RtGetEnabledXStateFeature

RtGetEnabledXStateFeature obtains the highest feature for a specified XState feature set supported on the running processor and enabled by RTX64.

Syntax

BOOL RtGetEnabledXStateFeature(
    XSTATE_BIT XStateBit,
    PENABLED_HIGHEST_FEATURE HighestFeature
);

Parameters

XStateBit

The XState feature set to obtain:

Values	Description
XStateFPU	MMX registers support
XStateSSE	SSE registers supported
XStateAVX	AVX registers supported
XStateMPX	MPX registers supported
XStatePT	PT registers supported

HighestFeature

A pointer to an ENABLED_HIGHEST_FEATURE structure which will be filled in with the highest version supported by the XState feature queried.

Return Value

Non-zero if the function completes successfully. Otherwise, the return value is zero.

Remarks

An RTSS application should call this function to determine what features are present and enabled on RTX64 before using an XState processor feature:

XState	Values	Description
All states	NotSupported	Floating point is not supported
XStateFPU	x87FPU	Floating point is supported
XStateSSE	SSE	SSE is supported
	SSE2	SSE/SSE2 is supported
	SSE3	SSE/SSE2/SSE3 is supported
	SSE4_1	SSE/SSE2/SSE3/SSE4.1 is supported
	SSE4_2	SSE/SSE2/SSE3/SSE4.2 is supported
XStateAVX	AVX	AVX is supported
	AVX2	AVX/AVX2 is supported
	AVX512	AVX/AVX2/AVX512 is supported
XStateMPX	MPX	MPX is supported
XStatePT	PT	PT is supported

typedef enum _XSTATE_BIT {
	XStateUndefined = -1,    // -1
	XStateFPU,               // 0 - x87 FPU
	XStateSSE,               // 1 - SSE
	XStateAVX,               // 2 - AVX
	XStateMPX,               // 3 - MPX
	XStatePT,                // 4 - PT
	XStateMaximum            // Invalid
} XSTATE_BIT, *PXSTATE_BIT;

PENABLED_HIGHEST_FEATURE is defined as follows:

typedef enum _ENABLED_HIGHEST_FEATURE {
	NotSupported = -1,
	x87FPU,
	SSE,
	SSE2,
	SSE3,
	SSSE3,
	SSE4_1,
	SSE4_2,
	AVX,
	AVX2,
	AVX512,
	MPX,
	PT
} ENABLED_HIGHEST_FEATURE, *PENABLED_HIGHEST_FEATURE;

For XState feature set XStateFPU, there is only one feature: x87FPU.

For XState feature set XStateSSE, the function returns the highest of the following six features: SSE, SSE2, SSE3, SSSE3, SSE4_1, SSE4_2.

For XState feature set XStateAVX, the function returns the highest of the following three features: AVX, AVX2, AVX512.

For XState feature set XStateMPX, there is only one feature: MPX.

For XState feature set XStatePT, there is only one feature: PT.

NOTE: Not all features supported by a processor may be enabled on the system. Using a feature which is not enabled may result in exceptions or undefined behavior.