fortran, libgfortran: Avoid using libquadmath for glibc 2.26+

As mentioned by Joseph in PR105101, glibc 2.26 or later has on x86
(both -m32/-m64), powerpc64le, ia64 and mips support for
*f128 math/complex APIs plus strtof128 and strfromf128, and these APIs allow
us to avoid libquadmath for Fortran purposes on these architectures,
replace *q math/complex APIs, strtof128 instead of strtoflt128 and,
while strfromf128 unfortunately isn't a perfect replacement to
quadmath_snprintf, it can be made to work.

The advantage of this is that when configured against such glibcs
(2.26 is now almost 5 years old), we can avoid linking against an extra shared
library and the math support in glibc is maintained better than libquadmath.

We need both a compiler change (so that for glibc 2.26+ it uses *f128 APIs
instead of *q) and library change.

The above mentioned problem with strfromf128 is that the strfrom* functions
are severely restricted versions of snprintf.  In libgfortran, we handle
!isfinite differently and just use snprintf/quadmath_snprintf for
%+-#.*{L,Q}{f,e} printing.
strfrom* doesn't allow +, -, # modifiers and it only supports .34 or
similar precision, not .* .  The L/Q etc. letters are omitted.
The + is there to force + sign at the start if it is positive.
Workaround in the patch is to add the + at the start manually for
!signbit (val).
The - (left alignment instead of right) I don't understand why we need it,
when minimum field width isn't specified (for strfrom* can't be specified),
no padding is ever added anywhere I believe.
The # is to force adding . - workaround is to search for first . or e or '\0'
character, if it is '\0', just append ., if it is e, insert . before e and
memmove the rest (which is just a few bytes, e, +/- and at most a few digits)
one byte later.
The .* case is handled by creating the format string for strfrom* by
snprintf into a temporary buffer.

As requested, this patch also switches from using __float128 type in
libgfortran to _Float128 which is equivalent on all arches that support
__float128.

The change is done in a backwards compatible change, when GCC is configured
against glibc 2.26 or newer, libgfortran.so.5 itself doesn't link against
-lquadmath nor uses any libquadmath APIs, libgfortran.a doesn't use any
libquadmath APIs either.  User programs and libraries when being linked
by gfortran driver are linked against -lgfortran and -lquadmath, but
the latter only in the --as-needed linker mode, which means it needs
to be around during linking and will be linked in if there are any
calls to math/complex functions with real(kind=16) or complex(kind=16)
in compilation units compiled by older versions of gcc, but if either
user code doesn't call those math/complex functions for the largest
supported kind, or the code is recompiled by gcc with this change in,
libquadmath won't be linked in.

