https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91406
Manuel López-Ibáñez <manu at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|gcc -Q -v lies about what |gcc -Q -v --help=optimizers
|flags are enabled |lies about what flags are
| |enabled
CC| |manu at gcc dot gnu.org
--- Comment #2 from Manuel López-Ibáñez <manu at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> -Q -v is only a wild guess given whether options are enabled or disabled may
> depend on the function context. There's really no way to implement it
> accurately
> (this -1 trick for "auto-detection" could eventually be handled in some
> generic way, saying not enabled/disabled but "<auto>" or "<unknown>")
The output of "-Q --help=optimizers" should at least match the documentation.
That is,
g++ -Q -O0 --help=optimizers | grep prefetch
-fprefetch-loop-arrays [enabled]
g++ -Q -Os --help=optimizers | grep prefetch
-fprefetch-loop-arrays [enabled]
is wrong.
I would expect that the option is NEVER enabled with -O0 or -Os independently
of any function context.
