1 files changed, 115 insertions, 0 deletions
diff --git a/tests/codegen-llvm/slice-iter-nonnull.rs b/tests/codegen-llvm/slice-iter-nonnull.rs
new file mode 100644
index 00000000000..87907e7ad0a
--- /dev/null
+++ b/tests/codegen-llvm/slice-iter-nonnull.rs
@@ -0,0 +1,115 @@
+//@ compile-flags: -Copt-level=3
+//@ needs-deterministic-layouts
+#![crate_type = "lib"]
+#![feature(exact_size_is_empty)]
+
+// The slice iterator used to `assume` that the `start` pointer was non-null.
+// That ought to be unneeded, though, since the type is `NonNull`, so this test
+// confirms that the appropriate metadata is included to denote that.
+
+// It also used to `assume` the `end` pointer was non-null, but that's no longer
+// needed as the code changed to read it as a `NonNull`, and thus gets the
+// appropriate `!nonnull` annotations naturally.
+
+// CHECK-LABEL: @slice_iter_next(
+#[no_mangle]
+pub fn slice_iter_next<'a>(it: &mut std::slice::Iter<'a, u32>) -> Option<&'a u32> {
+    // CHECK: %[[START:.+]] = load ptr, ptr %it,
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+    // CHECK: %[[ENDP:.+]] = getelementptr inbounds{{( nuw)?}} i8, ptr %it, {{i32 4|i64 8}}
+    // CHECK: %[[END:.+]] = load ptr, ptr %[[ENDP]]
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+    // CHECK: icmp eq ptr %[[START]], %[[END]]
+
+    // CHECK: store ptr{{.+}}, ptr %it,
+
+    it.next()
+}
+
+// CHECK-LABEL: @slice_iter_next_back(
+#[no_mangle]
+pub fn slice_iter_next_back<'a>(it: &mut std::slice::Iter<'a, u32>) -> Option<&'a u32> {
+    // CHECK: %[[ENDP:.+]] = getelementptr inbounds{{( nuw)?}} i8, ptr %it, {{i32 4|i64 8}}
+    // CHECK: %[[END:.+]] = load ptr, ptr %[[ENDP]]
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+    // CHECK: %[[START:.+]] = load ptr, ptr %it,
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+    // CHECK: icmp eq ptr %[[START]], %[[END]]
+
+    // CHECK: store ptr{{.+}}, ptr %[[ENDP]],
+
+    it.next_back()
+}
+
+// The slice iterator `new` methods used to `assume` that the pointer is non-null,
+// but passing slices already requires that, to the extent that LLVM actually
+// removed the `call @llvm.assume` anyway.  These tests just demonstrate that the
+// attribute is there, and confirms adding the assume back doesn't do anything.
+
+// CHECK-LABEL: @slice_iter_new
+// CHECK-SAME: (ptr noalias noundef nonnull {{.+}} %slice.0, {{.+}} noundef %slice.1)
+#[no_mangle]
+pub fn slice_iter_new(slice: &[u32]) -> std::slice::Iter<'_, u32> {
+    // CHECK-NOT: slice
+    // CHECK: %[[END:.+]] = getelementptr inbounds{{( nuw)?}} i32{{.+}} %slice.0{{.+}} %slice.1
+    // CHECK-NOT: slice
+    // CHECK: insertvalue {{.+}} ptr %slice.0, 0
+    // CHECK-NOT: slice
+    // CHECK: insertvalue {{.+}} ptr %[[END]], 1
+    // CHECK-NOT: slice
+    // CHECK: }
+    slice.iter()
+}
+
+// CHECK-LABEL: @slice_iter_mut_new
+// CHECK-SAME: (ptr noalias noundef nonnull {{.+}} %slice.0, {{.+}} noundef %slice.1)
+#[no_mangle]
+pub fn slice_iter_mut_new(slice: &mut [u32]) -> std::slice::IterMut<'_, u32> {
+    // CHECK-NOT: slice
+    // CHECK: %[[END:.+]] = getelementptr inbounds{{( nuw)?}} i32{{.+}} %slice.0{{.+}} %slice.1
+    // CHECK-NOT: slice
+    // CHECK: insertvalue {{.+}} ptr %slice.0, 0
+    // CHECK-NOT: slice
+    // CHECK: insertvalue {{.+}} ptr %[[END]], 1
+    // CHECK-NOT: slice
+    // CHECK: }
+    slice.iter_mut()
+}
+
+// CHECK-LABEL: @slice_iter_is_empty
+#[no_mangle]
+pub fn slice_iter_is_empty(it: &std::slice::Iter<'_, u32>) -> bool {
+    // CHECK: %[[ENDP:.+]] = getelementptr inbounds{{( nuw)?}} i8, ptr %it, {{i32 4|i64 8}}
+    // CHECK: %[[END:.+]] = load ptr, ptr %[[ENDP]]
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+    // CHECK: %[[START:.+]] = load ptr, ptr %it,
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+
+    // CHECK: %[[RET:.+]] = icmp eq ptr %[[START]], %[[END]]
+    // CHECK: ret i1 %[[RET]]
+    it.is_empty()
+}
+
+// CHECK-LABEL: @slice_iter_len
+#[no_mangle]
+pub fn slice_iter_len(it: &std::slice::Iter<'_, u32>) -> usize {
+    // CHECK: %[[ENDP:.+]] = getelementptr inbounds{{( nuw)?}} i8, ptr %it, {{i32 4|i64 8}}
+    // CHECK: %[[END:.+]] = load ptr, ptr %[[ENDP]]
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+    // CHECK: %[[START:.+]] = load ptr, ptr %it,
+    // CHECK-SAME: !nonnull
+    // CHECK-SAME: !noundef
+
+    // CHECK: ptrtoint
+    // CHECK: ptrtoint
+    // CHECK: sub nuw
+    // CHECK: lshr exact
+    it.len()
+}