2022-06-28  Jakub Jelinek  <jakub@redhat.com>

gcc/fortran/
	* gfortran.h (gfc_real_info): Add use_iec_60559 bitfield.
	* trans-types.h (gfc_real16_use_iec_60559): Declare.
	* trans-types.cc (gfc_real16_use_iec_60559): Define.
	(gfc_init_kinds): When building powerpc64le-linux libgfortran
	on glibc 2.26 to 2.31, set gfc_real16_use_iec_60559 and
	use_iec_60559.
	(gfc_build_real_type): Set gfc_real16_use_iec_60559 and use_iec_60559
	on glibc 2.26 or later.
	* trans-intrinsic.cc (gfc_build_intrinsic_lib_fndecls): Adjust
	comment.  Handle gfc_real16_use_iec_60559.
	(gfc_get_intrinsic_lib_fndecl): Handle use_iec_60559.
libgfortran/
	* configure.ac: Check for strtof128 and strfromf128.
	Check for math and complex *f128 functions.  Set
	have_iec_60559_libc_support to yes if *f128 support is around, for
	--enable-libquadmath-support default to "default" rather than yes if
	have_iec_60559_libc_support is yes.
	* acinclude.m4 (LIBGFOR_CHECK_FLOAT128): Test
	_Float128/_Complex _Float128 rather than __float128 and
	_Complex float __attribute__((mode(TC))).  If libquadmath support
	is defaulted and have_iec_60559_libc_support is yes, define and subst
	USE_IEC_60559.  Remove unused LIBGFOR_BUILD_QUAD conditional.
	* Makefile.am (kinds.h): Pass @USE_IEC_60559@ as an extra
	mk-kinds-h.sh argument.
	* mk-kinds-h.sh: Accept 4th use_iec_60559 argument.  Use
	_Float128/_Complex _Float128 types instead of __float128 and
	_Complex float __attribute__((mode(TC))), and if use_iec_60559 is yes,
	use f128 suffix instead of q and define GFC_REAL_16_USE_IEC_60559.
	* kinds-override.h: Use _Float128/_Complex _Float128 types instead of
	__float128 and _Complex float __attribute__((mode(TC))), if
	USE_IEC_60559 is defined, use f128 suffixes instead of q and
	define GFC_REAL_17_USE_IEC_60559.
	* libgfortran.h: Don't include quadmath_weak.h if USE_IEC_60559 is
	defined.
	(GFC_REAL_16_INFINITY, GFC_REAL_16_QUIET_NAN): Define
	for GFC_REAL_16_USE_IEC_60559 differently.
	* caf/single.c (convert_type): Use _Float128/_Complex _Float128
	instead of __float128 and _Complex float __attribute__((mode(TC))).
	For HAVE_GFC_REAL_10 when HAVE_GFC_REAL_16 isn't defined use
	_Complex long double instead of long double.
	* ieee/issignaling_fallback.h (ieee854_float128_shape_type): Use
	_Float128 instead of __float128.
	(__issignalingf128): Change argument type to _Float128.
	(issignaling): Use _Float128 instead of __float128 in _Generic.
	* intrinsics/cshift0.c (cshift0): Use _Float128 instead of __float128
	in a comment.  Fix a comment typo, logn double -> long double.
	* intrinsics/erfc_scaled.c (_THRESH, _M_2_SQRTPI, _INF, _ERFC, _EXP):
	Use different definitions if GFC_REAL_16_USE_IEC_60559.
	(_THRESH, _M_2_SQRTPI): Use GFC_REAL_17_LITERAL macro.
	(_ERFC, _EXP): Use different definitions if GFC_REAL_17_USE_IEC_60559.
	* intrinsics/spread_generic.c (spread, spread_scalar): Use _Float128
	instead of __float128 in a comment.  Fix a comment typo,
	logn double -> long double.
	* intrinsics/trigd.c (ENABLE_SIND, ENABLE_COSD, ENABLE_TAND): Handle
	GFC_REAL_16_USE_IEC_60559.
	* intrinsics/pack_generic.c (pack): Use _Float128 instead of
	__float128 in a comment.  Fix a comment typo, logn double ->
	long double.
	* intrinsics/unpack_generic.c (unpack1, unpack0): Likewise.
	* runtime/in_pack_generic.c (internal_pack): Likewise.
	* runtime/in_unpack_generic.c (internal_unpack): Likewise.
	* io/read.c (convert_real, convert_infnan): Handle
	GFC_REAL_16_USE_IEC_60559 and GFC_REAL_17_USE_IEC_60559.
	* io/transfer128.c (tmp1, tmp2): Don't define if libquadmath
	isn't needed.
	* io/write_float.def (gfor_strfromf128): New function.
	(DTOA2Q, FDTOA2Q): Define differently if
	GFC_REAL_16_USE_IEC_60559 or GFC_REAL_17_USE_IEC_60559.
	* m4/mtype.m4: Use different suffix if GFC_REAL_16_USE_IEC_60559
	or GFC_REAL_17_USE_IEC_60559.
	* config.h.in: Regenerated.
	* configure: Regenerated.
	* Makefile.in: Regenerated.
	* generated/bessel_r16.c: Regenerated.
	* generated/bessel_r17.c: Regenerated.
	* generated/norm2_r16.c: Regenerated.
	* generated/norm2_r17.c: Regenerated.

gcc/fortran/gfortran.h

@@ -2665,6 +2665,9 @@ typedef struct
   unsigned int c_double : 1;
   unsigned int c_long_double : 1;
   unsigned int c_float128 : 1;
+  /* True if for _Float128 C2X IEC 60559 *f128 APIs should be used
+     instead of libquadmath *q APIs.  */
+  unsigned int use_iec_60559 : 1;
 }
 gfc_real_info;
 

gcc/fortran/trans-intrinsic.cc

@@ -692,7 +692,7 @@ gfc_build_intrinsic_lib_fndecls (void)
   {
     /* If we have soft-float types, we create the decls for their
        C99-like library functions.  For now, we only handle _Float128
-       q-suffixed functions.  */
+       q-suffixed or IEC 60559 f128-suffixed functions.  */
 
     tree type, complex_type, func_1, func_2, func_cabs, func_frexp;
     tree func_iround, func_lround, func_llround, func_scalbn, func_cpow;
@@ -739,7 +739,10 @@ gfc_build_intrinsic_lib_fndecls (void)
        builtin_decl_for_float_type(). The others are all constructed by
        gfc_get_intrinsic_lib_fndecl().  */
 #define OTHER_BUILTIN(ID, NAME, TYPE, CONST) \
-  quad_decls[BUILT_IN_ ## ID] = define_quad_builtin (NAME "q", func_ ## TYPE, CONST);
+    quad_decls[BUILT_IN_ ## ID]						\
+      = define_quad_builtin (gfc_real16_use_iec_60559			\
+			     ? NAME "f128" : NAME "q", func_ ## TYPE,	\
+			     CONST);
 
 #include "mathbuiltins.def"
 
@@ -751,8 +754,9 @@ gfc_build_intrinsic_lib_fndecls (void)
     /* There is one built-in we defined manually, because it gets called
        with builtin_decl_for_precision() or builtin_decl_for_float_type()
        even though it is not an OTHER_BUILTIN: it is SQRT.  */
-    quad_decls[BUILT_IN_SQRT] = define_quad_builtin ("sqrtq", func_1, true);
+    quad_decls[BUILT_IN_SQRT]
-
+      = define_quad_builtin (gfc_real16_use_iec_60559
+			     ? "sqrtf128" : "sqrtq", func_1, true);
   }
 
