using System;
using Unity.Burst;
#if !UNITY_DOTSPLAYER
#if !BURST_INTERNAL
using AOT;
using UnityEngine;
#endif
using System.Runtime.InteropServices;
#endif
namespace Unity.Burst.Intrinsics
{
#if !BURST_INTERNAL && !UNITY_DOTSPLAYER
[BurstCompile]
#endif
public unsafe static partial class X86
{
/// <summary>
/// The 32-bit MXCSR register contains control and status information for SSE and AVX SIMD floating-point operations.
/// </summary>
[Flags]
public enum MXCSRBits
{
/// <summary>
/// Bit 15 (FTZ) of the MXCSR register enables the flush-to-zero mode, which controls the masked response to a SIMD floating-point underflow condition.
/// </summary>
/// <remarks>
/// When the underflow exception is masked and the flush-to-zero mode is enabled, the processor performs the following operations when it detects a floating-point underflow condition.
/// - Returns a zero result with the sign of the true result
/// - Sets the precision and underflow exception flags.
///
/// If the underflow exception is not masked, the flush-to-zero bit is ignored.
///
/// The flush-to-zero mode is not compatible with IEEE Standard 754. The IEEE-mandated masked response to under-flow is to deliver the denormalized result.
/// The flush-to-zero mode is provided primarily for performance reasons. At the cost of a slight precision loss, faster execution can be achieved for applications where underflows
/// are common and rounding the underflow result to zero can be tolerated. The flush-to-zero bit is cleared upon a power-up or reset of the processor, disabling the flush-to-zero mode.
/// </remarks>
FlushToZero = 1 << 15,
/// <summary>
/// Mask for rounding control bits.
/// </summary>
///
/// The rounding modes have no effect on comparison operations, operations that produce exact results, or operations that produce NaN results.
RoundingControlMask = (1 << 14) | (1 << 13),
/// <summary>
/// Rounded result is the closest to the infinitely precise result. If two values are equally close, the result is the even value (that is, the one with the least-significant bit of zero). Default.
/// </summary>
RoundToNearest = 0,
/// <summary>
/// Rounded result is closest to but no greater than the infinitely precise result.
/// </summary>
RoundDown = (1 << 13),
/// <summary>
/// Rounded result is closest to but no less than the infinitely precise result.
/// </summary>
RoundUp = (1 << 14),
/// <summary>
/// Rounded result is closest to but no greater in absolute value than the infinitely precise result.
/// </summary>
RoundTowardZero = (1 << 13) | (1 << 14),
/// <summary>Bits 7 through 12 provide individual mask bits for the SIMD floating-point exceptions. An exception type is masked if the corresponding mask bit is set, and it is unmasked if the bit is clear. These mask bits are set upon a power-up or reset. This causes all SIMD floating-point exceptions to be initially masked.</summary>
PrecisionMask = 1 << 12,
/// <summary>Bits 7 through 12 provide individual mask bits for the SIMD floating-point exceptions. An exception type is masked if the corresponding mask bit is set, and it is unmasked if the bit is clear. These mask bits are set upon a power-up or reset. This causes all SIMD floating-point exceptions to be initially masked.</summary>
UnderflowMask = 1 << 11,
/// <summary>Bits 7 through 12 provide individual mask bits for the SIMD floating-point exceptions. An exception type is masked if the corresponding mask bit is set, and it is unmasked if the bit is clear. These mask bits are set upon a power-up or reset. This causes all SIMD floating-point exceptions to be initially masked.</summary>
OverflowMask = 1 << 10,
/// <summary>Bits 7 through 12 provide individual mask bits for the SIMD floating-point exceptions. An exception type is masked if the corresponding mask bit is set, and it is unmasked if the bit is clear. These mask bits are set upon a power-up or reset. This causes all SIMD floating-point exceptions to be initially masked.</summary>
DivideByZeroMask = 1 << 9,
/// <summary>Bits 7 through 12 provide individual mask bits for the SIMD floating-point exceptions. An exception type is masked if the corresponding mask bit is set, and it is unmasked if the bit is clear. These mask bits are set upon a power-up or reset. This causes all SIMD floating-point exceptions to be initially masked.</summary>
DenormalOperationMask = 1 << 8,
/// <summary>Bits 7 through 12 provide individual mask bits for the SIMD floating-point exceptions. An exception type is masked if the corresponding mask bit is set, and it is unmasked if the bit is clear. These mask bits are set upon a power-up or reset. This causes all SIMD floating-point exceptions to be initially masked.</summary>
InvalidOperationMask = 1 << 7,
/// <summary>
/// Combine all bits for exception masking into one mask for convenience.
