Bit Reversal Utilities

Bit-reversal permutation utilities for FFT algorithms.

bitReverse()

Reverses the bits of an integer.

function bitReverse(value: number, bitWidth: number): number;

Example

import { bitReverse } from 'webgpu-fft';

// Reverse 3 bits of value 1 (001 → 100)
const result = bitReverse(1, 3); // 4

log2()

Base-2 logarithm.

function log2(n: number): number;

Example

import { log2 } from 'webgpu-fft';

console.log(log2(1024)); // 10

isPowerOf2()

Checks if a number is a power of 2.

function isPowerOf2(n: number): boolean;

Example

import { isPowerOf2 } from 'webgpu-fft';

console.log(isPowerOf2(1024)); // true
console.log(isPowerOf2(1000)); // false

bitReversalPermutation()

Returns a permutation array for bit-reversal reordering.

function bitReversalPermutation(size: number): number[];

Example

import { bitReversalPermutation } from 'webgpu-fft';

const perm = bitReversalPermutation(8);
// [0, 4, 2, 6, 1, 5, 3, 7]

bitReversalPermutationInPlace()

Reorders an array in-place using bit-reversal.

function bitReversalPermutationInPlace<T>(array: T[]): void;

Example

import { bitReversalPermutationInPlace } from 'webgpu-fft';

const data = [0, 1, 2, 3, 4, 5, 6, 7];
bitReversalPermutationInPlace(data);
// data is now [0, 4, 2, 6, 1, 5, 3, 7]

Related

• 1D FFT Tutorial — FFT basics
• CPU FFT API — CPU implementation uses these utilities