search for: vandrunen

hi, While surfing on net I found that LLVM is using sparse version of E-path_PRE approach in file PRE.cpp but I could not get what actually code is doing and I could not find the name of the developer in the file. Just want to know to because I could not able to find any paper on sparse version of this algorithm. Thanks in Advance -- Dheeraj Kumar M. Tech. I yr (CSE)

> To me, GVN-PRE and a MIPS backend would be the most useful ones. Do you > have MIPS hardware to test on? If not, a GVNPRE pass might be better, > though you could do the port with a good simulator. Daniel Berlin knows > much about GVNPRE, so he could probably comment more on it. I implemented GVN-PRE for GCC. You could probably do an implementation for LLVM in three months,

Hi, I am Jill, I'm new here and new with llvm. I find that its old PRE.cpp has been removed from llvm-1.9 and the project homepage says that a GVN-PRE pass is being implemented. Since many PRE algorithms have been suggested, and I think PRE further differs according to the specific defination of equivalence, whether it is an "optimal" algorithm and optimal at what metric, etc, can I

Thanks, Owen. It helps a lot:) ------ Jill, The old PRE never really worked properly, or at least was never really finished. We're planning to implement GVN-PRE (ftp:// ftp.cs.purdue.edu/pub/hosking/papers/vandrunen.pdf) as it is a more powerful algorithm. You are right, of course, that the ability of the PRE to determine the equivalence of two expression. This is an area that can always be improved, and it's mostly an issue of if it's worth the amount of work required to prove a given equivalence....