Add narrowing multiply functions.

This patch adds the narrowing multiply functions from TS 18661-1 to
glibc's libm: fmul, fmull, dmull, f32mulf64, f32mulf32x, f32xmulf64
for all configurations; f32mulf64x, f32mulf128, f64mulf64x,
f64mulf128, f32xmulf64x, f32xmulf128, f64xmulf128 for configurations
with _Float64x and _Float128; __nldbl_dmull for ldbl-opt.

The changes are mostly essentially the same as for the narrowing add
functions, so the description of those generally applies to this patch
as well.  f32xmulf64 for i386 cannot use precision control as used for
add and subtract, because that would result in double rounding for
subnormal results, so that uses round-to-odd with long double
intermediate result instead.  The soft-fp support involves adding a
new FP_TRUNC_COOKED since soft-fp multiplication uses cooked inputs
and outputs.

Tested for x86_64, x86, mips64 (all three ABIs, both hard and soft
float) and powerpc, and with build-many-glibcs.py.

	* math/Makefile (libm-narrow-fns): Add mul.
	(libm-test-funcs-narrow): Likewise.
	* math/Versions (GLIBC_2.28): Add narrowing multiply functions.
	* math/bits/mathcalls-narrow.h (mul): Use __MATHCALL_NARROW.
	* math/gen-auto-libm-tests.c (test_functions): Add mul.
	* math/math-narrow.h (CHECK_NARROW_MUL): New macro.
	(NARROW_MUL_ROUND_TO_ODD): Likewise.
	(NARROW_MUL_TRIVIAL): Likewise.
	* soft-fp/op-common.h (FP_TRUNC_COOKED): Likewise.
	* sysdeps/ieee754/float128/float128_private.h (__fmull): New
	macro.
	(__dmull): Likewise.
	* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fmul and
	dmul.
	(CFLAGS-nldbl-dmul.c): New variable.
	(CFLAGS-nldbl-fmul.c): Likewise.
	* sysdeps/ieee754/ldbl-opt/Versions (GLIBC_2.28): Add
	__nldbl_dmull.
	* sysdeps/ieee754/ldbl-opt/nldbl-compat.h (__nldbl_dmull): New
	prototype.
	* manual/arith.texi (Misc FP Arithmetic): Document fmul, fmull,
	dmull, fMmulfN, fMmulfNx, fMxmulfN and fMxmulfNx.
	* math/auto-libm-test-in: Add tests of mul.
	* math/auto-libm-test-out-narrow-mul: New generated file.
	* math/libm-test-narrow-mul.inc: New file.
	* sysdeps/i386/fpu/s_f32xmulf64.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_f32xmulf64.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_fmul.c: Likewise.
	* sysdeps/ieee754/float128/s_f32mulf128.c: Likewise.
	* sysdeps/ieee754/float128/s_f64mulf128.c: Likewise.
	* sysdeps/ieee754/float128/s_f64xmulf128.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_dmull.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_f64xmulf128.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_fmull.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_dmull.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_fmull.c: Likewise.
	* sysdeps/ieee754/ldbl-96/s_dmull.c: Likewise.
	* sysdeps/ieee754/ldbl-96/s_fmull.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/nldbl-dmul.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/nldbl-fmul.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_dmull.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_fmul.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_fmull.c: Likewise.
	* sysdeps/powerpc/fpu/libm-test-ulps: Update.
	* sysdeps/mach/hurd/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist: Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/riscv/rv64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.

21 files changed, 541 insertions, 2 deletions

diff --git a/sysdeps/ieee754/dbl-64/s_f32xmulf64.c b/sysdeps/ieee754/dbl-64/s_f32xmulf64.c
new file mode 100644
index 0000000000..f899c84567
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/s_f32xmulf64.c
@@ -0,0 +1,30 @@
+/* Multiply _Float64 values, converting the result to _Float32x.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define dmull __hide_dmull
+#include <math.h>
+#undef dmull
+
+#include <math-narrow.h>
+
+_Float32x
+__f32xmulf64 (_Float64 x, _Float64 y)
+{
+  NARROW_MUL_TRIVIAL (x, y, _Float32x);
+}
+libm_alias_float32x_float64 (mul)
diff --git a/sysdeps/ieee754/dbl-64/s_fmul.c b/sysdeps/ieee754/dbl-64/s_fmul.c
new file mode 100644
index 0000000000..ad9ab7e94d
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/s_fmul.c
@@ -0,0 +1,34 @@
+/* Multiply double values, narrowing the result to float.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32mulf64 __hide_f32mulf64
+#define f32mulf32x __hide_f32mulf32x
+#define fmull __hide_fmull
+#include <math.h>
+#undef f32mulf64
+#undef f32mulf32x
+#undef fmull
+
+#include <math-narrow.h>
+
+float
+__fmul (double x, double y)
+{
+  NARROW_MUL_ROUND_TO_ODD (x, y, float, union ieee754_double, , mantissa1);
+}
+libm_alias_float_double (mul)
diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
index 7606026593..9136e5351b 100644
--- a/sysdeps/ieee754/float128/float128_private.h
+++ b/sysdeps/ieee754/float128/float128_private.h
@@ -258,6 +258,8 @@
 