/// </summary>
ExceptionMask = PrecisionMask | UnderflowMask | OverflowMask | DivideByZeroMask | DenormalOperationMask | InvalidOperationMask,
/// <summary>
/// Bit 6 (DAZ) of the MXCSR register enables the denormals-are-zeros mode, which controls the processor’s response to a SIMD floating-point denormal operand condition.
/// </summary>
///
/// When the denormals-are-zeros flag is set, the processor converts all denormal source operands to a zero with the sign of the original operand before performing any computations on them.
/// The processor does not set the denormal-operand exception flag (DE), regardless of the setting of the denormal-operand exception mask bit (DM); and it does not generate a denormal-operand
/// exception if the exception is unmasked.The denormals-are-zeros mode is not compatible with IEEE Standard 754.
///
/// The denormals-are-zeros mode is provided to improve processor performance for applications such as streaming media processing, where rounding a denormal operand to zero does not
/// appreciably affect the quality of the processed data. The denormals-are-zeros flag is cleared upon a power-up or reset of the processor, disabling the denormals-are-zeros mode.
///
/// The denormals-are-zeros mode was introduced in the Pentium 4 and Intel Xeon processor with the SSE2 extensions; however, it is fully compatible with the SSE SIMD floating-point instructions
/// (that is, the denormals-are-zeros flag affects the operation of the SSE SIMD floating-point instructions). In earlier IA-32 processors and in some models of the Pentium 4 processor, this flag
/// (bit 6) is reserved. Attempting to set bit 6 of the MXCSR register on processors that do not support the DAZ flag will cause a general-protection exception (#GP).
DenormalsAreZeroes = 1 << 6,
/// <summary>Bits 0 through 5 of the MXCSR register indicate whether a SIMD floating-point exception has been detected. They are "sticky" flags. That is, after a flag is set, it remains set until explicitly cleared. To clear these flags, use the LDMXCSR or the FXRSTOR instruction to write zeroes to them.</summary>
PrecisionFlag = 1 << 5,
/// <summary>Bits 0 through 5 of the MXCSR register indicate whether a SIMD floating-point exception has been detected. They are "sticky" flags. That is, after a flag is set, it remains set until explicitly cleared. To clear these flags, use the LDMXCSR or the FXRSTOR instruction to write zeroes to them.</summary>
UnderflowFlag = 1 << 4,
/// <summary>Bits 0 through 5 of the MXCSR register indicate whether a SIMD floating-point exception has been detected. They are "sticky" flags. That is, after a flag is set, it remains set until explicitly cleared. To clear these flags, use the LDMXCSR or the FXRSTOR instruction to write zeroes to them.</summary>
OverflowFlag = 1 << 3,
/// <summary>Bits 0 through 5 of the MXCSR register indicate whether a SIMD floating-point exception has been detected. They are "sticky" flags. That is, after a flag is set, it remains set until explicitly cleared. To clear these flags, use the LDMXCSR or the FXRSTOR instruction to write zeroes to them.</summary>
DivideByZeroFlag = 1 << 2,
/// <summary>Bits 0 through 5 of the MXCSR register indicate whether a SIMD floating-point exception has been detected. They are "sticky" flags. That is, after a flag is set, it remains set until explicitly cleared. To clear these flags, use the LDMXCSR or the FXRSTOR instruction to write zeroes to them.</summary>
DenormalFlag = 1 << 1,
/// <summary>Bits 0 through 5 of the MXCSR register indicate whether a SIMD floating-point exception has been detected. They are "sticky" flags. That is, after a flag is set, it remains set until explicitly cleared. To clear these flags, use the LDMXCSR or the FXRSTOR instruction to write zeroes to them.</summary>
InvalidOperationFlag = 1 << 0,
/// <summary>
/// Combines all bits for flags into one mask for convenience.
