Don't (unconditionally) use getSCEVAtScope to simplify the step

expression in IVUsers, because in the case of a use of a non-linear
addrec outside of a loop, this causes the addrec to be evaluated as
a linear addrec.

llvm-svn: 73774

1 files changed, 18 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll b/llvm/test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll
new file mode 100644
index 00000000000..d15c2dc3135
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll
@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | opt -analyze -iv-users -disable-output | grep {Stride i64 {1,+,2}<loop>:}
+
+; The value of %r is dependent on a polynomial iteration expression.
+
+define i64 @foo(i64 %n) {
+entry:
+  br label %loop
+
+loop:
+  %indvar = phi i64 [ 0, %entry ], [ %indvar.next, %loop ]
+  %indvar.next = add i64 %indvar, 1
+  %c = icmp eq i64 %indvar.next, %n
+  br i1 %c, label %exit, label %loop
+
+exit:
+  %r = mul i64 %indvar, %indvar
+  ret i64 %r
+}