[LLVMdev] Dependence Analysis [was: Flow-Sensitive AA]

Vikram S. Adve vadve at cs.uiuc.edu
Fri Aug 22 15:05:24 PDT 2008

On Aug 22, 2008, at 4:49 PM, John Regehr wrote:

> Has anyone quantified the optimizations afforded by undefined signed
> overflow?  I'd expect that the benefits are minimal for most codes.

In most cases, I agree.  But for codes that depend heavily on  
dependence analysis, I would think that being conservative with index  
expressions would really kill any disambiguation capability and make  
many loop optimizations and other dependence-based optimizations much  
weaker.  For example, static scheduling of array intensive loops seems  
vulnerable to this.


More information about the llvm-dev mailing list