@extra-bit/sign-extend

Sign extends variable bit-width integer.

Usage no npm install needed!

<script type="module">
  import extraBitSignExtend from 'https://cdn.skypack.dev/@extra-bit/sign-extend';
</script>

README

Sign extends variable bit-width integer. :package: :smiley_cat: :running: :vhs: :moon: :scroll: :newspaper: :blue_book:

This is part of package extra-bit.

bit.signExtend(x, [w]);
// x: variable bit-width integer
// w: bit width (32)

const bit = require("extra-bit");

bit.signExtend(15, 4);
// -1 (1111 ⇒ -1)

bit.signExtend(3, 3);
// 3  (011 ⇒ 3)

bit.signExtend(4, 3);
// -4 (100 ⇒ -4)

References

Bit Twiddling Hacks: By Sean Eron Anderson