RtGetEnabledXStateFeature

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

Syntax

BOOL RtGetEnabledXStateFeature(
    [in]    XSTATE_BIT XStateBit,
    [out]   PENABLED_HIGHEST_FEATURE HighestFeature
);

Parameters

[in] XStateBit

The XState feature set to obtain:

[out] 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

If the function succeeds, it returns a non-zero value. If the function fails, it returns zero.

Remarks

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

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.