   /* Add GCC builtin functions.  */
@@ -875,7 +879,8 @@ gfc_get_intrinsic_lib_fndecl (gfc_intrinsic_map_t * m, gfc_expr * expr)
 		  ts->type == BT_COMPLEX ? "c" : "", m->name, "l");
       else if (gfc_real_kinds[n].c_float128)
 	snprintf (name, sizeof (name), "%s%s%s",
-		  ts->type == BT_COMPLEX ? "c" : "", m->name, "q");
+		  ts->type == BT_COMPLEX ? "c" : "", m->name,
+		  gfc_real_kinds[n].use_iec_60559 ? "f128" : "q");
       else
 	gcc_unreachable ();
     }

gcc/fortran/trans-types.cc

@@ -72,6 +72,7 @@ tree gfc_float128_type_node = NULL_TREE;
 tree gfc_complex_float128_type_node = NULL_TREE;
 
 bool gfc_real16_is_float128 = false;
+bool gfc_real16_use_iec_60559 = false;
 
 static GTY(()) tree gfc_desc_dim_type;
 static GTY(()) tree gfc_max_array_element_size;
@@ -522,6 +523,11 @@ gfc_init_kinds (void)
 		&& (TARGET_GLIBC_MAJOR < 2
 		    || (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR < 32)))
 	      {
+		if (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 26)
+		  {
+		    gfc_real16_use_iec_60559 = true;
+		    gfc_real_kinds[i].use_iec_60559 = 1;
+		  }
 		gfc_real16_is_float128 = true;
 		gfc_real_kinds[i].c_float128 = 1;
 	      }
@@ -878,6 +884,12 @@ gfc_build_real_type (gfc_real_info *info)
       /* TODO: see PR101835.  */
       info->c_float128 = 1;
       gfc_real16_is_float128 = true;
+      if (TARGET_GLIBC_MAJOR > 2
+	  || (TARGET_GLIBC_MAJOR == 2 && TARGET_GLIBC_MINOR >= 26))
+	{
+	  info->use_iec_60559 = 1;
+	  gfc_real16_use_iec_60559 = true;
+	}
     }
 
   if (TYPE_PRECISION (float_type_node) == mode_precision)

gcc/fortran/trans-types.h

@@ -58,6 +58,10 @@ extern GTY(()) tree gfc_charlen_type_node;
    and _Float128.  */
 extern bool gfc_real16_is_float128;
 
+/* True if IEC 60559 *f128 APIs should be used for _Float128 rather than
+   libquadmath *q APIs.  */
+extern bool gfc_real16_use_iec_60559;
+
 enum gfc_packed {
   PACKED_NO = 0,
   PACKED_PARTIAL,

libgfortran/Makefile.am

@@ -1167,7 +1167,9 @@ I_M4_DEPS8=$(I_M4_DEPS) m4/ifindloc1.m4
 I_M4_DEPS9=$(I_M4_DEPS) m4/ifindloc2.m4
 
 kinds.h: $(srcdir)/mk-kinds-h.sh
-	$(SHELL) $(srcdir)/mk-kinds-h.sh '@LIBGOMP_CHECKED_INT_KINDS@' '@LIBGOMP_CHECKED_REAL_KINDS@' '$(FCCOMPILE)' > $@ || rm $@
+	$(SHELL) $(srcdir)/mk-kinds-h.sh '@LIBGOMP_CHECKED_INT_KINDS@' \
+					 '@LIBGOMP_CHECKED_REAL_KINDS@' \
+					 '$(FCCOMPILE)' '@USE_IEC_60559@' > $@ || rm $@
 
 kinds.inc: kinds.h $(srcdir)/kinds-override.h
 	cat kinds.h $(srcdir)/kinds-override.h | grep '^#' | grep -v include > $@

libgfortran/Makefile.in

@@ -664,6 +664,7 @@ SED = @SED@
 SET_MAKE = @SET_MAKE@
 SHELL = @SHELL@
 STRIP = @STRIP@
+USE_IEC_60559 = @USE_IEC_60559@
 VERSION = @VERSION@
 abs_builddir = @abs_builddir@
 abs_srcdir = @abs_srcdir@
@@ -7674,7 +7675,9 @@ ieee_arithmetic.mod: ieee_arithmetic.lo
 @onestep_TRUE@	$(LTCOMPILE) -c -o $@ $^ -combine
 
 kinds.h: $(srcdir)/mk-kinds-h.sh
-	$(SHELL) $(srcdir)/mk-kinds-h.sh '@LIBGOMP_CHECKED_INT_KINDS@' '@LIBGOMP_CHECKED_REAL_KINDS@' '$(FCCOMPILE)' > $@ || rm $@
+	$(SHELL) $(srcdir)/mk-kinds-h.sh '@LIBGOMP_CHECKED_INT_KINDS@' \
+					 '@LIBGOMP_CHECKED_REAL_KINDS@' \
+					 '$(FCCOMPILE)' '@USE_IEC_60559@' > $@ || rm $@
 
 kinds.inc: kinds.h $(srcdir)/kinds-override.h
 	cat kinds.h $(srcdir)/kinds-override.h | grep '^#' | grep -v include > $@

libgfortran/acinclude.m4

@@ -264,31 +264,35 @@ __mingw_snprintf (NULL, 0, "%d\n", 1);
 dnl Check whether we have a __float128 type
 AC_DEFUN([LIBGFOR_CHECK_FLOAT128], [
   LIBQUADSPEC=
+  LIBQUADLIB=
+  LIBQUADLIB_DEP=
+  LIBQUADINCLUDE=
+  USE_IEC_60559=no
 
   if test "x$enable_libquadmath_support" != xno; then
 
-  AC_CACHE_CHECK([whether we have a usable __float128 type],
+  AC_CACHE_CHECK([whether we have a usable _Float128 type],
                  libgfor_cv_have_float128, [
    GCC_TRY_COMPILE_OR_LINK([
-    typedef _Complex float __attribute__((mode(TC))) __complex128;
+    _Float128 foo (_Float128 x)
-
-    __float128 foo (__float128 x)
     {
 
