This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH] clarify documentation of -Q --help=optimizers
- From: Martin Sebor <msebor at gmail dot com>
- To: Joseph Myers <joseph at codesourcery dot com>
- Cc: Alexander Monakov <amonakov at ispras dot ru>, Gcc Patch List <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 05 Nov 2015 11:44:54 -0700
- Subject: Re: [PATCH] clarify documentation of -Q --help=optimizers
- Authentication-results: sourceware.org; auth=none
- References: <56299713 dot 6040204 at gmail dot com> <562997A9 dot 3090203 at gmail dot com> <alpine dot LNX dot 2 dot 20 dot 1511031309390 dot 3529 at monopod dot intra dot ispras dot ru> <563A9A31 dot 5060306 at gmail dot com> <alpine dot DEB dot 2 dot 10 dot 1511050053500 dot 18787 at digraph dot polyomino dot org dot uk> <alpine dot LNX dot 2 dot 20 dot 1511051343310 dot 10819 at monopod dot intra dot ispras dot ru> <563B7CA1 dot 6080801 at gmail dot com> <alpine dot DEB dot 2 dot 10 dot 1511051707030 dot 26133 at digraph dot polyomino dot org dot uk> <563B960E dot 20508 at gmail dot com> <alpine dot DEB dot 2 dot 10 dot 1511051806400 dot 26133 at digraph dot polyomino dot org dot uk>
On 11/05/2015 11:07 AM, Joseph Myers wrote:
On Thu, 5 Nov 2015, Martin Sebor wrote:
There are several options marked Optimization that are actually matters of
language semantics that I don't think have anything to do with -O options,
e.g. -fexceptions and -fcx-limited-range. The Optimization tag really
just means that it's saved and restored under certain circumstances.
Both -fexceptions and -fcx-limited-range are reported as disabled
at -O0, so they're not the examples I'm looking for. The set of
But reporting that is nonsense.
What I said (meant) was that they are reported as "[disabled]" when
-O0 is used (and they are not explicitly enabled on the command line).
It took me a while to see that you're talking about something slightly
different.
They are disabled by default for C. If
you pass the option on the command line, it's enabled regardless of -O
options, and should not be reported as disabled.
Yes, I agree that printing "disabled by -O0" when -fexceptions is
explicitly enabled on the command line is not right if the option
isn't actually affected by -O0. This would be prevented if we knew
which of the -fxxx options are or aren't controlled by -O0. Can you
help identify them?
Martin