From 09825de61bb4e9a339b3c6759d73ebb4c0b6c7b1 Mon Sep 17 00:00:00 2001 From: Ariel Ben-Yehuda Date: Mon, 6 Feb 2017 17:27:09 +0100 Subject: emit "align 1" metadata on loads/stores of packed structs According to the LLVM reference: > A value of 0 or an omitted align argument means that the operation has the ABI alignment for the target. So loads/stores of fields of packed structs need to have their align set to 1. Implement that by tracking the alignment of `LvalueRef`s. Fixes #39376. --- src/test/codegen/packed.rs | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 src/test/codegen/packed.rs (limited to 'src/test/codegen') diff --git a/src/test/codegen/packed.rs b/src/test/codegen/packed.rs new file mode 100644 index 00000000000..db2cd3b4165 --- /dev/null +++ b/src/test/codegen/packed.rs @@ -0,0 +1,29 @@ +// Copyright 2016 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +// compile-flags: -C no-prepopulate-passes + +#![crate_type = "lib"] + +#[repr(packed)] +pub struct Packed { + dealign: u8, + data: u32 +} + +// CHECK-LABEL: @write_pkd +#[no_mangle] +pub fn write_pkd(pkd: &mut Packed) -> u32 { +// CHECK: %{{.*}} = load i32, i32* %{{.*}}, align 1 +// CHECK: store i32 42, i32* %{{.*}}, align 1 + let result = pkd.data; + pkd.data = 42; + result +} -- cgit 1.4.1-3-g733a5