-     __complex128 z1, z2;
+     _Complex _Float128 z1, z2;
 
      z1 = x;
-     z2 = x / 7.Q;
+     z2 = x / 7.F128;
      z2 /= z1;
 
-     return (__float128) z2;
+     return (_Float128) z2;
     }
 
-    __float128 bar (__float128 x)
+    _Float128 bar (_Float128 x)
     {
-      return x * __builtin_huge_valq ();
+      return x * __builtin_huge_valf128 ();
     }
   ],[
+    foo (1.2F128);
+    bar (1.2F128);
     foo (1.2Q);
     bar (1.2Q);
   ],[
@@ -297,8 +301,16 @@ AC_DEFUN([LIBGFOR_CHECK_FLOAT128], [
     libgfor_cv_have_float128=no
 ])])
 
+    if test "x$have_iec_60559_libc_support$enable_libquadmath_support$libgfor_cv_have_float128" = xyesdefaultyes; then
+      USE_IEC_60559=yes
+    fi
+
+
   if test "x$libgfor_cv_have_float128" = xyes; then
-    AC_DEFINE(HAVE_FLOAT128, 1, [Define if have a usable __float128 type.])
+    if test "x$USE_IEC_60559" = xyes; then
+      AC_DEFINE(USE_IEC_60559, 1, [Define if IEC 60559 *f128 APIs should be used for _Float128.])
+    fi
+    AC_DEFINE(HAVE_FLOAT128, 1, [Define if have a usable _Float128 type.])
 
     dnl Check whether -Wl,--as-needed resp. -Wl,-zignore is supported
     dnl 
@@ -339,26 +351,30 @@ AC_DEFUN([LIBGFOR_CHECK_FLOAT128], [
     ])
 
     dnl For static libgfortran linkage, depend on libquadmath only if needed.
+    dnl If using *f128 APIs from libc/libm, depend on libquadmath only if needed
+    dnl even for dynamic libgfortran linkage, and don't link libgfortran against
+    dnl -lquadmath.
     if test "x$libgfor_cv_have_as_needed" = xyes; then
-      LIBQUADSPEC="%{static-libgfortran:$libgfor_cv_as_needed_option} -lquadmath %{static-libgfortran:$libgfor_cv_no_as_needed_option}"
+      if test "x$USE_IEC_60559" = xyes; then
+	LIBQUADSPEC="$libgfor_cv_as_needed_option -lquadmath $libgfor_cv_no_as_needed_option"
+      else
+	LIBQUADSPEC="%{static-libgfortran:$libgfor_cv_as_needed_option} -lquadmath %{static-libgfortran:$libgfor_cv_no_as_needed_option}"
+      fi
     else
       LIBQUADSPEC="-lquadmath"
     fi
-    if test -f ../libquadmath/libquadmath.la; then
+    if test "x$USE_IEC_60559" != xyes; then
-      LIBQUADLIB=../libquadmath/libquadmath.la
+      if test -f ../libquadmath/libquadmath.la; then
-      LIBQUADLIB_DEP=../libquadmath/libquadmath.la
+	LIBQUADLIB=../libquadmath/libquadmath.la
-      LIBQUADINCLUDE='-I$(srcdir)/../libquadmath'
+	LIBQUADLIB_DEP=../libquadmath/libquadmath.la
-    else
+	LIBQUADINCLUDE='-I$(srcdir)/../libquadmath'
-      LIBQUADLIB="-lquadmath"
+      else
-      LIBQUADLIB_DEP=
+	LIBQUADLIB="-lquadmath"
-      LIBQUADINCLUDE=
+      fi
     fi
-  fi
   else
-    # for --disable-quadmath
+    USE_IEC_60559=no
-    LIBQUADLIB=
+  fi
-    LIBQUADLIB_DEP=
-    LIBQUADINCLUDE=
   fi
 
   dnl For the spec file
@@ -366,9 +382,7 @@ AC_DEFUN([LIBGFOR_CHECK_FLOAT128], [
   AC_SUBST(LIBQUADLIB)
   AC_SUBST(LIBQUADLIB_DEP)
   AC_SUBST(LIBQUADINCLUDE)
-
+  AC_SUBST(USE_IEC_60559)
-  dnl We need a conditional for the Makefile
-  AM_CONDITIONAL(LIBGFOR_BUILD_QUAD, [test "x$libgfor_cv_have_float128" = xyes])
 ])
 
