From 89b8a97aead4aa366eb2587ffdcfa7df39f3815a Mon Sep 17 00:00:00 2001
From: Dániel Buga <bugadani@gmail.com>
Date: Sun, 20 Sep 2020 14:46:07 +0200
Subject: Refactor memchr to allow optimization

---
 src/test/codegen/issue-75659.rs | 62 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 src/test/codegen/issue-75659.rs

(limited to 'src/test/codegen')

diff --git a/src/test/codegen/issue-75659.rs b/src/test/codegen/issue-75659.rs
new file mode 100644
index 00000000000..8a4b7ef8c43
--- /dev/null
+++ b/src/test/codegen/issue-75659.rs
@@ -0,0 +1,62 @@
+// This test checks that the call to memchr/slice_contains is optimized away
+// when searching in small slices.
+
+// compile-flags: -O
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @foo1
+#[no_mangle]
+pub fn foo1(x: u8, data: &[u8; 1]) -> bool {
+    // CHECK-NOT: memchr
+    // CHECK-NOT: slice_contains
+    data.contains(&x)
+}
+
+// CHECK-LABEL: @foo2
+#[no_mangle]
+pub fn foo2(x: u8, data: &[u8; 2]) -> bool {
+    // CHECK-NOT: memchr
+    // CHECK-NOT: slice_contains
+    data.contains(&x)
+}
+
+// CHECK-LABEL: @foo3
+#[no_mangle]
+pub fn foo3(x: u8, data: &[u8; 3]) -> bool {
+    // CHECK-NOT: memchr
+    // CHECK-NOT: slice_contains
+    data.contains(&x)
+}
+
+// CHECK-LABEL: @foo4
+#[no_mangle]
+pub fn foo4(x: u8, data: &[u8; 4]) -> bool {
+    // CHECK-NOT: memchr
+    // CHECK-NOT: slice_contains
+    data.contains(&x)
+}
+
+// CHECK-LABEL: @foo8
+#[no_mangle]
+pub fn foo8(x: u8, data: &[u8; 8]) -> bool {
+    // CHECK-NOT: memchr
+    // CHECK-NOT: slice_contains
+    data.contains(&x)
+}
+
+// CHECK-LABEL: @foo8_i8
+#[no_mangle]
+pub fn foo8_i8(x: i8, data: &[i8; 8]) -> bool {
+    // CHECK-NOT: memchr
+    // CHECK-NOT: slice_contains
+    !data.contains(&x)
+}
+
+// Check that the general case isn't inlined
+// CHECK-LABEL: @foo80
+#[no_mangle]
+pub fn foo80(x: u8, data: &[u8; 80]) -> bool {
+    // CHECK: call core::slice::memchr
+    data.contains(&x)
+}
-- 
cgit 1.4.1-3-g733a5