Update SoftFloat.cs
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LDj3SNuD
GitHub
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commit
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1 changed files with 357 additions and 158 deletions
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@ -13,187 +13,68 @@ namespace ChocolArm64.Instructions
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InvSqrtEstimateTable = BuildInvSqrtEstimateTable();
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}
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private static readonly byte[] RecipEstimateTable;
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private static readonly byte[] InvSqrtEstimateTable;
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internal static readonly byte[] RecipEstimateTable;
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internal static readonly byte[] InvSqrtEstimateTable;
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private static byte[] BuildRecipEstimateTable()
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{
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byte[] table = new byte[256];
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for (ulong index = 0; index < 256; index++)
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byte[] tbl = new byte[256];
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for (uint idx = 0u; idx < 256u; idx++)
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{
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ulong a = index | 0x100;
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uint src = idx + 256u;
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a = (a << 1) + 1;
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ulong b = 0x80000 / a;
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b = (b + 1) >> 1;
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Debug.Assert(256u <= src && src < 512u);
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table[index] = (byte)(b & 0xFF);
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src = (src << 1) + 1u;
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uint aux = 0x00080000u / src;
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uint dst = (aux + 1u) >> 1;
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Debug.Assert(256u <= dst && dst < 512u);
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tbl[idx] = (byte)(dst - 256u);
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}
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return table;
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return tbl;
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}
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private static byte[] BuildInvSqrtEstimateTable()
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{
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byte[] table = new byte[512];
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for (ulong index = 128; index < 512; index++)
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byte[] tbl = new byte[384];
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for (uint idx = 0u; idx < 384u; idx++)
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{
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ulong a = index;
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if (a < 256)
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uint src = idx + 128u;
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Debug.Assert(128u <= src && src < 512u);
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if (src < 256u)
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{
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a = (a << 1) + 1;
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src = (src << 1) + 1u;
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}
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else
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{
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a = (a | 1) << 1;
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src = (src >> 1) << 1;
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src = (src + 1u) << 1;
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}
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ulong b = 256;
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while (a * (b + 1) * (b + 1) < (1ul << 28))
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uint aux = 512u;
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while (src * (aux + 1u) * (aux + 1u) < 0x10000000u)
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{
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b++;
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}
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b = (b + 1) >> 1;
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table[index] = (byte)(b & 0xFF);
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}
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return table;
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}
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static float RecipEstimate(float x)
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{
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return (float)RecipEstimate((double)x);
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}
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public static double RecipEstimate(double x)
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{
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ulong xBits = (ulong)BitConverter.DoubleToInt64Bits(x);
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ulong xSign = xBits & 0x8000000000000000;
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ulong xExp = (xBits >> 52) & 0x7FF;
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ulong scaled = xBits & ((1ul << 52) - 1);
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if (xExp >= 2045)
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{
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if (xExp == 0x7ff && scaled != 0)
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{
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// NaN
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return BitConverter.Int64BitsToDouble((long)(xBits | 0x0008000000000000));
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aux = aux + 1u;
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}
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// Infinity, or Out of range -> Zero
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return BitConverter.Int64BitsToDouble((long)xSign);
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uint dst = (aux + 1u) >> 1;
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Debug.Assert(256u <= dst && dst < 512u);
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tbl[idx] = (byte)(dst - 256u);
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}
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if (xExp == 0)
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{
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if (scaled == 0)
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{
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// Zero -> Infinity
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return BitConverter.Int64BitsToDouble((long)(xSign | 0x7FF0000000000000));
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}
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// Denormal
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if ((scaled & (1ul << 51)) == 0)
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{
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xExp = ~0ul;
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scaled <<= 2;
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}
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else
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{
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scaled <<= 1;
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}
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}
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scaled >>= 44;
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scaled &= 0xFF;
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ulong resultExp = (2045 - xExp) & 0x7FF;
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ulong estimate = (ulong)RecipEstimateTable[scaled];
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ulong fraction = estimate << 44;
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if (resultExp == 0)