/// </summary>
FlagMask = PrecisionFlag | UnderflowFlag | OverflowFlag | DivideByZeroFlag | DenormalFlag | InvalidOperationFlag,
}
/// <summary>
/// Rounding mode flags
/// </summary>
[Flags]
public enum RoundingMode
{
/// <summary>
/// Round to the nearest integer
/// </summary>
FROUND_TO_NEAREST_INT = 0x00,
/// <summary>
/// Round to negative infinity
/// </summary>
FROUND_TO_NEG_INF = 0x01,
/// <summary>
/// Round to positive infinity
/// </summary>
FROUND_TO_POS_INF = 0x02,
/// <summary>
/// Round to zero
/// </summary>
FROUND_TO_ZERO = 0x03,
/// <summary>
/// Round to current direction
/// </summary>
FROUND_CUR_DIRECTION = 0x04,
/// <summary>
/// Do not suppress exceptions
/// </summary>
FROUND_RAISE_EXC = 0x00,
/// <summary>
/// Suppress exceptions
/// </summary>
FROUND_NO_EXC = 0x08,
/// <summary>
/// Round to the nearest integer without suppressing exceptions
/// </summary>
FROUND_NINT = FROUND_TO_NEAREST_INT | FROUND_RAISE_EXC,
/// <summary>
/// Round using Floor function without suppressing exceptions
/// </summary>
FROUND_FLOOR = FROUND_TO_NEG_INF | FROUND_RAISE_EXC,
/// <summary>
/// Round using Ceiling function without suppressing exceptions
/// </summary>
FROUND_CEIL = FROUND_TO_POS_INF | FROUND_RAISE_EXC,
/// <summary>
/// Round by truncating without suppressing exceptions
/// </summary>
FROUND_TRUNC = FROUND_TO_ZERO | FROUND_RAISE_EXC,
/// <summary>
/// Round using MXCSR.RC without suppressing exceptions
/// </summary>
FROUND_RINT = FROUND_CUR_DIRECTION | FROUND_RAISE_EXC,
/// <summary>
/// Round using MXCSR.RC and suppressing exceptions
/// </summary>
FROUND_NEARBYINT = FROUND_CUR_DIRECTION | FROUND_NO_EXC,
/// <summary>
/// Round to nearest integer and suppressing exceptions
/// </summary>
FROUND_NINT_NOEXC = FROUND_TO_NEAREST_INT | FROUND_NO_EXC,
/// <summary>
/// Round using Floor function and suppressing exceptions
/// </summary>
FROUND_FLOOR_NOEXC = FROUND_TO_NEG_INF | FROUND_NO_EXC,
/// <summary>
/// Round using Ceiling function and suppressing exceptions
/// </summary>
FROUND_CEIL_NOEXC = FROUND_TO_POS_INF | FROUND_NO_EXC,
/// <summary>
/// Round by truncating and suppressing exceptions
/// </summary>
FROUND_TRUNC_NOEXC = FROUND_TO_ZERO | FROUND_NO_EXC,
/// <summary>
/// Round using MXCSR.RC and suppressing exceptions
/// </summary>
FROUND_RINT_NOEXC = FROUND_CUR_DIRECTION | FROUND_NO_EXC,
}
internal struct RoundingScope : IDisposable
{
private MXCSRBits OldBits;
public RoundingScope(MXCSRBits roundingMode)
{
OldBits = MXCSR;
MXCSR = (OldBits & ~MXCSRBits.RoundingControlMask) | roundingMode;
}
public void Dispose()
{
MXCSR = OldBits;
}
}
#if UNITY_DOTSPLAYER
internal static int getcsr_raw()
{
throw new NotImplementedException("getcsr_raw not supported from managed in this configuration");
}
internal static void setcsr_raw(int bits)
{
throw new NotImplementedException("setcsr_raw not supported from managed in this configuration");
}
#endif
#if !BURST_INTERNAL && !UNITY_DOTSPLAYER
private static void BurstIntrinsicSetCSRFromManaged(int _) { }
private static int BurstIntrinsicGetCSRFromManaged() { return 0; }
internal static int getcsr_raw() => DoGetCSRTrampoline();
internal static void setcsr_raw(int bits) => DoSetCSRTrampoline(bits);
[BurstCompile(CompileSynchronously = true)]
private static void DoSetCSRTrampoline(int bits)
{
if (Sse.IsSseSupported)
BurstIntrinsicSetCSRFromManaged(bits);
}
[BurstCompile(CompileSynchronously = true)]
private static int DoGetCSRTrampoline()
{
if (Sse.IsSseSupported)
return BurstIntrinsicGetCSRFromManaged();
return 0;
}
#elif BURST_INTERNAL
// Internally inside burst for unit tests we can't recurse from tests into burst again,
// so we pinvoke to a dummy wrapper DLL that exposes CSR manipulation
[DllImport("burst-dllimport-native", EntryPoint = "x86_getcsr")]
internal static extern int getcsr_raw();
[DllImport("burst-dllimport-native", EntryPoint = "x86_setcsr")]
internal static extern void setcsr_raw(int bits);
#endif
/// <summary>
/// Allows access to the CSR register
/// </summary>
public static MXCSRBits MXCSR
{
[BurstTargetCpu(BurstTargetCpu.X64_SSE2)]
get
{
return (MXCSRBits)getcsr_raw();
}
[BurstTargetCpu(BurstTargetCpu.X64_SSE2)]
set
{
setcsr_raw((int)value);
}
}
}
}