From 3815c6abbaf077fbfe798578953dbe332090917e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?D=C3=A1niel=20Buga?= <bugadani@gmail.com>
Date: Fri, 23 Oct 2020 00:12:20 +0200
Subject: [PATCH] Add codegen test for #45964

---
 .../issue-45964-bounds-check-slice-pos.rs     | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/test/codegen/issue-45964-bounds-check-slice-pos.rs

diff --git a/src/test/codegen/issue-45964-bounds-check-slice-pos.rs b/src/test/codegen/issue-45964-bounds-check-slice-pos.rs
new file mode 100644
index 0000000000000..aa59c713b7846
--- /dev/null
+++ b/src/test/codegen/issue-45964-bounds-check-slice-pos.rs
@@ -0,0 +1,38 @@
+// This test case checks that slice::{r}position functions do not
+// prevent optimizing away bounds checks
+
+// compile-flags: -O
+
+#![crate_type="rlib"]
+
+// CHECK-LABEL: @test
+#[no_mangle]
+pub fn test(y: &[u32], x: &u32, z: &u32) -> bool {
+    let result = match y.iter().position(|a| a == x) {
+        Some(p) => Ok(p),
+        None => Err(()),
+    };
+
+    if let Ok(p) = result {
+        // CHECK-NOT: panic
+        y[p] == *z
+    } else {
+        false
+    }
+}
+
+// CHECK-LABEL: @rtest
+#[no_mangle]
+pub fn rtest(y: &[u32], x: &u32, z: &u32) -> bool {
+    let result = match y.iter().rposition(|a| a == x) {
+        Some(p) => Ok(p),
+        None => Err(()),
+    };
+
+    if let Ok(p) = result {
+        // CHECK-NOT: panic
+        y[p] == *z
+    } else {
+        false
+    }
+}