
value = value.FPUnpack(out FpType type, out bool sign, out uint op, state);
float result;
if (type == FpType.SNaN || type == FpType.QNaN)
{
result = FPProcessNaN(type, op, state);
}
else if (type == FpType.Zero)
{
result = FPZero(sign);
}
else if (type == FpType.Infinity && !sign)
{
result = FPInfinity(sign);
}
else if (sign)
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else
{
result = MathF.Sqrt(value);
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
return result;
}
public static float FPSub(float value1, float value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPSub: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out uint op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out uint op2, state);
float result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if (inf1 && inf2 && sign1 == sign2)
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if ((inf1 && !sign1) || (inf2 && sign2))
{
result = FPInfinity(false);
}
else if ((inf1 && sign1) || (inf2 && !sign2))
{
result = FPInfinity(true);
}
else if (zero1 && zero2 && sign1 == !sign2)
{
result = FPZero(sign1);
}
else
{
result = value1 - value2;
if (state.GetFpcrFlag(Fpcr.Fz) && float.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0f);
}
}
}
return result;
}
private static float FPDefaultNaN()
{
return -float.NaN;
}
private static float FPInfinity(bool sign)
{
return sign ? float.NegativeInfinity : float.PositiveInfinity;
}
private static float FPZero(bool sign)
{
return sign ? -0f : +0f;
}
private static float FPTwo(bool sign)
{
return sign ? -2f : +2f;
}
private static float FPOnePointFive(bool sign)
{
return sign ? -1.5f : +1.5f;
}
private static float FPNeg(this float value)
{
return -value;
}
private static float FPUnpack(
this float value,
out FpType type,
out bool sign,
out uint valueBits,
CpuThreadState state)
{
valueBits = (uint)BitConverter.SingleToInt32Bits(value);
sign = (~valueBits & 0x80000000u) == 0u;
if ((valueBits & 0x7F800000u) == 0u)
{
if ((valueBits & 0x007FFFFFu) == 0u || state.GetFpcrFlag(Fpcr.Fz))
{
type = FpType.Zero;
value = FPZero(sign);
if ((valueBits & 0x007FFFFFu) != 0u)
{
FPProcessException(FpExc.InputDenorm, state);
}
}
else
{
type = FpType.Nonzero;
}
}
else if ((~valueBits & 0x7F800000u) == 0u)
{
if ((valueBits & 0x007FFFFFu) == 0u)
{
type = FpType.Infinity;
}
else
{
type = (~valueBits & 0x00400000u) == 0u ? FpType.QNaN : FpType.SNaN;
value = FPZero(sign);
}
}
else
{
type = FpType.Nonzero;
}
return value;
}
private static float FPProcessNaNs(
FpType type1,
FpType type2,
uint op1,
uint op2,
out bool done,
CpuThreadState state)
{
done = true;
if (type1 == FpType.SNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.SNaN)
{
return FPProcessNaN(type2, op2, state);
}
else if (type1 == FpType.QNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.QNaN)
{
return FPProcessNaN(type2, op2, state);
}
done = false;
return FPZero(false);
}
private static float FPProcessNaNs3(
FpType type1,
FpType type2,
FpType type3,
uint op1,
uint op2,
uint op3,
out bool done,
CpuThreadState state)
{
done = true;
if (type1 == FpType.SNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.SNaN)
{
return FPProcessNaN(type2, op2, state);
}
else if (type3 == FpType.SNaN)
{
return FPProcessNaN(type3, op3, state);
}
else if (type1 == FpType.QNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.QNaN)
{
return FPProcessNaN(type2, op2, state);
}
else if (type3 == FpType.QNaN)
{
return FPProcessNaN(type3, op3, state);
}
done = false;
return FPZero(false);
}
private static float FPProcessNaN(FpType type, uint op, CpuThreadState state)
{
if (type == FpType.SNaN)
{
op |= 1u << 22;
FPProcessException(FpExc.InvalidOp, state);
}
if (state.GetFpcrFlag(Fpcr.Dn))
{
return FPDefaultNaN();
}
return BitConverter.Int32BitsToSingle((int)op);
}
private static void FPProcessException(FpExc exc, CpuThreadState state)
{
int enable = (int)exc + 8;
if ((state.Fpcr & (1 << enable)) != 0)
{
throw new NotImplementedException("Floating-point trap handling.");
}
else
{
