Move SNAN_TESTS_TYPE_CAST out of math-tests.h.

The math-tests.h header has many different macros and groups of
macros, defined using #ifndef in the generic version which is included
by architecture versions with #include_next after possibly defining
non-default versions of some of those macros.

This use of #ifndef is contrary to our normal typo-proof conventions
for macro definitions.  This patch moves one of the macros,
SNAN_TESTS_TYPE_CAST, out to its own sysdeps header, to follow those
typo-proof conventions more closely.

Tested with build-many-glibcs.py.

2018-08-01  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/generic/math-tests-snan-cast.h: New file.
	* sysdeps/powerpc/math-tests-snan-cast.h: Likewise.
	* sysdeps/generic/math-tests.h: Include <math-tests-snan-cast.h>.
	(SNAN_TESTS_TYPE_CAST): Do not define macro here.
	* sysdeps/powerpc/math-tests.h (SNAN_TESTS_TYPE_CAST): Likewise.

2 files changed, 28 insertions, 6 deletions

diff --git a/sysdeps/generic/math-tests-snan-cast.h b/sysdeps/generic/math-tests-snan-cast.h
new file mode 100644
index 0000000000..ff64c1cd9a
--- /dev/null
+++ b/sysdeps/generic/math-tests-snan-cast.h
@@ -0,0 +1,26 @@
+/* Configuration for math tests: casts of sNaN values.  Generic version.
+   Copyright (C) 2013-2018 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/>.  */
+
+#ifndef _MATH_TESTS_SNAN_CAST_H
+#define _MATH_TESTS_SNAN_CAST_H 1
+
+/* Indicate whether to run tests involving type casts of sNaN values.
+   These are run unless overridden.  */
+#define SNAN_TESTS_TYPE_CAST	1
+
+#endif /* math-tests-snan-cast.h.  */
diff --git a/sysdeps/generic/math-tests.h b/sysdeps/generic/math-tests.h
index cf9eff4691..8f5f80635b 100644
--- a/sysdeps/generic/math-tests.h
+++ b/sysdeps/generic/math-tests.h
@@ -52,12 +52,6 @@
 /* Return nonzero value if to run tests involving sNaN values for X.  */
 #define SNAN_TESTS(x) MATH_TESTS_TG (SNAN_TESTS_, , x)
 
-/* Indicate whether to run tests involving type casts of sNaN values.  These
-   are run unless overridden.  */
-#ifndef SNAN_TESTS_TYPE_CAST
-# define SNAN_TESTS_TYPE_CAST	1
-#endif
-
 /* Indicate whether operations on signaling NaNs preserve the payload
    (if possible; it is not possible with a zero payload if the high
    bit is set for signaling NaNs) when generating a quiet NaN, and
@@ -122,3 +116,5 @@
 #ifndef EXCEPTION_SET_FORCES_TRAP
 # define EXCEPTION_SET_FORCES_TRAP 0
 #endif
+
+#include <math-tests-snan-cast.h>