Re: [PATCH] libm/machine/riscv: Add custom fma/sqrt functions when supported [v2]

Kito Cheng via Newlib <[email protected]>
Newsgroups gmane.comp.lib.newlib
Message-ID <CA+yXCZBZTkkPJoO7GOo6Cd+HbaC8c6frvXWRmSNqhkwayiSUmw@mail.gmail.com> 
LGTM :)

On Wed, Aug 12, 2020 at 10:48 AM Keith Packard via Newlib
<[email protected]> wrote:
>
> Check for HW FMA and SQRT support and use those instructions in place
> of software implementations.
>
> Signed-off-by: Keith Packard <[email protected]>
>
> ---
>
> v2:
>         Detect 64-bit hw float using __riscv_flen >= 64
>
>         Suggested-by: Kito Cheng <[email protected]>
> ---
>  newlib/libm/common/math_config.h      |  4 +-
>  newlib/libm/machine/riscv/Makefile.am |  3 +-
>  newlib/libm/machine/riscv/Makefile.in | 31 +++++++++++++++-
>  newlib/libm/machine/riscv/s_fma.c     | 49 +++++++++++++++++++++++++
>  newlib/libm/machine/riscv/s_sqrt.c    | 53 +++++++++++++++++++++++++++
>  newlib/libm/machine/riscv/sf_fma.c    | 49 +++++++++++++++++++++++++
>  newlib/libm/machine/riscv/sf_sqrt.c   | 53 +++++++++++++++++++++++++++
>  7 files changed, 237 insertions(+), 5 deletions(-)
>  create mode 100644 newlib/libm/machine/riscv/s_fma.c
>  create mode 100644 newlib/libm/machine/riscv/s_sqrt.c
>  create mode 100644 newlib/libm/machine/riscv/sf_fma.c
>  create mode 100644 newlib/libm/machine/riscv/sf_sqrt.c
>
> diff --git a/newlib/libm/common/math_config.h b/newlib/libm/common/math_config.h
> index e7a8bb7fe..0f78b5c09 100644
> --- a/newlib/libm/common/math_config.h
> +++ b/newlib/libm/common/math_config.h
> @@ -72,7 +72,7 @@
>
>  /* Compiler can inline fma as a single instruction.  */
>  #ifndef HAVE_FAST_FMA
> -# if __aarch64__ || (__ARM_FEATURE_FMA && (__ARM_FP & 8))
> +# if __aarch64__ || (__ARM_FEATURE_FMA && (__ARM_FP & 8)) || __riscv_flen >= 64
>  #   define HAVE_FAST_FMA 1
>  # else
>  #   define HAVE_FAST_FMA 0
> @@ -80,7 +80,7 @@
>  #endif
>
>  #ifndef HAVE_FAST_FMAF
> -# if HAVE_FAST_FMA || (__ARM_FEATURE_FMA && (__ARM_FP & 4))
> +# if HAVE_FAST_FMA || (__ARM_FEATURE_FMA && (__ARM_FP & 4)) || __riscv_flen >= 32
>  #  define HAVE_FAST_FMAF 1
>  # else
>  #  define HAVE_FAST_FMAF 0
> diff --git a/newlib/libm/machine/riscv/Makefile.am b/newlib/libm/machine/riscv/Makefile.am
> index 1b9f48a25..a7783797a 100644
> --- a/newlib/libm/machine/riscv/Makefile.am
> +++ b/newlib/libm/machine/riscv/Makefile.am
> @@ -6,7 +6,8 @@ INCLUDES = -I $(newlib_basedir)/../newlib/libm/common $(NEWLIB_CFLAGS) \
>  LIB_SOURCES = \
>         feclearexcept.c fe_dfl_env.c fegetenv.c fegetexceptflag.c \
>         fegetround.c feholdexcept.c feraiseexcept.c fesetenv.c \
> -       fesetexceptflag.c fesetround.c fetestexcept.c feupdateenv.c
> +       fesetexceptflag.c fesetround.c fetestexcept.c feupdateenv.c \
> +       s_fma.c s_sqrt.c sf_fma.c sf_sqrt.c
>
>  noinst_LIBRARIES = lib.a
>  lib_a_SOURCES = $(LIB_SOURCES)
> diff --git a/newlib/libm/machine/riscv/Makefile.in b/newlib/libm/machine/riscv/Makefile.in
> index a5023a51e..c56830569 100644
> --- a/newlib/libm/machine/riscv/Makefile.in
> +++ b/newlib/libm/machine/riscv/Makefile.in
> @@ -76,7 +76,9 @@ am__objects_1 = lib_a-feclearexcept.$(OBJEXT) \
>         lib_a-feholdexcept.$(OBJEXT) lib_a-feraiseexcept.$(OBJEXT) \
>         lib_a-fesetenv.$(OBJEXT) lib_a-fesetexceptflag.$(OBJEXT) \
