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?
Uros.
> > + if (Pmode != ptr_mode)
> > + {
> > + tp = lowpart_subreg (ptr_mode, tp, Pmode);
> > + dest = lowpart_subreg (ptr_mode, dest, Pmode);
> > + dest = gen_rtx_PLUS (ptr_mode, tp, dest);
> > + dest = gen_rtx_ZERO_EXTEND (Pmode, dest);
> > + }
> > + else
> > + dest = gen_rtx_PLUS (Pmode, tp, dest);
> > + dest = force_reg (Pmode, dest);
>
> Sholdn't we use
>
> tp = get_thread_pointer (ptr_mode, true);
>
> then? If Pmode == ptr_mode, then we have the same functionality,
> otherwise we don't have to subreg tp to ptr_mode.
>
> Can we use the same approach as in ix86_zero_extend_to_Pmode here, like:
>
> dest = gen_rtx_PLUS (ptr_mode, tp, dest);
> dest = force_reg (Pmode, convert_to_mode (Pmode, dest, 1));
>
> Uros.
