devela::_dep::sdl3::sys::bits

Function SDL_MostSignificantBitIndex32

pub const fn SDL_MostSignificantBitIndex32(x: u32) -> i32
Available on crate feature dep_sdl3 only.
Expand description

Get the index of the most significant (set) bit in a 32-bit number.

Result is undefined when called with 0. This operation can also be stated as “count leading zeroes” and “log base 2”.

Note that this is a forced-inline function in a header, and not a public API function available in the SDL library (which is to say, the code is embedded in the calling program and the linker and dynamic loader will not be able to find this function inside SDL itself).

§Parameters

  • x: the 32-bit value to examine.

§Return value

Returns the index of the most significant bit, or -1 if the value is 0.

§Thread safety

It is safe to call this function from any thread.

§Availability

This function is available since SDL 3.2.0.