Set errno for log1p on pole/domain error.

According to bug 6792, errno is not set to ERANGE/EDOM
by calling log1p/log1pf/log1pl with x = -1 or x < -1.

This patch adds a wrapper which sets errno in those cases
and returns the value of the existing __log1p function.
The log1p is now an alias to the wrapper function
instead of __log1p.

The files in sysdeps are reflecting these changes.
The ia64 implementation sets errno by itself,
thus the wrapper-file is empty.

The libm-test is adjusted for log1p-tests to check errno.

	[BZ #6792]
	* math/w_log1p.c: New file.
	* math/w_log1pf.c: Likewise.
	* math/w_log1pl.c: Likewise.
	* math/Makefile (libm-calls): Add w_log1p.
	* math/s_log1pl.c (log1pl): Remove weak_alias.
	* sysdeps/i386/fpu/s_log1p.S (log1p): Likewise.
	* sysdeps/i386/fpu/s_log1pf.S (log1pf): Likewise.
	* sysdeps/i386/fpu/s_log1pl.S (log1pl): Likewise.
	* sysdeps/x86_64/fpu/s_log1pl.S (log1pl): Likewise.
	* sysdeps/ieee754/dbl-64/s_log1p.c (log1p): Likewise.
	[NO_LONG_DOUBLE] (log1pl): Likewise.
	* sysdeps/ieee754/flt-32/s_log1pf.c (log1pf): Likewise.
	* sysdeps/ieee754/ldbl-128/s_log1pl.c (log1pl): Likewise.
	* sysdeps/ieee754/ldbl-64-128/s_log1pl.c
	(log1p): Remove long_double_symbol.
	* sysdeps/ieee754/ldbl-128ibm/s_log1pl.c (log1pl): Likewise.
	* sysdeps/ieee754/ldbl-64-128/w_log1pl.c: New file.
	* sysdeps/ieee754/ldbl-128ibm/w_log1pl.c: Likewise.
	* sysdeps/m68k/m680x0/fpu/s_log1p.c: Define empty weak_alias to
	remove weak_alias for corresponding log1p function.
	* sysdeps/m68k/m680x0/fpu/s_log1pf.c: Likewise.
	* sysdeps/m68k/m680x0/fpu/s_log1pl.c: Likewise.
	* sysdeps/ia64/fpu/w_log1p.c: New file.
	* sysdeps/ia64/fpu/w_log1pf.c: Likewise.
	* sysdeps/ia64/fpu/w_log1pl.c: Likewise.
	* math/libm-test.inc (log1p_test_data):	Add errno expectations.

1 files changed, 41 insertions, 0 deletions

diff --git a/math/w_log1p.c b/math/w_log1p.c
new file mode 100644
index 0000000000..28b621b301
--- /dev/null
+++ b/math/w_log1p.c
@@ -0,0 +1,41 @@
+/* Wrapper for __log1p that handles setting errno.
+   Copyright (C) 2015 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 <errno.h>
+#include <math.h>
+#include <math_private.h>
+
+double
+__w_log1p (double x)
+{
+  if (__glibc_unlikely (islessequal (x, -1.0)))
+    {
+      if (x == -1.0)
+	__set_errno (ERANGE);
+      else
+	__set_errno (EDOM);
+    }
+
+  return __log1p (x);
+}
+weak_alias (__w_log1p, log1p)
+
+#ifdef NO_LONG_DOUBLE
+strong_alias (__w_log1p, __log1pl)
+weak_alias (__w_log1p, log1pl)
+#endif