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, 32 insertions, 28 deletions

diff --git a/sysdeps/x86/bits/floatn.h b/sysdeps/x86/bits/floatn.h
index 5a21fd4ff0..5ca6bba672 100644
--- a/sysdeps/x86/bits/floatn.h
+++ b/sysdeps/x86/bits/floatn.h
@@ -42,64 +42,68 @@
 # define __HAVE_DISTINCT_FLOAT128 0
 #endif
 
+#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##q
-# else
-#  define __f128(x) x##f128
+#   define __f128(x) x##q
+#  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
+# if __HAVE_FLOAT128
+#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
 /* Add a typedef for older GCC compilers which don't natively support
    _Complex _Float128.  */
 typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
-#  define __CFLOAT128 __cfloat128
-# else
-#  define __CFLOAT128 _Complex _Float128
+#   define __CFLOAT128 __cfloat128
+#  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 __float128 _Float128;
-# endif
+#  endif
 
 /* __builtin_huge_valf128 doesn't exist before GCC 7.0.  */
-# if !__GNUC_PREREQ (7, 0)
-#  define __builtin_huge_valf128() ((_Float128) __builtin_huge_val ())
-# endif
+#  if !__GNUC_PREREQ (7, 0)
+#   define __builtin_huge_valf128() ((_Float128) __builtin_huge_val ())
+#  endif
 
 /* Older GCC has only a subset of built-in functions for _Float128 on
    x86, and __builtin_infq is not usable in static initializers.
    Converting a narrower sNaN to _Float128 produces a quiet NaN, so
    attempts to use _Float128 sNaNs will not work properly with older
    compilers.  */
-# if !__GNUC_PREREQ (7, 0)
-#  define __builtin_copysignf128 __builtin_copysignq
-#  define __builtin_fabsf128 __builtin_fabsq
-#  define __builtin_inff128() ((_Float128) __builtin_inf ())
-#  define __builtin_nanf128(x) ((_Float128) __builtin_nan (x))
-#  define __builtin_nansf128(x) ((_Float128) __builtin_nans (x))
-# endif
+#  if !__GNUC_PREREQ (7, 0)
+#   define __builtin_copysignf128 __builtin_copysignq
+#   define __builtin_fabsf128 __builtin_fabsq
+#   define __builtin_inff128() ((_Float128) __builtin_inf ())
+#   define __builtin_nanf128(x) ((_Float128) __builtin_nan (x))
+#   define __builtin_nansf128(x) ((_Float128) __builtin_nans (x))
+#  endif
 
 /* In math/math.h, __MATH_TG will expand signbit to __builtin_signbit*,
    e.g.: __builtin_signbitf128, before GCC 6.  However, there has never
    been a __builtin_signbitf128 in GCC and the type-generic builtin is
    only available since GCC 6.  */
-# if !__GNUC_PREREQ (6, 0)
-#  define __builtin_signbitf128 __signbitf128
+#  if !__GNUC_PREREQ (6, 0)
+#   define __builtin_signbitf128 __signbitf128
+#  endif
+
 # endif
 
-#endif
+#endif /* !__ASSEMBLER__.  */
 
 #include <bits/floatn-common.h>