SVDF Functions

Machine-readable model

• arm_svdf_f32functionStateful singular value decomposition filter.
• arm_svdf_f32_input_ctx_get_buffer_sizefunctionGet size of the inputctx staging buffer required by armsvdff32().
• arm_svdf_f32_output_ctx_get_buffer_sizefunctionGet size of the outputctx staging buffer required by armsvdff32().
• arm_svdf_f16functionStateful singular value decomposition filter, float16 variant.
• arm_svdf_f16_input_ctx_get_buffer_sizefunctionGet size of the inputctx staging buffer required by armsvdff16().
• arm_svdf_f16_output_ctx_get_buffer_sizefunctionGet size of the outputctx staging buffer required by armsvdff16().

function

arm_svdf_f32

C

Stateful singular value decomposition filter.

Include/arm_nnfunctions_flt.h:1694

arm_cmsis_nn_status arm_svdf_f32(
    const cmsis_nn_context *ctx,
    const cmsis_nn_context *input_ctx,
    const cmsis_nn_context *output_ctx,
    const cmsis_nn_svdf_params_f32 *svdf_params,
    const cmsis_nn_dims *input_dims,
    const float32_t *input_data,
    const cmsis_nn_dims *state_dims,
    float32_t *state_data,
    const cmsis_nn_dims *weights_feature_dims,
    const float32_t *weights_feature_data,
    const cmsis_nn_dims *weights_time_dims,
    const float32_t *weights_time_data,
    const cmsis_nn_dims *bias_dims,
    const float32_t *bias_data,
    const cmsis_nn_dims *output_dims,
    float32_t *output_data
)

Stateful singular value decomposition filter.

Parameters

Parameters of arm_svdf_f32

Name	Type	Direction	Description
ctx	const cmsis_nn_context *	in	Unused by this function. Reserved for future use; may be NULL.
input_ctx	const cmsis_nn_context *	in, out	Mandatory, not optional: a NULL input_ctx, or a NULL input_ctx->buf, is diagnosed with ARM_CMSIS_NN_ARG_ERROR on every build. Staging buffer written by this function, holding one element per (input batch, feature batch). Written before it is read, so its contents on entry do not matter, but it is written on EVERY build, not only under MVE. Sized by arm_svdf_f32_input_ctx_get_buffer_size(input_dims, weights_feature_dims): input_dims->n * weights_feature_dims->n * sizeof(float32_t) bytes. Setting input_ctx->size lets this function reject an undersized buffer with ARM_CMSIS_NN_ARG_ERROR; leaving it at zero opts out of that check. The caller is expected to clear the buffer, if applicable, for security reasons.
output_ctx	const cmsis_nn_context *	in, out	Mandatory, not optional: a NULL output_ctx, or a NULL output_ctx->buf, is diagnosed with ARM_CMSIS_NN_ARG_ERROR on every build. Staging buffer written by this function, holding one element per (input batch, output unit). Written before it is read, so its contents on entry do not matter, but it is written on EVERY build, not only under MVE. Sized by arm_svdf_f32_output_ctx_get_buffer_size(svdf_params, input_dims, weights_feature_dims): input_dims->n * (weights_feature_dims->n / svdf_params->rank) * sizeof(float32_t) bytes, truncating division. Setting output_ctx->size lets this function reject an undersized buffer with ARM_CMSIS_NN_ARG_ERROR; leaving it at zero opts out of that check. The caller is expected to clear the buffer, if applicable, for security reasons.
svdf_params	const cmsis_nn_svdf_params_f32 *	in	SVDF operator parameters.
input_dims	const cmsis_nn_dims *	in	Input tensor dimensions.
input_data	const float32_t *	in	Pointer to the input tensor data.
state_dims	const cmsis_nn_dims *	in	State tensor dimensions.
state_data	float32_t *	in, out	Pointer to the mutable state tensor.
weights_feature_dims	const cmsis_nn_dims *	in	Feature-weight tensor dimensions.
weights_feature_data	const float32_t *	in	Pointer to the feature-weight tensor.
weights_time_dims	const cmsis_nn_dims *	in	Time-weight tensor dimensions.
weights_time_data	const float32_t *	in	Pointer to the time-weight tensor.
bias_dims	const cmsis_nn_dims *	in	Bias tensor dimensions.
bias_data	const float32_t *	in	Optional bias tensor data.
output_dims	const cmsis_nn_dims *	in	Output tensor dimensions.
output_data	float32_t *	out	Pointer to the output tensor data.