 #define __faddl __f32addf128
 #define __daddl __f64addf128
+#define __fmull __f32mulf128
+#define __dmull __f64mulf128
 #define __fsubl __f32subf128
 #define __dsubl __f64subf128
 
diff --git a/sysdeps/ieee754/float128/s_f32mulf128.c b/sysdeps/ieee754/float128/s_f32mulf128.c
new file mode 100644
index 0000000000..45fdc66ba6
--- /dev/null
+++ b/sysdeps/ieee754/float128/s_f32mulf128.c
@@ -0,0 +1,6 @@
+#define f32mulf64x __hide_f32mulf64x
+#define f32mulf128 __hide_f32mulf128
+#include <float128_private.h>
+#undef f32mulf64x
+#undef f32mulf128
+#include "../ldbl-128/s_fmull.c"
diff --git a/sysdeps/ieee754/float128/s_f64mulf128.c b/sysdeps/ieee754/float128/s_f64mulf128.c
new file mode 100644
index 0000000000..47a645ac4d
--- /dev/null
+++ b/sysdeps/ieee754/float128/s_f64mulf128.c
@@ -0,0 +1,10 @@
+#define f32xmulf64x __hide_f32xmulf64x
+#define f32xmulf128 __hide_f32xmulf128
+#define f64mulf64x __hide_f64mulf64x
+#define f64mulf128 __hide_f64mulf128
+#include <float128_private.h>
+#undef f32xmulf64x
+#undef f32xmulf128
+#undef f64mulf64x
+#undef f64mulf128
+#include "../ldbl-128/s_dmull.c"
diff --git a/sysdeps/ieee754/float128/s_f64xmulf128.c b/sysdeps/ieee754/float128/s_f64xmulf128.c
new file mode 100644
index 0000000000..085bf9fe4e
--- /dev/null
+++ b/sysdeps/ieee754/float128/s_f64xmulf128.c
@@ -0,0 +1,2 @@
+#include <float128_private.h>
+#include "../ldbl-128/s_f64xmulf128.c"
diff --git a/sysdeps/ieee754/ldbl-128/s_dmull.c b/sysdeps/ieee754/ldbl-128/s_dmull.c
new file mode 100644
index 0000000000..d32c4284e0
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_dmull.c
@@ -0,0 +1,37 @@
+/* Multiply long double (ldbl-128) values, narrowing the result to double.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32xmulf64x __hide_f32xmulf64x
+#define f32xmulf128 __hide_f32xmulf128
+#define f64mulf64x __hide_f64mulf64x
+#define f64mulf128 __hide_f64mulf128
+#include <math.h>
+#undef f32xmulf64x
+#undef f32xmulf128
+#undef f64mulf64x
+#undef f64mulf128
+
+#include <math-narrow.h>
+
+double
+__dmull (_Float128 x, _Float128 y)
+{
+  NARROW_MUL_ROUND_TO_ODD (x, y, double, union ieee854_long_double, l,
+			   mantissa3);
+}
+libm_alias_double_ldouble (mul)
diff --git a/sysdeps/ieee754/ldbl-128/s_f64xmulf128.c b/sysdeps/ieee754/ldbl-128/s_f64xmulf128.c
new file mode 100644
index 0000000000..ed88eabe40
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_f64xmulf128.c
@@ -0,0 +1,38 @@
+/* Multiply _Float128 values, converting the result to _Float64x.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <math-narrow.h>
+
+/* math_ldbl.h defines _Float128 to long double for this directory,
+   but when they are different, this function must be defined with
+   _Float128 arguments to avoid defining an alias with an incompatible
+   type.  */
+#undef _Float128
+
+_Float64x
+__f64xmulf128 (_Float128 x, _Float128 y)
+{
