Function getFloat16Decoder

tfjs-core/src/io/io_utils.ts:720–741

()

 *          the Uint16Array of Float16 bytes to a Float32Array.
 */
export function getFloat16Decoder(): (buffer: Uint16Array) => Float32Array {
  // Algorithm is based off of
  // http://www.fox-toolkit.org/ftp/fasthalffloatconversion.pdf

  // Cache lookup tables
  const mantisaTable = computeFloat16MantisaTable();
  const exponentTable = computeFloat16ExponentTable();
  const offsetTable = computeFloat16OffsetTable();

  return (quantizedArray: Uint16Array) => {
    const buffer = new ArrayBuffer(4 * quantizedArray.length);
    const bufferUint32View = new Uint32Array(buffer);
    for (let index = 0; index < quantizedArray.length; index++) {
      const float16Bits = quantizedArray[index];
      const float32Bits =
          mantisaTable[offsetTable[float16Bits >> 10] + (float16Bits & 0x3ff)] +
          exponentTable[float16Bits >> 10];
      bufferUint32View[index] = float32Bits;
    }
    return new Float32Array(buffer);
  };
}