Returns

Returns of arm_svdf_f32

Description
`ARM_CMSIS_NN_SUCCESS` on success or `ARM_CMSIS_NN_ARG_ERROR` on invalid arguments.

function

arm_svdf_f32_input_ctx_get_buffer_size

C

Get size of the inputctx staging buffer required by armsvdff32().

Include/arm_nnfunctions_flt.h:1734

int32_t arm_svdf_f32_input_ctx_get_buffer_size(
    const cmsis_nn_dims *input_dims,
    const cmsis_nn_dims *weights_feature_dims
)

Get size of the input_ctx staging buffer required by arm_svdf_f32().

Note

This query reports an out-of-range shape as -1, following the SVDF family (arm_svdf_s8_get_buffer_size()). That differs from the float convolution and fully-connected queries in this header, which report an out-of-range size as 0. The reason is that arm_svdf_f32() reads ctx->size, and size == 0 is the opt-out signal for its scratch-size check: a 0-on-overflow answer fed straight back as buf = alloc(0), size = 0 would silently disable the check over a zero-byte allocation, whereas alloc((size_t)-1) fails and the NULL check catches it.

Note

0 is still a valid return for a degenerate shape (input_dims->n == 0). Unlike the general rule in README.md, a 0 here does NOT mean you may pass { NULL, 0 }: arm_svdf_f32() rejects a NULL input_ctx->buf with ARM_CMSIS_NN_ARG_ERROR regardless of the size. Allocate a non-NULL pointer, or do not call the kernel for a shape that produces no output.

Parameters

Parameters of arm_svdf_f32_input_ctx_get_buffer_size

Name	Type	Direction	Description
input_dims	const cmsis_nn_dims *	in	Input tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f32()`.
weights_feature_dims	const cmsis_nn_dims *	in	Feature-weight tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f32()`.

Returns

Returns of arm_svdf_f32_input_ctx_get_buffer_size

Description
Required buffer size in bytes: input_dims->n * weights_feature_dims->n * sizeof(float32_t). Returns -1 if either pointer is NULL, if input_dims->n or weights_feature_dims->n is negative, or if the product would not fit in an int32_t. The figure and the validation are the same on every build target, since `arm_svdf_f32()` stages this buffer on every build rather than only under MVE.

function

arm_svdf_f32_output_ctx_get_buffer_size

C

Get size of the outputctx staging buffer required by armsvdff32().

Include/arm_nnfunctions_flt.h:1754

int32_t arm_svdf_f32_output_ctx_get_buffer_size(
    const cmsis_nn_svdf_params_f32 *svdf_params,
    const cmsis_nn_dims *input_dims,
    const cmsis_nn_dims *weights_feature_dims
)

Get size of the output_ctx staging buffer required by arm_svdf_f32().

Note

Same -1 and degenerate-0 contract as arm_svdf_f32_input_ctx_get_buffer_size(), including that a 0 does not license passing { NULL, 0 }.

Parameters

Parameters of arm_svdf_f32_output_ctx_get_buffer_size

Name	Type	Direction	Description
svdf_params	const cmsis_nn_svdf_params_f32 *	in	SVDF operator parameters; only svdf_params->rank is read.
input_dims	const cmsis_nn_dims *	in	Input tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f32()`.
weights_feature_dims	const cmsis_nn_dims *	in	Feature-weight tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f32()`.

Returns

Returns of arm_svdf_f32_output_ctx_get_buffer_size

Description
Required buffer size in bytes: input_dims->n * (weights_feature_dims->n / svdf_params->rank) * sizeof(float32_t), truncating division to match the kernel's own unit count. Returns -1 if any pointer is NULL, if svdf_params->rank is zero or negative, if input_dims->n or weights_feature_dims->n is negative, or if the product would not fit in an int32_t.

function

arm_svdf_f16

C

Stateful singular value decomposition filter, float16 variant.

