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ermig1979 merged 1 commit into from
Jun 9, 2026
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Improve SimdLib type descriptions #387

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6 changes: 6 additions & 0 deletions docs/2026.html
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Original file line number Diff line number Diff line change
Expand Up @@ -85,6 +85,12 @@ <h5>Improving</h5>
<li>Description of type SimdBayerLayoutType.</li>
<li>Description of type SimdBool.</li>
<li>Description of type SimdCompareType.</li>
<li>Description of type SimdConvolutionActivationType.</li>
<li>Description of type SimdCpuDescType.</li>
<li>Description of type SimdCpuInfoType.</li>
<li>Description of type SimdDetectionInfoFlags.</li>
<li>Description of type SimdGridSampleInterpType.</li>
<li>Description of type SimdGridSamplePaddingType.</li>
<li>Description of function SimdBgrToLab.</li>
<li>Description of function SimdBgrToRgb.</li>
<li>Description of function SimdBgrToYuv420pV2.</li>
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125 changes: 75 additions & 50 deletions src/Simd/SimdLib.h
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Expand Up @@ -180,49 +180,56 @@ typedef enum
} SimdCompareType;

/*! @ingroup synet_types
Describes type of activation function.
It is used in ::SimdSynetConvolution32fInit, ::SimdSynetConvolution8iInit, ::SimdSynetDeconvolution32fInit,
::SimdSynetInnerProduct32fInit, ::SimdSynetMergedConvolution32fInit and ::SimdSynetMergedConvolution8iInit.
Describes activation functions used by Synet convolution, deconvolution, inner product, merged convolution,
quantized convolution and quantized add APIs.

Activations are applied after bias/normalization/addition as documented by the corresponding function.
Parameters are passed through the \c params or \c actParams arguments of those functions. A NULL parameter
pointer is valid only for activations that do not use parameters.
*/
typedef enum
{
/*!
Identity (activation function is absent).
Identity activation: no transformation is applied.
\verbatim
dst[i] = src[i];
\endverbatim
*/
SimdConvolutionActivationIdentity = 0,
/*!
ReLU activation function.
ReLU activation function. It does not use parameters.
\verbatim
dst[i] = Max(0, src[i]);
\endverbatim
*/
SimdConvolutionActivationRelu,
/*!
Leaky ReLU activation function.
It has one parameter: slope (params[0]).
It has one parameter: negative slope (params[0]).
\verbatim
dst[i] = src[i] > 0 ? src[i] : slope*src[i];
\endverbatim
*/
SimdConvolutionActivationLeakyRelu,
/*!
The activation function restricts range.
It has two parameters: lower (params[0]) and upper (params[1]) bound.
RestrictRange activation function.
It clamps the value to the interval [lower, upper], where lower = params[0] and upper = params[1].
\verbatim
dst[i] = Min(Max(lower, src[i]), upper);
\endverbatim
*/
SimdConvolutionActivationRestrictRange,
/*!
Leaky PReLU activation function.
It has m parameters: slopes[m] (m = dstC, n = dstH*dstW).
PReLU activation function.
It uses one negative slope per destination channel. For a convolution output with dstC channels and
spatial size n = dstH*dstW, params[c] is used for channel c.
\verbatim
dst[i*n + j] = src[i*n + j] > 0 ? src[i*n + j] : slopes[i]*src[i*n + j];
dst[c*n + j] = src[c*n + j] > 0 ? src[c*n + j] : params[c]*src[c*n + j];
\endverbatim
*/
SimdConvolutionActivationPrelu,
/*!
Leaky ELU activation function.
ELU activation function.
It has one parameter: alpha (params[0]).
\verbatim
dst[i] = src[i] >= 0 ? src[i] : alpha*(Exp(src[i]) - 1);
Expand All @@ -231,17 +238,17 @@ typedef enum
SimdConvolutionActivationElu,
/*!
H-Swish (https://arxiv.org/pdf/1905.02244.pdf) activation function.
It has two parameters: shift (params[0]) and scale (params[1]).
It has two parameters: shift (params[0]) and scale (params[1]). Typical values are shift = 3 and scale = 1/6.
\verbatim
dst[i] = Max(Min(src[i], shift) + shift, 0)*scale*src[i];
\endverbatim
*/
SimdConvolutionActivationHswish,
/*!
Mish (https://arxiv.org/abs/1908.08681) activation function.
It has parameter: threshold (params[0]).
It has one parameter: threshold (params[0]). Values greater than threshold are returned unchanged.
\verbatim
dst[i] = src[i] > threshold ? src[i] : src[i] * tanh(log(exp(src[i]) + 1));
dst[i] = src[i] > threshold ? src[i] : src[i]*(1 - 2/(Square(Exp(src[i]) + 1) + 1));
\endverbatim
*/
SimdConvolutionActivationMish,
Expand All @@ -263,6 +270,7 @@ typedef enum
SimdConvolutionActivationSwish,
/*!
GELU (https://en.wikipedia.org/wiki/Activation_function) activation function.
It does not use parameters.
\verbatim
dst[i] = src[i] * (1 + erf(src[i]/sqrt(2))) / 2;
\endverbatim
Expand All @@ -271,79 +279,96 @@ typedef enum
} SimdConvolutionActivationType;

