Add narrowing divide functions.

This patch adds the narrowing divide functions from TS 18661-1 to
glibc's libm: fdiv, fdivl, ddivl, f32divf64, f32divf32x, f32xdivf64
for all configurations; f32divf64x, f32divf128, f64divf64x,
f64divf128, f32xdivf64x, f32xdivf128, f64xdivf128 for configurations
with _Float64x and _Float128; __nldbl_ddivl for ldbl-opt.

The changes are mostly essentially the same as for the other narrowing
functions, so the description of those generally applies to this patch
as well.

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 div.
	(libm-test-funcs-narrow): Likewise.
	* math/Versions (GLIBC_2.28): Add narrowing divide functions.
	* math/bits/mathcalls-narrow.h (div): Use __MATHCALL_NARROW.
	* math/gen-auto-libm-tests.c (test_functions): Add div.
	* math/math-narrow.h (CHECK_NARROW_DIV): New macro.
	(NARROW_DIV_ROUND_TO_ODD): Likewise.
	(NARROW_DIV_TRIVIAL): Likewise.
	* sysdeps/ieee754/float128/float128_private.h (__fdivl): New
	macro.
	(__ddivl): Likewise.
	* sysdeps/ieee754/ldbl-opt/Makefile (libnldbl-calls): Add fdiv and
	ddiv.
	(CFLAGS-nldbl-ddiv.c): New variable.
	(CFLAGS-nldbl-fdiv.c): Likewise.
	* sysdeps/ieee754/ldbl-opt/Versions (GLIBC_2.28): Add
	__nldbl_ddivl.
	* sysdeps/ieee754/ldbl-opt/nldbl-compat.h (__nldbl_ddivl): New
	prototype.
	* manual/arith.texi (Misc FP Arithmetic): Document fdiv, fdivl,
	ddivl, fMdivfN, fMdivfNx, fMxdivfN and fMxdivfNx.
	* math/auto-libm-test-in: Add tests of div.
	* math/auto-libm-test-out-narrow-div: New generated file.
	* math/libm-test-narrow-div.inc: New file.
	* sysdeps/i386/fpu/s_f32xdivf64.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_f32xdivf64.c: Likewise.
	* sysdeps/ieee754/dbl-64/s_fdiv.c: Likewise.
	* sysdeps/ieee754/float128/s_f32divf128.c: Likewise.
	* sysdeps/ieee754/float128/s_f64divf128.c: Likewise.
	* sysdeps/ieee754/float128/s_f64xdivf128.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_ddivl.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_f64xdivf128.c: Likewise.
	* sysdeps/ieee754/ldbl-128/s_fdivl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_ddivl.c: Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_fdivl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/s_ddivl.c: Likewise.
	* sysdeps/ieee754/ldbl-96/s_fdivl.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/nldbl-ddiv.c: Likewise.
	* sysdeps/ieee754/ldbl-opt/nldbl-fdiv.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_ddivl.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_fdiv.c: Likewise.
