Functions to acceleratе activation functions in Synet Framework. More...

Functions
SIMD_API void	SimdSynetElu32f (const float src, size_t size, const float alpha, float *dst)
	Calculates ELU activation function for 32-bit float array. More...

SIMD_API void	SimdSynetGelu32f (const float src, size_t size, float dst)
	This function is used for forward propagation of GeluLayer. More...

SIMD_API void	SimdSynetHardSigmoid32f (const float src, size_t size, const float scale, const float shift, float dst)
	Calculates HardSigmoid activation function (https://pytorch.org/docs/stable/generated/torch.nn.Hardsigmoid.html) for 32-bit float array. More...

SIMD_API void	SimdSynetHswish32f (const float src, size_t size, const float shift, const float scale, float dst)
	Calculates H-Swish activation function (https://arxiv.org/pdf/1905.02244.pdf) for 32-bit float array. More...

SIMD_API void	SimdSynetMish32f (const float src, size_t size, const float threshold, float *dst)

SIMD_API void	SimdSynetPreluLayerForward (const float src, const float slope, size_t channels, size_t spatial, float *dst, SimdTensorFormatType format)
	This function is used for forward propagation of PreluLayer (PReLU). More...

SIMD_API void	SimdSynetRelu32f (const float src, size_t size, const float slope, float *dst)
	Calculates ReLU (rectified linear unit) function for 32-bit float array. More...

SIMD_API void	SimdSynetRestrictRange32f (const float src, size_t size, const float lower, const float upper, float dst)
	This function is used in order to restrict range for given 320bit float array. More...

SIMD_API void	SimdSynetSigmoid32f (const float src, size_t size, const float slope, float *dst)
	This function is used for forward propagation of SigmoidLayer. More...

SIMD_API void	SimdSynetSoftplus32f (const float src, size_t size, const float beta, const float threshold, float dst)
	This function is used for forward propagation of SoftplusLayer. More...

SIMD_API void	SimdSynetSwish32f (const float src, size_t size, const float slope, float *dst)
	This function is used for forward propagation of SwishLayer. More...

SIMD_API void	SimdSynetTanh32f (const float src, size_t size, const float slope, float *dst)
	Calculates hyperbolic tangent for 32-bit float array. More...

Detailed Description

Functions to acceleratе activation functions in Synet Framework.

Function Documentation

◆ SimdSynetElu32f()

void SimdSynetElu32f	(	const float *	src,
		size_t	size,
		const float *	alpha,
		float *	dst
	)

Calculates ELU activation function for 32-bit float array.

The input and output arrays must have the same size.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = src[i] >= 0 ? src[i] : alpha*(Exp(src[i]) - 1);

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	alpha	- a pointer to alpha parameter.
[out]	dst	- a pointer to the output 32-bit float array.

◆ SimdSynetGelu32f()

void SimdSynetGelu32f	(	const float *	src,
		size_t	size,
		float *	dst
	)

This function is used for forward propagation of GeluLayer.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = src[i] * (1 + erf(src[i]/sqrt(2))) / 2;

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the 32-bit float array.
[in]	size	- a size of input and output arrays.
[out]	dst	- a pointer to output 32-bit float array.

◆ SimdSynetHardSigmoid32f()

void SimdSynetHardSigmoid32f	(	const float *	src,
		size_t	size,
		const float *	scale,
		const float *	shift,
		float *	dst
	)

Calculates HardSigmoid activation function (https://pytorch.org/docs/stable/generated/torch.nn.Hardsigmoid.html) for 32-bit float array.

Input and output arrays must have the same size.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = Max(0, Min(src[i] * scale + shift, 1));

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	scale	- a pointer to scale parameter. This parameter is equal to 1/6 in Pytorch documentation.
[in]	shift	- a pointer to shift parameter. This parameter is equal to 1/2 in Pytorch documentation.
[out]	dst	- a pointer to the output 32-bit float array.

◆ SimdSynetHswish32f()

void SimdSynetHswish32f	(	const float *	src,
		size_t	size,
		const float *	shift,
		const float *	scale,
		float *	dst
	)

Calculates H-Swish activation function (https://arxiv.org/pdf/1905.02244.pdf) for 32-bit float array.

Input and output arrays must have the same size.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = Max(Min(src[i], shift) + shift, 0)*scale*src[i];

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	shift	- a pointer to shift parameter. It is equal to 3 in original paper.
[in]	scale	- a pointer to scale parameter. It is equal to 1/6 in original paper.
[out]	dst	- a pointer to the output 32-bit float array.

◆ SimdSynetMish32f()

void SimdSynetMish32f	(	const float *	src,
		size_t	size,
		const float *	threshold,
		float *	dst
	)

Calculates Mish activation function (https://arxiv.org/abs/1908.08681) for 32-bit float array

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = src[i] > threshold ? src[i] : src[i] * tanh(log(exp(src[i]) + 1));

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	threshold	- a pointer to 'threshold' parameter.
[out]	dst	- a pointer to the output 32-bit float array.

