Add codegen tests for vec::IntoIter::next_chunk

Author: scottmcm

tests/codegen/vec-iter.rs

@@ -1,8 +1,11 @@
 //@ compile-flags: -O
+//@ min-llvm-version: 18 (which added `dead_on_unwind`)
 #![crate_type = "lib"]
 #![feature(exact_size_is_empty)]
+#![feature(iter_advance_by)]
+#![feature(iter_next_chunk)]
 
-use std::vec;
+use std::{array, vec};
 
 // CHECK-LABEL: @vec_iter_len_nonnull
 #[no_mangle]
@@ -56,3 +59,60 @@ pub fn vec_iter_next_back_nonnull(it: &mut vec::IntoIter<u8>) -> Option<u8> {
     // CHECK: ret
     it.next_back()
 }
+
+// CHECK-LABEL: @vec_iter_next_transfers_ownership
+#[no_mangle]
+pub fn vec_iter_next_transfers_ownership(it: &mut vec::IntoIter<Box<i32>>) -> Option<Box<i32>> {
+    // CHECK-NOT: __rust_dealloc
+    it.next()
+}
+
+// CHECK-LABEL: @vec_iter_advance_drops_item
+#[no_mangle]
+pub fn vec_iter_advance_drops_item(it: &mut vec::IntoIter<Box<i32>>) {
+    // CHECK-NOT: __rust_dealloc
+    // CHECK: call void @__rust_dealloc
+    // CHECK-SAME: noundef 4
+    // CHECK-SAME: noundef 4
+    // CHECK-NOT: __rust_dealloc
+    _ = it.advance_by(1);
+}
+
+// CHECK-LABEL: @vec_iter_next_chunk_short
+// CHECK-SAME: ptr{{.+}}%[[RET:.+]],
+#[no_mangle]
+pub fn vec_iter_next_chunk_short(
+    it: &mut vec::IntoIter<u8>,
+) -> Result<[u8; 4], array::IntoIter<u8, 4>> {
+    // CHECK-NOT: alloca
+    // CHECK: %[[ACTUAL_LEN:.+]] = sub nuw
+
+    // CHECK: %[[OUT1:.+]] = getelementptr inbounds i8, ptr %[[RET]]
+    // CHECK: call void @llvm.memcpy{{.+}}(ptr{{.+}}%[[OUT1]],{{.+}} %[[ACTUAL_LEN]], i1 false)
+    // CHECK: br
+
+    // CHECK: %[[FULL:.+]] = load i32,
+    // CHECK: %[[OUT2:.+]] = getelementptr inbounds i8, ptr %[[RET]]
+    // CHECK: store i32 %[[FULL]], ptr %[[OUT2]]
+    // CHECK: br
+    it.next_chunk::<4>()
+}
+
+// CHECK-LABEL: @vec_iter_next_chunk_long
+// CHECK-SAME: ptr{{.+}}%[[RET:.+]],
+#[no_mangle]
+pub fn vec_iter_next_chunk_long(
+    it: &mut vec::IntoIter<u8>,
+) -> Result<[u8; 123], array::IntoIter<u8, 123>> {
+    // CHECK-NOT: alloca
+    // CHECK: %[[ACTUAL_LEN:.+]] = sub nuw
+
+    // CHECK: %[[OUT1:.+]] = getelementptr inbounds i8, ptr %[[RET]]
+    // CHECK: call void @llvm.memcpy{{.+}}(ptr{{.+}}%[[OUT1]],{{.+}} %[[ACTUAL_LEN]], i1 false)
+    // CHECK: br
+
+    // CHECK: %[[OUT2:.+]] = getelementptr inbounds i8, ptr %[[RET]]
+    // CHECK: call void @llvm.memcpy{{.+}}(ptr{{.+}}%[[OUT2]],{{.+}} 123, i1 false)
+    // CHECK: br
+    it.next_chunk::<123>()
+}