Submitter:CFP
Submission Date: 2026-08-03
Document: WG14 N3948
Proposal category:Technical
Title: quantum exponent of fromfp family
Reference Documents:SC22WG14.36384 & CFP 3915, issue #30

Summary

Joseph S. Myers asked if we should specify the quantum exponent of the return value of the fromfp family of functions.

Discussion

fromfp, fromfpx, ufromfp, ufromfpx are similar to roundeven, round, trunc, ceil, floor, rint, nearbyint in that they all return an integer (in floating-point format). Therefore, they should be treated the same for the preferred quantum exponent.

Proposal

In section 5.3.5.3.4, add to the entry for roundeven, round, trunc, ceil, floor, rint, nearbyint in Table 5.2 Preferred quantum exponents:

fromfp, fromfpx, ufromfp, ufromfpx