	* sysdeps/ieee754/soft-fp/s_fdivl.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_f32xdivf64.c b/sysdeps/ieee754/dbl-64/s_f32xdivf64.c
new file mode 100644
index 0000000000..24dc25dc0c
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/s_f32xdivf64.c
@@ -0,0 +1,30 @@
+/* Divide _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 ddivl __hide_ddivl
+#include <math.h>
+#undef ddivl
+
+#include <math-narrow.h>
+
+_Float32x
+__f32xdivf64 (_Float64 x, _Float64 y)
+{
+  NARROW_DIV_TRIVIAL (x, y, _Float32x);
+}
+libm_alias_float32x_float64 (div)
diff --git a/sysdeps/ieee754/dbl-64/s_fdiv.c b/sysdeps/ieee754/dbl-64/s_fdiv.c
new file mode 100644
index 0000000000..cdd2649df0
--- /dev/null
+++ b/sysdeps/ieee754/dbl-64/s_fdiv.c
@@ -0,0 +1,34 @@
+/* Divide 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 f32divf64 __hide_f32divf64
+#define f32divf32x __hide_f32divf32x
+#define fdivl __hide_fdivl
+#include <math.h>
+#undef f32divf64
+#undef f32divf32x
+#undef fdivl
+
+#include <math-narrow.h>
+
+float
+__fdiv (double x, double y)
+{
+  NARROW_DIV_ROUND_TO_ODD (x, y, float, union ieee754_double, , mantissa1);
+}
+libm_alias_float_double (div)
diff --git a/sysdeps/ieee754/float128/float128_private.h b/sysdeps/ieee754/float128/float128_private.h
index 9136e5351b..9dd15601e6 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 __fdivl __f32divf128
+#define __ddivl __f64divf128
 #define __fmull __f32mulf128
 #define __dmull __f64mulf128
 #define __fsubl __f32subf128
diff --git a/sysdeps/ieee754/float128/s_f32divf128.c b/sysdeps/ieee754/float128/s_f32divf128.c
new file mode 100644
index 0000000000..de8d252e80
--- /dev/null
+++ b/sysdeps/ieee754/float128/s_f32divf128.c
@@ -0,0 +1,6 @@
+#define f32divf64x __hide_f32divf64x
+#define f32divf128 __hide_f32divf128
+#include <float128_private.h>
+#undef f32divf64x
+#undef f32divf128
+#include "../ldbl-128/s_fdivl.c"
diff --git a/sysdeps/ieee754/float128/s_f64divf128.c b/sysdeps/ieee754/float128/s_f64divf128.c
new file mode 100644
index 0000000000..ea37e8bcaf
--- /dev/null
+++ b/sysdeps/ieee754/float128/s_f64divf128.c
@@ -0,0 +1,10 @@
+#define f32xdivf64x __hide_f32xdivf64x
+#define f32xdivf128 __hide_f32xdivf128
+#define f64divf64x __hide_f64divf64x
+#define f64divf128 __hide_f64divf128
+#include <float128_private.h>
+#undef f32xdivf64x
+#undef f32xdivf128
+#undef f64divf64x
+#undef f64divf128
+#include "../ldbl-128/s_ddivl.c"
diff --git a/sysdeps/ieee754/float128/s_f64xdivf128.c b/sysdeps/ieee754/float128/s_f64xdivf128.c
new file mode 100644
index 0000000000..55cc953ba6
--- /dev/null
+++ b/sysdeps/ieee754/float128/s_f64xdivf128.c
@@ -0,0 +1,2 @@
+#include <float128_private.h>
+#include "../ldbl-128/s_f64xdivf128.c"
diff --git a/sysdeps/ieee754/ldbl-128/s_ddivl.c b/sysdeps/ieee754/ldbl-128/s_ddivl.c
new file mode 100644
index 0000000000..c76df92bfb
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_ddivl.c
@@ -0,0 +1,37 @@
+/* Divide 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 f32xdivf64x __hide_f32xdivf64x
+#define f32xdivf128 __hide_f32xdivf128
+#define f64divf64x __hide_f64divf64x
+#define f64divf128 __hide_f64divf128
+#include <math.h>
+#undef f32xdivf64x
+#undef f32xdivf128
+#undef f64divf64x
+#undef f64divf128
+
+#include <math-narrow.h>
+
+double
+__ddivl (_Float128 x, _Float128 y)
+{
+  NARROW_DIV_ROUND_TO_ODD (x, y, double, union ieee854_long_double, l,
+			   mantissa3);
+}
+libm_alias_double_ldouble (div)
diff --git a/sysdeps/ieee754/ldbl-128/s_f64xdivf128.c b/sysdeps/ieee754/ldbl-128/s_f64xdivf128.c
new file mode 100644
index 0000000000..64356bbdd7
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_f64xdivf128.c
@@ -0,0 +1,38 @@
+/* Divide _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
+__f64xdivf128 (_Float128 x, _Float128 y)
+{
+#if __HAVE_FLOAT64X_LONG_DOUBLE && __HAVE_DISTINCT_FLOAT128
+  NARROW_DIV_ROUND_TO_ODD (x, y, _Float64x, union ieee854_long_double, l,
+			   mantissa3);
+#else
+  NARROW_DIV_TRIVIAL (x, y, _Float64x);
+#endif
+}
+libm_alias_float64x_float128 (div)
diff --git a/sysdeps/ieee754/ldbl-128/s_fdivl.c b/sysdeps/ieee754/ldbl-128/s_fdivl.c
new file mode 100644
index 0000000000..b00fdb4eaa
