stdc_bit_ceil(3)

stdc_bit_ceil3

Round up to the next power of 2

Usage

Standard C Library (libc, -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 Ns Pq Em value

stdc_bit_ceil(value);

Overview

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.

Releases

2 releases since FreeBSD 15.1-RELEASE; the text changed 1 time.

  1. 15.1
  2. 16.0

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.

Authors

Robert Clausecker ⟨[email protected]⟩

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.