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{
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fraction >>= 1;
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fraction |= 1ul << 51;
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}
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else if (resultExp == 0x7FF)
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{
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resultExp = 0;
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fraction >>= 2;
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fraction |= 1ul << 50;
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}
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ulong result = xSign | (resultExp << 52) | fraction;
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return BitConverter.Int64BitsToDouble((long)result);
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}
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[MethodImpl(MethodImplOptions.AggressiveInlining)]
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public static float InvSqrtEstimate(float x)
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{
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return (float)InvSqrtEstimate((double)x);
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}
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public static double InvSqrtEstimate(double x)
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{
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ulong xBits = (ulong)BitConverter.DoubleToInt64Bits(x);
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ulong xSign = xBits & 0x8000000000000000;
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long xExp = (long)((xBits >> 52) & 0x7FF);
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ulong scaled = xBits & ((1ul << 52) - 1);
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if (xExp == 0x7FF && scaled != 0)
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{
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// NaN
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return BitConverter.Int64BitsToDouble((long)(xBits | 0x0008000000000000));
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}
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if (xExp == 0)
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{
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if (scaled == 0)
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{
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// Zero -> Infinity
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return BitConverter.Int64BitsToDouble((long)(xSign | 0x7FF0000000000000));
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}
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// Denormal
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while ((scaled & (1 << 51)) == 0)
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{
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scaled <<= 1;
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xExp--;
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}
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scaled <<= 1;
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}
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if (xSign != 0)
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{
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// Negative -> NaN
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return BitConverter.Int64BitsToDouble((long)0x7FF8000000000000);
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}
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if (xExp == 0x7ff && scaled == 0)
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{
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// Infinity -> Zero
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return BitConverter.Int64BitsToDouble((long)xSign);
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}
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if (((ulong)xExp & 1) == 1)
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{
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scaled >>= 45;
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scaled &= 0xFF;
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scaled |= 0x80;
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}
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else
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{
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scaled >>= 44;
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scaled &= 0xFF;
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scaled |= 0x100;
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}
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ulong resultExp = ((ulong)(3068 - xExp) / 2) & 0x7FF;
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ulong estimate = (ulong)InvSqrtEstimateTable[scaled];
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ulong fraction = estimate << 44;
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ulong result = xSign | (resultExp << 52) | fraction;
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return BitConverter.Int64BitsToDouble((long)result);
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return tbl;
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}
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}
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@ -1276,6 +1157,95 @@ namespace ChocolArm64.Instructions
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return result;
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}
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public static float FPRecipEstimate(float value, CpuThreadState state)
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{
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Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRecipEstimate: state.Fpcr = 0x{state.Fpcr:X8}");
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value.FPUnpack(out FpType type, out bool sign, out uint op, state);
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float result;
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if (type == FpType.SNaN || type == FpType.QNaN)
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{
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result = FPProcessNaN(type, op, state);
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}
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else if (type == FpType.Infinity)
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{
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result = FPZero(sign);
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}
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else if (type == FpType.Zero)
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{
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result = FPInfinity(sign);
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FPProcessException(FpExc.DivideByZero, state);
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}
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else if (MathF.Abs(value) < MathF.Pow(2f, -128))
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{
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bool overflowToInf;
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switch (state.FPRoundingMode())
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{
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default:
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case RoundMode.ToNearest: overflowToInf = true; break;
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case RoundMode.TowardsPlusInfinity: overflowToInf = !sign; break;
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case RoundMode.TowardsMinusInfinity: overflowToInf = sign; break;
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case RoundMode.TowardsZero: overflowToInf = false; break;
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}
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result = overflowToInf ? FPInfinity(sign) : FPMaxNormal(sign);
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FPProcessException(FpExc.Overflow, state);
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FPProcessException(FpExc.Inexact, state);
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}
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else if (state.GetFpcrFlag(Fpcr.Fz) && (MathF.Abs(value) >= MathF.Pow(2f, 126)))
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{
