From 8e7d8ddffe802180b504e0ecaaa40b10b28b291e Mon Sep 17 00:00:00 2001 From: Ben Kimock Date: Mon, 17 Mar 2025 21:29:07 -0400 Subject: Lower to a memset(undef) when Rvalue::Repeat repeats uninit --- tests/codegen/uninit-repeat-in-aggregate.rs | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 tests/codegen/uninit-repeat-in-aggregate.rs (limited to 'tests/codegen') diff --git a/tests/codegen/uninit-repeat-in-aggregate.rs b/tests/codegen/uninit-repeat-in-aggregate.rs new file mode 100644 index 00000000000..0fa2eb7d56c --- /dev/null +++ b/tests/codegen/uninit-repeat-in-aggregate.rs @@ -0,0 +1,21 @@ +//@ compile-flags: -Copt-level=3 + +#![crate_type = "lib"] + +use std::mem::MaybeUninit; + +// We need to make sure len is at offset 0, otherwise codegen needs an extra instruction +#[repr(C)] +pub struct SmallVec { + pub len: u64, + pub arr: [MaybeUninit; 24], +} + +// CHECK-LABEL: @uninit_arr_via_const +#[no_mangle] +pub fn uninit_arr_via_const() -> SmallVec { + // CHECK-NEXT: start: + // CHECK-NEXT: store i64 0, + // CHECK-NEXT: ret + SmallVec { len: 0, arr: [const { MaybeUninit::uninit() }; 24] } +} -- cgit 1.4.1-3-g733a5