/*! @ingroup c_types
Describes type of description which can return function ::SimdCpuDesc.
Describes string descriptions available from ::SimdCpuDesc.

Unknown values passed to ::SimdCpuDesc return NULL. Returned strings are owned by the library and remain valid
until the process exits.
*/
typedef enum
{
SimdCpuDescModel, /*!< A CPU model name. */
SimdCpuDescModel, /*!< CPU brand/model name string. It can be empty when the platform does not expose it. */
} SimdCpuDescType;

/*! @ingroup c_types
Describes type of information which can return function ::SimdCpuInfo.
Describes CPU information queries supported by ::SimdCpuInfo.

Topology and memory queries return counts or byte sizes. SIMD extension queries return 1 only when the
extension is both supported by the current CPU and enabled in this build of the library; otherwise they return 0.
Unsupported query values also return 0.
*/
typedef enum
{
SimdCpuInfoSockets,/*!< A number of sockets. */
SimdCpuInfoCores, /*!< A number of physical CPU cores. */
SimdCpuInfoThreads, /*!< A number of logical CPU cores. */
SimdCpuInfoCacheL1, /*!< A size of level 1 data cache in bytes. */
SimdCpuInfoCacheL2, /*!< A size of level 2 cache in bytes. */
SimdCpuInfoCacheL3, /*!< A size of level 3 cache in bytes. */
SimdCpuInfoRam, /*!< A size of physical RAM in bytes. */
SimdCpuInfoSse41, /*!< Availability of SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2 (x86). */
SimdCpuInfoAvx2, /*!< Availability of AVX, FMA, AVX2 (x86). */
SimdCpuInfoAvx512bw, /*!< Availability of AVX-512F, AVX-512BW (x86). */
SimdCpuInfoAvx512vnni, /*!< Availability of AVX-512VNNI (x86). */
SimdCpuInfoAmxBf16, /*!< Availability of AVX-512VBMI, AVX-512FP16, AMX-BF16, AMX-INT8 (x86). */
SimdCpuInfoNeon, /*!< Availability of NEON (ARM). */
SimdCpuInfoSve, /*!< Availability of SVE (ARM). */
SimdCpuInfoSveSize, /*!< A size of SVE/SVE2 (ARM) vector in bytes. */
SimdCpuInfoSve2, /*!< Availability of SVE2 (ARM). */
SimdCpuInfoHvx, /*!< Availability of HVX (Hexagon). */
SimdCpuInfoCurrentFrequency, /*!< Gets CPU current frequency (for current CPU core). */
SimdCpuInfoSockets, /*!< Number of CPU sockets. */
SimdCpuInfoCores, /*!< Number of physical CPU cores. */
SimdCpuInfoThreads, /*!< Number of logical CPU threads. */
SimdCpuInfoCacheL1, /*!< Size in bytes of the level 1 data cache. */
SimdCpuInfoCacheL2, /*!< Size in bytes of the level 2 cache. */
SimdCpuInfoCacheL3, /*!< Size in bytes of the level 3 cache. */
SimdCpuInfoRam, /*!< Size in bytes of physical RAM. */
SimdCpuInfoSse41, /*!< Availability of x86 SSE4.1 code path and required lower SSE levels. */
SimdCpuInfoAvx2, /*!< Availability of x86 AVX2 code path with AVX and FMA support. */
SimdCpuInfoAvx512bw, /*!< Availability of x86 AVX-512BW code path with AVX-512F support. */
SimdCpuInfoAvx512vnni, /*!< Availability of x86 AVX-512VNNI code path. */
SimdCpuInfoAmxBf16, /*!< Availability of x86 AMX-BF16 code path with AMX-INT8, AVX-512VBMI and AVX-512FP16 support. */
SimdCpuInfoNeon, /*!< Availability of ARM NEON code path. */
SimdCpuInfoSve, /*!< Availability of ARM SVE code path. */
SimdCpuInfoSveSize, /*!< Size in bytes of the ARM SVE/SVE2 vector register; 0 if SVE is unavailable. */
SimdCpuInfoSve2, /*!< Availability of ARM SVE2 code path. */
SimdCpuInfoHvx, /*!< Availability of Hexagon HVX code path. */
SimdCpuInfoCurrentFrequency, /*!< Current frequency in Hz of the CPU core executing the query; 0 if unavailable. */
} SimdCpuInfoType;

