On Mon, Apr 29, 2013 at 7:34 PM, Nikhil Patil <nikhilpatil3...@gmail.com> wrote: > Hello, > > 1. Which passes of gcc make use of points-to information in > SSA_NAME_PTR_INFO (or more precisely, pt_solution) in doing > optimizations?
All passes that query the alias oracle (tree-ssa-alias.h) which is almost all passes doing optimization of memory accesses. > > 2. Also, who computes this points-to information and populates > pt_solution? Is it ONLY ipa-pta pass? It is points-to analysis, both the IPA variant and the local variant (ealias and alias passes). > When I accessed pt_solution through a plugin which REPLACES ipa-pta > pass, I found that the information (in pt_solution) with and without > ipa-pta pass differs only in terms of flags in pt_solution. Here with > the examples I could construct, I found that the bitmap 'vars' in > pt_solution is same for both the cases. Is it always true? In theory IPA PTA should be able to compute a more precise solution, thus have different (less) bits set in 'vars'. There are several testcases that show this, look for ipa-pta* testcases in gcc/testsuite/ Richard. > Can someone please help in clarifying these doubts. > > Thanks in advance. > > -- > Regards, > Nikhil Patil.
