NAME

       shuffle - Constructs a permutation of elements from one (or two) input vectors.

       gentypen shuffle(gentypem x, ugentypen mask);

       gentypen shuffle2(gentypem x, gentypem y, ugentypen mask);

DESCRIPTION

       The shuffle and shuffle2 built-in functions construct a permutation of elements from one
       or two input vectors respectively that are of the same type, returning a vector with the
       same element type as the input and length that is the same as the shuffle mask. The size
       of each element in the mask must match the size of each element in the result. For
       shuffle, only the ilogb(3clc)(2m-1) least significant bits of each mask element are
       considered. For shuffle2, only the ilogb(3clc)(2m-1)+1 least significant bits of each mask
       element are considered. Other bits in the mask shall be ignored.

       The elements of the input vectors are numbered from left to right across one or both of
       the vectors. For this purpose, the number of elements in a vector is given by
       vec_step(3clc)(gentypem). The shuffle mask operand specifies, for each element of the
       result vector, which element of the one or two input vectors the result element gets.

       We use the generic type name gentypen (or gentypem) to indicate the built-in data types
       char{2|4|8|16}, uchar{2|4|8|16}, short{2|4|8|16}, ushort{2|4|8|16}, int{2|4|8|16},
       uint{2|4|8|16}, long{2|4|8|16}, ulong{2|4|8|16}, or float{2|4|8|16} as the type for the
       arguments unless otherwise stated. We use the generic name ugentypen to indicate the
       built-in unsigned integer data types. If the double is supported, then gentypen (or
       gentypem) also indicate the built-in data types double{2|4|8|16}.

       The generic type name gentypen (or gentypem) may indicate the data type half{2|4|8|16} if
       the cl_khr_fp16(3clc) extension is supported.

   Example
       uint4 mask = (uint4)(3, 2, 1, 0); float4 a;
       float4 r = shuffle(a, mask); // r.s0123 = a.wzyx

       uint8 mask = (uint8)(0, 1, 2, 3, 4, 5, 6, 7);

       float4 a, b; float8 r = shuffle2(a, b, mask); //
       r.s0123 = a.xyzw // r.s4567 = b.xyzw

       uint4 mask; float8 a; float4 b; b = shuffle(a,
       mask);

       Examples that are not valid are:

       uint8 mask; short16 a; short8 b; b = shuffle(a,
       mask);

SPECIFICATION

       OpenCL Specification[1]

SEE ALSO

       miscVectorFunctions(3clc)

AUTHORS

       The Khronos Group

COPYRIGHT

       Copyright © 2007-2011 The Khronos Group Inc.
       Permission is hereby granted, free of charge, to any person obtaining a copy of this
       software and/or associated documentation files (the "Materials"), to deal in the Materials
       without restriction, including without limitation the rights to use, copy, modify, merge,
       publish, distribute, sublicense, and/or sell copies of the Materials, and to permit
       persons to whom the Materials are furnished to do so, subject to the condition that this
       copyright notice and permission notice shall be included in all copies or substantial
       portions of the Materials.

NOTES

        1. OpenCL Specification
           page 282, section 6.12.12 Miscellaneous Vector Functions