/*! @ingroup c_types
Describes types and flags to get information about classifier cascade with using function ::SimdDetectionInfo.
Describes classifier cascade type and capability flags returned by ::SimdDetectionInfo.

The low bits selected by ::SimdDetectionInfoFeatureMask encode the cascade feature type. Other bits describe
optional cascade properties. Test flags with bit operations, for example:
<tt>(flags & SimdDetectionInfoFeatureMask)</tt> and <tt>(flags & SimdDetectionInfoHasTilted)</tt>.
\note This type is used for implementation of Simd::Detection.
*/
typedef enum
{
/*! A HAAR cascade classifier type. */
/*! HAAR cascade classifier type, stored in the feature-type bits. */
SimdDetectionInfoFeatureHaar = 0,
/*! A LBP cascade classifier type. */
/*! LBP cascade classifier type, stored in the feature-type bits. */
SimdDetectionInfoFeatureLbp,
/*! A mask to select cascade classifier type. */
/*! Mask used to extract the feature type from a ::SimdDetectionInfoFlags value. */
SimdDetectionInfoFeatureMask = 3,
/*! A flag which defines existence of tilted features in the HAAR cascade. */
/*! Flag set when a HAAR cascade contains tilted features and requires a tilted integral image. */
SimdDetectionInfoHasTilted = 4,
/*! A flag which defines possibility to use 16-bit integers for calculation. */
/*! Flag set when an LBP cascade can use the 16-bit integer detection path. */
SimdDetectionInfoCanInt16 = 8,
} SimdDetectionInfoFlags;

/*! @ingroup synet_grid_sample
Describes grid sample interpolation type. It is used in function ::SimdSynetGridSample2dInit.
Describes interpolation modes used by ::SimdSynetGridSample2dInit.

The grid tensor stores normalized <tt>(x, y)</tt> coordinates. During ::SimdSynetGridSample2dForward these
modes define how source pixels around each denormalized coordinate are combined.
*/
typedef enum
{
/*! Using of bilinear interpolation. */
/*! Bilinear interpolation from the four neighboring source pixels. */
SimdGridSampleInterpBilinear = 0,
/*! Using of nearest pixel value. */
/*! Nearest-neighbor interpolation after rounding the denormalized coordinate. */
SimdGridSampleInterpNearest,
/*! Using of bicubic interpolation. */
/*! Bicubic interpolation from a 4x4 neighborhood. */
SimdGridSampleInterpBicubic,
} SimdGridSampleInterpType;

/*! @ingroup synet_grid_sample
Describes grid sample padding type. It is used in function ::SimdSynetGridSample2dInit.
Describes padding modes used by ::SimdSynetGridSample2dInit.

Padding is applied when a denormalized grid coordinate falls outside the source image. The border used for
this test depends on the \c align parameter of ::SimdSynetGridSample2dInit.
*/
typedef enum
{
/*! Using of 0 for out-of-bound grid locations. */
/*! Use zero for out-of-bound source samples. */
SimdGridSamplePaddingZeros = 0,
/*! Using of border values for out-of-bound grid locations. */
/*! Clamp out-of-bound source samples to the nearest border pixel. */
SimdGridSamplePaddingBorder,
/*! Using of values at locations reflected by the border for out-of-bound grid locations. */
/*! Reflect out-of-bound source samples across the border before reading the source pixel. */
SimdGridSamplePaddingReflect,
} SimdGridSamplePaddingType;

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