[SCEV] Mark AddExprs as nsw or nuw if legal

Summary:
This uses `ScalarEvolution::getRange` and not potentially control
dependent `nsw` and `nuw` bits on the arithmetic instruction.

Reviewers: atrick, hfinkel, nlewycky

Subscribers: llvm-commits, sanjoy

Differential Revision: http://reviews.llvm.org/D13613

llvm-svn: 251048
diff --git a/llvm/test/Analysis/ScalarEvolution/min-max-exprs.ll b/llvm/test/Analysis/ScalarEvolution/min-max-exprs.ll
index a4be9c1..e8c1e33 100644
--- a/llvm/test/Analysis/ScalarEvolution/min-max-exprs.ll
+++ b/llvm/test/Analysis/ScalarEvolution/min-max-exprs.ll
@@ -33,7 +33,7 @@
   %tmp9 = select i1 %tmp4, i64 %tmp5, i64 %tmp6
 ;                  min(N, i+3)
 ; CHECK:           select i1 %tmp4, i64 %tmp5, i64 %tmp6
-; CHECK-NEXT:  --> (-1 + (-1 * ((-1 + (-1 * (sext i32 {3,+,1}<nw><%bb1> to i64))<nsw>) smax (-1 + (-1 * (sext i32 %N to i64))<nsw>)))<nsw>)
+; CHECK-NEXT:  --> (-1 + (-1 * ((-1 + (-1 * (sext i32 {3,+,1}<nuw><%bb1> to i64))<nsw>)<nsw> smax (-1 + (-1 * (sext i32 %N to i64))<nsw>)<nsw>))<nsw>)<nsw>
   %tmp11 = getelementptr inbounds i32, i32* %A, i64 %tmp9
   %tmp12 = load i32, i32* %tmp11, align 4
   %tmp13 = shl nsw i32 %tmp12, 1