> Hi, > I wish to selectively enable specific optimizations to observe its effect > on the source. My project requires me to do this analysis. It seemed, the > -f* flags would enable me to do that. But it turns out that individual > optimizations can't be enabled like that, and all the optimizations at a > specific level gets enabled when I use a -Ox switch. This faq at > http://gcc.gnu.org/wiki/FAQ#optimization-options, says this too. > > So here are my two questions : > > a) Is there any way to observe the effect of a particular optimization, > without the obvious option of using a lot of -fno switches. > b) And do the -f* switches serve any purpose, if I can't enable individual > optimizations using them.
I suspect that in practice that this isn't a particularly interesting question. Optimizations often interact with each other in complex ways, with the end result being significantly different to the naive sum of their parts. Paul
