Support bits/floatn.h inclusion from .S files.

Further _FloatN / _FloatNx type alias support will involve making
architecture-specific .S files use the common macros for libm function
aliases.  Making them use those macros will also serve to simplify
existing code for aliases / symbol versions in various cases, similar
to such simplifications for ldbl-opt code.

The libm-alias-*.h files sometimes need to include <bits/floatn.h> to
determine which aliases they should define.  At present, this does not
work for inclusion from .S files because <bits/floatn.h> can define
typedefs for old compilers.  This patch changes all the
<bits/floatn.h> and <bits/floatn-common.h> headers to include
__ASSEMBLER__ conditionals.  Those conditionals disable everything
related to C syntax in the __ASSEMBLER__ case, not just the problem
typedefs, as that seemed cleanest.  The __HAVE_* definitions remain in
the __ASSEMBLER__ case, as those provide information that is required
to define the correct set of aliases.

Tested with build-many-glibcs.py for a representative set of
configurations (x86_64-linux-gnu i686-linux-gnu ia64-linux-gnu
powerpc64le-linux-gnu mips64-linux-gnu-n64 sparc64-linux-gnu) with GCC
6.  Also tested with GCC 6 for i686-linux-gnu in conjunction with
changes to use alias macros in .S files.

	* bits/floatn-common.h [!__ASSEMBLER]: Disable everything related
	to C syntax instead of availability and properties of types.
	* bits/floatn.h [!__ASSEMBLER]: Likewise.
	* sysdeps/ia64/bits/floatn.h [!__ASSEMBLER]: Likewise.
	* sysdeps/ieee754/ldbl-128/bits/floatn.h [!__ASSEMBLER]: Likewise.
	* sysdeps/mips/ieee754/bits/floatn.h [!__ASSEMBLER]: Likewise.
	* sysdeps/powerpc/bits/floatn.h [!__ASSEMBLER]: Likewise.
	* sysdeps/x86/bits/floatn.h [!__ASSEMBLER]: Likewise.

1 files changed, 25 insertions, 21 deletions

diff --git a/sysdeps/mips/ieee754/bits/floatn.h b/sysdeps/mips/ieee754/bits/floatn.h
index 957343daf7..4131991ded 100644
--- a/sysdeps/mips/ieee754/bits/floatn.h
+++ b/sysdeps/mips/ieee754/bits/floatn.h
@@ -39,43 +39,47 @@
    from the default float, double and long double types in this glibc.  */
 #define __HAVE_DISTINCT_FLOAT128 0
 
+#ifndef __ASSEMBLER__
+
 /* 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
+# if __HAVE_FLOAT128
+#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
 /* The literal suffix f128 exists only since GCC 7.0.  */
-#  define __f128(x) x##l
-# else
-#  define __f128(x) x##f128
+#   define __f128(x) x##l
+#  else
+#   define __f128(x) x##f128
+#  endif
 # endif
-#endif
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
-#if __HAVE_FLOAT128
-# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
-#  define __CFLOAT128 _Complex long double
-# else
-#  define __CFLOAT128 _Complex _Float128
+# if __HAVE_FLOAT128
+#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#   define __CFLOAT128 _Complex long double
+#  else
+#   define __CFLOAT128 _Complex _Float128
+#  endif
 # endif
-#endif
 
 /* The remaining of this file provides support for older compilers.  */
-#if __HAVE_FLOAT128
+# if __HAVE_FLOAT128
 
 /* The type _Float128 exists only since GCC 7.0.  */
-# if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
 typedef long double _Float128;
-# endif
+#  endif
 
 /* Various built-in functions do not exist before GCC 7.0.  */
-# if !__GNUC_PREREQ (7, 0)
-#  define __builtin_huge_valf128() (__builtin_huge_vall ())
-#  define __builtin_inff128() (__builtin_infl ())
-#  define __builtin_nanf128(x) (__builtin_nanl (x))
-#  define __builtin_nansf128(x) (__builtin_nansl (x))
+#  if !__GNUC_PREREQ (7, 0)
+#   define __builtin_huge_valf128() (__builtin_huge_vall ())
+#   define __builtin_inff128() (__builtin_infl ())
+#   define __builtin_nanf128(x) (__builtin_nanl (x))
+#   define __builtin_nansf128(x) (__builtin_nansl (x))
+#  endif
+
 # endif
 
-#endif
+#endif /* !__ASSEMBLER__.  */
 
 #include <bits/floatn-common.h>