STDC_BIT_CEIL(3)       FreeBSD Library Functions Manual       STDC_BIT_CEIL(3)

NAME

     stdc_bit_ceil - round up to the next power of 2

SYNOPSIS

     /* -lc */
     #include <stdbit.h>

     unsigned char
     stdc_bit_ceil_uc(unsigned char value);

     unsigned short
     stdc_bit_ceil_us(unsigned short value);

     unsigned int
     stdc_bit_ceil_ui(unsigned int value);

     unsigned long
     stdc_bit_ceil_ul(unsigned long value);

     unsigned long long
     stdc_bit_ceil_ull(unsigned long long value);

     typeof(value)
     stdc_bit_ceil(value);

DESCRIPTION

     The stdc_bit_ceil_type() family of functions rounds value up to the next
     power of 2, where value is of type unsigned char, unsigned short,
     unsigned int, unsigned long, or unsigned long long for type being uc, us,
     ui, ul, or ull respectively.  The stdc_bit_ceil(value) type-generic macro
     picks the appropriate stdc_bit_ceil_type() function based on the type of
     value.

RETURN VALUES

     Returns value round up to the next power of 2.  If this value is not
     representable, 0 is returned.

SEE ALSO

     stdbit(3), stdc_bit_floor(3)

STANDARDS

     The stdc_bit_ceil_type() family of functions and the stdc_bit_ceil()
     type-generic macro conform to ISO/IEC 9899:2024 ("ISO C23").

HISTORY

     The stdc_bit_ceil_type() family of functions and the stdc_bit_ceil()
     type-generic macro were added in FreeBSD 15.1.

AUTHOR

     Robert Clausecker <fuz@FreeBSD.org>

FreeBSD 15.1-STABLE-HBSD       November 9, 2025               STDC_BIT_CEIL(3)