 

libgfortran/caf/single.c

@@ -478,12 +478,11 @@ convert_type (void *dst, int dst_type, int dst_kind, void *src, int src_type,
   typedef long double real128t;
   typedef _Complex long double complex128t;
 #elif defined(HAVE_GFC_REAL_16)
-  typedef _Complex float __attribute__((mode(TC))) __complex128;
+  typedef _Float128 real128t;
-  typedef __float128 real128t;
+  typedef _Complex _Float128 complex128t;
-  typedef __complex128 complex128t;
 #elif defined(HAVE_GFC_REAL_10)
   typedef long double real128t;
-  typedef long double complex128t;
+  typedef _Complex long double complex128t;
 #else
   typedef double real128t;
   typedef _Complex double complex128t;

libgfortran/config.h.in

@@ -12,12 +12,18 @@
 /* Define to 1 if you have the `acosf' function. */
 #undef HAVE_ACOSF
 
+/* Define to 1 if you have the `acosf128' function. */
+#undef HAVE_ACOSF128
+
 /* Define to 1 if you have the `acosh' function. */
 #undef HAVE_ACOSH
 
 /* Define to 1 if you have the `acoshf' function. */
 #undef HAVE_ACOSHF
 
+/* Define to 1 if you have the `acoshf128' function. */
+#undef HAVE_ACOSHF128
+
 /* Define to 1 if you have the `acoshl' function. */
 #undef HAVE_ACOSHL
 
@@ -33,12 +39,18 @@
 /* Define to 1 if you have the `asinf' function. */
 #undef HAVE_ASINF
 
+/* Define to 1 if you have the `asinf128' function. */
+#undef HAVE_ASINF128
+
 /* Define to 1 if you have the `asinh' function. */
 #undef HAVE_ASINH
 
 /* Define to 1 if you have the `asinhf' function. */
 #undef HAVE_ASINHF
 
+/* Define to 1 if you have the `asinhf128' function. */
+#undef HAVE_ASINHF128
+
 /* Define to 1 if you have the `asinhl' function. */
 #undef HAVE_ASINHL
 
@@ -54,18 +66,27 @@
 /* Define to 1 if you have the `atan2f' function. */
 #undef HAVE_ATAN2F
 
+/* Define to 1 if you have the `atan2f128' function. */
+#undef HAVE_ATAN2F128
+
 /* Define to 1 if you have the `atan2l' function. */
 #undef HAVE_ATAN2L
 
 /* Define to 1 if you have the `atanf' function. */
 #undef HAVE_ATANF
 
+/* Define to 1 if you have the `atanf128' function. */
+#undef HAVE_ATANF128
+
 /* Define to 1 if you have the `atanh' function. */
 #undef HAVE_ATANH
 
 /* Define to 1 if you have the `atanhf' function. */
 #undef HAVE_ATANHF
 
+/* Define to 1 if you have the `atanhf128' function. */
+#undef HAVE_ATANHF128
+
 /* Define to 1 if you have the `atanhl' function. */
 #undef HAVE_ATANHL
 
@@ -99,6 +120,9 @@
 /* Define to 1 if you have the `cabsf' function. */
 #undef HAVE_CABSF
 
+/* Define to 1 if you have the `cabsf128' function. */
+#undef HAVE_CABSF128
+
 /* Define to 1 if you have the `cabsl' function. */
 #undef HAVE_CABSL
 
@@ -108,12 +132,18 @@
 /* Define to 1 if you have the `cacosf' function. */
 #undef HAVE_CACOSF
 
+/* Define to 1 if you have the `cacosf128' function. */
+#undef HAVE_CACOSF128
+
 /* Define to 1 if you have the `cacosh' function. */
 #undef HAVE_CACOSH
 
 /* Define to 1 if you have the `cacoshf' function. */
 #undef HAVE_CACOSHF
 
+/* Define to 1 if you have the `cacoshf128' function. */
+#undef HAVE_CACOSHF128
+
 /* Define to 1 if you have the `cacoshl' function. */
 #undef HAVE_CACOSHL
 
@@ -126,6 +156,9 @@
 /* Define to 1 if you have the `cargf' function. */
 #undef HAVE_CARGF
 
+/* Define to 1 if you have the `cargf128' function. */
+#undef HAVE_CARGF128
+
 /* Define to 1 if you have the `cargl' function. */
 #undef HAVE_CARGL
 
@@ -135,12 +168,18 @@
 /* Define to 1 if you have the `casinf' function. */
 #undef HAVE_CASINF
 
+/* Define to 1 if you have the `casinf128' function. */
+#undef HAVE_CASINF128
+
 /* Define to 1 if you have the `casinh' function. */
 #undef HAVE_CASINH
 
 /* Define to 1 if you have the `casinhf' function. */
 #undef HAVE_CASINHF
 
+/* Define to 1 if you have the `casinhf128' function. */
+#undef HAVE_CASINHF128
+
 /* Define to 1 if you have the `casinhl' function. */
 #undef HAVE_CASINHL
 
@@ -153,12 +192,18 @@
 /* Define to 1 if you have the `catanf' function. */
 #undef HAVE_CATANF
 
+/* Define to 1 if you have the `catanf128' function. */
+#undef HAVE_CATANF128
+
 /* Define to 1 if you have the `catanh' function. */
 #undef HAVE_CATANH
 
 /* Define to 1 if you have the `catanhf' function. */
 #undef HAVE_CATANHF
 
+/* Define to 1 if you have the `catanhf128' function. */
+#undef HAVE_CATANHF128
+
 /* Define to 1 if you have the `catanhl' function. */
 #undef HAVE_CATANHL
 
@@ -171,12 +216,18 @@
 /* Define to 1 if you have the `ccosf' function. */
 #undef HAVE_CCOSF
 
