NAME

       signbit - Test for sign bit.

       int signbit(float );

       intn signbit(floatn );

       int signbit(double );

       longn signbit(doublen );

       int signbit (half)      // if half extension
       enabled

       shortn signbit (halfn)      // if half extension
       enabled

DESCRIPTION

       The built-in function signbit tests for sign bit. The scalar version of the function
       returns a 1 if the sign bit in the float is set else returns 0. The vector version of the
       function returns the following for each component in floatn: -1 (i.e. all bits set) if the
       sign bit in the float is set else returns 0.

NOTES

       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.

       The function returns a 0 if the specified relation is false and a 1 if the specified
       relation is true for scalar argument types. These functions shall return a 0 if the
       specified relation is false and a - 1 (i.e. all bits set) if the specified relation is
       true for vector argument types.

SPECIFICATION

       OpenCL Specification[1]

SEE ALSO

       relationalFunctions(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 264, section 6.12.6 - Relational Functions