powerpc64le: Enable float128

This patch adds ULPs for the float128 type, updates the abilist for libc
and libm, and adds the files bits/floatn.h and float128-abi.h, in order to
enable the new type for powerpc64le.

This patch also adds the implementation of sqrtf128 for powerpc64le, since
it is not implemented in libgcc.  The sfp-machine.h header is taken from
libgcc.

Tested for powerpc64le (GCC 6.2 and GCC 7.1), powerpc64 and s390x.

	* manual/math.texi (Mathematics): Mention the enabling of float128
	for powerpc64le.
	* sysdeps/powerpc/bits/floatn.h: New file.
	* sysdeps/powerpc/fpu/libm-test-ulps: Regenerated.
	* sysdeps/powerpc/fpu/math_private.h:
	(__ieee754_sqrtf128): New inline override.
	* sysdeps/powerpc/powerpc64le/Implies-before: New file.
	* sysdeps/powerpc/powerpc64le/Makefile: New file.
	* sysdeps/powerpc/powerpc64le/fpu/e_sqrtf128.c: New file.
	* sysdeps/powerpc/powerpc64le/fpu/sfp-machine.h: New file.
	* sysdeps/powerpc/powerpc64le/power9/fpu/e_sqrtf128.c: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
	Updated.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64le/float128-abi.h:
	New file.

1 files changed, 92 insertions, 0 deletions

diff --git a/sysdeps/powerpc/bits/floatn.h b/sysdeps/powerpc/bits/floatn.h
new file mode 100644
index 0000000000..be57e7015f
--- /dev/null
+++ b/sysdeps/powerpc/bits/floatn.h
@@ -0,0 +1,92 @@
+/* Macros to control TS 18661-3 glibc features on powerpc.
+   Copyright (C) 2017 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/>.  */
+
+#ifndef _BITS_FLOATN_H
+#define _BITS_FLOATN_H
+
+#include <features.h>
+
+/* Defined to 1 if the current compiler invocation provides a
+   floating-point type with the IEEE 754 binary128 format, and this glibc
+   includes corresponding *f128 interfaces for it.  */
+#if defined _ARCH_PWR8 && defined __LITTLE_ENDIAN__ && (_CALL_ELF == 2) \
+    && defined __FLOAT128__
+# define __HAVE_FLOAT128 1
+#else
+# define __HAVE_FLOAT128 0
+#endif
+
+/* Defined to 1 if __HAVE_FLOAT128 is 1 and the type is ABI-distinct
+   from the default float, double and long double types in this glibc.  */
+#if __HAVE_FLOAT128
+# define __HAVE_DISTINCT_FLOAT128 1
+#else
+# define __HAVE_DISTINCT_FLOAT128 0
+#endif
+
+/* Defined to concatenate the literal suffix to be used with _Float128
+   types, if __HAVE_FLOAT128 is 1. */
+#if __HAVE_FLOAT128
+# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+/* The literal suffix (f128) exist for powerpc only since GCC 7.0.  */
+#  define __f128(x) x##q
+# else
+#  define __f128(x) x##f128
+# endif
+#endif
+
+/* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
+#if __HAVE_FLOAT128
+# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+/* Add a typedef for older GCC compilers which don't natively support
+   _Complex _Float128.  */
+typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__KC__)));
+#  define __CFLOAT128 __cfloat128
+# else
+#  define __CFLOAT128 _Complex _Float128
+# endif
+#endif
+
+/* The remaining of this file provides support for older compilers.  */
+#if __HAVE_FLOAT128
+
+/* The type _Float128 exist for powerpc only since GCC 7.0.  */
+# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+typedef __float128 _Float128;
+# endif
+
+/* Builtin __builtin_huge_valf128 doesn't exist before GCC 7.0.  */
+# if !__GNUC_PREREQ (7, 0)
+#  define __builtin_huge_valf128() ((_Float128) __builtin_huge_val ())
+# endif
+
+/* The following builtins (suffixed with 'q') are available in GCC >= 6.2,
+   which is the minimum version required for float128 support on powerpc64le.
+   Since GCC 7.0 the builtins suffixed with f128 are also available, then
+   there is no need to redefined them.  */
+# if !__GNUC_PREREQ (7, 0)
+#  define __builtin_copysignf128 __builtin_copysignq
+#  define __builtin_fabsf128 __builtin_fabsq
+#  define __builtin_inff128 __builtin_infq
+#  define __builtin_nanf128 __builtin_nanq
+#  define __builtin_nansf128 __builtin_nansq
+# endif
+
+#endif
+
+#endif /* _BITS_FLOATN_H */