state.Fpsr |= 1 << (int)exc;
}
}
}
static class SoftFloat64
{
public static double FPAdd(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPAdd: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if (inf1 && inf2 && sign1 == !sign2)
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if ((inf1 && !sign1) || (inf2 && !sign2))
{
result = FPInfinity(false);
}
else if ((inf1 && sign1) || (inf2 && sign2))
{
result = FPInfinity(true);
}
else if (zero1 && zero2 && sign1 == sign2)
{
result = FPZero(sign1);
}
else
{
result = value1 + value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
public static int FPCompare(double value1, double value2, bool signalNaNs, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPCompare: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out _, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out _, state);
int result;
if (type1 == FpType.SNaN || type1 == FpType.QNaN || type2 == FpType.SNaN || type2 == FpType.QNaN)
{
result = 0b0011;
if (type1 == FpType.SNaN || type2 == FpType.SNaN || signalNaNs)
{
FPProcessException(FpExc.InvalidOp, state);
}
}
else
{
if (value1 == value2)
{
result = 0b0110;
}
else if (value1 < value2)
{
result = 0b1000;
}
else
{
result = 0b0010;
}
}
return result;
}
public static double FPDiv(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPDiv: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && inf2) || (zero1 && zero2))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if (inf1 || zero2)
{
result = FPInfinity(sign1 ^ sign2);
if (!inf1)
{
FPProcessException(FpExc.DivideByZero, state);
}
}
else if (zero1 || inf2)
{
result = FPZero(sign1 ^ sign2);
}
else
{
result = value1 / value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
public static double FPMax(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMax: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
if (value1 > value2)
{
if (type1 == FpType.Infinity)
{
result = FPInfinity(sign1);
}
else if (type1 == FpType.Zero)
{
result = FPZero(sign1 && sign2);
}
else
{
result = value1;
}
}
else
{
if (type2 == FpType.Infinity)
{
result = FPInfinity(sign2);
}
else if (type2 == FpType.Zero)
{
result = FPZero(sign1 && sign2);
}
else
{
result = value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
}
return result;
}
public static double FPMaxNum(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMaxNum: state.Fpcr = 0x{state.Fpcr:X8}");
value1.FPUnpack(out FpType type1, out _, out _, state);
value2.FPUnpack(out FpType type2, out _, out _, state);
if (type1 == FpType.QNaN && type2 != FpType.QNaN)
{
value1 = FPInfinity(true);
}
else if (type1 != FpType.QNaN && type2 == FpType.QNaN)
{
value2 = FPInfinity(true);
}
return FPMax(value1, value2, state);
}
public static double FPMin(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMin: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
if (value1 < value2)
{
if (type1 == FpType.Infinity)
{
result = FPInfinity(sign1);
}
else if (type1 == FpType.Zero)
{
result = FPZero(sign1 || sign2);
}
else
{
result = value1;
}
}
else
{
if (type2 == FpType.Infinity)
{
result = FPInfinity(sign2);
}
else if (type2 == FpType.Zero)
{
result = FPZero(sign1 || sign2);
}
else
{
result = value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
}
return result;
}
public static double FPMinNum(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMinNum: state.Fpcr = 0x{state.Fpcr:X8}");
value1.FPUnpack(out FpType type1, out _, out _, state);
value2.FPUnpack(out FpType type2, out _, out _, state);
if (type1 == FpType.QNaN && type2 != FpType.QNaN)
{
value1 = FPInfinity(false);
}
else if (type1 != FpType.QNaN && type2 == FpType.QNaN)
{
value2 = FPInfinity(false);
}
return FPMin(value1, value2, state);
}
public static double FPMul(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMul: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else if (zero1 || zero2)
{
result = FPZero(sign1 ^ sign2);
}
else
{
result = value1 * value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