Include/arm_nnfunctions_flt.h:3479

arm_cmsis_nn_status arm_svdf_f16(
    const cmsis_nn_context *ctx,
    const cmsis_nn_context *input_ctx,
    const cmsis_nn_context *output_ctx,
    const cmsis_nn_svdf_params_f16 *svdf_params,
    const cmsis_nn_dims *input_dims,
    const float16_t *input_data,
    const cmsis_nn_dims *state_dims,
    float16_t *state_data,
    const cmsis_nn_dims *weights_feature_dims,
    const float16_t *weights_feature_data,
    const cmsis_nn_dims *weights_time_dims,
    const float16_t *weights_time_data,
    const cmsis_nn_dims *bias_dims,
    const float16_t *bias_data,
    const cmsis_nn_dims *output_dims,
    float16_t *output_data
)

Stateful singular value decomposition filter, float16 variant.

Note

Sizing an f16 layer with the arm_svdf_f32() queries over-allocates and is safe. Sizing an f32 layer with the arm_svdf_f16() queries under-allocates by half: arm_svdf_f32() returns ARM_CMSIS_NN_ARG_ERROR if ctx->size carries that undersized figure, but corrupts memory if ctx->size is left at 0, which opts out of the check.

Note

NaN propagates through the activation clamps that take the bit-classified scalar clamp of #380, at every optimization level on the gated toolchains, including the shipped -Ofast: the input-activation clamp is that scalar clamp on EVERY build, and the output-activation clamp is on non-MVE builds. On MVE builds the output-activation clamp is vmaxnmq/vminnmq with no NaN restore, so a NaN resolves to a clamp bound there instead.

Parameters

Parameters of arm_svdf_f16

Name	Type	Direction	Description
ctx	const cmsis_nn_context *	in	Unused by this function. Reserved for future use; may be NULL.
input_ctx	const cmsis_nn_context *	in, out	Mandatory, not optional: a NULL input_ctx, or a NULL input_ctx->buf, is diagnosed with ARM_CMSIS_NN_ARG_ERROR on every build. Staging buffer written by this function, holding one element per (input batch, feature batch). Written before it is read, so its contents on entry do not matter, but it is written on EVERY build, not only under MVE. Sized by arm_svdf_f16_input_ctx_get_buffer_size(input_dims, weights_feature_dims): input_dims->n * weights_feature_dims->n * sizeof(float16_t) bytes. Note this is float16_t, half the `arm_svdf_f32()` figure for the same shape. Setting input_ctx->size lets this function reject an undersized buffer with ARM_CMSIS_NN_ARG_ERROR; leaving it at zero opts out of that check. The caller is expected to clear the buffer, if applicable, for security reasons.
output_ctx	const cmsis_nn_context *	in, out	Mandatory, not optional: a NULL output_ctx, or a NULL output_ctx->buf, is diagnosed with ARM_CMSIS_NN_ARG_ERROR on every build. Staging buffer written by this function, holding one element per (input batch, output unit). Written before it is read, so its contents on entry do not matter, but it is written on EVERY build, not only under MVE. Sized by arm_svdf_f16_output_ctx_get_buffer_size(svdf_params, input_dims, weights_feature_dims): input_dims->n * (weights_feature_dims->n / svdf_params->rank) * sizeof(float16_t) bytes, truncating division. Note this is float16_t, half the `arm_svdf_f32()` figure for the same shape. Setting output_ctx->size lets this function reject an undersized buffer with ARM_CMSIS_NN_ARG_ERROR; leaving it at zero opts out of that check. The caller is expected to clear the buffer, if applicable, for security reasons.
svdf_params	const cmsis_nn_svdf_params_f16 *	in	SVDF operator parameters.
input_dims	const cmsis_nn_dims *	in	Input tensor dimensions.
input_data	const float16_t *	in	Pointer to the input tensor data.
state_dims	const cmsis_nn_dims *	in	State tensor dimensions.
state_data	float16_t *	in, out	Pointer to the mutable state tensor.
weights_feature_dims	const cmsis_nn_dims *	in	Feature-weight tensor dimensions.
weights_feature_data	const float16_t *	in	Pointer to the feature-weight tensor.
weights_time_dims	const cmsis_nn_dims *	in	Time-weight tensor dimensions.
weights_time_data	const float16_t *	in	Pointer to the time-weight tensor.
bias_dims	const cmsis_nn_dims *	in	Bias tensor dimensions.
bias_data	const float16_t *	in	Optional bias tensor data.
output_dims	const cmsis_nn_dims *	in	Output tensor dimensions.
output_data	float16_t *	out	Pointer to the output tensor data.

