Fix bogus overflow checks by replacing them with actual

overflow checks.

llvm-svn: 71284

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/test/Analysis/ScalarEvolution/div-overflow.ll b/llvm/test/Analysis/ScalarEvolution/div-overflow.ll
new file mode 100644
index 00000000000..cb64b856a77
--- /dev/null
+++ b/llvm/test/Analysis/ScalarEvolution/div-overflow.ll
@@ -0,0 +1,10 @@
+; RUN: llvm-as < %s | opt -scalar-evolution -analyze -disable-output \
+; RUN:  | grep {\\-->  ((-128 \\* %a) /u -128)}
+
+; Don't let ScalarEvolution fold this div away.
+
+define i8 @foo(i8 %a) {
+        %t0 = shl i8 %a, 7
+        %t1 = lshr i8 %t0, 7
+        ret i8 %t1
+}