countbits.md

layout	stdlib-reference

countbits

Description

Population count. Counts the number of set bits in the binary representation of a value.

Signature

uint countbits(uint value);

vector<uint, N> countbits<N:int>(vector<uint, N> value);

Generic Parameters

N : int {#decl-N}

Parameters

value : uint {#decl-value}

The value to count bits in.

value : vector<uint, N> {#decl-value}

The value to count bits in.

Return value

The number of bits in the binary representation of value that are set to one.

Remarks

For SPIR-V, this function maps to OpBitCount.

Availability and Requirements

Defined for the following targets:

hlsl

Available in all stages.

glsl

Available in all stages.

cpp

Available in all stages.

cuda

Available in all stages.

metal

Available in all stages.

wgsl

Available in all stages.

spirv

Available in all stages.