Function fppi

src/big-decimal/utils.ts:644–653

(bits: number)

let _fppiCache: { bits: number; value: bigint } | null = null;

function fppi(bits: number): bigint {
  if (_fppiCache !== null) {
    if (_fppiCache.bits === bits) return _fppiCache.value;
    if (_fppiCache.bits > bits)
      return _fppiCache.value >> BigInt(_fppiCache.bits - bits);
  }
  const value = computeFppi(bits);
  _fppiCache = { bits, value };
  return value;
}

function computeFppi(bits: number): bigint {
  // We need ~bits·log10(2) decimal digits of PI, plus guard digits.