+/* Define to 1 if you have the `ccosf128' function. */
+#undef HAVE_CCOSF128
+
 /* Define to 1 if you have the `ccosh' function. */
 #undef HAVE_CCOSH
 
 /* Define to 1 if you have the `ccoshf' function. */
 #undef HAVE_CCOSHF
 
+/* Define to 1 if you have the `ccoshf128' function. */
+#undef HAVE_CCOSHF128
+
 /* Define to 1 if you have the `ccoshl' function. */
 #undef HAVE_CCOSHL
 
@@ -189,6 +240,9 @@
 /* Define to 1 if you have the `ceilf' function. */
 #undef HAVE_CEILF
 
+/* Define to 1 if you have the `ceilf128' function. */
+#undef HAVE_CEILF128
+
 /* Define to 1 if you have the `ceill' function. */
 #undef HAVE_CEILL
 
@@ -198,6 +252,9 @@
 /* Define to 1 if you have the `cexpf' function. */
 #undef HAVE_CEXPF
 
+/* Define to 1 if you have the `cexpf128' function. */
+#undef HAVE_CEXPF128
+
 /* Define to 1 if you have the `cexpl' function. */
 #undef HAVE_CEXPL
 
@@ -222,12 +279,18 @@
 /* Define to 1 if you have the `clog10f' function. */
 #undef HAVE_CLOG10F
 
+/* Define to 1 if you have the `clog10f128' function. */
+#undef HAVE_CLOG10F128
+
 /* Define to 1 if you have the `clog10l' function. */
 #undef HAVE_CLOG10L
 
 /* Define to 1 if you have the `clogf' function. */
 #undef HAVE_CLOGF
 
+/* Define to 1 if you have the `clogf128' function. */
+#undef HAVE_CLOGF128
+
 /* Define to 1 if you have the `clogl' function. */
 #undef HAVE_CLOGL
 
@@ -240,6 +303,9 @@
 /* Define to 1 if you have the `copysignf' function. */
 #undef HAVE_COPYSIGNF
 
+/* Define to 1 if you have the `copysignf128' function. */
+#undef HAVE_COPYSIGNF128
+
 /* Define to 1 if you have the `copysignl' function. */
 #undef HAVE_COPYSIGNL
 
@@ -249,12 +315,18 @@
 /* Define to 1 if you have the `cosf' function. */
 #undef HAVE_COSF
 
+/* Define to 1 if you have the `cosf128' function. */
+#undef HAVE_COSF128
+
 /* Define to 1 if you have the `cosh' function. */
 #undef HAVE_COSH
 
 /* Define to 1 if you have the `coshf' function. */
 #undef HAVE_COSHF
 
+/* Define to 1 if you have the `coshf128' function. */
+#undef HAVE_COSHF128
+
 /* Define to 1 if you have the `coshl' function. */
 #undef HAVE_COSHL
 
@@ -267,6 +339,9 @@
 /* Define to 1 if you have the `cpowf' function. */
 #undef HAVE_CPOWF
 
+/* Define to 1 if you have the `cpowf128' function. */
+#undef HAVE_CPOWF128
+
 /* Define to 1 if you have the `cpowl' function. */
 #undef HAVE_CPOWL
 
@@ -279,12 +354,18 @@
 /* Define to 1 if you have the `csinf' function. */
 #undef HAVE_CSINF
 
+/* Define to 1 if you have the `csinf128' function. */
+#undef HAVE_CSINF128
+
 /* Define to 1 if you have the `csinh' function. */
 #undef HAVE_CSINH
 
 /* Define to 1 if you have the `csinhf' function. */
 #undef HAVE_CSINHF
 
+/* Define to 1 if you have the `csinhf128' function. */
+#undef HAVE_CSINHF128
+
 /* Define to 1 if you have the `csinhl' function. */
 #undef HAVE_CSINHL
 
@@ -297,6 +378,9 @@
 /* Define to 1 if you have the `csqrtf' function. */
 #undef HAVE_CSQRTF
 
+/* Define to 1 if you have the `csqrtf128' function. */
+#undef HAVE_CSQRTF128
+
 /* Define to 1 if you have the `csqrtl' function. */
 #undef HAVE_CSQRTL
 
@@ -306,12 +390,18 @@
 /* Define to 1 if you have the `ctanf' function. */
 #undef HAVE_CTANF
 
+/* Define to 1 if you have the `ctanf128' function. */
+#undef HAVE_CTANF128
+
 /* Define to 1 if you have the `ctanh' function. */
 #undef HAVE_CTANH
 
 /* Define to 1 if you have the `ctanhf' function. */
 #undef HAVE_CTANHF
 
+/* Define to 1 if you have the `ctanhf128' function. */
+#undef HAVE_CTANHF128
+
 /* Define to 1 if you have the `ctanhl' function. */
 #undef HAVE_CTANHL
 
@@ -333,18 +423,27 @@
 /* Define to 1 if you have the `erfcf' function. */
 #undef HAVE_ERFCF
 
+/* Define to 1 if you have the `erfcf128' function. */
+#undef HAVE_ERFCF128
+
 /* Define to 1 if you have the `erfcl' function. */
 #undef HAVE_ERFCL
 
