Re: [PATCH v8 3/4] x86_64: roundeven with sse4.1 support

[Sunil Pandey <skpgkp2@gmail.com>]

On Wed, Apr 27, 2022 at 5:11 PM Sunil Pandey <skpgkp2@gmail.com> wrote:
>
> On Wed, Jun 23, 2021 at 3:32 PM H.J. Lu via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
> >
> > From: Shen-Ta Hsieh <ibmibmibm.tw@gmail.com>
> >
> > This patch adds support for the sse4.1 hardware floating point
> > roundeven.
> >
> > Here is some benchmark results on my systems:
> >
> > =AMD Ryzen 9 3900X 12-Core Processor=
> >
> > * benchmark result before this commit
> > |            |    roundeven |   roundevenf |
> > |------------|--------------|--------------|
> > | duration   |  3.75587e+09 |  3.75114e+09 |
> > | iterations |  3.93053e+08 |  4.35402e+08 |
> > | max        | 52.592       | 58.71        |
> > | min        |  7.98        |  7.22        |
> > | mean       |  9.55563     |  8.61535     |
> >
> > * benchmark result after this commit
> > |            |     roundeven |   roundevenf |
> > |------------|---------------|--------------|
> > | duration   |   3.73815e+09 |  3.73738e+09 |
> > | iterations |   5.82692e+08 |  5.91498e+08 |
> > | max        |  56.468       | 51.642       |
> > | min        |   6.27        |  6.156       |
> > | mean       |   6.41532     |  6.3185      |
> >
> > =Intel(R) Pentium(R) CPU D1508 @ 2.20GHz=
> >
> > * benchmark result before this commit
> > |            |    roundeven |   roundevenf |
> > |------------|--------------|--------------|
> > | duration   |  2.18208e+09 |  2.18258e+09 |
> > | iterations |  2.39932e+08 |  2.46924e+08 |
> > | max        | 96.378       | 98.035       |
> > | min        |  6.776       |  5.94        |
> > | mean       |  9.09456     |  8.83907     |
> >
> > * benchmark result after this commit
> > |            |    roundeven |   roundevenf |
> > |------------|--------------|--------------|
> > | duration   |  2.17415e+09 |  2.17005e+09 |
> > | iterations |  3.56193e+08 |  4.09824e+08 |
> > | max        | 51.693       | 97.192       |
> > | min        |  5.926       |  5.093       |
> > | mean       |  6.10385     |  5.29507     |
> >
> > Signed-off-by: Shen-Ta Hsieh <ibmibmibm.tw@gmail.com>
> > Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
> > ---
> >  sysdeps/x86_64/fpu/multiarch/Makefile         |  5 +--
> >  sysdeps/x86_64/fpu/multiarch/s_roundeven-c.c  |  2 ++
> >  .../x86_64/fpu/multiarch/s_roundeven-sse4_1.S | 24 ++++++++++++++
> >  sysdeps/x86_64/fpu/multiarch/s_roundeven.c    | 31 +++++++++++++++++++
> >  sysdeps/x86_64/fpu/multiarch/s_roundevenf-c.c |  3 ++
> >  .../fpu/multiarch/s_roundevenf-sse4_1.S       | 24 ++++++++++++++
> >  sysdeps/x86_64/fpu/multiarch/s_roundevenf.c   | 31 +++++++++++++++++++
> >  7 files changed, 118 insertions(+), 2 deletions(-)
> >  create mode 100644 sysdeps/x86_64/fpu/multiarch/s_roundeven-c.c
> >  create mode 100644 sysdeps/x86_64/fpu/multiarch/s_roundeven-sse4_1.S
> >  create mode 100644 sysdeps/x86_64/fpu/multiarch/s_roundeven.c
> >  create mode 100644 sysdeps/x86_64/fpu/multiarch/s_roundevenf-c.c
> >  create mode 100644 sysdeps/x86_64/fpu/multiarch/s_roundevenf-sse4_1.S
> >  create mode 100644 sysdeps/x86_64/fpu/multiarch/s_roundevenf.c
> >
> > diff --git a/sysdeps/x86_64/fpu/multiarch/Makefile b/sysdeps/x86_64/fpu/multiarch/Makefile
> > index 57892c56bb..d425ffd6d3 100644
> > --- a/sysdeps/x86_64/fpu/multiarch/Makefile
> > +++ b/sysdeps/x86_64/fpu/multiarch/Makefile
> > @@ -1,11 +1,12 @@
> >  ifeq ($(subdir),math)
> >  libm-sysdep_routines += s_floor-c s_ceil-c s_floorf-c s_ceilf-c \
> >                         s_rint-c s_rintf-c s_nearbyint-c s_nearbyintf-c \
> > -                       s_trunc-c s_truncf-c
> > +                       s_roundeven-c s_roundevenf-c s_trunc-c s_truncf-c
> >
> >  libm-sysdep_routines += s_ceil-sse4_1 s_ceilf-sse4_1 s_floor-sse4_1 \
> >                         s_floorf-sse4_1 s_nearbyint-sse4_1 \
> > -                       s_nearbyintf-sse4_1 s_rint-sse4_1 s_rintf-sse4_1 \
> > +                       s_nearbyintf-sse4_1 s_roundeven-sse4_1 \
> > +                       s_roundevenf-sse4_1 s_rint-sse4_1 s_rintf-sse4_1 \
> >                         s_trunc-sse4_1 s_truncf-sse4_1
> >
> >  libm-sysdep_routines += e_exp-fma e_log-fma e_pow-fma s_atan-fma \
> > diff --git a/sysdeps/x86_64/fpu/multiarch/s_roundeven-c.c b/sysdeps/x86_64/fpu/multiarch/s_roundeven-c.c
> > new file mode 100644
> > index 0000000000..c7be43cb22
> > --- /dev/null
