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SELECT(3clc) OpenCL Manual SELECT(3clc)


select - For each component of a vector type, result[i] = if MSB of c[i] is set ? b[i] : a[i]. For scalar type, result = c ? b : a.

gentype select(gentype a, gentype b, igentype c);
gentype select(gentype a, gentype b, ugentype c);

halfn select (halfn a, halfn b, shortn c) // if half extension enabled halfn select (halfn a, halfn b, ushortn c) // if half extension enabled


For each component of a vector type, result[ i] = if MSB of c[i] is set ? b[i] : a[i].
For scalar type, result = c ? b : a.
igentype and ugentype must have the same number of elements and bits as gentype.


The argment type gentype can be char, charn,uchar, ucharn, short, shortn, ushort, ushortn, int, intn, uint, uintn, long, longn, ulong, ulongn, float, floatn, double, and double n.
The argument type igentype refers to signed integer types, i.e. char, charn, short, shortn, int, intn, long, and longn.
The argument type ugentype refers to unsigned integer types, i.e. uchar, ucharn, ushort, ushortn, uint, uintn, ulong, and ulongn. n is 2, 3, 4, 8, or 16.
If an implementation extends this specification to support IEEE-754 flags or exceptions, then all built-in relational functions shall proceed without raising the invalid floating-point exception when one or more of the operands are NaNs.
The built-in relational functions are extended with cl_khr_fp16(3clc) to include appropriate versions of functions that take half, and half{2|3|4|8|16} as arguments and return values.


OpenCL Specification[1]




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OpenCL Specification
page 264, section 6.12.6 - Relational Functions
06/18/2014 The Khronos Group