Refactor long double information into bits/long-double.h.

Information about whether the ABI of long double is the same as that
of double is split between bits/mathdef.h and bits/wordsize.h.

When the ABIs are the same, bits/mathdef.h defines
__NO_LONG_DOUBLE_MATH.  In addition, in the case where the same glibc
binary supports both -mlong-double-64 and -mlong-double-128,
bits/wordsize.h defines __LONG_DOUBLE_MATH_OPTIONAL, along with
__NO_LONG_DOUBLE_MATH if this particular compilation is with
-mlong-double-64.

As part of the refactoring I proposed in
<https://sourceware.org/ml/libc-alpha/2016-11/msg00745.html>, this
patch puts all that information in a single header,
bits/long-double.h.  It is included from sys/cdefs.h alongside the
include of bits/wordsize.h, so other headers generally do not need to
include bits/long-double.h directly.

Previously, various bits/mathdef.h headers and bits/wordsize.h headers
had this long double information (including implicitly in some
bits/mathdef.h headers through not having the defines present in the
default version).  After the patch, it's all in six bits/long-double.h
headers.  Furthermore, most of those new headers are not
architecture-specific.  Architectures with optional long double all
use the ldbl-opt sysdeps directory, either in the order (ldbl-64-128,
ldbl-opt, ldbl-128) or (ldbl-128ibm, ldbl-opt).  Thus a generic header
for the case where long double = double, and headers in ldbl-128,
ldbl-96 and ldbl-opt, suffices to cover every architecture except for
cases where long double properties vary between different ABIs sharing
a set of installed headers; fortunately all the ldbl-opt cases share a
single compiler-predefined macro __LONG_DOUBLE_128__ that can be used
to tell whether this compilation is -mlong-double-64 or
-mlong-double-128.

The two cases where a set of headers is shared between ABIs with
different long double properties, MIPS (o32 has long double = double,
other ABIs use ldbl-128) and SPARC (32-bit has optional long double,
64-bit has required long double), need their own bits/long-double.h
headers.

As with bits/wordsize.h, multiple-include protection for this header
is generally implicit through the include guards on sys/cdefs.h, and
multiple inclusion is harmless in any case.  There is one subtlety:
the header must not define __LONG_DOUBLE_MATH_OPTIONAL if
__NO_LONG_DOUBLE_MATH was defined before its inclusion, because doing
so breaks how sysdeps/ieee754/ldbl-opt/nldbl-compat.h defines
__NO_LONG_DOUBLE_MATH itself before including system headers.  Subject
to keeping that working, it would be reasonable to move these macros
from defined/undefined #ifdef to always-defined 1/0 #if semantics, but
this patch does not attempt to do so, just rearranges where the macros
are defined.

After this patch, the only use of bits/mathdef.h is the alpha one for
modifying complex function ABIs for old GCC.  Thus, all versions of
the header other than the default and alpha versions are removed, as
is the include from math.h.

Tested for x86_64 and x86.  Also did compilation-only testing with
build-many-glibcs.py.

