Support _Float64x in libm_alias macros.

This patch adds support for libm_alias_ldouble and libm_alias_float128
to create *f64x function aliases when appropriate.

Making such aliases work for functions defined in assembly sources
requires adding some semicolons after weak_alias calls in alias macro
definitions.  For C, semicolons are already present in the macros
called when required, but a GNU C extension allows excess semicolons
at file scope in a source file (and glibc already uses this), so it is
OK to have extra semicolons present in the macro definitions.  For
assembly sources, making multiple alias macro calls from a single
macro expansion means there are no newlines between the calls, so an
explicit separator is needed.  If hppa were to have .S sources in
libm, a more complicated approach would be needed that used
ASM_LINE_SEP when building assembly sources but not for C, but right
now there are no such sources so just using a semicolon (as already
present unconditionally in some such macro expansions) suffices.

Tested for x86_64, including in conjunction with _Float64x support
patches.

	* sysdeps/generic/libm-alias-float128.h: Include <bits/floatn.h>.
	(libm_alias_float128_other_r): If
	[__HAVE_FLOAT64X && !__HAVE_FLOAT64X_LONG_DOUBLE], define f64x
	alias.
	(libm_alias_float128_r): Add semicolon after weak_alias call.
	* sysdeps/generic/libm-alias-ldouble.h
	(libm_alias_ldouble_other_r_f128): New macro.
	(libm_alias_ldouble_other_r_f64x): Likewise.
	(libm_alias_ldouble_other_r): Use libm_alias_ldouble_other_r_f128
	and libm_alias_ldouble_other_r_f64x.
	(libm_alias_ldouble_r): Add semicolon after weak_alias call.
	* sysdeps/ieee754/ldbl-opt/libm-alias-ldouble.h
	(libm_alias_ldouble_other_r_f128): New macro.
	(libm_alias_ldouble_other_r_f64x): Likewise.
	(libm_alias_ldouble_other_r): Use libm_alias_ldouble_other_r_f128
	and libm_alias_ldouble_other_r_f64x.

1 files changed, 9 insertions, 2 deletions

diff --git a/sysdeps/generic/libm-alias-float128.h b/sysdeps/generic/libm-alias-float128.h
index 8a7ebf3..b739cdf 100644
--- a/sysdeps/generic/libm-alias-float128.h
+++ b/sysdeps/generic/libm-alias-float128.h
@@ -19,12 +19,19 @@
 #ifndef _LIBM_ALIAS_FLOAT128_H
 #define _LIBM_ALIAS_FLOAT128_H
 
+#include <bits/floatn.h>
+
 /* Define _FloatN / _FloatNx aliases (other than that for _Float128)
    for a _Float128 libm function that has internal name FROM ## f128
    ## R and public names TO ## suffix ## R for each suffix of a
    supported _FloatN / _FloatNx floating-point type with the same
    format as _Float128.  */
-#define libm_alias_float128_other_r(from, to, r)
+#if __HAVE_FLOAT64X && !__HAVE_FLOAT64X_LONG_DOUBLE
+# define libm_alias_float128_other_r(from, to, r)	\
+  weak_alias (from ## f128 ## r, to ## f64x ## r)
+#else
+# define libm_alias_float128_other_r(from, to, r)
+#endif
 
 /* Likewise, but without the R suffix.  */
 #define libm_alias_float128_other(from, to)	\
@@ -39,7 +46,7 @@
    per format, not per type) or for obsolescent functions not provided
    for _FloatN types.  */
 #define libm_alias_float128_r(from, to, r)		\
-  weak_alias (from ## f128 ## r, to ## f128 ## r)	\
+  weak_alias (from ## f128 ## r, to ## f128 ## r);	\
   libm_alias_float128_other_r (from, to, r)
 
 /* Likewise, but without the R suffix.  */