>         lib_a-fesetround.$(OBJEXT) lib_a-fetestexcept.$(OBJEXT) \
> -       lib_a-feupdateenv.$(OBJEXT)
> +       lib_a-feupdateenv.$(OBJEXT) lib_a-s_fma.$(OBJEXT) \
> +       lib_a-s_sqrt.$(OBJEXT) lib_a-sf_fma.$(OBJEXT) \
> +       lib_a-sf_sqrt.$(OBJEXT)
>  am_lib_a_OBJECTS = $(am__objects_1)
>  lib_a_OBJECTS = $(am_lib_a_OBJECTS)
>  DEFAULT_INCLUDES = -I.@am__isrc@
> @@ -204,7 +206,8 @@ INCLUDES = -I $(newlib_basedir)/../newlib/libm/common $(NEWLIB_CFLAGS) \
>  LIB_SOURCES = \
>         feclearexcept.c fe_dfl_env.c fegetenv.c fegetexceptflag.c \
>         fegetround.c feholdexcept.c feraiseexcept.c fesetenv.c \
> -       fesetexceptflag.c fesetround.c fetestexcept.c feupdateenv.c
> +       fesetexceptflag.c fesetround.c fetestexcept.c feupdateenv.c \
> +       s_fma.c s_sqrt.c sf_fma.c sf_sqrt.c
>
>  noinst_LIBRARIES = lib.a
>  lib_a_SOURCES = $(LIB_SOURCES)
> @@ -354,6 +357,30 @@ lib_a-feupdateenv.o: feupdateenv.c
>  lib_a-feupdateenv.obj: feupdateenv.c
>         $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-feupdateenv.obj `if test -f 'feupdateenv.c'; then $(CYGPATH_W) 'feupdateenv.c'; else $(CYGPATH_W) '$(srcdir)/feupdateenv.c'; fi`
>
> +lib_a-s_fma.o: s_fma.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_fma.o `test -f 's_fma.c' || echo '$(srcdir)/'`s_fma.c
> +
> +lib_a-s_fma.obj: s_fma.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_fma.obj `if test -f 's_fma.c'; then $(CYGPATH_W) 's_fma.c'; else $(CYGPATH_W) '$(srcdir)/s_fma.c'; fi`
> +
> +lib_a-s_sqrt.o: s_sqrt.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_sqrt.o `test -f 's_sqrt.c' || echo '$(srcdir)/'`s_sqrt.c
> +
> +lib_a-s_sqrt.obj: s_sqrt.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-s_sqrt.obj `if test -f 's_sqrt.c'; then $(CYGPATH_W) 's_sqrt.c'; else $(CYGPATH_W) '$(srcdir)/s_sqrt.c'; fi`
> +
> +lib_a-sf_fma.o: sf_fma.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_fma.o `test -f 'sf_fma.c' || echo '$(srcdir)/'`sf_fma.c
> +
> +lib_a-sf_fma.obj: sf_fma.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_fma.obj `if test -f 'sf_fma.c'; then $(CYGPATH_W) 'sf_fma.c'; else $(CYGPATH_W) '$(srcdir)/sf_fma.c'; fi`
> +
> +lib_a-sf_sqrt.o: sf_sqrt.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_sqrt.o `test -f 'sf_sqrt.c' || echo '$(srcdir)/'`sf_sqrt.c
> +
> +lib_a-sf_sqrt.obj: sf_sqrt.c
> +       $(CC) $(DEFS) $(DEFAULT_INCLUDES) $(INCLUDES) $(AM_CPPFLAGS) $(CPPFLAGS) $(lib_a_CFLAGS) $(CFLAGS) -c -o lib_a-sf_sqrt.obj `if test -f 'sf_sqrt.c'; then $(CYGPATH_W) 'sf_sqrt.c'; else $(CYGPATH_W) '$(srcdir)/sf_sqrt.c'; fi`
> +
>  ID: $(HEADERS) $(SOURCES) $(LISP) $(TAGS_FILES)
>         list='$(SOURCES) $(HEADERS) $(LISP) $(TAGS_FILES)'; \
>         unique=`for i in $$list; do \
> diff --git a/newlib/libm/machine/riscv/s_fma.c b/newlib/libm/machine/riscv/s_fma.c
> new file mode 100644
> index 000000000..b7f378071
> --- /dev/null
> +++ b/newlib/libm/machine/riscv/s_fma.c
> @@ -0,0 +1,49 @@
> +/*
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright © 2020 Keith Packard
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + *    copyright notice, this list of conditions and the following
> + *    disclaimer in the documentation and/or other materials provided
> + *    with the distribution.
