On Sun, Jan 19, 2020 at 7:07 PM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> On Sun, Jan 19, 2020 at 9:48 AM Uros Bizjak <ubiz...@gmail.com> wrote:
> >
> > On Sun, Jan 19, 2020 at 6:43 PM Uros Bizjak <ubiz...@gmail.com> wrote:
> > >
> > > On Sun, Jan 19, 2020 at 2:58 PM H.J. Lu <hjl.to...@gmail.com> wrote:
> > > >
> > > > To add x32 support to -mtls-dialect=gnu2, we need to replace DI with
> > > > P in GNU2 TLS patterns. Since thread pointer is in ptr_mode, PLUS in
> > > > GNU2 TLS address computation must be done in ptr_mode to support
> > > > -maddress-mode=long. Also drop the "q" suffix from lea to support
> > > > both "lea foo@TLSDESC(%rip), %eax" and "foo@TLSDESC(%rip), %rax".
> > >
> > > Please use "lea%z0" instead.
> > >
> > > > Tested on Linux/x86-64. OK for master?
> > > >
> > > > Thanks.
> > > >
> > > > H.J.
> > > > ---
> > > > gcc/
> > > >
> > > > PR target/93319
> > > > * config/i386/i386.c (legitimize_tls_address): Pass Pmode to
> > > > gen_tls_dynamic_gnu2_64. Compute GNU2 TLS address in ptr_mode.
> > > > * config/i386/i386.md (tls_dynamic_gnu2_64): Renamed to ...
> > > > (@tls_dynamic_gnu2_64_<mode>): This. Replace DI with P.
> > > > (*tls_dynamic_gnu2_lea_64): Renamed to ...
> > > > (*tls_dynamic_gnu2_lea_64_<mode>): This. Replace DI with P.
> > > > Remove the {q} suffix from lea.
> > > > (*tls_dynamic_gnu2_call_64): Renamed to ...
> > > > (*tls_dynamic_gnu2_call_64_<mode>): This. Replace DI with P.
> > > > (*tls_dynamic_gnu2_combine_64): Renamed to ...
> > > > (*tls_dynamic_gnu2_combine_64_<mode>): This. Replace DI with P.
> > > > Pass Pmode to gen_tls_dynamic_gnu2_64.
> > > >
> > > > gcc/testsuite/
> > > >
> > > > PR target/93319
> > > > * gcc.target/i386/pr93319-1a.c: New test.
> > > > * gcc.target/i386/pr93319-1b.c: Likewise.
> > > > * gcc.target/i386/pr93319-1c.c: Likewise.
> > > > * gcc.target/i386/pr93319-1d.c: Likewise.
> > > > ---
> > > > gcc/config/i386/i386.c | 31 +++++++++++--
> > > > gcc/config/i386/i386.md | 54 +++++++++++-----------
> > > > gcc/testsuite/gcc.target/i386/pr93319-1a.c | 24 ++++++++++
> > > > gcc/testsuite/gcc.target/i386/pr93319-1b.c | 7 +++
> > > > gcc/testsuite/gcc.target/i386/pr93319-1c.c | 7 +++
> > > > gcc/testsuite/gcc.target/i386/pr93319-1d.c | 7 +++
> > > > 6 files changed, 99 insertions(+), 31 deletions(-)
> > > > create mode 100644 gcc/testsuite/gcc.target/i386/pr93319-1a.c
> > > > create mode 100644 gcc/testsuite/gcc.target/i386/pr93319-1b.c
> > > > create mode 100644 gcc/testsuite/gcc.target/i386/pr93319-1c.c
> > > > create mode 100644 gcc/testsuite/gcc.target/i386/pr93319-1d.c
> > > >
> > > > diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> > > > index 2c087a4a3e0..8c437dbe1f3 100644
> > > > --- a/gcc/config/i386/i386.c
> > > > +++ b/gcc/config/i386/i386.c
> > > > @@ -10764,12 +10764,24 @@ legitimize_tls_address (rtx x, enum tls_model
> > > > model, bool for_mov)
> > > > if (TARGET_GNU2_TLS)
> > > > {
> > > > if (TARGET_64BIT)
> > > > - emit_insn (gen_tls_dynamic_gnu2_64 (dest, x));
> > > > + emit_insn (gen_tls_dynamic_gnu2_64 (Pmode, dest, x));
> > > > else
> > > > emit_insn (gen_tls_dynamic_gnu2_32 (dest, x, pic));
> > > >
> > > > tp = get_thread_pointer (Pmode, true);
> > > > - dest = force_reg (Pmode, gen_rtx_PLUS (Pmode, tp, dest));
> > > > +
> > > > + /* NB: Since thread pointer is in ptr_mode, make sure that
> > > > + PLUS is done in ptr_mode. */
> >
> > Actually, thread_pointer is in Pmode, see the line just above your
> > change. Also, dest is in Pmode, so why do we need all this subreg
> > dance?
>
> dest set from gen_tls_dynamic_gnu2_64 is in ptr_mode by
>
> call *foo@TLSCALL(%rax)
It looks to me that we have Pmode/ptr_mode mixup in
legitimize_tls_address & friends for TARGET_GNU2_TLS. I think that we
need to perform all calculations in ptr_mode, since get_thread_pointer
in effect always returns ptr_mode (SImode) value, and also the above
call always returns ptr_mode (SImode) value. In case of
-maddress-mode=long, the value would be zero-extended to Pmode.
Uros.