+#if __HAVE_FLOAT64X_LONG_DOUBLE && __HAVE_DISTINCT_FLOAT128
+  NARROW_MUL_ROUND_TO_ODD (x, y, _Float64x, union ieee854_long_double, l,
+			   mantissa3);
+#else
+  NARROW_MUL_TRIVIAL (x, y, _Float64x);
+#endif
+}
+libm_alias_float64x_float128 (mul)
diff --git a/sysdeps/ieee754/ldbl-128/s_fmull.c b/sysdeps/ieee754/ldbl-128/s_fmull.c
new file mode 100644
index 0000000000..dd399f9590
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_fmull.c
@@ -0,0 +1,33 @@
+/* Multiply long double (ldbl-128) values, narrowing the result to float.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32mulf64x __hide_f32mulf64x
+#define f32mulf128 __hide_f32mulf128
+#include <math.h>
+#undef f32mulf64x
+#undef f32mulf128
+
+#include <math-narrow.h>
+
+float
+__fmull (_Float128 x, _Float128 y)
+{
+  NARROW_MUL_ROUND_TO_ODD (x, y, float, union ieee854_long_double, l,
+			   mantissa3);
+}
+libm_alias_float_ldouble (mul)
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_dmull.c b/sysdeps/ieee754/ldbl-128ibm/s_dmull.c
new file mode 100644
index 0000000000..7b75b2b0f1
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_dmull.c
@@ -0,0 +1,27 @@
+/* Multiply long double (ldbl-128ibm) values, narrowing the result to double.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <math-narrow.h>
+
+double
+__dmull (long double x, long double y)
+{
+  NARROW_MUL_TRIVIAL (x, y, double);
+}
+libm_alias_double_ldouble (mul)
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_fmull.c b/sysdeps/ieee754/ldbl-128ibm/s_fmull.c
new file mode 100644
index 0000000000..d1988f168d
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_fmull.c
@@ -0,0 +1,27 @@
+/* Multiply long double (ldbl-128ibm) values, narrowing the result to float.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <math-narrow.h>
+
+float
+__fmull (long double x, long double y)
+{
+  NARROW_MUL_TRIVIAL (x, y, float);
+}
+libm_alias_float_ldouble (mul)
diff --git a/sysdeps/ieee754/ldbl-96/s_dmull.c b/sysdeps/ieee754/ldbl-96/s_dmull.c
new file mode 100644
index 0000000000..a717b0aa07
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/s_dmull.c
@@ -0,0 +1,33 @@
+/* Multiply long double (ldbl-96) values, narrowing the result to double.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32xmulf64x __hide_f32xmulf64x
+#define f64mulf64x __hide_f64mulf64x
+#include <math.h>
+#undef f32xmulf64x
+#undef f64mulf64x
+
+#include <math-narrow.h>
+
+double
+__dmull (long double x, long double y)
+{
+  NARROW_MUL_ROUND_TO_ODD (x, y, double, union ieee854_long_double, l,
+			   mantissa1);
+}
+libm_alias_double_ldouble (mul)
diff --git a/sysdeps/ieee754/ldbl-96/s_fmull.c b/sysdeps/ieee754/ldbl-96/s_fmull.c
new file mode 100644
index 0000000000..b7582526a6
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/s_fmull.c
@@ -0,0 +1,31 @@
