Re: [PATCH] x86-64: Use R10 and R11 for profiling large model with PIC

[Uros Bizjak <ubizjak@gmail.com>]

On Fri, Jan 8, 2021 at 2:28 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> 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?

+          fprintf (file, "\tmovabsq\t$%s@PLTOFF, %%r11\n",
+               mcount_name);

Please put mcount_name in the same line (and please do the same for
case CM_MEDIUM_PIC).

OK with the above fixes.

Thanks,
Uros.