From aa7ad7d0df37dcf8e90ae312e8d0217b7ffc43f1 Mon Sep 17 00:00:00 2001 From: Vivian Wang Date: Fri, 10 Apr 2026 17:22:31 +0800 Subject: [PATCH] Clarify the word "canonical" in "canonical NaN" We define a "canonical NaN" for each format, which is unrelated to the concept of canonical encodings in IEEE 754. The latter only makes sense for decimal encodings anyway. Add a non-normative note clarifying this. IEEE 754-2019 adds a clarifying note that "In binary interchange formats, all number and NaN encodings are canonical." However, I think it's more confusing to explain it this way in the context of this note, so I didn't mention it. Signed-off-by: Vivian Wang --- src/unpriv/f-st-ext.adoc | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/src/unpriv/f-st-ext.adoc b/src/unpriv/f-st-ext.adoc index de2724dc3..5eb849283 100644 --- a/src/unpriv/f-st-ext.adoc +++ b/src/unpriv/f-st-ext.adoc @@ -193,6 +193,12 @@ quiet bit. For single-precision floating-point, this corresponds to the pattern (((NaN, generation))) (((NaN, propagation))) +[NOTE] +==== +The canonical NaN as defined here is unrelated to the definition of +canonical encodings in IEEE 754-2008 for decimal interchange formats. +==== +''' [NOTE] ==== We considered propagating NaN payloads, as is recommended by IEEE