DSPLIB_qrd

Introduction

Kernel for QR decomposition of input matrix.

• This function decomposes the real square matrix \(A\) into an orthogonal matrix and an upper right triangular matrix as:

  \begin{eqnarray*} A = Q \times R \qquad where\;&(1)&\;Q\;is\;an\;orthogonal\;matrix\;(i.e. Q^{T}Q=I)\\ &(2)&\;R\;is\;upper\;triangular\;matrix. \end{eqnarray*}

• The Householder algorithm is used to zero the columns below the diagonal in the original \(A\) matrix to produce the \(R\) matrix.
• The \(Q\) matrix is generated during the process.

Data Structures
struct	DSPLIB_qrdInitArgs
	Structure containing the parameters to initialize the kernel. More...

Functions
int32_t	DSPLIB_qrd_getHandleSize (DSPLIB_qrdInitArgs *pKerInitArgs)
	This is a query function to calculate the size of internal handle. More...
DSPLIB_STATUS	DSPLIB_qrd_init (DSPLIB_kernelHandle handle, DSPLIB_bufParams2D_t *bufParamsA, DSPLIB_bufParams2D_t *bufParamsQ, DSPLIB_bufParams2D_t *bufParamsR, DSPLIB_bufParams1D_t *bufParamsU, const DSPLIB_qrdInitArgs *pKerInitArgs)
	This function should be called before the DSPLIB_qrd_exec function is called. This function takes care of any one-time operations such as setting up the configuration of required hardware resources such as the streaming engine and streaming address generator. The results of these operations are stored in the handle. More...
DSPLIB_STATUS	DSPLIB_qrd_init_checkParams (DSPLIB_kernelHandle handle, DSPLIB_bufParams2D_t *bufParamsA, DSPLIB_bufParams2D_t *bufParamsQ, DSPLIB_bufParams2D_t *bufParamsR, DSPLIB_bufParams1D_t *bufParamsU, const DSPLIB_qrdInitArgs *pKerInitArgs)
	This function checks the validity of the parameters passed to DSPLIB_qrd_init function. This function is called with the same parameters as the DSPLIB_qrd_init, and this function must be called before the DSPLIB_qrd_init is called. More...
DSPLIB_STATUS	DSPLIB_qrd_exec_checkParams (DSPLIB_kernelHandle handle, const void *restrict pA, const void *restrict pQ, const void *restrict pR, const void *restrict pU, const void *restrict pScratch)
	This function checks the validity of the parameters passed to DSPLIB_qrd_exec function. This function is called with the same parameters as the DSPLIB_qrd_exec, and this function must be called before the DSPLIB_qrd_exec is called. More...
DSPLIB_STATUS	DSPLIB_qrd_exec (DSPLIB_kernelHandle handle, const void *restrict pA, const void *restrict pQ, const void *restrict pR, const void *restrict pU, const void *restrict pScratch)
	This function is the main kernel compute function. More...

Function Documentation

DSPLIB_qrd_getHandleSize()

int32_t DSPLIB_qrd_getHandleSize

(

DSPLIB_qrdInitArgs *

pKerInitArgs

)

This is a query function to calculate the size of internal handle.

Parameters

[in]

pKerInitArgs

: Pointer to structure holding init parameters

Returns

Size of the buffer in bytes

Remarks

Application is expected to allocate buffer of the requested size and provide it as input to other functions requiring it.

Definition at line 25 of file DSPLIB_qrd.cpp.

DSPLIB_qrd_init()

DSPLIB_STATUS DSPLIB_qrd_init	(	DSPLIB_kernelHandle	handle,
		DSPLIB_bufParams2D_t *	bufParamsA,
		DSPLIB_bufParams2D_t *	bufParamsQ,
		DSPLIB_bufParams2D_t *	bufParamsR,
		DSPLIB_bufParams1D_t *	bufParamsU,
		const DSPLIB_qrdInitArgs *	pKerInitArgs
	)

This function should be called before the DSPLIB_qrd_exec function is called. This function takes care of any one-time operations such as setting up the configuration of required hardware resources such as the streaming engine and streaming address generator. The results of these operations are stored in the handle.

Parameters

[in]	handle	: Active handle to the kernel
[in]	bufParamsA	: Pointer to the structure containing dimensional information of input matrix A
[out]	bufParamsQ	: Pointer to the structure containing dimensional information of output matrix Q
[out]	bufParamsR	: Pointer to the structure containing dimensional information of output matrix R
[in]	bufParamsU	: Pointer to the structure containing dimensional information of temporary vector U.
[in]	pKerInitArgs	: Pointer to the structure holding init parameters

Returns

Status value indicating success or failure. Refer to DSPLIB_STATUS.

