Floating-Point Intel® FPGA IP User Guide

ID 683750
Date 8/30/2024
Public
Document Table of Contents

1.5.3. Rounding

The IEEE-754 standard defines four types of rounding, which are:
  • Round to nearest with tie breaking to even
  • Round-toward-zero
  • Round-toward-positive-infinity
  • Round-toward-negative-infinity

Intel floating-point IPs support only the most commonly used rounding, which is round to nearest with tie breaking to even (TO_NEAREST). With round to nearest with tie breaking to even, the IP rounds the result to the nearest floating-point number. If the result is exactly halfway between two floating-point numbers, the IP rounds the result so that the LSB becomes a zero, which is even.