 /* Define to 1 if you have the `erff' function. */
 #undef HAVE_ERFF
 
+/* Define to 1 if you have the `erff128' function. */
+#undef HAVE_ERFF128
+
 /* Define to 1 if you have the `exp' function. */
 #undef HAVE_EXP
 
 /* Define to 1 if you have the `expf' function. */
 #undef HAVE_EXPF
 
+/* Define to 1 if you have the `expf128' function. */
+#undef HAVE_EXPF128
+
 /* Define to 1 if you have the `expl' function. */
 #undef HAVE_EXPL
 
@@ -354,6 +453,9 @@
 /* Define to 1 if you have the `fabsf' function. */
 #undef HAVE_FABSF
 
+/* Define to 1 if you have the `fabsf128' function. */
+#undef HAVE_FABSF128
+
 /* Define to 1 if you have the `fabsl' function. */
 #undef HAVE_FABSL
 
@@ -366,7 +468,7 @@
 /* Define to 1 if you have the <fenv.h> header file. */
 #undef HAVE_FENV_H
 
-/* Define if have a usable __float128 type. */
+/* Define if have a usable _Float128 type. */
 #undef HAVE_FLOAT128
 
 /* Define to 1 if you have the <floatingpoint.h> header file. */
@@ -378,6 +480,9 @@
 /* Define to 1 if you have the `floorf' function. */
 #undef HAVE_FLOORF
 
+/* Define to 1 if you have the `floorf128' function. */
+#undef HAVE_FLOORF128
+
 /* Define to 1 if you have the `floorl' function. */
 #undef HAVE_FLOORL
 
@@ -393,6 +498,9 @@
 /* Define to 1 if you have the `fmaf' function. */
 #undef HAVE_FMAF
 
+/* Define to 1 if you have the `fmaf128' function. */
+#undef HAVE_FMAF128
+
 /* Define to 1 if you have the `fmal' function. */
 #undef HAVE_FMAL
 
@@ -402,6 +510,9 @@
 /* Define to 1 if you have the `fmodf' function. */
 #undef HAVE_FMODF
 
+/* Define to 1 if you have the `fmodf128' function. */
+#undef HAVE_FMODF128
+
 /* Define to 1 if you have the `fmodl' function. */
 #undef HAVE_FMODL
 
@@ -450,6 +561,9 @@
 /* Define to 1 if you have the `frexpf' function. */
 #undef HAVE_FREXPF
 
+/* Define to 1 if you have the `frexpf128' function. */
+#undef HAVE_FREXPF128
+
 /* Define to 1 if you have the `frexpl' function. */
 #undef HAVE_FREXPL
 
@@ -507,6 +621,9 @@
 /* Define to 1 if you have the `hypotf' function. */
 #undef HAVE_HYPOTF
 
+/* Define to 1 if you have the `hypotf128' function. */
+#undef HAVE_HYPOTF128
+
 /* Define to 1 if you have the `hypotl' function. */
 #undef HAVE_HYPOTL
 
@@ -537,18 +654,27 @@
 /* Define to 1 if you have the `j0f' function. */
 #undef HAVE_J0F
 
+/* Define to 1 if you have the `j0f128' function. */
+#undef HAVE_J0F128
+
 /* Define to 1 if you have the `j1' function. */
 #undef HAVE_J1
 
 /* Define to 1 if you have the `j1f' function. */
 #undef HAVE_J1F
 
+/* Define to 1 if you have the `j1f128' function. */
+#undef HAVE_J1F128
+
 /* Define to 1 if you have the `jn' function. */
 #undef HAVE_JN
 
 /* Define to 1 if you have the `jnf' function. */
 #undef HAVE_JNF
 
+/* Define to 1 if you have the `jnf128' function. */
+#undef HAVE_JNF128
+
 /* Define to 1 if you have the `jnl' function. */
 #undef HAVE_JNL
 
@@ -561,6 +687,9 @@
 /* Define to 1 if you have the `ldexpf' function. */
 #undef HAVE_LDEXPF
 
+/* Define to 1 if you have the `ldexpf128' function. */
+#undef HAVE_LDEXPF128
+
 /* Define to 1 if you have the `ldexpl' function. */
 #undef HAVE_LDEXPL
 
@@ -570,6 +699,9 @@
 /* Define to 1 if you have the `lgammaf' function. */
 #undef HAVE_LGAMMAF
 
+/* Define to 1 if you have the `lgammaf128' function. */
+#undef HAVE_LGAMMAF128
+
 /* Define to 1 if you have the `m' library (-lm). */
 #undef HAVE_LIBM
 
@@ -582,6 +714,9 @@
 /* Define to 1 if you have the `llroundf' function. */
 #undef HAVE_LLROUNDF
 
+/* Define to 1 if you have the `llroundf128' function. */
+#undef HAVE_LLROUNDF128
+
 /* Define to 1 if you have the `llroundl' function. */
 #undef HAVE_LLROUNDL
 
@@ -597,12 +732,18 @@
 /* Define to 1 if you have the `log10f' function. */
 #undef HAVE_LOG10F
 
+/* Define to 1 if you have the `log10f128' function. */
+#undef HAVE_LOG10F128
+
 /* Define to 1 if you have the `log10l' function. */
 #undef HAVE_LOG10L
 
