Move float128 inlines from sysdeps/generic/math_private.h to include/math.h.

Continuing the cleanup of math_private.h, with a view to it becoming
the header for the APIs defined therein and not also a header with
inline variants of math.h APIs, this patch moves inline definitions of
__isinff128 and fabsf128 to include/math.h, so that any users of
math.h in glibc automatically get the optimized functions rather than
quietly missing them if they do not also include math_private.h.

Tested for x86_64 and x86, and with build-many-glibcs.py with GCC 6.
There are changes to installed stripped libc.so on configurations with
distinct _Float128, because of __printf_fp_l code that now gets the
__isinff128 inline where previously it called the out-of-line
function because of the lack of a math_private.h call.  It seems
appropriate that this code does get the inline (as it would
automatically with GCC 7 and later when the built-in function is used)
rather than being the only place in glibc that does not.

	* sysdeps/generic/math_private.h
	[__HAVE_DISTINCT_FLOAT128 && !__GNUC_PREREQ (7, 0)] (__isinff128):
	Move this inline function ....
	[__HAVE_DISTINCT_FLOAT128] (fabsf128): And this one ....
	* include/math.h [!_ISOMAC]: To here....

1 files changed, 23 insertions, 0 deletions

diff --git a/include/math.h b/include/math.h
index e21d34b..9ab7aa4 100644
--- a/include/math.h
+++ b/include/math.h
@@ -54,6 +54,29 @@ libm_hidden_proto (__expf128)
 libm_hidden_proto (__expm1f128)
 # endif
 
+# if __HAVE_DISTINCT_FLOAT128
+
+/* __builtin_isinf_sign is broken in GCC < 7 for float128.  */
+#  if ! __GNUC_PREREQ (7, 0)
+#   include <ieee754_float128.h>
+extern inline int
+__isinff128 (_Float128 x)
+{
+  int64_t hx, lx;
+  GET_FLOAT128_WORDS64 (hx, lx, x);
+  lx |= (hx & 0x7fffffffffffffffLL) ^ 0x7fff000000000000LL;
+  lx |= -lx;
+  return ~(lx >> 63) & (hx >> 62);
+}
+#  endif
+
+extern inline _Float128
+fabsf128 (_Float128 x)
+{
+  return __builtin_fabsf128 (x);
+}
+# endif
+
 # if !(defined __FINITE_MATH_ONLY__ && __FINITE_MATH_ONLY__ > 0)
 #  ifndef NO_MATH_REDIRECT
 /* Declare sqrt for use within GLIBC.  Compilers typically inline sqrt as a