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.

5 files changed, 85 insertions, 18 deletions

diff --git a/include/math.h b/include/math.h
index a274f2bdfd..1b3199b3f6 100644
--- a/include/math.h
+++ b/include/math.h
@@ -18,7 +18,8 @@ hidden_proto (__finitef)
 hidden_proto (__isinff)
 hidden_proto (__isnanf)
 
-#  ifndef __NO_LONG_DOUBLE_MATH
+#  if !defined __NO_LONG_DOUBLE_MATH \
+      && __LONG_DOUBLE_USES_FLOAT128 == 0
 hidden_proto (__finitel)
 hidden_proto (__isinfl)
 hidden_proto (__isnanl)
@@ -40,7 +41,8 @@ libm_hidden_proto (__exp)
 libm_hidden_proto (__expf)
 libm_hidden_proto (__roundeven)
 
-# ifndef __NO_LONG_DOUBLE_MATH
+#  if !defined __NO_LONG_DOUBLE_MATH \
+      && __LONG_DOUBLE_USES_FLOAT128 == 0
 libm_hidden_proto (__fpclassifyl)
 libm_hidden_proto (__issignalingl)
 libm_hidden_proto (__expl)
@@ -140,7 +142,8 @@ fabsf128 (_Float128 x)
   double (FUNC) (ARGS (double)) asm (PREFIX #FUNC );		\
   MATH_REDIRECT_LDBL (FUNC, PREFIX, ARGS)			\
   MATH_REDIRECT_F128 (FUNC, PREFIX, ARGS)
-#   ifdef __NO_LONG_DOUBLE_MATH
+#   if defined __NO_LONG_DOUBLE_MATH 				\
+       || __LONG_DOUBLE_USES_FLOAT128 == 1
 #    define MATH_REDIRECT_LDBL(FUNC, PREFIX, ARGS)
 #   else
 #    define MATH_REDIRECT_LDBL(FUNC, PREFIX, ARGS)			\
diff --git a/math/bits/mathcalls-helper-functions.h b/math/bits/mathcalls-helper-functions.h
index 5b1e9edb01..8d1970df81 100644
--- a/math/bits/mathcalls-helper-functions.h
+++ b/math/bits/mathcalls-helper-functions.h
@@ -16,28 +16,30 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
-
 /* Classify given number.  */
-__MATHDECL_1 (int, __fpclassify,, (_Mdouble_ __value))
+__MATHDECL_ALIAS (int, __fpclassify,, (_Mdouble_ __value), fpclassify)
      __attribute__ ((__const__));
 
 /* Test for negative number.  */
-__MATHDECL_1 (int, __signbit,, (_Mdouble_ __value))
+__MATHDECL_ALIAS (int, __signbit,, (_Mdouble_ __value), signbit)
      __attribute__ ((__const__));
 
 /* Return 0 if VALUE is finite or NaN, +1 if it
    is +Infinity, -1 if it is -Infinity.  */
-__MATHDECL_1 (int, __isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
+__MATHDECL_ALIAS (int, __isinf,, (_Mdouble_ __value), isinf)
+  __attribute__ ((__const__));
 
 /* Return nonzero if VALUE is finite and not NaN.  Used by isfinite macro.  */
-__MATHDECL_1 (int, __finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
+__MATHDECL_ALIAS (int, __finite,, (_Mdouble_ __value), finite)
+  __attribute__ ((__const__));
 
 /* Return nonzero if VALUE is not a number.  */
-__MATHDECL_1 (int, __isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
+__MATHDECL_ALIAS (int, __isnan,, (_Mdouble_ __value), isnan)
+  __attribute__ ((__const__));
 
 /* Test equality.  */
-__MATHDECL_1 (int, __iseqsig,, (_Mdouble_ __x, _Mdouble_ __y));
+__MATHDECL_ALIAS (int, __iseqsig,, (_Mdouble_ __x, _Mdouble_ __y), iseqsig);
 
