http://llvm.org/bugs/show_bug.cgi?id=12740
Eli Friedman <[email protected]> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED CC| |[email protected] Resolution| |INVALID --- Comment #2 from Eli Friedman <[email protected]> 2012-05-05 15:53:59 CDT --- (In reply to comment #0) > Created attachment 8494 [details] > Simple loop IR which basicaa incorrectly analyzes > > After moving from 2.9 to 3.0 we noticed that -basicaa was giving us some false > "NoAlias" responses, even in very simple cases. > > For example, in IR resulting from a C loop such as this: > > for(i=0; i<100; i++){ A[i] = A[i] + A[i+1] } > > -basicaa in 3.0 will say that A[i] and A[i+1] do not alias. While this is true > in the context of a single iteration, it is not true in general. This is intentional. If we tried to compute alias analysis based on all the possible values a Instruction could have through the entire program, alias analysis would be nearly useless. There's a current thread on llvmdev discussing a new LoopDependenceAnalysis pass, if that's what you're looking for. -- Configure bugmail: http://llvm.org/bugs/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. _______________________________________________ LLVMbugs mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/llvmbugs