+/* Multiply long double (ldbl-96) values, narrowing the result to float.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32mulf64x __hide_f32mulf64x
+#include <math.h>
+#undef f32mulf64x
+
+#include <math-narrow.h>
+
+float
+__fmull (long double x, long double y)
+{
+  NARROW_MUL_ROUND_TO_ODD (x, y, float, union ieee854_long_double, l,
+			   mantissa1);
+}
+libm_alias_float_ldouble (mul)
diff --git a/sysdeps/ieee754/ldbl-opt/Makefile b/sysdeps/ieee754/ldbl-opt/Makefile
index 7cdeaad2f2..90b2c928a9 100644
--- a/sysdeps/ieee754/ldbl-opt/Makefile
+++ b/sysdeps/ieee754/ldbl-opt/Makefile
@@ -45,7 +45,7 @@ libnldbl-calls = asprintf dprintf fprintf fscanf fwprintf fwscanf iovfscanf \
 		 nextup nextdown totalorder totalordermag getpayload \
 		 canonicalize setpayload setpayloadsig llogb fmaxmag fminmag \
 		 roundeven fromfp ufromfp fromfpx ufromfpx fadd dadd \
-		 fsub dsub
+		 fmul dmul fsub dsub
 libnldbl-routines = $(libnldbl-calls:%=nldbl-%)
 libnldbl-inhibit-o = $(object-suffixes)
 libnldbl-static-only-routines = $(libnldbl-routines)
@@ -88,6 +88,7 @@ CFLAGS-nldbl-csqrt.c = -fno-builtin-csqrtl
 CFLAGS-nldbl-ctan.c = -fno-builtin-ctanl
 CFLAGS-nldbl-ctanh.c = -fno-builtin-ctanhl
 CFLAGS-nldbl-dadd.c = -fno-builtin-daddl
+CFLAGS-nldbl-dmul.c = -fno-builtin-dmull
 CFLAGS-nldbl-dsub.c = -fno-builtin-dsubl
 CFLAGS-nldbl-erf.c = -fno-builtin-erfl
 CFLAGS-nldbl-erfc.c = -fno-builtin-erfcl
@@ -106,6 +107,7 @@ CFLAGS-nldbl-fmaxmag.c = -fno-builtin-fmaxmagl
 CFLAGS-nldbl-fmin.c = -fno-builtin-fminl
 CFLAGS-nldbl-fminmag.c = -fno-builtin-fminmagl
 CFLAGS-nldbl-fmod.c = -fno-builtin-fmodl
+CFLAGS-nldbl-fmul.c = -fno-builtin-fmull
 CFLAGS-nldbl-frexp.c = -fno-builtin-frexpl
 CFLAGS-nldbl-fromfp.c = -fno-builtin-fromfpl
 CFLAGS-nldbl-fromfpx.c = -fno-builtin-fromfpxl
diff --git a/sysdeps/ieee754/ldbl-opt/Versions b/sysdeps/ieee754/ldbl-opt/Versions
index c33dc42d81..17aa035248 100644
--- a/sysdeps/ieee754/ldbl-opt/Versions
+++ b/sysdeps/ieee754/ldbl-opt/Versions
@@ -101,6 +101,6 @@ libm {
     # Functions taking long double = double argument and rounding
     # result to double (same as f32x*f64 functions, but those names
     # are not reserved in TS 18661-1).
-    __nldbl_daddl; __nldbl_dsubl;
+    __nldbl_daddl; __nldbl_dmull; __nldbl_dsubl;
   }
 }
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-compat.h b/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
index 4f5ae2dd26..e0d12545a3 100644
--- a/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
+++ b/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
@@ -104,6 +104,7 @@ extern void __nldbl___vsyslog_chk (int, int, const char *, va_list);
 /* The original declarations of these were hidden by the including
    file.  */
 extern double __nldbl_daddl (double, double) __THROW;
+extern double __nldbl_dmull (double, double) __THROW;
 extern double __nldbl_dsubl (double, double) __THROW;
 