public static double FPMulAdd(
double valueA,
double value1,
double value2,
CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMulAdd: state.Fpcr = 0x{state.Fpcr:X8}");
valueA = valueA.FPUnpack(out FpType typeA, out bool signA, out ulong addend, state);
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
double result = FPProcessNaNs3(typeA, type1, type2, addend, op1, op2, out bool done, state);
if (typeA == FpType.QNaN && ((inf1 && zero2) || (zero1 && inf2)))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
if (!done)
{
bool infA = typeA == FpType.Infinity; bool zeroA = typeA == FpType.Zero;
bool signP = sign1 ^ sign2;
bool infP = inf1 || inf2;
bool zeroP = zero1 || zero2;
if ((inf1 && zero2) || (zero1 && inf2) || (infA && infP && signA != signP))
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if ((infA && !signA) || (infP && !signP))
{
result = FPInfinity(false);
}
else if ((infA && signA) || (infP && signP))
{
result = FPInfinity(true);
}
else if (zeroA && zeroP && signA == signP)
{
result = FPZero(signA);
}
else
{
// TODO: When available, use: T Math.FusedMultiplyAdd(T, T, T);
// https://github.com/dotnet/corefx/issues/31903
result = valueA + (value1 * value2);
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static double FPMulSub(
double valueA,
double value1,
double value2,
CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMulSub: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPNeg();
return FPMulAdd(valueA, value1, value2, state);
}
public static double FPMulX(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPMulX: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPTwo(sign1 ^ sign2);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else if (zero1 || zero2)
{
result = FPZero(sign1 ^ sign2);
}
else
{
result = value1 * value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
public static double FPRecipStepFused(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPRecipStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPNeg();
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPTwo(false);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else
{
// TODO: When available, use: T Math.FusedMultiplyAdd(T, T, T);
// https://github.com/dotnet/corefx/issues/31903
result = 2d + (value1 * value2);
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
public static double FPRecpX(double value, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPRecpX: state.Fpcr = 0x{state.Fpcr:X8}");
value.FPUnpack(out FpType type, out bool sign, out ulong op, state);
double result;
if (type == FpType.SNaN || type == FpType.QNaN)
{
result = FPProcessNaN(type, op, state);
}
else
{
ulong notExp = (~op >> 52) & 0x7FFul;
ulong maxExp = 0x7FEul;
result = BitConverter.Int64BitsToDouble(
(long)((sign ? 1ul : 0ul) << 63 | (notExp == 0x7FFul ? maxExp : notExp) << 52));
}
return result;
}
public static double FPRSqrtStepFused(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPRSqrtStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPNeg();
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if ((inf1 && zero2) || (zero1 && inf2))
{
result = FPOnePointFive(false);
}
else if (inf1 || inf2)
{
result = FPInfinity(sign1 ^ sign2);
}
else
{
// TODO: When available, use: T Math.FusedMultiplyAdd(T, T, T);
// https://github.com/dotnet/corefx/issues/31903
result = (3d + (value1 * value2)) / 2d;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
public static double FPSqrt(double value, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPSqrt: state.Fpcr = 0x{state.Fpcr:X8}");
value = value.FPUnpack(out FpType type, out bool sign, out ulong op, state);
double result;
if (type == FpType.SNaN || type == FpType.QNaN)
{
result = FPProcessNaN(type, op, state);
}
else if (type == FpType.Zero)
{
result = FPZero(sign);
}
else if (type == FpType.Infinity && !sign)
{
result = FPInfinity(sign);
}
else if (sign)
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else
{
result = Math.Sqrt(value);
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
