Re: [PATCH v5 2/2] x86_64: roundeven with sse4.1 support

["謝昇達(Shen-Ta Hsieh)" <ibmibmibm.tw@gmail.com>]

H.J. Lu <hjl.tools@gmail.com> 於 2020年5月28日 週四 下午8:06寫道：
>
> On Sat, May 2, 2020 at 8:06 AM Shen-Ta Hsieh via Libc-alpha
> <libc-alpha@sourceware.org> wrote:
> >
> > This patch adds support for the sse4.1 hardware floating point
> > roundeven.
>
> Do you have FSF paper on file?
Yes. Should I send a PDF copy to you?

Shen-Ta Hsieh <ibmibmibm.tw@gmail.com> 於 2020年9月28日 週一 下午4:48寫道：
>
> This patch adds support for the sse4.1 hardware floating point
> roundeven.
>
> Here is a benchmark result on my AMD Ryzen 9 3900X system:
>
> * benchmark result before this commit
> |            |    roundeven |   roundevenf |
> |------------|--------------|--------------|
> | duration   |  3.77591e+09 |  3.77481e+09 |
> | iterations |  4.30692e+08 |  4.55274e+08 |
> | max        | 74.556       | 65.132       |
> | min        |  6.004       |  6.004       |
> | mean       |  8.76708     |  8.29129     |
>
> * benchmark result after this commit
> |            |    roundeven |   roundevenf |
> |------------|--------------|--------------|
> | duration   |  3.76981e+09 |  3.76958e+09 |
> | iterations |  6.04808e+08 |  6.20046e+08 |
> | max        | 84.587       | 70.642       |
> | min        |  6.042       |  5.928       |
> | mean       |  6.23308     |  6.07952     |
> ---
>  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 | 26 ++++++++++++++++
>  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       | 26 ++++++++++++++++
>  sysdeps/x86_64/fpu/multiarch/s_roundevenf.c   | 31 +++++++++++++++++++
>  7 files changed, 122 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 3836574f48..7e3a3f78cb 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..6db88a1649
> --- /dev/null
> +++ b/sysdeps/x86_64/fpu/multiarch/s_roundeven-sse4_1.S
> @@ -0,0 +1,26 @@
> +/* Round to nearest integer value, rounding halfway cases to even.
> +   double version.
> +   Copyright (C) 2019 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..bd777b0ca7
> --- /dev/null
> +++ b/sysdeps/x86_64/fpu/multiarch/s_roundeven.c
> @@ -0,0 +1,31 @@
> +/* Multiple versions of __roundeven.
> +   Copyright (C) 2019 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..74102bac0d
> --- /dev/null
> +++ b/sysdeps/x86_64/fpu/multiarch/s_roundevenf-sse4_1.S
> @@ -0,0 +1,26 @@
> +/* Round to nearest integer value, rounding halfway cases to even.
> +   float version.
> +   Copyright (C) 2019 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..8ae1944d2b
> --- /dev/null
> +++ b/sysdeps/x86_64/fpu/multiarch/s_roundevenf.c
> @@ -0,0 +1,31 @@
> +/* Multiple versions of __roundevenf.
> +   Copyright (C) 2019 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)
> --
> 2.28.0
>