 /* Test for signaling NaN.  */
-__MATHDECL_1 (int, __issignaling,, (_Mdouble_ __value))
+__MATHDECL_ALIAS (int, __issignaling,, (_Mdouble_ __value), issignaling)
      __attribute__ ((__const__));
diff --git a/math/bits/mathcalls.h b/math/bits/mathcalls.h
index 43e5481b94..d39c2fa5f1 100644
--- a/math/bits/mathcalls.h
+++ b/math/bits/mathcalls.h
@@ -174,12 +174,14 @@ __MATHCALL (fmod,, (_Mdouble_ __x, _Mdouble_ __y));
       && !__MATH_DECLARING_FLOATN
 /* Return 0 if VALUE is finite or NaN, +1 if it
    is +Infinity, -1 if it is -Infinity.  */
-__MATHDECL_1 (int,isinf,, (_Mdouble_ __value)) __attribute__ ((__const__));
+__MATHDECL_ALIAS (int,isinf,, (_Mdouble_ __value), isinf)
+  __attribute__ ((__const__));
 # endif
 
 # if !__MATH_DECLARING_FLOATN
 /* Return nonzero if VALUE is finite and not NaN.  */
-__MATHDECL_1 (int,finite,, (_Mdouble_ __value)) __attribute__ ((__const__));
+__MATHDECL_ALIAS (int,finite,, (_Mdouble_ __value), finite)
+  __attribute__ ((__const__));
 
 /* Return the remainder of X/Y.  */
 __MATHCALL (drem,, (_Mdouble_ __x, _Mdouble_ __y));
@@ -208,7 +210,8 @@ __MATHCALL (nan,, (const char *__tagb));
        || __MATH_DECLARING_DOUBLE == 0)) /* isnanf or isnanl don't.  */ \
       && !__MATH_DECLARING_FLOATN
 /* Return nonzero if VALUE is not a number.  */
-__MATHDECL_1 (int,isnan,, (_Mdouble_ __value)) __attribute__ ((__const__));
+__MATHDECL_ALIAS (int,isnan,, (_Mdouble_ __value), isnan)
+  __attribute__ ((__const__));
 # endif
 #endif
 
diff --git a/math/math.h b/math/math.h
index e13b3f3a29..1692ff4a45 100644
--- a/math/math.h
+++ b/math/math.h
@@ -283,6 +283,10 @@ enum
   extern type __MATH_PRECNAME(function,suffix) args __THROW
 #define __MATHDECL_1(type, function, suffix, args) \
   __MATHDECL_1_IMPL(type, function, suffix, args)
+/* Ignore the alias by default.  The alias is only useful with
+   redirections.  */
+#define __MATHDECL_ALIAS(type, function, suffix, args, alias) \
+  __MATHDECL_1(type, function, suffix, args)
 
 #define __MATHREDIR(type, function, suffix, args, to) \
   extern type __REDIRECT_NTH (__MATH_PRECNAME (function, suffix), args, to)
@@ -338,6 +342,35 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #   undef __MATHDECL_1
 #   define __MATHDECL_1(type, function,suffix, args) \
   __MATHREDIR(type, function, suffix, args, __CONCAT(function,suffix))
+
+#  elif __LONG_DOUBLE_USES_FLOAT128 == 1
+#   ifdef __REDIRECT_NTH
+#    ifdef __USE_ISOC99
+extern float __REDIRECT_NTH (nexttowardf, (float __x, long double __y),
+			    __nexttowardf_to_ieee128)
+  __attribute__ ((__const__));
+extern double __REDIRECT_NTH (nexttoward, (double __x, long double __y),
+			     __nexttoward_to_ieee128)
+  __attribute__ ((__const__));
+
+#define __dremieee128 __remainderieee128
+#define __gammaieee128 __lgammaieee128
+
+#    endif
+#   endif
+
+#   undef __MATHDECL_1
+#   undef __MATHDECL_ALIAS
+
+#   define __REDIRTO(function, suffix) \
+  __ ## function ## ieee128 ## suffix
+#   define __REDIRTO_ALT(function, suffix) \
+  __ ## function ## f128 ## suffix
+
+#   define __MATHDECL_1(type, function, suffix, args) \
+  __MATHREDIR (type, function, suffix, args, __REDIRTO (function, suffix))
+#   define __MATHDECL_ALIAS(type, function, suffix, args, alias) \
+  __MATHREDIR (type, function, suffix, args, __REDIRTO_ALT (alias, suffix))
 #  endif
 