Remarks

Application is expected to provide a valid handle.

Definition at line 92 of file DSPLIB_qrd.cpp.

DSPLIB_qrd_init_checkParams()

DSPLIB_STATUS DSPLIB_qrd_init_checkParams	(	DSPLIB_kernelHandle	handle,
		DSPLIB_bufParams2D_t *	bufParamsA,
		DSPLIB_bufParams2D_t *	bufParamsQ,
		DSPLIB_bufParams2D_t *	bufParamsR,
		DSPLIB_bufParams1D_t *	bufParamsU,
		const DSPLIB_qrdInitArgs *	pKerInitArgs
	)

This function checks the validity of the parameters passed to DSPLIB_qrd_init function. This function is called with the same parameters as the DSPLIB_qrd_init, and this function must be called before the DSPLIB_qrd_init is called.

Parameters

[in]	handle	: Active handle to the kernel
[in]	bufParamsA	: Pointer to the structure containing dimensional information of input matrix A
[out]	bufParamsQ	: Pointer to the structure containing dimensional information of output matrix Q
[out]	bufParamsR	: Pointer to the structure containing dimensional information of output matrix R
[in]	bufParamsU	: Pointer to the structure containing dimensional information of temporary vector U.
[in]	pKerInitArgs	: Pointer to the structure holding init parameters

Returns

Status value indicating success or failure. Refer to DSPLIB_STATUS.

Remarks

None

Definition at line 34 of file DSPLIB_qrd.cpp.

DSPLIB_qrd_exec_checkParams()

DSPLIB_STATUS DSPLIB_qrd_exec_checkParams	(	DSPLIB_kernelHandle	handle,
		const void *restrict	pA,
		const void *restrict	pQ,
		const void *restrict	pR,
		const void *restrict	pU,
		const void *restrict	pScratch
	)

This function checks the validity of the parameters passed to DSPLIB_qrd_exec function. This function is called with the same parameters as the DSPLIB_qrd_exec, and this function must be called before the DSPLIB_qrd_exec is called.

Parameters

[in]	handle	: Active handle to the kernel
[in]	pA	: Pointer to the input matrix A
[out]	pQ	: Pointer to the output matrix Q
[out]	pR	: Pointer to the output matrix R
[in]	pU	: Pointer to the temporary vector U
[in]	pScratch	: Pointer to the intermediate scratch buffer Scratch

Returns

Status value indicating success or failure. Refer to DSPLIB_STATUS.

Remarks

None

Definition at line 70 of file DSPLIB_qrd.cpp.

DSPLIB_qrd_exec()

DSPLIB_STATUS DSPLIB_qrd_exec	(	DSPLIB_kernelHandle	handle,
		const void *restrict	pA,
		const void *restrict	pQ,
		const void *restrict	pR,
		const void *restrict	pU,
		const void *restrict	pScratch
	)

This function is the main kernel compute function.

Please refer to details under DSPLIB_qrd_exec

Parameters

[in]	handle	: Active handle to the kernel
[in]	pA	: Pointer to the input matrix A
[out]	pQ	: Pointer to the output matrix Q
[out]	pR	: Pointer to the output matrix R
[in]	pU	: Pointer to the temporary vector U
[in]	pScratch	: Pointer to the intermediate scratch buffer Scratch

Memory Requirements

Buffer	dimY	dimX	Comments
pA	M	M	Input Square Matrix
pQ	M	M	Output Square Matrix
pR	M	M	Output Square Matrix
pU	1	M	Scrath buffer to store intermediate values
pScratch	1	M	Scratch buffer to store intermediate sum values

Returns

Status value indicating success or failure. Refer to DSPLIB_STATUS.

Assumptions:

• None

Performance Considerations:

For best performance,

• The input and output data buffers are expected to be in L2 memory
• The buffer pointers are assumed to be 64-byte aligned
• Ensure that the starting point of adjacent rows in a 2-D matrix are allocated from different banks in L2 memory with the help of memory padding.
  

Remarks

Before calling this function, application is expected to call DSPLIB_qrd_init and DSPLIB_qrd_exec_checkParams functions. This ensures resource configuration and error checks are done only once for several invocations of this function.

Definition at line 144 of file DSPLIB_qrd.cpp.