From: Chris Lattner
The load-vn pass uses alias analysis to provide value numbering -information for load instructions and pointer values. If your analysis -or transformation can be modeled in a form that uses value numbering -information, you don't have to do anything special to handle load instructions: -just use the load-vn pass, which uses alias analysis.
+The memdep pass uses alias analysis to provide high-level dependence +information about memory-using instructions. This will tell you which store +feeds into a load, for example. It uses caching and other techniques to be +efficient, and is used by Dead Store Elimination, GVN, and memcpy optimizations. +
The -load-vn pass uses alias analysis to "value -number" loads and pointers values, which is used by the GCSE pass to -eliminate instructions. The -load-vn pass relies on alias information -and must-alias information. This combination of passes can make the following -transformations:
- -These passes use AliasAnalysis information to reason about loads and stores. +