## table of contents

HALF_RECIP, NATIVE_R(3clc) | OpenCL Manual | HALF_RECIP, NATIVE_R(3clc) |

# NAME¶

half_recip,_native_recip - Floating point reciprocal.

# ¶

**gentype half_recip(gentype ***x***);**

**gentype
native_recip(gentype ***x***);**

# DESCRIPTION¶

The **half_recip** computes reciprocal.

**native_recip** computes reciprocal over an
implementation-defined range. The maximum error is
implementation-defined.

# NOTES¶

This built-in math function takes scalar or vector arguments. The
generic type name **gentype** is used to indicate that the function can
take **float**, **float2**, **float4**, **float8**, or
**float16** as the type for the arguments. For any specific use of these
function, the actual type has to be the same for all arguments and the
return type.

Functions with the **half_** prefix are implemented with a
minimum of 10-bits of accuracy i.e. an ULP value less than or equal to 8192
ulp.

Functions with the **native__** prefix may map to one or more
native device instructions and will typically have better performance
compared to the corresponding functions (without the **native__**
prefix). The accuracy (and in some cases the input range(s)) of these
functions is implementation-defined.

The vector versions of the math functions operate component-wise. The description is per-component.

The built-in math functions are not affected by the prevailing rounding mode in the calling environment, and always return the same value as they would if called with the round to nearest even rounding mode.

# SPECIFICATION¶

**OpenCL Specification**[1]

# SEE ALSO¶

**mathFunctions**(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

01/14/2021 | The Khronos Group |