	* bits/long-double.h: New file.
	* sysdeps/ieee754/ldbl-128/bits/long-double.h: Likewise.
	* sysdeps/ieee754/ldbl-96/bits/long-double.h: Likewise.
	* sysdeps/ieee754/ldbl-opt/bits/long-double.h: Likewise.
	* sysdeps/mips/bits/long-double.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/long-double.h: Likewise.
	* math/Makefile (headers): Add bits/long-double.h.
	* misc/sys/cdefs.h: Include <bits/long-double.h>.
	* stdlib/strtold.c: Include <bits/long-double.h> instead of
	<bits/wordsize.h>.
	* bits/mathdef.h [!_COMPLEX_H]: Do not allow inclusion.
	[!__NO_LONG_DOUBLE_MATH]: Remove conditional code.
	* math/math.h: Do not include <bits/mathdef.h>.
	* sysdeps/aarch64/bits/mathdef.h: Remove file.
	* sysdeps/alpha/bits/mathdef.h [!_COMPLEX_H]: Do not allow
	inclusion.
	* sysdeps/ia64/bits/mathdef.h: Remove file.
	* sysdeps/m68k/m680x0/bits/mathdef.h: Likewise.
	* sysdeps/mips/bits/mathdef.h: Likewise.
	* sysdeps/powerpc/bits/mathdef.h: Likewise.
	* sysdeps/s390/bits/mathdef.h: Likewise.
	* sysdeps/sparc/bits/mathdef.h: Likewise.
	* sysdeps/x86/bits/mathdef.h: Likewise.
	* sysdeps/s390/s390-32/bits/wordsize.h
	[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]: Remove
	conditional code.
	* sysdeps/s390/s390-64/bits/wordsize.h
	[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
	Likewise.
	* sysdeps/unix/sysv/linux/alpha/bits/wordsize.h
	[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
	[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
	Likewise.
	* sysdeps/unix/sysv/linux/sparc/bits/wordsize.h
	[!__NO_LONG_DOUBLE_MATH && !__LONG_DOUBLE_MATH_OPTIONAL]:
	Likewise.

14 files changed, 37 insertions, 152 deletions

diff --git a/sysdeps/alpha/bits/mathdef.h b/sysdeps/alpha/bits/mathdef.h
index 021563f211..e56f3e5212 100644
--- a/sysdeps/alpha/bits/mathdef.h
+++ b/sysdeps/alpha/bits/mathdef.h
@@ -15,8 +15,8 @@
    License along with the GNU C Library.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
+#ifndef _COMPLEX_H
+# error "Never use <bits/mathdef.h> directly; include <complex.h> instead"
 #endif
 
 #if defined _COMPLEX_H && !defined _COMPLEX_H_MATHDEF
diff --git a/sysdeps/ia64/bits/mathdef.h b/sysdeps/ieee754/ldbl-128/bits/long-double.h
index e689835716..3f10da8486 100644
--- a/sysdeps/ia64/bits/mathdef.h
+++ b/sysdeps/ieee754/ldbl-128/bits/long-double.h
@@ -1,9 +1,10 @@
-/* Copyright (C) 2000-2016 Free Software Foundation, Inc.
+/* Properties of long double type.  ldbl-128 version.
+   Copyright (C) 2016 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
+   License  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,
@@ -15,6 +16,5 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
-#endif
+/* long double is distinct from double, so there is nothing to
+   define here.  */
diff --git a/sysdeps/aarch64/bits/mathdef.h b/sysdeps/ieee754/ldbl-96/bits/long-double.h
index 2213635bd8..180a7cf343 100644
--- a/sysdeps/aarch64/bits/mathdef.h
+++ b/sysdeps/ieee754/ldbl-96/bits/long-double.h
@@ -1,10 +1,10 @@
-/* Copyright (C) 1999-2016 Free Software Foundation, Inc.
-
+/* Properties of long double type.  ldbl-96 version.
+   Copyright (C) 2016 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
+   License  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,
@@ -16,6 +16,5 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
-#endif
+/* long double is distinct from double, so there is nothing to
+   define here.  */
diff --git a/sysdeps/s390/bits/mathdef.h b/sysdeps/ieee754/ldbl-opt/bits/long-double.h
index eeea6fcdc2..dce98c38c6 100644
--- a/sysdeps/s390/bits/mathdef.h
+++ b/sysdeps/ieee754/ldbl-opt/bits/long-double.h
@@ -1,9 +1,10 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
+/* Properties of long double type.  ldbl-opt version.
+   Copyright (C) 2016 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
+   License  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,
@@ -15,6 +16,9 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
+#ifndef __NO_LONG_DOUBLE_MATH
+# define __LONG_DOUBLE_MATH_OPTIONAL	1
+# ifndef __LONG_DOUBLE_128__
+#  define __NO_LONG_DOUBLE_MATH		1
+# endif
 #endif
diff --git a/sysdeps/m68k/m680x0/bits/mathdef.h b/sysdeps/m68k/m680x0/bits/mathdef.h
deleted file mode 100644
index 7926c6aaf7..0000000000
--- a/sysdeps/m68k/m680x0/bits/mathdef.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* Copyright (C) 1997-2016 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/>.  */
-
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
-#endif
diff --git a/sysdeps/sparc/bits/mathdef.h b/sysdeps/mips/bits/long-double.h
index 65ab45aad3..b51fce8e6e 100644
--- a/sysdeps/sparc/bits/mathdef.h
+++ b/sysdeps/mips/bits/long-double.h
@@ -1,9 +1,10 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
+/* Properties of long double type.  MIPS version.
+   Copyright (C) 2016 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
+   License  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,
@@ -15,8 +16,8 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
-#endif
+#include <sgidefs.h>
 
