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

Description

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.

Note
The above definition means that the behavior of select and the ternary operator for vector and scalar types is dependent on different interpretations of the bit pattern of c.

Notes

General information about relational functions:

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 doublen.

The argument type igentype refers to the built-in signed integer types, i.e. char, charn, short, shortn, int, intn, long, and longn. n is 2, 3, 4, 8, or 16.

The argument type ugentype refers to the built-in 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 to include versions that take half, and half{2|3|4|8|16} as arguments.

Also see

Specification