From af0e35e6a6837aba121c873e6f91fff6df61d268 Mon Sep 17 00:00:00 2001
From: Scott McMurray <scottmcm@users.noreply.github.com>
Date: Sat, 15 Jun 2019 20:54:04 -0700
Subject: Help LLVM better optimize slice::Iter(Mut)::len

---
 src/test/codegen/slice-iter-len-eq-zero.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 src/test/codegen/slice-iter-len-eq-zero.rs

(limited to 'src/test/codegen')

diff --git a/src/test/codegen/slice-iter-len-eq-zero.rs b/src/test/codegen/slice-iter-len-eq-zero.rs
new file mode 100644
index 00000000000..a5516833900
--- /dev/null
+++ b/src/test/codegen/slice-iter-len-eq-zero.rs
@@ -0,0 +1,14 @@
+// no-system-llvm
+// compile-flags: -O
+#![crate_type = "lib"]
+
+type Demo = [u8; 3];
+
+// CHECK-LABEL: @slice_iter_len_eq_zero
+#[no_mangle]
+pub fn slice_iter_len_eq_zero(y: std::slice::Iter<'_, Demo>) -> bool {
+    // CHECK-NOT: sub
+    // CHECK: %2 = icmp eq i8* %1, %0
+    // CHECK: ret i1 %2
+    y.len() == 0
+}
-- 
cgit 1.4.1-3-g733a5