> + *
> + * 3. Neither the name of the copyright holder nor the names of its
> + *    contributors may be used to endorse or promote products derived
> + *    from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
> + * OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <math.h>
> +#include "math_config.h"
> +
> +#if HAVE_FAST_FMA
> +
> +double
> +fma (double x, double y, double z)
> +{
> +       double result;
> +       asm ("fmadd.d %0, %1, %2, %3" : "=f" (result) : "f" (x), "f" (y), "f" (z));
> +       return result;
> +}
> +
> +#endif
> diff --git a/newlib/libm/machine/riscv/s_sqrt.c b/newlib/libm/machine/riscv/s_sqrt.c
> new file mode 100644
> index 000000000..abccf4b1c
> --- /dev/null
> +++ b/newlib/libm/machine/riscv/s_sqrt.c
> @@ -0,0 +1,53 @@
> +/*
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright © 2020 Keith Packard
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + *    copyright notice, this list of conditions and the following
> + *    disclaimer in the documentation and/or other materials provided
> + *    with the distribution.
> + *
> + * 3. Neither the name of the copyright holder nor the names of its
> + *    contributors may be used to endorse or promote products derived
> + *    from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
> + * OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <math.h>
> +#include "math_config.h"
> +
> +#if defined(__riscv_fsqrt) && __riscv_flen >= 64
> +
> +double
> +__ieee754_sqrt (double x)
> +{
> +       double result;
> +       asm ("fsqrt.d %0, %1" : "=f" (result) : "f" (x));
> +       return result;
> +}
> +
> +#if defined(_IEEE_LIBM) && defined(HAVE_ALIAS_ATTRIBUTE)
> +__strong_reference(__ieee754_sqrt, sqrt);
> +#endif
> +
> +#endif
> diff --git a/newlib/libm/machine/riscv/sf_fma.c b/newlib/libm/machine/riscv/sf_fma.c
> new file mode 100644
> index 000000000..8061a8abb
> --- /dev/null
> +++ b/newlib/libm/machine/riscv/sf_fma.c
> @@ -0,0 +1,49 @@
> +/*
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright © 2020 Keith Packard
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + *    copyright notice, this list of conditions and the following
> + *    disclaimer in the documentation and/or other materials provided
> + *    with the distribution.
> + *
> + * 3. Neither the name of the copyright holder nor the names of its
> + *    contributors may be used to endorse or promote products derived
> + *    from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
> + * OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <math.h>
> +#include "math_config.h"
> +
> +#if HAVE_FAST_FMAF
> +
> +float
> +fmaf (float x, float y, float z)
> +{
> +       float result;
> +       asm ("fmadd.s %0, %1, %2, %3" : "=f" (result) : "f" (x), "f" (y), "f" (z));
> +       return result;
> +}
> +
> +#endif
> diff --git a/newlib/libm/machine/riscv/sf_sqrt.c b/newlib/libm/machine/riscv/sf_sqrt.c
> new file mode 100644
> index 000000000..9a67906c9
> --- /dev/null
> +++ b/newlib/libm/machine/riscv/sf_sqrt.c
> @@ -0,0 +1,53 @@
> +/*
> + * SPDX-License-Identifier: BSD-3-Clause
> + *
> + * Copyright © 2020 Keith Packard
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + *
> + * 1. Redistributions of source code must retain the above copyright
> + *    notice, this list of conditions and the following disclaimer.
> + *
> + * 2. Redistributions in binary form must reproduce the above
> + *    copyright notice, this list of conditions and the following
> + *    disclaimer in the documentation and/or other materials provided
> + *    with the distribution.
> + *
> + * 3. Neither the name of the copyright holder nor the names of its
> + *    contributors may be used to endorse or promote products derived
> + *    from this software without specific prior written permission.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
> + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
> + * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
> + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
> + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
> + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
> + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
> + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
> + * OF THE POSSIBILITY OF SUCH DAMAGE.
> + */
> +
> +#include <math.h>
> +#include "math_config.h"
> +
> +#if defined(__riscv_fsqrt) && __riscv_flen >= 32
> +
> +float
> +__ieee754_sqrtf (float x)
> +{
> +       float result;
> +       asm ("fsqrt.s %0, %1" : "=f" (result) : "f" (x));
> +       return result;
> +}
> +
> +#if defined(_IEEE_LIBM) && defined(HAVE_ALIAS_ATTRIBUTE)
> +__strong_reference(__ieee754_sqrtf, sqrtf);
> +#endif
> +
> +#endif
> --
> 2.28.0
>
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