Sanjoy Das 1af442e572 Bugfix: ScalarEvolution incorrectly assumes that the start of certain
add recurrences don't overflow.

This change makes the optimization more restrictive.  It still assumes
that an overflowing `add nsw` is undefined behavior; and this change
will need revisiting once we have a consistent semantics for poison
values.

Differential Revision: http://reviews.llvm.org/D7331



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228552 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-08 22:52:17 +00:00
..