zig-bigfloat

zig-bigfloat represents a floating point value as s * 2^e, where 1 >= |s| > 2 is a regular floating point number and e is a signed integer. This allows for extremely large and small numbers to be represented with a fixed number of bits, without excessive precision by selecting a suitable floating point type.

zig-bigfloat is primarily optimized for speed over precision. Benchmark results are in src/bench.zig.

Usage

In your project folder, run this to add zig-bigfloat to your build.zig.zon:

zig fetch --save git+https://github.com/TemariVirus/zig-bigfloat#<COMMIT-HASH>

Then, add the following to your build.zig:

pub fn build(b: *std.Build) void {
    const target = b.standardTargetOptions(.{});
    const optimize = b.standardOptimizeOption(.{});

    // ...other build code

    // Import zig-bigfloat's module into your own
    const bigfloat = b.dependency("zig-bigfloat", .{
        .target = target,
        .optimize = optimize,
    });
    exe_mod.addImport("bigfloat", bigfloat.module("bigfloat"));

    // ...other build code
}

Now you can use zig-bigfloat in your code:

const std = @import("std");
const F = @import("bigfloat").BigFloat(.{ .Significand = f64, .Exponent = i64 });

pub fn main() void {
    const pie: F = .init(3.14);
    const ans = pie.powi(8008135); // Or, if you prefer: F.powi(pie, 8008135)
    // pie ** BOOBIES = 5.097e3979479
    std.debug.print("pie ** BOOBIES = {e:.3}\n", .{ans});
}

Features

• 0 memory allocation
• Fast with decent accuracy
• Identical behaviour on any platform (assuming floating point +, -, * and / are consistent)

This library is NOT

• Arbitrary precision (you decide the precision at compile time)
• IEEE-754 compilant (especially with respect to rounding when formatting/parsing)

Use cases

• Incremental games that require numbers larger than f128 can represent (~10^4932)
• not sure, I just wanted to make an incremental game with big ass numbers