On Thu, Nov 05, 2015 at 08:58:25AM -0700, Martin Sebor wrote: > I don't think that reiterating in a condensed form what the manual > doesn't make clear in many more words will help. First, even users > who do find the relevant text in the manual often misunderstand it. > Others are misled by the "[enabled]" output into expecting the > optimizations to take place at -O0.
The -Q --help* output is primarily aimed at GCC developers, just like plain -Q is. The main problem here seems to be that the documentation pushes beginner GCC users to use this. Perhaps we should have a higher-level, more easy to use way to query what flags will do what, possibly integrated with the pass manager. > Those who are in doubt and > ask on gcc-help are then told by GCC experts that -O0 disables > all optimizations without exception, And it does, for the plain meaning of "optimization"; anything else is arguably a bug. But people have many different understandings of what a "compiler optimization" is, all the way to "anything the compiler does". Segher
