Swizzling

Description

Swizzle/deinterleave functions on Vec's.

Functions
template<size_t N, typename T , size_t SIMD_WIDTH>
static void	simd::swizzle (Vec< T, SIMD_WIDTH > v[N])
	Swizzle/de-interleave/convert from AoS to SoA multiple Vec's in-place.
template<size_t N, typename T , size_t SIMD_WIDTH>
static void	simd::swizzle2 (Vec< T, SIMD_WIDTH > v[2 *N])
	Swizzle/de-interleave/convert from AoS to SoA multiple Vec's in-place.
template<size_t N, typename T , size_t SIMD_WIDTH>
static void	simd::unswizzle (Vec< T, SIMD_WIDTH > v[2 *N])
	Unswizzle/interleave/convert from SoA to AoS multiple Vec's in-place.

Function Documentation

swizzle()

template<size_t N, typename T , size_t SIMD_WIDTH>

static void simd::swizzle ( Vec< T, SIMD_WIDTH > v[N] )

inlinestatic

Swizzle/de-interleave/convert from AoS to SoA multiple Vec's in-place.

This function swizzles/de-interleaves/converts from AoS (Array of Structs) to SoA (Struct of Arrays) multiple Vec's in-place.

Example:

Example for a swizzle distance of 3 with 3 Vec's of 8 elements each:

input stream (structures indicated by curly brackets):

{0 1 2} {3 4 5} {6 7 8} {9 10 11} ... {21 22 23}

input vectors:

v[0] =  0  1  2  3  4  5  6  7
v[1] =  8  9 10 11 12 13 14 15
v[2] = 16 17 18 19 20 21 22 23

output vectors:

v[0] =  0  3  6  9 12 15 18 21
v[1] =  1  4  7 10 13 16 19 22
v[2] =  2  5  8 11 14 17 20 23

Template Parameters

N	swizzle distance, must be between 1 and 5

Parameters

[in,out]

v

array of Vec's to swizzle

See also

swizzle2(): swizzle function that takes double the number of Vec's with potentially better performance

unswizzle()

swizzle2()

template<size_t N, typename T , size_t SIMD_WIDTH>

static void simd::swizzle2 ( Vec< T, SIMD_WIDTH > v[2 *N] )

inlinestatic

Swizzle/de-interleave/convert from AoS to SoA multiple Vec's in-place.

This function swizzles/de-interleaves/converts from AoS (Array of Structs) to SoA (Struct of Arrays) multiple Vec's in-place.

In contrast to swizzle(), this function takes double the number of Vec's as input and might be faster.

Example:

Example for a swizzle distance of 3 with 6 Vec's of 8 elements each:

input stream (structures indicated by curly brackets):

{0 1 2} {3 4 5} {6 7 8} {9 10 11} ... {45 46 47}

input vectors:

v[0] =  0  1  2  3  4  5  6  7
v[1] =  8  9 10 11 12 13 14 15
v[2] = 16 17 18 19 20 21 22 23
v[3] = 24 25 26 27 28 29 30 31
v[4] = 32 33 34 35 36 37 38 39
v[5] = 40 41 42 43 44 45 46 47

output vectors:

v[0] =  0  6 12 18 24 30 36 42
v[1] =  1  7 13 19 25 31 37 43
v[2] =  2  8 14 20 26 32 38 44
v[3] =  3  9 15 21 27 33 39 45
v[4] =  4 10 16 22 28 34 40 46
v[5] =  5 11 17 23 29 35 41 47

Template Parameters

N	swizzle distance, must be between 1 and 5

Parameters

[in,out]

v

array of Vec's to swizzle

See also

swizzle(): swizzles half the number of Vec's as this function

unswizzle()

unswizzle()

template<size_t N, typename T , size_t SIMD_WIDTH>

static void simd::unswizzle ( Vec< T, SIMD_WIDTH > v[2 *N] )

inlinestatic

Unswizzle/interleave/convert from SoA to AoS multiple Vec's in-place.

This function unswizzles/interleaves/converts from SoA (Struct of Arrays) to AoS (Array of Structs) multiple Vec's in-place.

Example:

Example for an unswizzle distance of 3 with 6 Vec's of 8 elements each:

input vectors:

v[0] =  0  6 12 18 24 30 36 42
v[1] =  1  7 13 19 25 31 37 43
v[2] =  2  8 14 20 26 32 38 44
v[3] =  3  9 15 21 27 33 39 45
v[4] =  4 10 16 22 28 34 40 46
v[5] =  5 11 17 23 29 35 41 47

output vectors:

v[0] =  0  1  2  3  4  5  6  7
v[1] =  8  9 10 11 12 13 14 15
v[2] = 16 17 18 19 20 21 22 23
v[3] = 24 25 26 27 28 29 30 31
v[4] = 32 33 34 35 36 37 38 39
v[5] = 40 41 42 43 44 45 46 47

Template Parameters

N	unswizzle distance

Parameters

[in,out]

v

array of Vec's to unswizzle

See also

swizzle(), swizzle2(): swizzle functions