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result = FPZero(sign);
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state.SetFpsrFlag(Fpsr.Ufc);
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}
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else
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{
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ulong fraction = (ulong)(op & 0x007FFFFFu) << 29;
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uint exp = (op & 0x7F800000u) >> 23;
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if (exp == 0u)
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{
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if ((fraction & 0x0008000000000000ul) == 0ul)
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{
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fraction = (fraction & 0x0003FFFFFFFFFFFFul) << 2;
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exp -= 1u;
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}
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else
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{
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fraction = (fraction & 0x0007FFFFFFFFFFFFul) << 1;
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}
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}
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uint scaled = (uint)(((fraction & 0x000FF00000000000ul) | 0x0010000000000000ul) >> 44);
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uint resultExp = 253u - exp;
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uint estimate = SoftFloat.RecipEstimateTable[scaled - 256u] + 256u;
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fraction = (ulong)(estimate & 0xFFu) << 44;
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if (resultExp == 0u)
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{
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fraction = ((fraction & 0x000FFFFFFFFFFFFEul) | 0x0010000000000000ul) >> 1;
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}
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else if (resultExp + 1u == 0u)
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{
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fraction = ((fraction & 0x000FFFFFFFFFFFFCul) | 0x0010000000000000ul) >> 2;
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resultExp = 0u;
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}
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result = BitConverter.Int32BitsToSingle(
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(int)((sign ? 1u : 0u) << 31 | (resultExp & 0xFFu) << 23 | (uint)(fraction >> 29) & 0x007FFFFFu));
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}
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return result;
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}
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public static float FPRecipStepFused(float value1, float value2, CpuThreadState state)
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{
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Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRecipStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
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@ -1343,6 +1313,71 @@ namespace ChocolArm64.Instructions
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return result;
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}
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public static float FPRSqrtEstimate(float value, CpuThreadState state)
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{
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Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRSqrtEstimate: state.Fpcr = 0x{state.Fpcr:X8}");
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value.FPUnpack(out FpType type, out bool sign, out uint op, state);
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float result;
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if (type == FpType.SNaN || type == FpType.QNaN)
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{
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result = FPProcessNaN(type, op, state);
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}
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else if (type == FpType.Zero)
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{
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result = FPInfinity(sign);
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FPProcessException(FpExc.DivideByZero, state);
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}
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else if (sign)
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{
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result = FPDefaultNaN();
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FPProcessException(FpExc.InvalidOp, state);
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}
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else if (type == FpType.Infinity)
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{
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result = FPZero(false);
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}
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else
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{
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ulong fraction = (ulong)(op & 0x007FFFFFu) << 29;
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uint exp = (op & 0x7F800000u) >> 23;
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if (exp == 0u)
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{
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while ((fraction & 0x0008000000000000ul) == 0ul)
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{
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fraction = (fraction & 0x0007FFFFFFFFFFFFul) << 1;
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exp -= 1u;
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}
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fraction = (fraction & 0x0007FFFFFFFFFFFFul) << 1;
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}
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uint scaled;
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if ((exp & 1u) == 0u)
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{
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scaled = (uint)(((fraction & 0x000FF00000000000ul) | 0x0010000000000000ul) >> 44);
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}
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else
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{
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scaled = (uint)(((fraction & 0x000FE00000000000ul) | 0x0010000000000000ul) >> 45);
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}
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uint resultExp = (380u - exp) >> 1;
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uint estimate = SoftFloat.InvSqrtEstimateTable[scaled - 128u] + 256u;
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result = BitConverter.Int32BitsToSingle((int)((resultExp & 0xFFu) << 23 | (estimate & 0xFFu) << 15));
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}
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return result;
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}
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public static float FPRSqrtStepFused(float value1, float value2, CpuThreadState state)
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{
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Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat32.FPRSqrtStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
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@ -1490,6 +1525,11 @@ namespace ChocolArm64.Instructions
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return sign ? -0f : +0f;
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}
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private static float FPMaxNormal(bool sign)
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{
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return sign ? float.MinValue : float.MaxValue;
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}
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private static float FPTwo(bool sign)
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{
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return sign ? -2f : +2f;
