Re: [PATCH v2 2/2] MIPS/gas: Fix misaligned address errors to disregard ISA mode bit

[Paul Hua <paul dot hua dot gm at gmail dot com>]

OK.

On Tue, Aug 13, 2019 at 1:32 PM Faraz Shahbazker
<fshahbazker@wavecomp.com> wrote:
>
> gas/
>         * config/tc-mips.c (fix_bad_misaligned_address): New function.
>         (fix_validate_branch): Call fix_bad_misaligned address_to
>         calculate the target address.
>         (md_apply_fix): Likewise.
>         (md_convert_frag): Update misaligned address calculation to
>         disregard ISA mode bit.
> ---
>
> Notes:
>     v2 of the patch fixes build warnings for gcc7
>
>  gas/config/tc-mips.c | 28 +++++++++++++++++++++++-----
>  1 file changed, 23 insertions(+), 5 deletions(-)
>
> diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
> index 38a1b8c..a386d11 100644
> --- a/gas/config/tc-mips.c
> +++ b/gas/config/tc-mips.c
> @@ -15743,6 +15743,24 @@ fix_bad_misaligned_branch_p (fixS *fixP)
>    return (val & 0x3) != isa_bit;
>  }
>
> +/* Calculate the relocation target by masking off ISA mode bit before
> +   combining symbol and addend.  */
> +
> +static valueT
> +fix_bad_misaligned_address (fixS *fixP)
> +{
> +  valueT val;
> +  valueT off;
> +  unsigned isa_mode;
> +  gas_assert (fixP != NULL && fixP->fx_addsy != NULL);
> +  val = S_GET_VALUE (fixP->fx_addsy);
> +  off = fixP->fx_offset;
> +  isa_mode = (ELF_ST_IS_COMPRESSED (S_GET_OTHER (fixP->fx_addsy))
> +             ? 1 : 0);
> +
> +  return ((val & ~isa_mode) + off);
> +}
> +
>  /* Make the necessary checks on a regular MIPS branch pointed to by FIXP
>     and its calculated value VAL.  */
>
> @@ -15759,7 +15777,7 @@ fix_validate_branch (fixS *fixP, valueT val)
>    else if (fix_bad_misaligned_branch_p (fixP))
>      as_bad_where (fixP->fx_file, fixP->fx_line,
>                   _("branch to misaligned address (0x%lx)"),
> -                 (long) (S_GET_VALUE (fixP->fx_addsy) + fixP->fx_offset));
> +                 (long) fix_bad_misaligned_address (fixP));
>    else if (HAVE_IN_PLACE_ADDENDS && (fixP->fx_offset & 0x3) != 0)
>      as_bad_where (fixP->fx_file, fixP->fx_line,
>                   _("cannot encode misaligned addend "
> @@ -15898,8 +15916,7 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
>         else if (fix_bad_misaligned_jump_p (fixP, shift))
>           as_bad_where (fixP->fx_file, fixP->fx_line,
>                         _("jump to misaligned address (0x%lx)"),
> -                       (long) (S_GET_VALUE (fixP->fx_addsy)
> -                               + fixP->fx_offset));
> +                       (long) fix_bad_misaligned_address (fixP));
>         else if (HAVE_IN_PLACE_ADDENDS
>                  && (fixP->fx_offset & ((1 << shift) - 1)) != 0)
>           as_bad_where (fixP->fx_file, fixP->fx_line,
> @@ -16153,7 +16170,7 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
>                && (fixP->fx_offset & 0x1) != 0)
>         as_bad_where (fixP->fx_file, fixP->fx_line,
>                       _("branch to misaligned address (0x%lx)"),
> -                     (long) (S_GET_VALUE (fixP->fx_addsy) + fixP->fx_offset));
> +                     (long) fix_bad_misaligned_address (fixP));
>        else if (HAVE_IN_PLACE_ADDENDS && (fixP->fx_offset & 0x1) != 0)
>         as_bad_where (fixP->fx_file, fixP->fx_line,
>                       _("cannot encode misaligned addend "
> @@ -19000,7 +19017,8 @@ md_convert_frag (bfd *abfd ATTRIBUTE_UNUSED, segT asec, fragS *fragp)
>               else if ((fragp->fr_offset & 0x1) != 0)
>                 as_bad_where (fragp->fr_file, fragp->fr_line,
>                               _("branch to misaligned address (0x%lx)"),
> -                             (long) val);
> +                             (long) (resolve_symbol_value (fragp->fr_symbol)
> +                                     + (fragp->fr_offset & ~1)));
>             }
>
>           val = mips16_pcrel_val (fragp, pcrel_op, val, 0);
> --
> 2.9.5
>