Re: [PATCH 3/4] math: signal underflow for fmaf results that are tiny before rounding
Joseph Myers <[email protected]> Tue, 4 Aug 2026 00:37:29 +0000 (UTC)
| Newsgroups | gmane.comp.lib.glibc.alpha |
|---|---|
| Message-ID | <[email protected]> |
On Mon, 3 Aug 2026, Matt Turner wrote: > fmaf computes the exact result as a double and lets the return convert > it to float, so that conversion is the operation's single rounding and > is what has to signal underflow. Where the exact result is tiny but > rounds up to the smallest normal float, architectures determining > tininess after rounding do not signal it, because the value they examine > is no longer tiny. As with the previous patch, is this general for after-rounding architectures, or specific to an Alpha hardware bug? In either case, I'd expect changes to be appropriately conditional to avoid executing unnecessary code on unaffected targets. -- Joseph S. Myers [email protected]