Re: [PATCH v2 2/3] target/riscv: Add MXLEN check for F/D/Q applies to zama16b

[LIU Zhiwei]

On 2024/8/2 13:47, Richard Henderson wrote:
> On 8/2/24 13:16, LIU Zhiwei wrote:
> > Zama16b loads and stores of no more than MXLEN bits defined in the F, 
> > D, and Q
> > extensions.
> >
> > Signed-off-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
> > ---
> >   target/riscv/insn_trans/trans_rvd.c.inc | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/target/riscv/insn_trans/trans_rvd.c.inc 
> > b/target/riscv/insn_trans/trans_rvd.c.inc
> > index 2be037930a..dbe508c7e0 100644
> > --- a/target/riscv/insn_trans/trans_rvd.c.inc
> > +++ b/target/riscv/insn_trans/trans_rvd.c.inc
> > @@ -52,7 +52,7 @@ static bool trans_fld(DisasContext *ctx, arg_fld *a)
> >        * in the F, D, and Q extensions. Otherwise, it falls through 
> > to default
> >        * MO_ATOM_IFALIGN.
> >        */
> > -    if ((ctx->xl >= MXL_RV64) && (ctx->cfg_ptr->ext_zama16b)) {
> > +    if ((ctx->misa_mxl_max >= MXL_RV64) && ctx->cfg_ptr->ext_zama16b) {
> >           memop |= MO_ATOM_WITHIN16;
> >       }
> >   @@ -72,7 +72,7 @@ static bool trans_fsd(DisasContext *ctx, arg_fsd *a)
> >       REQUIRE_FPU;
> >       REQUIRE_EXT(ctx, RVD);
> >   -    if (ctx->cfg_ptr->ext_zama16b) {
> > +    if ((ctx->misa_mxl_max >= MXL_RV64) && ctx->cfg_ptr->ext_zama16b) {
> >           memop |= MO_ATOM_WITHIN16;
> >       }
>
> I guess this is ok, because MXL cannot currently be changed. But since 
> that is a possible future enhancement, perhaps add a get_mxl(ctx) 
> accessor anyway, for documentation purposes.
Can we use the existing get_xl_max(ctx) instead of adding a new 
get_mxl(ctx).

Thanks,
Zhiwei

> r~