-#include <bits/wordsize.h>
+#if !defined __NO_LONG_DOUBLE_MATH && _MIPS_SIM == _ABIO32
+# define __NO_LONG_DOUBLE_MATH	1
+#endif
diff --git a/sysdeps/mips/bits/mathdef.h b/sysdeps/mips/bits/mathdef.h
deleted file mode 100644
index 31fc4001df..0000000000
--- a/sysdeps/mips/bits/mathdef.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/* Copyright (C) 1997-2016 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/>.  */
-
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
-#endif
-
-#include <sgidefs.h>
-
-#if ! defined __NO_LONG_DOUBLE_MATH && _MIPS_SIM == _ABIO32
-/* Signal that we do not really have a `long double'.  This disables the
-   declaration of all the `long double' function variants.  */
-# define __NO_LONG_DOUBLE_MATH	1
-#endif
diff --git a/sysdeps/s390/s390-32/bits/wordsize.h b/sysdeps/s390/s390-32/bits/wordsize.h
index c7a5fbf655..129e47182b 100644
--- a/sysdeps/s390/s390-32/bits/wordsize.h
+++ b/sysdeps/s390/s390-32/bits/wordsize.h
@@ -9,14 +9,3 @@
 #endif
 
 #define __WORDSIZE_TIME64_COMPAT32     0
-
-#if !defined __NO_LONG_DOUBLE_MATH && !defined __LONG_DOUBLE_MATH_OPTIONAL
-
-/* Signal that we didn't used to have a `long double'. The changes all
-   the `long double' function variants to be redirects to the double
-   functions.  */
-# define __LONG_DOUBLE_MATH_OPTIONAL   1
-# ifndef __LONG_DOUBLE_128__
-#  define __NO_LONG_DOUBLE_MATH        1
-# endif
-#endif
diff --git a/sysdeps/s390/s390-64/bits/wordsize.h b/sysdeps/s390/s390-64/bits/wordsize.h
index 31e0ec6699..00e88b0628 100644
--- a/sysdeps/s390/s390-64/bits/wordsize.h
+++ b/sysdeps/s390/s390-64/bits/wordsize.h
@@ -9,14 +9,3 @@
 #endif
 
 #define __WORDSIZE_TIME64_COMPAT32     0
-
-#if !defined __NO_LONG_DOUBLE_MATH && !defined __LONG_DOUBLE_MATH_OPTIONAL
-
-/* Signal that we didn't used to have a `long double'. The changes all
-   the `long double' function variants to be redirects to the double
-   functions.  */
-# define __LONG_DOUBLE_MATH_OPTIONAL   1
-# ifndef __LONG_DOUBLE_128__
-#  define __NO_LONG_DOUBLE_MATH        1
-# endif
-#endif
diff --git a/sysdeps/unix/sysv/linux/alpha/bits/wordsize.h b/sysdeps/unix/sysv/linux/alpha/bits/wordsize.h
index f0961f69cc..2ef70a98dd 100644
--- a/sysdeps/unix/sysv/linux/alpha/bits/wordsize.h
+++ b/sysdeps/unix/sysv/linux/alpha/bits/wordsize.h
@@ -17,14 +17,3 @@
 