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128/s_fdivl.c
@@ -0,0 +1,33 @@
+/* Divide 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 f32divf64x __hide_f32divf64x
+#define f32divf128 __hide_f32divf128
+#include <math.h>
+#undef f32divf64x
+#undef f32divf128
+
+#include <math-narrow.h>
+
+float
+__fdivl (_Float128 x, _Float128 y)
+{
+  NARROW_DIV_ROUND_TO_ODD (x, y, float, union ieee854_long_double, l,
+			   mantissa3);
+}
+libm_alias_float_ldouble (div)
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_ddivl.c b/sysdeps/ieee754/ldbl-128ibm/s_ddivl.c
new file mode 100644
index 0000000000..6bbbbcf09d
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_ddivl.c
@@ -0,0 +1,27 @@
+/* Divide 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
+__ddivl (long double x, long double y)
+{
+  NARROW_DIV_TRIVIAL (x, y, double);
+}
+libm_alias_double_ldouble (div)
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_fdivl.c b/sysdeps/ieee754/ldbl-128ibm/s_fdivl.c
new file mode 100644
index 0000000000..dd34c05502
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-128ibm/s_fdivl.c
@@ -0,0 +1,27 @@
+/* Divide 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
+__fdivl (long double x, long double y)
+{
+  NARROW_DIV_TRIVIAL (x, y, float);
+}
+libm_alias_float_ldouble (div)
diff --git a/sysdeps/ieee754/ldbl-96/s_ddivl.c b/sysdeps/ieee754/ldbl-96/s_ddivl.c
new file mode 100644
index 0000000000..9c266d1ff3
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/s_ddivl.c
@@ -0,0 +1,33 @@
+/* Divide 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 f32xdivf64x __hide_f32xdivf64x
+#define f64divf64x __hide_f64divf64x
+#include <math.h>
+#undef f32xdivf64x
+#undef f64divf64x
+
+#include <math-narrow.h>
+
+double
+__ddivl (long double x, long double y)
+{
+  NARROW_DIV_ROUND_TO_ODD (x, y, double, union ieee854_long_double, l,
+			   mantissa1);
+}
+libm_alias_double_ldouble (div)
diff --git a/sysdeps/ieee754/ldbl-96/s_fdivl.c b/sysdeps/ieee754/ldbl-96/s_fdivl.c
new file mode 100644
index 0000000000..ccb87ccd15
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/s_fdivl.c
@@ -0,0 +1,31 @@
+/* Divide 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 f32divf64x __hide_f32divf64x
+#include <math.h>
+#undef f32divf64x
+
+#include <math-narrow.h>
+
+float
+__fdivl (long double x, long double y)
+{
+  NARROW_DIV_ROUND_TO_ODD (x, y, float, union ieee854_long_double, l,
+			   mantissa1);
+}
+libm_alias_float_ldouble (div)
diff --git a/sysdeps/ieee754/ldbl-opt/Makefile b/sysdeps/ieee754/ldbl-opt/Makefile
index 90b2c928a9..ef790adc77 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 \
-		 fmul dmul fsub dsub
+		 fdiv ddiv 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-ddiv.c = -fno-builtin-ddivl
 CFLAGS-nldbl-dmul.c = -fno-builtin-dmull
 CFLAGS-nldbl-dsub.c = -fno-builtin-dsubl
 CFLAGS-nldbl-erf.c = -fno-builtin-erfl
@@ -99,6 +100,7 @@ CFLAGS-nldbl-expm1.c = -fno-builtin-expm1l
 CFLAGS-nldbl-fabs.c = -fno-builtin-fabsl
 CFLAGS-nldbl-fadd.c = -fno-builtin-faddl
 CFLAGS-nldbl-fdim.c = -fno-builtin-fdiml
+CFLAGS-nldbl-fdiv.c = -fno-builtin-fdivl
 CFLAGS-nldbl-finite.c = -fno-builtin-finitel
 CFLAGS-nldbl-floor.c = -fno-builtin-floorl
 CFLAGS-nldbl-fma.c = -fno-builtin-fmal
diff --git a/sysdeps/ieee754/ldbl-opt/Versions b/sysdeps/ieee754/ldbl-opt/Versions
index 17aa035248..af0c4a098c 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_dmull; __nldbl_dsubl;
+    __nldbl_daddl; __nldbl_ddivl; __nldbl_dmull; __nldbl_dsubl;
   }
 }
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-compat.h b/sysdeps/ieee754/ldbl-opt/nldbl-compat.h
index e0d12545a3..888f561cac 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_ddivl (double, double) __THROW;
 extern double __nldbl_dmull (double, double) __THROW;
 extern double __nldbl_dsubl (double, double) __THROW;
 
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-ddiv.c b/sysdeps/ieee754/ldbl-opt/nldbl-ddiv.c
new file mode 100644
index 0000000000..5cb4606b7d
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-opt/nldbl-ddiv.c
@@ -0,0 +1,28 @@
+/* Compatibility routine for IEEE double as long double for ddiv.
