Skip to content
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 11 additions & 2 deletions src/librustc_codegen_ssa/mir/place.rs
Original file line number Diff line number Diff line change
Expand Up @@ -335,11 +335,20 @@ impl<'a, 'tcx: 'a, V: CodegenObject> PlaceRef<'tcx, V> {
bx: &mut Bx,
llindex: V
) -> Self {
// Statically compute the offset if we can, otherwise just use the element size,
// as this will yield the lowest alignment.
let layout = self.layout.field(bx, 0);
let offset = if bx.is_const_integral(llindex) {
layout.size.checked_mul(bx.const_to_uint(llindex), bx).unwrap_or(layout.size)
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I think this checked_mul is not strictly necessary, as such cases won't reach here, but included it to be sure.

} else {
layout.size
};

PlaceRef {
llval: bx.inbounds_gep(self.llval, &[bx.cx().const_usize(0), llindex]),
llextra: None,
layout: self.layout.field(bx.cx(), 0),
align: self.align
layout,
align: self.align.restrict_for_offset(offset),
}
}

Expand Down
3 changes: 2 additions & 1 deletion src/librustc_codegen_ssa/mir/rvalue.rs
Original file line number Diff line number Diff line change
Expand Up @@ -131,8 +131,9 @@ impl<'a, 'tcx: 'a, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
let keep_going = header_bx.icmp(IntPredicate::IntNE, current, end);
header_bx.cond_br(keep_going, body_bx.llbb(), next_bx.llbb());

let align = dest.align.restrict_for_offset(dest.layout.field(bx.cx(), 0).size);
cg_elem.val.store(&mut body_bx,
PlaceRef::new_sized(current, cg_elem.layout, dest.align));
PlaceRef::new_sized(current, cg_elem.layout, align));

let next = body_bx.inbounds_gep(current, &[bx.cx().const_usize(1)]);
body_bx.br(header_bx.llbb());
Expand Down
44 changes: 44 additions & 0 deletions src/test/codegen/issue-56927.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,44 @@
// compile-flags: -C no-prepopulate-passes

#![crate_type="rlib"]
use std::usize;

#[repr(align(16))]
pub struct S {
arr: [u32; 4],
}

// CHECK-LABEL: @test1
// CHECK: store i32 0, i32* %{{.+}}, align 16
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Please check for the label before the store instructions.

// CHECK: store i32 1, i32* %{{.+}}, align 4
// CHECK: store i32 2, i32* %{{.+}}, align 8
// CHECK: store i32 3, i32* %{{.+}}, align 4
#[no_mangle]
pub fn test1(s: &mut S) {
s.arr[0] = 0;
s.arr[1] = 1;
s.arr[2] = 2;
s.arr[3] = 3;
}

// CHECK-LABEL: @test2
// CHECK: store i32 4, i32* %{{.+}}, align 4
#[allow(const_err)]
#[no_mangle]
pub fn test2(s: &mut S) {
s.arr[usize::MAX / 4 + 1] = 4;
}

// CHECK-LABEL: @test3
// CHECK: store i32 5, i32* %{{.+}}, align 4
#[no_mangle]
pub fn test3(s: &mut S, i: usize) {
s.arr[i] = 5;
}

// CHECK-LABEL: @test4
// CHECK: store i32 6, i32* %{{.+}}, align 4
#[no_mangle]
pub fn test4(s: &mut S) {
s.arr = [6; 4];
}
36 changes: 36 additions & 0 deletions src/test/codegen/packed.rs
Original file line number Diff line number Diff line change
Expand Up @@ -84,6 +84,42 @@ pub fn call_pkd2(f: fn() -> Array) -> BigPacked2 {
BigPacked2 { dealign: 0, data: f() }
}

// CHECK-LABEL: @write_packed_array1
// CHECK: store i32 0, i32* %{{.+}}, align 1
// CHECK: store i32 1, i32* %{{.+}}, align 1
// CHECK: store i32 2, i32* %{{.+}}, align 1
#[no_mangle]
pub fn write_packed_array1(p: &mut BigPacked1) {
p.data.0[0] = 0;
p.data.0[1] = 1;
p.data.0[2] = 2;
}

// CHECK-LABEL: @write_packed_array2
// CHECK: store i32 0, i32* %{{.+}}, align 2
// CHECK: store i32 1, i32* %{{.+}}, align 2
// CHECK: store i32 2, i32* %{{.+}}, align 2
#[no_mangle]
pub fn write_packed_array2(p: &mut BigPacked2) {
p.data.0[0] = 0;
p.data.0[1] = 1;
p.data.0[2] = 2;
}

// CHECK-LABEL: @repeat_packed_array1
// CHECK: store i32 42, i32* %{{.+}}, align 1
#[no_mangle]
pub fn repeat_packed_array1(p: &mut BigPacked1) {
p.data.0 = [42; 8];
}

// CHECK-LABEL: @repeat_packed_array2
// CHECK: store i32 42, i32* %{{.+}}, align 2
#[no_mangle]
pub fn repeat_packed_array2(p: &mut BigPacked2) {
p.data.0 = [42; 8];
}

#[repr(packed)]
#[derive(Copy, Clone)]
pub struct Packed1Pair(u8, u32);
Expand Down