 #define __WORDSIZE	64
 #define __WORDSIZE_TIME64_COMPAT32	0
-
-#if !defined __NO_LONG_DOUBLE_MATH && !defined __LONG_DOUBLE_MATH_OPTIONAL
-
-/* Signal that we didn't used to have a `long double'. The changes all
-   the `long double' function variants to be redirects to the double
-   functions.  */
-# define __LONG_DOUBLE_MATH_OPTIONAL	1
-# ifndef __LONG_DOUBLE_128__
-#  define __NO_LONG_DOUBLE_MATH		1
-# endif
-#endif
diff --git a/sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h b/sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
index 109f08ccdc..04ca9debf0 100644
--- a/sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
+++ b/sysdeps/unix/sysv/linux/powerpc/bits/wordsize.h
@@ -9,14 +9,3 @@
 # define __WORDSIZE32_SIZE_ULONG	0
 # define __WORDSIZE32_PTRDIFF_LONG	0
 #endif
-
-#if !defined __NO_LONG_DOUBLE_MATH && !defined __LONG_DOUBLE_MATH_OPTIONAL
-
-/* Signal the glibc ABI didn't used to have a `long double'.
-   The changes all the `long double' function variants to be redirects
-   to the double functions.  */
-# define __LONG_DOUBLE_MATH_OPTIONAL   1
-# ifndef __LONG_DOUBLE_128__
-#  define __NO_LONG_DOUBLE_MATH        1
-# endif
-#endif
diff --git a/sysdeps/powerpc/bits/mathdef.h b/sysdeps/unix/sysv/linux/sparc/bits/long-double.h
index eeea6fcdc2..20039ce4ce 100644
--- a/sysdeps/powerpc/bits/mathdef.h
+++ b/sysdeps/unix/sysv/linux/sparc/bits/long-double.h
@@ -1,9 +1,10 @@
-/* Copyright (C) 1997-2016 Free Software Foundation, Inc.
+/* Properties of long double type.  SPARC version.
+   Copyright (C) 2016 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
+   License  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,
@@ -15,6 +16,11 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
+#include <bits/wordsize.h>
+
+#if !defined __NO_LONG_DOUBLE_MATH && __WORDSIZE == 32
+# define __LONG_DOUBLE_MATH_OPTIONAL   1
+# ifndef __LONG_DOUBLE_128__
+#  define __NO_LONG_DOUBLE_MATH        1
+# endif
 #endif
diff --git a/sysdeps/unix/sysv/linux/sparc/bits/wordsize.h b/sysdeps/unix/sysv/linux/sparc/bits/wordsize.h
index 121b4fe8c9..7562875ee2 100644
--- a/sysdeps/unix/sysv/linux/sparc/bits/wordsize.h
+++ b/sysdeps/unix/sysv/linux/sparc/bits/wordsize.h
@@ -9,16 +9,3 @@
 # define __WORDSIZE32_PTRDIFF_LONG	0
 # define __WORDSIZE_TIME64_COMPAT32	0
 #endif
-
-#if !defined __NO_LONG_DOUBLE_MATH && !defined __LONG_DOUBLE_MATH_OPTIONAL
-
-# if __WORDSIZE == 32
-/* Signal that in 32bit ABI we didn't used to have a `long double'.
-   The changes all the `long double' function variants to be redirects
-   to the double functions.  */
-#  define __LONG_DOUBLE_MATH_OPTIONAL   1
-#  ifndef __LONG_DOUBLE_128__
-#   define __NO_LONG_DOUBLE_MATH        1
-#  endif
-# endif
-#endif
diff --git a/sysdeps/x86/bits/mathdef.h b/sysdeps/x86/bits/mathdef.h
deleted file mode 100644
index 1c6aee6ba5..0000000000
--- a/sysdeps/x86/bits/mathdef.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* Copyright (C) 2001-2016 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/>.  */
-
-#if !defined _MATH_H && !defined _COMPLEX_H
-# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
-#endif