## table of contents

ILOGB(3clc) | OpenCL Manual | ILOGB(3clc) |

# NAME¶

ilogb - Exponent as an integer value.# ¶

**intn ilogb(floatn ***x***);**

**int ilogb(float ***x***);**

**intn ilogb(doublen ***x***);**

**int ilogb(double ***x***);**

**intn ilogb(halfn ***x***);**

**int ilogb(half ***x***);**

# DESCRIPTION¶

Returns the exponent as an integer value.# NOTES¶

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.

The built-in math functions take scalar or vector arguments. For any specific use of these function, the actual type has to be the same for all arguments and the return type unless otherwise specified.

The generic type name **gentype** is used to indicate that the
function can take **float**, **float2**, **float3**, **float4**,
**float8**, **float16**, **double**, **double2**,
**double3**, **double4**, **double8**, or **double16** as the
type for the arguments.

If extended with **cl_khr_fp16**(3clc), generic type name
**gentype** may indicate **half** and **half{2|3|4|8|16}** as
arguments and return values.

The generic type name **gentypef** is used to indicate that the
function can take **float**, **float2**, **float3**, **float4**,
**float8**, or **float16** as the type for the arguments.

The generic type name **gentyped** is used to indicate that the
function can take **double**, **double2**, **double3**,
**double4**, **double8**, or **double16** as the type for the
arguments.

The following macros shall expand to integer constant expressions
whose values are returned by **ilogb**(*x*) if *x* is zero or
NaN, respectively. The value of **FP_ILOGB0** shall be either
{**INT_MIN**} or - {**INT_MAX**}. The value of **FP_ILOGBNAN**
shall be either {**INT_MAX**} or {**INT_MIN**}.

# 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

02/03/2019 | The Khronos Group |