Returns

Returns of arm_svdf_f16

Description
`ARM_CMSIS_NN_SUCCESS` on success or `ARM_CMSIS_NN_ARG_ERROR` on invalid arguments.

function

arm_svdf_f16_input_ctx_get_buffer_size

C

Get size of the inputctx staging buffer required by armsvdff16().

Include/arm_nnfunctions_flt.h:3521

int32_t arm_svdf_f16_input_ctx_get_buffer_size(
    const cmsis_nn_dims *input_dims,
    const cmsis_nn_dims *weights_feature_dims
)

Get size of the input_ctx staging buffer required by arm_svdf_f16().

Note

arm_svdf_f16() stages float16_t, so this is HALF the byte count arm_svdf_f32_input_ctx_get_buffer_size() returns for the same shape. Sizing an f16 layer with the f32 query over-allocates and is safe; sizing an f32 layer with this one under-allocates by half.

Note

This query reports an out-of-range shape as -1, following the SVDF family (arm_svdf_s8_get_buffer_size()), not the 0 used by the float convolution and fully-connected queries in this header. The reason is that arm_svdf_f16() reads ctx->size, and size == 0 is the opt-out signal for its scratch-size check: a 0-on-overflow answer fed straight back as buf = alloc(0), size = 0 would silently disable the check over a zero-byte allocation, whereas alloc((size_t)-1) fails and the NULL check catches it.

Note

0 is still a valid return for a degenerate shape (input_dims->n == 0). Unlike the general rule in README.md, a 0 here does NOT mean you may pass { NULL, 0 }: arm_svdf_f16() rejects a NULL input_ctx->buf with ARM_CMSIS_NN_ARG_ERROR regardless of the size.

Parameters

Parameters of arm_svdf_f16_input_ctx_get_buffer_size

Name	Type	Direction	Description
input_dims	const cmsis_nn_dims *	in	Input tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f16()`.
weights_feature_dims	const cmsis_nn_dims *	in	Feature-weight tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f16()`.

Returns

Returns of arm_svdf_f16_input_ctx_get_buffer_size

Description
Required buffer size in bytes: input_dims->n * weights_feature_dims->n * sizeof(float16_t). Returns -1 if either pointer is NULL, if input_dims->n or weights_feature_dims->n is negative, or if the product would not fit in an int32_t. The figure and the validation are the same on every build target, since `arm_svdf_f16()` stages this buffer on every build rather than only under MVE.

function

arm_svdf_f16_output_ctx_get_buffer_size

C

Get size of the outputctx staging buffer required by armsvdff16().

Include/arm_nnfunctions_flt.h:3544

int32_t arm_svdf_f16_output_ctx_get_buffer_size(
    const cmsis_nn_svdf_params_f16 *svdf_params,
    const cmsis_nn_dims *input_dims,
    const cmsis_nn_dims *weights_feature_dims
)

Get size of the output_ctx staging buffer required by arm_svdf_f16().

Note

arm_svdf_f16() stages float16_t, so this is HALF the byte count arm_svdf_f32_output_ctx_get_buffer_size() returns for the same shape.

Note

Same -1 and degenerate-0 contract as arm_svdf_f16_input_ctx_get_buffer_size(), including that a 0 does not license passing { NULL, 0 }. A rank greater than weights_feature_dims->n truncates the unit count to 0 and so returns 0.

Parameters

Parameters of arm_svdf_f16_output_ctx_get_buffer_size

Name	Type	Direction	Description
svdf_params	const cmsis_nn_svdf_params_f16 *	in	SVDF operator parameters; only svdf_params->rank is read.
input_dims	const cmsis_nn_dims *	in	Input tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f16()`.
weights_feature_dims	const cmsis_nn_dims *	in	Feature-weight tensor dimensions, i.e. the same `cmsis_nn_dims` passed to `arm_svdf_f16()`.

Returns

Returns of arm_svdf_f16_output_ctx_get_buffer_size

Description
Required buffer size in bytes: input_dims->n * (weights_feature_dims->n / svdf_params->rank) * sizeof(float16_t), truncating division to match the kernel's own unit count. Returns -1 if any pointer is NULL, if svdf_params->rank is zero or negative, if input_dims->n or weights_feature_dims->n is negative, or if the product would not fit in an int32_t.