search for: mulinttoptr

...sses other than my own. I'm writing a ModulePass. I am observing a situation where I compile a C++ file with no optimization and I get code as I would expect that uses getelementptr. However, if I enable optimization with -O3, *some* of my getelementptr instructions are lowered to ptrtoint/add-mulinttoptr sequences, but not others. As far as I can tell, there is no advantage to what LLVM is doing here (such as re-using pointer arithmetic computations). The 'Often Misunderstood GEP page' makes it sound like optimization always replaces pointer arithmetic with GEP instructions at the end, ev...

...I'm writing a ModulePass. > > I am observing a situation where I compile a C++ file with no optimization > and I get code as I would expect that uses getelementptr. However, if I > enable optimization with -O3, *some* of my getelementptr instructions are > lowered to ptrtoint/add-mulinttoptr sequences, but not others. > > As far as I can tell, there is no advantage to what LLVM is doing here (such > as re-using pointer arithmetic computations). > > The 'Often Misunderstood GEP page' makes it sound like optimization always > replaces pointer arithmetic with GEP...