+   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 ddivl __hide_ddivl
+#include "nldbl-compat.h"
+#undef ddivl
+
+double
+attribute_hidden
+ddivl (double x, double y)
+{
+  return __nldbl_ddivl (x, y);
+}
diff --git a/sysdeps/ieee754/ldbl-opt/nldbl-fdiv.c b/sysdeps/ieee754/ldbl-opt/nldbl-fdiv.c
new file mode 100644
index 0000000000..2d043fc721
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-opt/nldbl-fdiv.c
@@ -0,0 +1,28 @@
+/* Compatibility routine for IEEE double as long double for fdiv.
+   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 fdivl __hide_fdivl
+#include "nldbl-compat.h"
+#undef fdivl
+
+float
+attribute_hidden
+fdivl (double x, double y)
+{
+  return fdiv (x, y);
+}
diff --git a/sysdeps/ieee754/soft-fp/s_ddivl.c b/sysdeps/ieee754/soft-fp/s_ddivl.c
new file mode 100644
index 0000000000..7e598a2132
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_ddivl.c
@@ -0,0 +1,59 @@
+/* Divide 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 f32xdivf64x __hide_f32xdivf64x
+#define f32xdivf128 __hide_f32xdivf128
+#define f64divf64x __hide_f64divf64x
+#define f64divf128 __hide_f64divf128
+#include <math.h>
+#undef f32xdivf64x
+#undef f32xdivf128
+#undef f64divf64x
+#undef f64divf128
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <double.h>
+#include <quad.h>
+
+double
+__ddivl (_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_DIV_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_DIV (ret, x, y);
+  return ret;
+}
+libm_alias_double_ldouble (div)
diff --git a/sysdeps/ieee754/soft-fp/s_fdiv.c b/sysdeps/ieee754/soft-fp/s_fdiv.c
new file mode 100644
index 0000000000..341339f5ed
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fdiv.c
@@ -0,0 +1,56 @@
+/* Divide 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 f32divf64 __hide_f32divf64
+#define f32divf32x __hide_f32divf32x
+#define fdivl __hide_fdivl
+#include <math.h>
+#undef f32divf64
+#undef f32divf32x
+#undef fdivl
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <single.h>
+#include <double.h>
+
+float
+__fdiv (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_DIV_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_DIV (ret, x, y);
+  return ret;
+}
+libm_alias_float_double (div)
diff --git a/sysdeps/ieee754/soft-fp/s_fdivl.c b/sysdeps/ieee754/soft-fp/s_fdivl.c
new file mode 100644
index 0000000000..7fb3709c73
--- /dev/null
+++ b/sysdeps/ieee754/soft-fp/s_fdivl.c
@@ -0,0 +1,55 @@
+/* Divide 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 f32divf64x __hide_f32divf64x
+#define f32divf128 __hide_f32divf128
+#include <math.h>
+#undef f32divf64x
+#undef f32divf128
+
+#include <math-narrow.h>
+#include <soft-fp.h>
+#include <single.h>
+#include <quad.h>
+
+float
+__fdivl (_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_DIV_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_DIV (ret, x, y);
+  return ret;
+}
+libm_alias_float_ldouble (div)