On Wed, 12 Oct 2022, Andre Vieira (lists) wrote:
> Hi,
>
> The bitposition calculation for the bitfield lowering in loop if conversion
> was not
> taking DECL_FIELD_OFFSET into account, which meant that it would result in
> wrong bitpositions for bitfields that did not end up having representations
> starting at the beginning of the struct.
>
> Bootstrappend and regression tested on aarch64-none-linux-gnu and
> x86_64-pc-linux-gnu.
+ {
+ tree bf_pos = fold_build2 (MULT_EXPR, bitsizetype,
+ DECL_FIELD_OFFSET (field_decl),
+ build_int_cst (bitsizetype, 8));
+ bf_pos = fold_build2 (PLUS_EXPR, bitsizetype, bf_pos,
+ DECL_FIELD_BIT_OFFSET (field_decl));
+ tree rep_pos = fold_build2 (MULT_EXPR, bitsizetype,
+ DECL_FIELD_OFFSET (rep_decl),
+ build_int_cst (bitsizetype, 8));
+ rep_pos = fold_build2 (PLUS_EXPR, bitsizetype, rep_pos,
+ DECL_FIELD_BIT_OFFSET (rep_decl));
you can use the invariant that DECL_FIELD_OFFSET of rep_decl
and field_decl are always the same. Also please use BITS_PER_UNIT
instead of '8'.
Richard.
