vshuffle ( v perm -- w )
Factor handbook » The language » Numbers » Vector operations » Vector component- and bit-wise logic

Prev:

vnone? ( v -- ? )

Vocabulary
math.vectors

Inputs

v	a SIMD array
perm	an array of integers, or a byte-array

Outputs

w	a SIMD array

Word description
Permutes the elements of a SIMD array. Duplicate entries are allowed in the permutation. The perm argument can have one of two forms:

•	A literal array of integers of the same length as the vector. This will perform a static, elementwise shuffle.
•	A byte array or SIMD vector of the same byte length as the vector. This will perform a variable bytewise shuffle. Each index wraps modulo the vector's byte length; a high index bit does not request a zero byte.

Examples

USING: alien.c-types math.vectors math.vectors.simd prettyprint ; int-4{ 69 42 911 13 } { 1 3 2 3 } vshuffle .
int-4{ 42 13 911 13 }

USING: alien.c-types combinators math.vectors math.vectors.simd namespaces prettyprint prettyprint.config ; IN: scratchpad : endian-swap ( size -- vector ) { { 1 [ uchar-16{ 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 } ] } { 2 [ uchar-16{ 1 0 3 2 5 4 7 6 9 8 11 10 13 12 15 14 } ] } { 4 [ uchar-16{ 3 2 1 0 7 6 5 4 11 10 9 8 15 14 13 12 } ] } } case ; int-4{ 0x11223344 0x11223344 0x11223344 0x11223344 } 4 endian-swap vshuffle 16 number-base [ . ] with-variable
int-4{ 0x44332211 0x44332211 0x44332211 0x44332211 }

Definition

IN: math.vectors

GENERIC: vshuffle ( v perm -- w )

Methods

USING: arrays math.vectors ;

M: array vshuffle vshuffle-elements ; inline


USING: byte-arrays kernel math.vectors math.vectors.simd
sequences ;

M: byte-array vshuffle
    dup length 16 =
    [ uchar-16 boa vshuffle-bytes ] [ bad-simd-vector ] if ;
    inline


USING: math.vectors math.vectors.simd ;

M: simd-128 vshuffle vshuffle-bytes ; inline