On Fri, Jan 8, 2021 at 4:50 AM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> On Fri, Jan 8, 2021 at 1:24 AM Uros Bizjak <ubizjak@gmail.com> wrote:
> >
> > > Since R10 is preserved when calling mcount, R10 can be used a scratch
> > > register to call mcount in large model.
> >
> > Please mention that R10 can be used as a static chain registers and is
> > preserved when calling mcount for nested functions.
> >
> > > gcc/
> > >
> > > PR target/98482
> > > * config/i386/i386.c (x86_function_profiler): Use R10 to call
> > > mcount in large model. Sorry for large model with PIC.
> > >
> > > gcc/testsuite/
> > >
> > > PR target/98482
> > > * gcc.target/i386/pr98482-1.c: New test.
> > > * gcc.target/i386/pr98482-1.c: Likewise.
> >
> > OK with comment fixes.
> >
> > Thanks,
> > Uros.
> >
> > +    case CM_LARGE:
> > +      /* NB: R10 can be used as a scratch register here since
> > +        R10 is preserved when calling mcount.  */
> >
> > Also mention that R10 can be used as a static chain register and is
> > preserved when calling mcount for nested functions.
> >
> > +      fprintf (file, "1:\tmovabsq\t$%s, %%r10\n\tcall\t*%%r10\n",
> > +       mcount_name);
> > +      break;
>
> This is the patch I am checking in.
>

For NO_PROFILE_COUNTERS targets, R11 is a scratch register.  We can use
R10 and R11 to call mcount in large model with PIC.

OK for master?

Thanks.

-- 
H.J.