Chris Lattner e2b5854e41 Allow basicaa to walk through geps with identical indices in
parallel, allowing it to decide that P/Q must alias if A/B
must alias in things like:
 P = gep A, 0, i, 1
 Q = gep B, 0, i, 1

This allows GVN to delete 62 more instructions out of 403.gcc.

llvm-svn: 60820
2008-12-10 01:04:47 +00:00
..
2008-12-10 00:15:44 +00:00