Hi Philippe,
On Fri, Sep 13, 2019 at 12:58:14PM +0200, Philippe Mathieu-Daudé wrote:
> Hi Sven,
>
> On 9/13/19 12:17 PM, Sven Schnelle wrote:
> > nullify_over() calls brcond which destroys all temporaries.
> >
> > Signed-off-by: Sven Schnelle <sv...@stackframe.org>
> > ---
> > target/hppa/translate.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/target/hppa/translate.c b/target/hppa/translate.c
> > index b12525d535..c1b2822f60 100644
> > --- a/target/hppa/translate.c
> > +++ b/target/hppa/translate.c
> > @@ -3404,10 +3404,6 @@ static bool do_depw_sar(DisasContext *ctx, unsigned
> > rt, unsigned c,
> > TCGv_reg mask, tmp, shift, dest;
> > unsigned msb = 1U << (len - 1);
> >
> > - if (c) {
> > - nullify_over(ctx);
> > - }
> > -
> > dest = dest_gpr(ctx, rt);
> > shift = tcg_temp_new();
> > tmp = tcg_temp_new();
> > @@ -3440,11 +3436,17 @@ static bool do_depw_sar(DisasContext *ctx, unsigned
> > rt, unsigned c,
> >
> > static bool trans_depw_sar(DisasContext *ctx, arg_depw_sar *a)
> > {
> > + if (a->c) {
> > + nullify_over(ctx);
> > + }
> > return do_depw_sar(ctx, a->t, a->c, a->nz, a->clen, load_gpr(ctx,
> > a->r));
> > }
> >
> > static bool trans_depwi_sar(DisasContext *ctx, arg_depwi_sar *a)
> > {
> > + if (a->c) {
> > + nullify_over(ctx);
> > + }
>
> I don't see how this patch helps or change anything, isn't it the same?
> You clean in the caller rather than the callee.
The Problem is that load_gpr()/load_const() allocate a temporary, which
gets destroyed in do_depw_sar() when nullify_over() is called. If we
move the nullify_over() before doing the load_gpr()/load_const() this
doesn't happen.
> > return do_depw_sar(ctx, a->t, a->c, a->nz, a->clen, load_const(ctx,
> > a->i));
> > }
> >
> >
Regards
Sven