 #endif /* __NLDBL_COMPAT_H */
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-dmul.c b/sysdeps/ieee754/ldbl-opt/nldbl-dmul.c
new file mode 100644
index 0000000000..9c9b94e067
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-opt/nldbl-dmul.c
@@ -0,0 +1,28 @@
+/* Compatibility routine for IEEE double as long double for dmul.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define dmull __hide_dmull
+#include "nldbl-compat.h"
+#undef dmull
+
+double
+attribute_hidden
+dmull (double x, double y)
+{
+  return __nldbl_dmull (x, y);
+}
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-fmul.c b/sysdeps/ieee754/ldbl-opt/nldbl-fmul.c
new file mode 100644
index 0000000000..2520d1b014
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-opt/nldbl-fmul.c
@@ -0,0 +1,28 @@
+/* Compatibility routine for IEEE double as long double for fmul.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define fmull __hide_fmull
+#include "nldbl-compat.h"
+#undef fmull
+
+float
+attribute_hidden
+fmull (double x, double y)
+{
+  return fmul (x, y);
+}
diff --git a/sysdeps/ieee754/soft-fp/s_dmull.c b/sysdeps/ieee754/soft-fp/s_dmull.c
new file mode 100644
index 0000000000..4ebf31140b
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_dmull.c
@@ -0,0 +1,59 @@
+/* Multiply long double (ldbl-128) values, narrowing the result to
+   double, using soft-fp.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32xmulf64x __hide_f32xmulf64x
+#define f32xmulf128 __hide_f32xmulf128
+#define f64mulf64x __hide_f64mulf64x
+#define f64mulf128 __hide_f64mulf128
+#include <math.h>
+#undef f32xmulf64x
+#undef f32xmulf128
+#undef f64mulf64x
+#undef f64mulf128
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <double.h>
+#include <quad.h>
+
+double
+__dmull (_Float128 x, _Float128 y)
+{
+  FP_DECL_EX;
+  FP_DECL_Q (X);
+  FP_DECL_Q (Y);
+  FP_DECL_Q (R);
+  FP_DECL_D (RN);
+  double ret;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_Q (X, x);
+  FP_UNPACK_Q (Y, y);
+  FP_MUL_Q (R, X, Y);
+#if (2 * _FP_W_TYPE_SIZE) < _FP_FRACBITS_Q
+  FP_TRUNC_COOKED (D, Q, 2, 4, RN, R);
+#else
+  FP_TRUNC_COOKED (D, Q, 1, 2, RN, R);
+#endif
+  FP_PACK_D (ret, RN);
+  FP_HANDLE_EXCEPTIONS;
+  CHECK_NARROW_MUL (ret, x, y);
+  return ret;
+}
+libm_alias_double_ldouble (mul)
diff --git a/sysdeps/ieee754/soft-fp/s_fmul.c b/sysdeps/ieee754/soft-fp/s_fmul.c
new file mode 100644
index 0000000000..5f679b1d45
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fmul.c
@@ -0,0 +1,56 @@
+/* Multiply double values, narrowing the result to float, using soft-fp.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32mulf64 __hide_f32mulf64
+#define f32mulf32x __hide_f32mulf32x
+#define fmull __hide_fmull
+#include <math.h>
+#undef f32mulf64
+#undef f32mulf32x
+#undef fmull
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <single.h>
+#include <double.h>
+
+float
+__fmul (double x, double y)
+{
+  FP_DECL_EX;
+  FP_DECL_D (X);
+  FP_DECL_D (Y);
+  FP_DECL_D (R);
+  FP_DECL_S (RN);
+  float ret;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_D (X, x);
+  FP_UNPACK_D (Y, y);
+  FP_MUL_D (R, X, Y);
+#if _FP_W_TYPE_SIZE < _FP_FRACBITS_D
+  FP_TRUNC_COOKED (S, D, 1, 2, RN, R);
+#else
+  FP_TRUNC_COOKED (S, D, 1, 1, RN, R);
+#endif
+  FP_PACK_S (ret, RN);
+  FP_HANDLE_EXCEPTIONS;
+  CHECK_NARROW_MUL (ret, x, y);
+  return ret;
+}
+libm_alias_float_double (mul)
diff --git a/sysdeps/ieee754/soft-fp/s_fmull.c b/sysdeps/ieee754/soft-fp/s_fmull.c
new file mode 100644
index 0000000000..da4a12c8ec
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fmull.c
@@ -0,0 +1,55 @@
+/* Multiply long double (ldbl-128) values, narrowing the result to
+   float, using soft-fp.
+   Copyright (C) 2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#define f32mulf64x __hide_f32mulf64x
+#define f32mulf128 __hide_f32mulf128
+#include <math.h>
+#undef f32mulf64x
+#undef f32mulf128
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <single.h>
+#include <quad.h>
+
+float
+__fmull (_Float128 x, _Float128 y)
+{
+  FP_DECL_EX;
+  FP_DECL_Q (X);
+  FP_DECL_Q (Y);
+  FP_DECL_Q (R);
+  FP_DECL_S (RN);
+  float ret;
+
+  FP_INIT_ROUNDMODE;
+  FP_UNPACK_Q (X, x);
+  FP_UNPACK_Q (Y, y);
+  FP_MUL_Q (R, X, Y);
+#if (2 * _FP_W_TYPE_SIZE) < _FP_FRACBITS_Q
+  FP_TRUNC_COOKED (S, Q, 1, 4, RN, R);
+#else
+  FP_TRUNC_COOKED (S, Q, 1, 2, RN, R);
+#endif
+  FP_PACK_S (ret, RN);
+  FP_HANDLE_EXCEPTIONS;
+  CHECK_NARROW_MUL (ret, x, y);
+  return ret;
+}
+libm_alias_float_ldouble (mul)