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

Check for HW FMA and SQRT support and use those instructions in place
of software implementations.

Signed-off-by: Keith Packard <keithp@keithp.com>

7 files changed, 237 insertions, 5 deletions

diff --git a/newlib/libm/common/math_config.h b/newlib/libm/common/math_config.h
index e7a8bb7..0f78b5c 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 1b9f48a..a778379 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 = $(LIB_SOURCES)
diff --git a/newlib/libm/machine/riscv/Makefile.in b/newlib/libm/machine/riscv/Makefile.in
index a5023a5..c568305 100644
--- a/newlib/libm/machine/riscv/Makefile.in
+++ b/newlib/libm/machine/riscv/Makefile.in
@@ -76,7 +76,9 @@ am__objects_1 = lib_a-feclearexcept.$(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 0000000..b7f3780
--- /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 0000000..abccf4b
--- /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 0000000..8061a8a
--- /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 0000000..9a67906
--- /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