 /* Include the file of declarations again, this time using `long double'
@@ -350,15 +383,22 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #  define __MATH_DECLARE_LDOUBLE   1
 #  include <bits/mathcalls-helper-functions.h>
 #  include <bits/mathcalls.h>
+
 #  undef _Mdouble_
 #  undef __MATH_PRECNAME
 #  undef __MATH_DECLARING_DOUBLE
 #  undef __MATH_DECLARING_FLOATN
 
-#  if defined __LDBL_COMPAT
+#  if defined __LDBL_COMPAT \
+      || __LONG_DOUBLE_USES_FLOAT128 == 1
+#   undef __REDIRTO
+#   undef __REDIRTO_ALT
 #   undef __MATHDECL_1
+#   undef __MATHDECL_ALIAS
 #   define __MATHDECL_1(type, function, suffix, args) \
   __MATHDECL_1_IMPL(type, function, suffix, args)
+#   define __MATHDECL_ALIAS(type, function, suffix, args, alias) \
+  __MATHDECL_1(type, function, suffix, args)
 #  endif
 # endif /* !(__NO_LONG_DOUBLE_MATH && _LIBC) || __LDBL_COMPAT */
 
@@ -488,6 +528,7 @@ extern long double __REDIRECT_NTH (nexttowardl,
 
 #undef	__MATHDECL_1_IMPL
 #undef	__MATHDECL_1
+#undef	__MATHDECL_ALIAS
 #undef	__MATHDECL
 #undef	__MATHCALL
 
@@ -521,12 +562,18 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #  undef __MATHCALL_NARROW
 #  define __MATHCALL_NARROW(func, redir, nargs) \
   __MATHCALL_NARROW_REDIR (func, redir, nargs)
+# elif __LONG_DOUBLE_USES_FLOAT128 == 1
+#  define __MATHCALL_REDIR_NAME(name) __ ## f32 ## name ## ieee128
+#  undef __MATHCALL_NARROW
+#  define __MATHCALL_NARROW(func, redir, nargs) \
+  __MATHCALL_NARROW_REDIR (func, redir, nargs)
 # endif
 # include <bits/mathcalls-narrow.h>
 # undef _Mret_
 # undef _Marg_
 # undef __MATHCALL_NAME
-# ifdef __LDBL_COMPAT
+# if defined __LDBL_COMPAT \
+     || __LONG_DOUBLE_USES_FLOAT128 == 1
 #  undef __MATHCALL_REDIR_NAME
 #  undef __MATHCALL_NARROW
 #  define __MATHCALL_NARROW(func, redir, nargs) \
@@ -541,12 +588,18 @@ extern long double __REDIRECT_NTH (nexttowardl,
 #  undef __MATHCALL_NARROW
 #  define __MATHCALL_NARROW(func, redir, nargs) \
   __MATHCALL_NARROW_REDIR (func, redir, nargs)
+# elif __LONG_DOUBLE_USES_FLOAT128 == 1
+#  define __MATHCALL_REDIR_NAME(name) __ ## f64 ## name ## ieee128
+#  undef __MATHCALL_NARROW
+#  define __MATHCALL_NARROW(func, redir, nargs) \
+  __MATHCALL_NARROW_REDIR (func, redir, nargs)
 # endif
 # include <bits/mathcalls-narrow.h>
 # undef _Mret_
 # undef _Marg_
 # undef __MATHCALL_NAME
-# ifdef __LDBL_COMPAT
+# if defined __LDBL_COMPAT \
+     || __LONG_DOUBLE_USES_FLOAT128 == 1
 #  undef __MATHCALL_REDIR_NAME
 #  undef __MATHCALL_NARROW
 #  define __MATHCALL_NARROW(func, redir, nargs) \
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
 }