math: Add math-use-builtins-fabs (BZ#29027)

Both float, double, and _Float128 are assumed to be supported
(float and double already only uses builtins).  Only long double
is parametrized due GCC bug 29253 which prevents its usage on
powerpc.

It allows to remove i686, ia64, x86_64, powerpc, and sparc arch
specific implementation.

On ia64 it also fixes the sNAN handling:

  math/test-float64x-fabs
  math/test-ldouble-fabs

Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc-linux-gnu,
powerpc64-linux-gnu, sparc64-linux-gnu, and ia64-linux-gnu.

1 files changed, 28 insertions, 0 deletions

diff --git a/sysdeps/ieee754/ldbl-96/s_fabsl.c b/sysdeps/ieee754/ldbl-96/s_fabsl.c
new file mode 100644
index 0000000..0eceb0c
--- /dev/null
+++ b/sysdeps/ieee754/ldbl-96/s_fabsl.c
@@ -0,0 +1,28 @@
+/* Absolute value of floating-point number.
+   Copyright (C) 2022 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
+   <https://www.gnu.org/licenses/>.  */
+
+#include <math.h>
+#include <libm-alias-ldouble.h>
+#include <math-use-builtins.h>
+
+long double
+__fabsl (long double x)
+{
+  return __builtin_fabsl (x);
+}
+libm_alias_ldouble (__fabs, fabs)