◆ SimdSynetPreluLayerForward()

void SimdSynetPreluLayerForward	(	const float *	src,
		const float *	slope,
		size_t	channels,
		size_t	spatial,
		float *	dst,
		SimdTensorFormatType	format
	)

This function is used for forward propagation of PreluLayer (PReLU).

Algorithm's details (example for NCHW tensor format):

for(c = 0; c < channels; ++c)
    for(s = 0; s < spatial; ++s)
        dst[c*spatial + s] = src[c*spatial + s] > 0 ? src[c*spatial + s] : slope[c]*src[c*spatial + s];

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the 32-bit float array with input image tensor. The size of the array is equal to channels * spatial.
[in]	slope	- a pointer to the 32-bit float array with slope coefficients. The size of the array is equal to channels.
[in]	channels	- a number of channels in the (input/output) image tensor
[in]	spatial	- a spatial size of (input/output) image tensor.
[out]	dst	- a pointer to the 32-bit float array with output image tensor. The size of the array is equal to channels * spatial.
[in]	format	- a format of (input/output) image tensor.

◆ SimdSynetRelu32f()

void SimdSynetRelu32f	(	const float *	src,
		size_t	size,
		const float *	slope,
		float *	dst
	)

Calculates ReLU (rectified linear unit) function for 32-bit float array.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] =  src[i] > 0 ? src[i] : slope*src[i];

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	slope	- a pointer to the 'slope' parameter.
[out]	dst	- a pointer to output 32-bit float array.

◆ SimdSynetRestrictRange32f()

void SimdSynetRestrictRange32f	(	const float *	src,
		size_t	size,
		const float *	lower,
		const float *	upper,
		float *	dst
	)

This function is used in order to restrict range for given 320bit float array.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = Min(Max(lower, src[i]), upper);

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	lower	- a pointer to lower restrict bound.
[in]	upper	- a pointer to upper restrict bound.
[out]	dst	- a pointer to the output 32-bit float array.

◆ SimdSynetSigmoid32f()

void SimdSynetSigmoid32f	(	const float *	src,
		size_t	size,
		const float *	slope,
		float *	dst
	)

This function is used for forward propagation of SigmoidLayer.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = 1/(1 + exp(-slope*src[i]));

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	slope	- a pointer to the 'slope' parameter.
[out]	dst	- a pointer to output 32-bit float array.

◆ SimdSynetSoftplus32f()

void SimdSynetSoftplus32f	(	const float *	src,
		size_t	size,
		const float *	beta,
		const float *	threshold,
		float *	dst
	)

This function is used for forward propagation of SoftplusLayer.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = src[i] > threshold ? src[i] : log(1 + exp(src[i]*beta))/beta;

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	beta	- a pointer to 'beta' parameter.
[in]	threshold	- a pointer to 'threshold' parameter.
[out]	dst	- a pointer to the output 32-bit float array.

◆ SimdSynetSwish32f()

void SimdSynetSwish32f	(	const float *	src,
		size_t	size,
		const float *	slope,
		float *	dst
	)

This function is used for forward propagation of SwishLayer.

Algorithm's details:

for(i = 0; i < size; ++i)
    dst[i] = src[i]/(1 + exp(-slope*src[i]));

Note: This function is used in Synet Framework.

Parameters

[in]	src	- a pointer to the 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	slope	- a pointer to the 'slope' parameter.
[out]	dst	- a pointer to output 32-bit float array.

◆ SimdSynetTanh32f()

void SimdSynetTanh32f	(	const float *	src,
		size_t	size,
		const float *	slope,
		float *	dst
	)

Calculates hyperbolic tangent for 32-bit float array.

Note: This function is used in Synet Framework.

Algorithm's details:

for(i = 0; i < size; ++i)
{
    x = slope*src[i];
    dst[i] = (exp(x) - exp(-x))/(exp(x) + exp(-x));
}

Parameters

[in]	src	- a pointer to the input 32-bit float array.
[in]	size	- a size of input and output arrays.
[in]	slope	- a pointer to the 'slope' parameter.
[out]	dst	- a pointer to output 32-bit float array.

Simd Library Documentation.

Functions

Detailed Description

Function Documentation

◆ SimdSynetElu32f()

◆ SimdSynetGelu32f()

◆ SimdSynetHardSigmoid32f()

◆ SimdSynetHswish32f()

◆ SimdSynetMish32f()

◆ SimdSynetPreluLayerForward()

◆ SimdSynetRelu32f()

◆ SimdSynetRestrictRange32f()

◆ SimdSynetSigmoid32f()

◆ SimdSynetSoftplus32f()

◆ SimdSynetSwish32f()

◆ SimdSynetTanh32f()