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@ -2201,6 +2241,95 @@ namespace ChocolArm64.Instructions
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return result;
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}
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public static double FPRecipEstimate(double value, CpuThreadState state)
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{
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Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPRecipEstimate: state.Fpcr = 0x{state.Fpcr:X8}");
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value.FPUnpack(out FpType type, out bool sign, out ulong op, state);
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double result;
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if (type == FpType.SNaN || type == FpType.QNaN)
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{
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result = FPProcessNaN(type, op, state);
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}
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else if (type == FpType.Infinity)
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{
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result = FPZero(sign);
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}
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else if (type == FpType.Zero)
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{
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result = FPInfinity(sign);
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FPProcessException(FpExc.DivideByZero, state);
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}
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else if (Math.Abs(value) < Math.Pow(2d, -1024))
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{
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bool overflowToInf;
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switch (state.FPRoundingMode())
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{
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default:
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case RoundMode.ToNearest: overflowToInf = true; break;
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case RoundMode.TowardsPlusInfinity: overflowToInf = !sign; break;
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case RoundMode.TowardsMinusInfinity: overflowToInf = sign; break;
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case RoundMode.TowardsZero: overflowToInf = false; break;
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}
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result = overflowToInf ? FPInfinity(sign) : FPMaxNormal(sign);
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FPProcessException(FpExc.Overflow, state);
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FPProcessException(FpExc.Inexact, state);
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}
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else if (state.GetFpcrFlag(Fpcr.Fz) && (Math.Abs(value) >= Math.Pow(2d, 1022)))
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{
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result = FPZero(sign);
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state.SetFpsrFlag(Fpsr.Ufc);
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}
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else
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{
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ulong fraction = op & 0x000FFFFFFFFFFFFFul;
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uint exp = (uint)((op & 0x7FF0000000000000ul) >> 52);
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if (exp == 0u)
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{
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if ((fraction & 0x0008000000000000ul) == 0ul)
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{
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fraction = (fraction & 0x0003FFFFFFFFFFFFul) << 2;
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exp -= 1u;
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}
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else
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{
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fraction = (fraction & 0x0007FFFFFFFFFFFFul) << 1;
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}
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}
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uint scaled = (uint)(((fraction & 0x000FF00000000000ul) | 0x0010000000000000ul) >> 44);
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uint resultExp = 2045u - exp;
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uint estimate = SoftFloat.RecipEstimateTable[scaled - 256u] + 256u;
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fraction = (ulong)(estimate & 0xFFu) << 44;
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if (resultExp == 0u)
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{
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fraction = ((fraction & 0x000FFFFFFFFFFFFEul) | 0x0010000000000000ul) >> 1;
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}
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else if (resultExp + 1u == 0u)
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{
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fraction = ((fraction & 0x000FFFFFFFFFFFFCul) | 0x0010000000000000ul) >> 2;
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resultExp = 0u;
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}
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result = BitConverter.Int64BitsToDouble(
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(long)((sign ? 1ul : 0ul) << 63 | (resultExp & 0x7FFul) << 52 | (fraction & 0x000FFFFFFFFFFFFFul)));
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}
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return result;
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}
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public static double FPRecipStepFused(double value1, double value2, CpuThreadState state)
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{
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Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPRecipStepFused: state.Fpcr = 0x{state.Fpcr:X8}");
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@ -2268,6 +2397,71 @@ namespace ChocolArm64.Instructions
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return result;
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}
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||||
|
||||
public static double FPRSqrtEstimate(double value, CpuThreadState state)
|
||||
{
|
||||
Debug.WriteLineIf(state.Fpcr != 0, $"SoftFloat64.FPRSqrtEstimate: 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 if (type == FpType.Zero)
|
||||
{
|
||||
result = FPInfinity(sign);
|
||||
|
||||
FPProcessException(FpExc.DivideByZero, state);
|
||||
}
|
||||
else if (sign)
|
||||
{
|
||||
result = FPDefaultNaN();
|
||||
|
||||
FPProcessException(FpExc.InvalidOp, state);
|
||||
}
|
||||
else if (type == FpType.Infinity)
|
||||
{
|
||||
result = FPZero(false);
|
||||
}
|
||||
else
|
||||
{
|
||||
ulong fraction = op & 0x000FFFFFFFFFFFFFul;
|
||||
uint exp = (uint)((op & 0x7FF0000000000000ul) >> 52);
|
||||
|
||||
if (exp == 0u)
|
||||
{
|
||||
while ((fraction & 0x0008000000000000ul) == 0ul)
|
||||
{
|
||||
fraction = (fraction & 0x0007FFFFFFFFFFFFul) << 1;
|
||||
exp -= 1u;
|
||||
}
|
||||
|
||||
fraction = (fraction & 0x0007FFFFFFFFFFFFul) << 1;
|
||||
}
|
||||
|
||||
uint scaled;
|
||||
|
||||
if ((exp & 1u) == 0u)
|
||||
{
|
||||
scaled = (uint)(((fraction & 0x000FF00000000000ul) | 0x0010000000000000ul) >> 44);
|
||||
}
|
||||
else
|
||||
{
|
||||
scaled = (uint)(((fraction & 0x000FE00000000000ul) | 0x0010000000000000ul) >> 45);
|
||||
}
|
||||
|
||||
uint resultExp = (3068u - exp) >> 1;
|
||||
|
||||
uint estimate = SoftFloat.InvSqrtEstimateTable[scaled - 128u] + 256u;
|
||||
|
||||
result = BitConverter.Int64BitsToDouble((long)((resultExp & 0x7FFul) << 52 | (estimate & 0xFFul) << 44));
|
||||
}
|
||||
|
||||
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}");
|
||||
|
|
@ -2415,6 +2609,11 @@ namespace ChocolArm64.Instructions
|
|||
return sign ? -0d : +0d;
|
||||
}
|
||||
|
||||
private static double FPMaxNormal(bool sign)
|
||||
{
|
||||
return sign ? double.MinValue : double.MaxValue;
|
||||
}
|
||||
|
||||
private static double FPTwo(bool sign)
|
||||
{
|
||||
return sign ? -2d : +2d;
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue