From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcio de Oliveira Buss To: gcc@gcc.gnu.org Subject: Re: CFG Date: Wed, 28 Jun 2000 14:36:00 -0000 Message-id: References: <5057.962226136@upchuck> X-SW-Source: 2000-06/msg00735.html Thus, is there an answer for this question? "what is the compilation point where I could take the most optimized CFG for a function to build another structure based on that CFG?" And which is the file representing this point. Thanks. On Wed, 28 Jun 2000, Jeffrey A Law wrote: > > Could you please help me? I want to know if the CFG > > constructed in the dataflow analysis is updated at each step > > subsequent steps of the compilation, and, in turn, remains until > > the Final phase of the compilation process. I want to transform > > the CFG into another structure but only after all the optimizations > > have been made over it. I know that the almost all optimizations > > are made over the RTL expressions, but I don't know if some > > optimization touchs the CFG. > > In other words, I would like to know if the CFG is > > destructed after the dataflow analysis, i.e., after the > > informations provided by the CFG are recorded for futures uses, or > > if the CFG remains untouchable. > Most of the time we [re]build the cfg when we need it (ie, we don't assume > it's valid, except in a few special cases). Most of the optimizers are > not using the cfg right now and do not keep it accurate. > jeff