DSP_mul32
[Math]

Collaboration diagram for DSP_mul32:

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Detailed Description

void	DSP_mul32 (const int *restrict x, const int *restrict y, int *restrict r, int nx)

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Function Documentation

void DSP_mul32	(	const int *restrict	x,
		const int *restrict	y,
		int *restrict	r,
		int	nx
	)

The function performs a Q.31 x Q.31 multiply and returns the upper 32 bits of the result. The result of the intermediate multiplies are accumulated into a 40-bit long register pair, as there could be potential overflow. The contribution of the multiplication of the two lower 16-bit halves are not considered. The output is in Q.30 format. Results are accurate to least significant bit.

Parameters:

	x	= Pointer to input data vector 1 of size nx
	y	= Pointer to input data vector 2 of size nx
	r	= Pointer to output data vector of size nx
	nx	= Number of elements in input and output vectors

Algorithm:

DSP_mul32_cn.c is the natural C equivalent of the optimized intrinsic C code without restrictions note that the intrinsic C code is optimized and restrictions may apply.

Assumptions:

nx must be a multiple of 4 and greater than or equal to 4.
Input and output vectors must be double-word aligned.

Implementation notes:

Endian Support: The code supports both big and little endian modes.
Interruptibility: The code is interruptible.

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Copyright 2014, Texas Instruments Incorporated