The "Options That Control Optimization" section of the manual is
currently divided into three parts (not subsections, just separate
option lists):
(1) General options like -O[n]
(2) Options that individually control options enabled by default at some
-O[n] setting
(3) Options controlling optimizations that aren't enabled by default, or
that are experimental
I've noted that a lot of options that belong in group (3) have been
added to group (2), and at least one from (2) into group (3). I'm
thinking that the distinction between (2) and (3) is not really useful
anyway; there are already both lists of which options are enabled at
each -O level, and info in the descriptions of individual options to say
what -O levels they're enabled at.
What would you think about reorganizing this section to add some
subsections grouping options by purpose, instead? E.g., loop
optimizations, floating-point optimizations, inlining, LTO, profiling
options, etc? The section is almost 60 pages long in the printed manual
and adding some structure would probably make it easier for users to
find things.
The other option would be just to list the options alphabetically, but
the index already does that if readers know the name of what they're
looking for (or they can search for it in their browser).
-Sandra