Document Lisp floats a bit better

* doc/lispref/numbers.texi (Float Basics):
* doc/misc/cl.texi (Implementation Parameters):
* lisp/emacs-lisp/cl-lib.el (cl-most-positive-float)
(cl-least-positive-float)
(cl-least-positive-normalized-float, cl-float-epsilon)
(cl-float-negative-epsilon):
Document IEEE floating point better.  Don’t suggest that Emacs
might use some floating-point format other than IEEE format, as
Emacs currently assumes IEEE in several places and there seems
little point in removing those assumptions.

1 files changed, 6 insertions, 2 deletions

diff --git a/doc/lispref/numbers.texi b/doc/lispref/numbers.texi
index 0c71387a8a7..939ad5c85a1 100644
--- a/doc/lispref/numbers.texi
+++ b/doc/lispref/numbers.texi
@@ -218,8 +218,12 @@ considered to be valid as a character.  @xref{Character Codes}.
   Floating-point numbers are useful for representing numbers that are
 not integral.  The range of floating-point numbers is
 the same as the range of the C data type @code{double} on the machine
-you are using.  On all computers currently supported by Emacs, this is
-double-precision @acronym{IEEE} floating point.
+you are using.  On all computers supported by Emacs, this is
+@acronym{IEEE} binary64 floating point format, which is standardized by
+@url{https://standards.ieee.org/standard/754-2019.html,,IEEE Std 754-2019}
+and is discussed further in David Goldberg's paper
+``@url{https://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html,
+What Every Computer Scientist Should Know About Floating-Point Arithmetic}''.
 
   The read syntax for floating-point numbers requires either a decimal
 point, an exponent, or both.  Optional signs (@samp{+} or @samp{-})