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AInstEmitSimdCvt: Half-precision to single-precision conversion (#235)

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This commit is contained in:
Merry 2018-07-12 19:51:02 +01:00 committed by gdkchan
parent cd18ab29df
commit b233ae964f
3 changed files with 80 additions and 4 deletions
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8
ChocolArm64/Instruction/AInstEmitSimdCvt.cs
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@ -45,10 +45,10 @@ namespace ChocolArm64.Instruction
{
if (SizeF == 0)
{
//TODO: This need the half precision floating point type,
//that is not yet supported on .NET. We should probably
//do our own implementation on the meantime.
throw new NotImplementedException();
EmitVectorExtractZx(Context, Op.Rn, Part + Index, 1);
Context.Emit(OpCodes.Conv_U2);
Context.EmitCall(typeof(ASoftFloat), nameof(ASoftFloat.ConvertHalfToSingle));
}
else /* if (SizeF == 1) */
{

36
ChocolArm64/Instruction/ASoftFloat.cs
View file

@ -225,5 +225,41 @@ namespace ChocolArm64.Instruction
return 2.0 + op1 * op2;
}
public static float ConvertHalfToSingle(ushort x)
{
uint x_sign = (uint)(x >> 15) & 0x0001;
uint x_exp = (uint)(x >> 10) & 0x001F;
uint x_mantissa = (uint)x & 0x03FF;
if (x_exp == 0 && x_mantissa == 0)
{
// Zero
return BitConverter.Int32BitsToSingle((int)(x_sign << 31));
}
if (x_exp == 0x1F)
{
// NaN or Infinity
return BitConverter.Int32BitsToSingle((int)((x_sign << 31) | 0x7F800000 | (x_mantissa << 13)));
}
int exponent = (int)x_exp - 15;
if (x_exp == 0)
{
// Denormal
x_mantissa <<= 1;
while ((x_mantissa & 0x0400) == 0)
{
x_mantissa <<= 1;
exponent--;
}
x_mantissa &= 0x03FF;
}
uint new_exp = (uint)((exponent + 127) & 0xFF) << 23;
return BitConverter.Int32BitsToSingle((int)((x_sign << 31) | new_exp | (x_mantissa << 13)));
}
}
}

40
Ryujinx.Tests/Cpu/CpuTestSimdCvt.cs Normal file
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@ -0,0 +1,40 @@
using ChocolArm64.State;
using NUnit.Framework;
using System.Runtime.Intrinsics;
using System.Runtime.Intrinsics.X86;
namespace Ryujinx.Tests.Cpu
{
public class CpuTestSimdCvt : CpuTest
{
[TestCase((ushort)0x0000, 0x00000000u)] // Positive Zero
[TestCase((ushort)0x8000, 0x80000000u)] // Negative Zero
[TestCase((ushort)0x3E00, 0x3FC00000u)] // +1.5
[TestCase((ushort)0xBE00, 0xBFC00000u)] // -1.5
[TestCase((ushort)0xFFFF, 0xFFFFE000u)] // -QNaN
[TestCase((ushort)0x7C00, 0x7F800000u)] // +Inf
[TestCase((ushort)0x3C00, 0x3F800000u)] // 1.0
[TestCase((ushort)0x3C01, 0x3F802000u)] // 1.0009765625
[TestCase((ushort)0xC000, 0xC0000000u)] // -2.0
[TestCase((ushort)0x7BFF, 0x477FE000u)] // 65504.0 (Largest Normal)
[TestCase((ushort)0x03FF, 0x387FC000u)] // 0.00006097555 (Largest Subnormal)
[TestCase((ushort)0x0001, 0x33800000u)] // 5.96046448e-8 (Smallest Subnormal)
public void Fcvtl_V_f16(ushort Value, uint Result)
{
uint Opcode = 0x0E217801;
Vector128<float> V0 = Sse.StaticCast<ushort, float>(Sse2.SetAllVector128(Value));
AThreadState ThreadState = SingleOpcode(Opcode, V0: V0);
Assert.Multiple(() =>
{
Assert.That(Sse41.Extract(Sse.StaticCast<float, uint>(ThreadState.V1), (byte)0), Is.EqualTo(Result));
Assert.That(Sse41.Extract(Sse.StaticCast<float, uint>(ThreadState.V1), (byte)1), Is.EqualTo(Result));
Assert.That(Sse41.Extract(Sse.StaticCast<float, uint>(ThreadState.V1), (byte)2), Is.EqualTo(Result));
Assert.That(Sse41.Extract(Sse.StaticCast<float, uint>(ThreadState.V1), (byte)3), Is.EqualTo(Result));
});
}
}
}