> > +++ b/sysdeps/x86_64/fpu/multiarch/s_roundeven-c.c
> > @@ -0,0 +1,2 @@
> > +#define __roundeven __roundeven_c
> > +#include <sysdeps/ieee754/dbl-64/s_roundeven.c>
> > diff --git a/sysdeps/x86_64/fpu/multiarch/s_roundeven-sse4_1.S b/sysdeps/x86_64/fpu/multiarch/s_roundeven-sse4_1.S
> > new file mode 100644
> > index 0000000000..6ae8f6b1d3
> > --- /dev/null
> > +++ b/sysdeps/x86_64/fpu/multiarch/s_roundeven-sse4_1.S
> > @@ -0,0 +1,24 @@
> > +/* Copyright (C) 2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <sysdep.h>
> > +
> > +       .section .text.sse4.1,"ax",@progbits
> > +ENTRY(__roundeven_sse41)
> > +       roundsd $8, %xmm0, %xmm0
> > +       ret
> > +END(__roundeven_sse41)
> > diff --git a/sysdeps/x86_64/fpu/multiarch/s_roundeven.c b/sysdeps/x86_64/fpu/multiarch/s_roundeven.c
> > new file mode 100644
> > index 0000000000..d92eda652a
> > --- /dev/null
> > +++ b/sysdeps/x86_64/fpu/multiarch/s_roundeven.c
> > @@ -0,0 +1,31 @@
> > +/* Multiple versions of __roundeven.
> > +   Copyright (C) 2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <libm-alias-double.h>
> > +
> > +#define roundeven __redirect_roundeven
> > +#define __roundeven __redirect___roundeven
> > +#include <math.h>
> > +#undef roundeven
> > +#undef __roundeven
> > +
> > +#define SYMBOL_NAME roundeven
> > +#include "ifunc-sse4_1.h"
> > +
> > +libc_ifunc_redirected (__redirect_roundeven, __roundeven, IFUNC_SELECTOR ());
> > +libm_alias_double (__roundeven, roundeven)
> > diff --git a/sysdeps/x86_64/fpu/multiarch/s_roundevenf-c.c b/sysdeps/x86_64/fpu/multiarch/s_roundevenf-c.c
> > new file mode 100644
> > index 0000000000..72a6e7d1fb
> > --- /dev/null
> > +++ b/sysdeps/x86_64/fpu/multiarch/s_roundevenf-c.c
> > @@ -0,0 +1,3 @@
> > +#undef __roundevenf
> > +#define __roundevenf __roundevenf_c
> > +#include <sysdeps/ieee754/flt-32/s_roundevenf.c>
> > diff --git a/sysdeps/x86_64/fpu/multiarch/s_roundevenf-sse4_1.S b/sysdeps/x86_64/fpu/multiarch/s_roundevenf-sse4_1.S
> > new file mode 100644
> > index 0000000000..a76e10807e
> > --- /dev/null
> > +++ b/sysdeps/x86_64/fpu/multiarch/s_roundevenf-sse4_1.S
> > @@ -0,0 +1,24 @@
> > +/* Copyright (C) 2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <sysdep.h>
> > +
> > +       .section .text.sse4.1,"ax",@progbits
> > +ENTRY(__roundevenf_sse41)
> > +       roundss $8, %xmm0, %xmm0
> > +       ret
> > +END(__roundevenf_sse41)
> > diff --git a/sysdeps/x86_64/fpu/multiarch/s_roundevenf.c b/sysdeps/x86_64/fpu/multiarch/s_roundevenf.c
> > new file mode 100644
> > index 0000000000..2ee196e68f
> > --- /dev/null
> > +++ b/sysdeps/x86_64/fpu/multiarch/s_roundevenf.c
> > @@ -0,0 +1,31 @@
> > +/* Multiple versions of __roundevenf.
> > +   Copyright (C) 2021 Free Software Foundation, Inc.
> > +   This file is part of the GNU C Library.
> > +
> > +   The GNU C Library is free software; you can redistribute it and/or
> > +   modify it under the terms of the GNU Lesser General Public
> > +   License as published by the Free Software Foundation; either
> > +   version 2.1 of the License, or (at your option) any later version.
> > +
> > +   The GNU C Library is distributed in the hope that it will be useful,
> > +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> > +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > +   Lesser General Public License for more details.
> > +
> > +   You should have received a copy of the GNU Lesser General Public
> > +   License along with the GNU C Library; if not, see
> > +   <https://www.gnu.org/licenses/>.  */
> > +
> > +#include <libm-alias-float.h>
> > +
> > +#define roundevenf __redirect_roundevenf
> > +#define __roundevenf __redirect___roundevenf
> > +#include <math.h>
> > +#undef roundevenf
> > +#undef __roundevenf
> > +
> > +#define SYMBOL_NAME roundevenf
> > +#include "ifunc-sse4_1.h"
> > +
> > +libc_ifunc_redirected (__redirect_roundevenf, __roundevenf, IFUNC_SELECTOR ());
> > +libm_alias_float (__roundeven, roundeven)
> > --
> > 2.31.1
> >
>
> I would like to backport this patch to release branches.
> Any comments or objections?
>
> --Sunil

I would like to backport this patch to release branch 2.33.

Any comments/suggestions or objections on this.

commit 1683249d17e14827b6579529742eb895027dfa84
Author: Shen-Ta Hsieh <ibmibmibm.tw@gmail.com>
Date:   Mon May 24 09:43:11 2021 +0800

    x86_64: roundeven with sse4.1 support

    This patch adds support for the sse4.1 hardware floating point
    roundeven.

    Here is some benchmark results on my systems: