ldbl-128ibm-compat: Redirect long double functions to f128/ieee128 functions

Modify the headers to redirect long double functions to global __*f128
symbols or to __*ieee128 otherwise.

Most of the functions in math.h benefit from the infrastructure already
available for __LDBL_COMPAT.  The only exceptions are nexttowardf and
nexttoward that need especial treatment.

Both math/bits/mathcalls-helper-functions.h and math/bits/mathcalls.h
were modified in order to provide alternative redirection destinations
that are essential to support functions that should not be redirected to
the same name pattern of the rest of the functions, i.e.: __fpclassify,
__signbit, __iseqsig, __issignaling, isinf, finite and isnan, which will
be redirected to __*f128 instead of __*ieee128 used for the rest.

1 files changed, 7 insertions, 1 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h b/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h
index 6eaf8add26..70da85f2cb 100644
--- a/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h
+++ b/sysdeps/ieee754/ldbl-128ibm/bits/iscanonical.h
@@ -23,8 +23,12 @@
 #ifdef __NO_LONG_DOUBLE_MATH
 # define iscanonical(x) ((void) (__typeof (x)) (x), 1)
 #else
+# if __LONG_DOUBLE_USES_FLOAT128 == 1
+# define __iscanonicall(x) ((void) (__typeof (x)) (x), 1)
+# else
 extern int __iscanonicall (long double __x)
      __THROW __attribute__ ((__const__));
+# endif
 # define __iscanonicalf(x) ((void) (__typeof (x)) (x), 1)
 # define __iscanonical(x) ((void) (__typeof (x)) (x), 1)
 # if __HAVE_DISTINCT_FLOAT128
@@ -50,7 +54,9 @@ extern "C++" {
 inline int iscanonical (float __val) { return __iscanonicalf (__val); }
 inline int iscanonical (double __val) { return __iscanonical (__val); }
 inline int iscanonical (long double __val) { return __iscanonicall (__val); }
-#  if __HAVE_DISTINCT_FLOAT128
+/* When using an IEEE 128-bit long double, _Float128 is defined as long double
+   in C++.  */
+#  if __HAVE_DISTINCT_FLOAT128 && __HAVE_FLOAT128_UNLIKE_LDBL
 inline int iscanonical (_Float128 __val) { return __iscanonicalf128 (__val); }
 #  endif
 }