diff options
| -rw-r--r-- | src/librustc_trans/trans/adt.rs | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/src/librustc_trans/trans/adt.rs b/src/librustc_trans/trans/adt.rs index ba227d6c38b..07d8175727b 100644 --- a/src/librustc_trans/trans/adt.rs +++ b/src/librustc_trans/trans/adt.rs @@ -400,6 +400,15 @@ fn represent_type_uncached<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, } } } + + // If the alignment is smaller than the chosen discriminant size, don't use the + // alignment as the final size. + let min_ty = ll_inttype(&cx, min_ity); + let min_size = machine::llsize_of_real(cx, min_ty); + if (align as u64) < min_size { + use_align = false; + } + let ity = if use_align { // Use the overall alignment match align { @@ -817,11 +826,11 @@ fn generic_type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, // FIXME #10604: this breaks when vector types are present. let (size, align) = union_size_and_align(&sts[..]); let align_s = align as u64; - assert_eq!(size % align_s, 0); - let align_units = size / align_s - 1; - let discr_ty = ll_inttype(cx, ity); let discr_size = machine::llsize_of_alloc(cx, discr_ty); + let padded_discr_size = roundup(discr_size, align); + assert_eq!(size % align_s, 0); // Ensure division in align_units comes out evenly + let align_units = (size - padded_discr_size) / align_s; let fill_ty = match align_s { 1 => Type::array(&Type::i8(cx), align_units), 2 => Type::array(&Type::i16(cx), align_units), @@ -833,10 +842,10 @@ fn generic_type_of<'a, 'tcx>(cx: &CrateContext<'a, 'tcx>, _ => panic!("unsupported enum alignment: {}", align) }; assert_eq!(machine::llalign_of_min(cx, fill_ty), align); - assert_eq!(align_s % discr_size, 0); + assert_eq!(padded_discr_size % discr_size, 0); // Ensure discr_ty can fill pad evenly let mut fields: Vec<Type> = [discr_ty, - Type::array(&discr_ty, align_s / discr_size - 1), + Type::array(&discr_ty, (padded_discr_size - discr_size)/discr_size), fill_ty].iter().cloned().collect(); if delay_drop_flag && dtor_needed { fields.pop(); |