Hello Sir, On Wed, Mar 4, 2009 at 7:44 PM, Manuel López-Ibáñez <lopeziba...@gmail.com> wrote: > I am no expert in this area, so please consider that I may be > misunderstanding something. > > This seems a data flow analyzer for GIMPLE. So the analysis results > can be used by the FE, am I wrong? >
( I am assuming by FE you mean, front end and VRP is value range propagation) GIMPLE is a stage after front end perticularely after AST, type checking etc is done. So I can't visualize how it can be used in FE. As far as i know, Data flow analysis is used for the purpose of, 1. Optimizations 2. Producing dignostic information about source code. > Could it be used to propagate constant values? What about VRP in the FE? > We have implemented bit vector analysis framework only. Constant propagation is not implemented yet, so no VRP :) > What is the overhead involved? We are using existing IR, existing APIs for accessing GIMPLE data structure. Only new pass to perform DFA has been added to the GCC pass structure. The space overhead is interms of storage of data flow values using sbitmap. > > I ask because I know that Clang performs data flow analysis in the FE > to provide better warnings, and Chris Lattner said that the overhead > of doing this was very low. > The beauty of GDFA code lies within, the specifications provided for GDFA. One does not have to implement local analysis in order to incorporate new data flow analysis. (for time being, bit vector analysis) - Seema > Cheers, > > Manuel. > > 2009/3/4 Seema Ravandale <ravandal...@gmail.com>: >> Announcement: gdfa - Generic data flow analyzer for GCC. >> Developed by: GCC resource center, IITB >> >> Patch and the Documentation can be found at the below link, >> >> http://www.cse.iitb.ac.in/grc/gdfa.html >> >> >> Ms. Seema S. Ravandale >> Project Engg, >> GCC Resource Center >> Department of Computer Science & Engg. >> IIT Bombay, Powai, Mumbai 400 076, India. >> email - se...@cse.iitb.ac.in >> >