return result;
}
public static double FPSub(double value1, double value2, CpuThreadState state)
{
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPSub: state.Fpcr = 0x{state.Fpcr:X8}");
value1 = value1.FPUnpack(out FpType type1, out bool sign1, out ulong op1, state);
value2 = value2.FPUnpack(out FpType type2, out bool sign2, out ulong op2, state);
double result = FPProcessNaNs(type1, type2, op1, op2, out bool done, state);
if (!done)
{
bool inf1 = type1 == FpType.Infinity; bool zero1 = type1 == FpType.Zero;
bool inf2 = type2 == FpType.Infinity; bool zero2 = type2 == FpType.Zero;
if (inf1 && inf2 && sign1 == sign2)
{
result = FPDefaultNaN();
FPProcessException(FpExc.InvalidOp, state);
}
else if ((inf1 && !sign1) || (inf2 && sign2))
{
result = FPInfinity(false);
}
else if ((inf1 && sign1) || (inf2 && !sign2))
{
result = FPInfinity(true);
}
else if (zero1 && zero2 && sign1 == !sign2)
{
result = FPZero(sign1);
}
else
{
result = value1 - value2;
if (state.GetFpcrFlag(Fpcr.Fz) && double.IsSubnormal(result))
{
state.SetFpsrFlag(Fpsr.Ufc);
result = FPZero(result < 0d);
}
}
}
return result;
}
private static double FPDefaultNaN()
{
return -double.NaN;
}
private static double FPInfinity(bool sign)
{
return sign ? double.NegativeInfinity : double.PositiveInfinity;
}
private static double FPZero(bool sign)
{
return sign ? -0d : +0d;
}
private static double FPTwo(bool sign)
{
return sign ? -2d : +2d;
}
private static double FPOnePointFive(bool sign)
{
return sign ? -1.5d : +1.5d;
}
private static double FPNeg(this double value)
{
return -value;
}
private static double FPUnpack(
this double value,
out FpType type,
out bool sign,
out ulong valueBits,
CpuThreadState state)
{
valueBits = (ulong)BitConverter.DoubleToInt64Bits(value);
sign = (~valueBits & 0x8000000000000000ul) == 0ul;
if ((valueBits & 0x7FF0000000000000ul) == 0ul)
{
if ((valueBits & 0x000FFFFFFFFFFFFFul) == 0ul || state.GetFpcrFlag(Fpcr.Fz))
{
type = FpType.Zero;
value = FPZero(sign);
if ((valueBits & 0x000FFFFFFFFFFFFFul) != 0ul)
{
FPProcessException(FpExc.InputDenorm, state);
}
}
else
{
type = FpType.Nonzero;
}
}
else if ((~valueBits & 0x7FF0000000000000ul) == 0ul)
{
if ((valueBits & 0x000FFFFFFFFFFFFFul) == 0ul)
{
type = FpType.Infinity;
}
else
{
type = (~valueBits & 0x0008000000000000ul) == 0ul ? FpType.QNaN : FpType.SNaN;
value = FPZero(sign);
}
}
else
{
type = FpType.Nonzero;
}
return value;
}
private static double FPProcessNaNs(
FpType type1,
FpType type2,
ulong op1,
ulong op2,
out bool done,
CpuThreadState state)
{
done = true;
if (type1 == FpType.SNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.SNaN)
{
return FPProcessNaN(type2, op2, state);
}
else if (type1 == FpType.QNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.QNaN)
{
return FPProcessNaN(type2, op2, state);
}
done = false;
return FPZero(false);
}
private static double FPProcessNaNs3(
FpType type1,
FpType type2,
FpType type3,
ulong op1,
ulong op2,
ulong op3,
out bool done,
CpuThreadState state)
{
done = true;
if (type1 == FpType.SNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.SNaN)
{
return FPProcessNaN(type2, op2, state);
}
else if (type3 == FpType.SNaN)
{
return FPProcessNaN(type3, op3, state);
}
else if (type1 == FpType.QNaN)
{
return FPProcessNaN(type1, op1, state);
}
else if (type2 == FpType.QNaN)
{
return FPProcessNaN(type2, op2, state);
}
else if (type3 == FpType.QNaN)
{
return FPProcessNaN(type3, op3, state);
}
done = false;
return FPZero(false);
}
private static double FPProcessNaN(FpType type, ulong op, CpuThreadState state)
{
if (type == FpType.SNaN)
{
op |= 1ul << 51;
FPProcessException(FpExc.InvalidOp, state);
}
if (state.GetFpcrFlag(Fpcr.Dn))
{
return FPDefaultNaN();
}
return BitConverter.Int64BitsToDouble((long)op);
}
private static void FPProcessException(FpExc exc, CpuThreadState state)
{
int enable = (int)exc + 8;
if ((state.Fpcr & (1 << enable)) != 0)
{
throw new NotImplementedException("Floating-point trap handling.");
}
else
{
state.Fpsr |= 1 << (int)exc;
}
}
}
}