 /* Define to 1 if you have the `logf' function. */
 #undef HAVE_LOGF
 
+/* Define to 1 if you have the `logf128' function. */
+#undef HAVE_LOGF128
+
 /* Define to 1 if you have the `logl' function. */
 #undef HAVE_LOGL
 
@@ -612,6 +753,9 @@
 /* Define to 1 if you have the `lroundf' function. */
 #undef HAVE_LROUNDF
 
+/* Define to 1 if you have the `lroundf128' function. */
+#undef HAVE_LROUNDF128
+
 /* Define to 1 if you have the `lroundl' function. */
 #undef HAVE_LROUNDL
 
@@ -642,6 +786,9 @@
 /* Define to 1 if you have the `nextafterf' function. */
 #undef HAVE_NEXTAFTERF
 
+/* Define to 1 if you have the `nextafterf128' function. */
+#undef HAVE_NEXTAFTERF128
+
 /* Define to 1 if you have the `nextafterl' function. */
 #undef HAVE_NEXTAFTERL
 
@@ -657,6 +804,9 @@
 /* Define to 1 if you have the `powf' function. */
 #undef HAVE_POWF
 
+/* Define to 1 if you have the `powf128' function. */
+#undef HAVE_POWF128
+
 /* Define to 1 if the system has the type `ptrdiff_t'. */
 #undef HAVE_PTRDIFF_T
 
@@ -672,6 +822,9 @@
 /* Define to 1 if you have the `roundf' function. */
 #undef HAVE_ROUNDF
 
+/* Define to 1 if you have the `roundf128' function. */
+#undef HAVE_ROUNDF128
+
 /* Define to 1 if you have the `roundl' function. */
 #undef HAVE_ROUNDL
 
@@ -681,6 +834,9 @@
 /* Define to 1 if you have the `scalbnf' function. */
 #undef HAVE_SCALBNF
 
+/* Define to 1 if you have the `scalbnf128' function. */
+#undef HAVE_SCALBNF128
+
 /* Define to 1 if you have the `scalbnl' function. */
 #undef HAVE_SCALBNL
 
@@ -699,12 +855,18 @@
 /* Define to 1 if you have the `sinf' function. */
 #undef HAVE_SINF
 
+/* Define to 1 if you have the `sinf128' function. */
+#undef HAVE_SINF128
+
 /* Define to 1 if you have the `sinh' function. */
 #undef HAVE_SINH
 
 /* Define to 1 if you have the `sinhf' function. */
 #undef HAVE_SINHF
 
+/* Define to 1 if you have the `sinhf128' function. */
+#undef HAVE_SINHF128
+
 /* Define to 1 if you have the `sinhl' function. */
 #undef HAVE_SINHL
 
@@ -723,6 +885,9 @@
 /* Define to 1 if you have the `sqrtf' function. */
 #undef HAVE_SQRTF
 
+/* Define to 1 if you have the `sqrtf128' function. */
+#undef HAVE_SQRTF128
+
 /* Define to 1 if you have the `sqrtl' function. */
 #undef HAVE_SQRTL
 
@@ -744,6 +909,9 @@
 /* Define if strerror_r takes two arguments and is available in <string.h>. */
 #undef HAVE_STRERROR_R_2ARGS
 
+/* Define to 1 if you have the `strfromf128' function. */
+#undef HAVE_STRFROMF128
+
 /* Define to 1 if you have the <strings.h> header file. */
 #undef HAVE_STRINGS_H
 
@@ -759,6 +927,9 @@
 /* Define to 1 if you have the `strtof' function. */
 #undef HAVE_STRTOF
 
+/* Define to 1 if you have the `strtof128' function. */
+#undef HAVE_STRTOF128
+
 /* Define to 1 if you have the `strtold' function. */
 #undef HAVE_STRTOLD
 
@@ -804,12 +975,18 @@
 /* Define to 1 if you have the `tanf' function. */
 #undef HAVE_TANF
 
+/* Define to 1 if you have the `tanf128' function. */
+#undef HAVE_TANF128
+
 /* Define to 1 if you have the `tanh' function. */
 #undef HAVE_TANH
 
 /* Define to 1 if you have the `tanhf' function. */
 #undef HAVE_TANHF
 
+/* Define to 1 if you have the `tanhf128' function. */
+#undef HAVE_TANHF128
+
 /* Define to 1 if you have the `tanhl' function. */
 #undef HAVE_TANHL
 
@@ -822,6 +999,9 @@
 /* Define to 1 if you have the `tgammaf' function. */
 #undef HAVE_TGAMMAF
 
+/* Define to 1 if you have the `tgammaf128' function. */
+#undef HAVE_TGAMMAF128
+
 /* Define to 1 if you have the `times' function. */
 #undef HAVE_TIMES
 
@@ -831,6 +1011,9 @@
 /* Define to 1 if you have the `truncf' function. */
 #undef HAVE_TRUNCF
 
+/* Define to 1 if you have the `truncf128' function. */
+#undef HAVE_TRUNCF128
+
 /* Define to 1 if you have the `truncl' function. */
 #undef HAVE_TRUNCL
 
@@ -876,18 +1059,27 @@
 /* Define to 1 if you have the `y0f' function. */
 #undef HAVE_Y0F
 
+/* Define to 1 if you have the `y0f128' function. */
+#undef HAVE_Y0F128
+
 /* Define to 1 if you have the `y1' function. */
 #undef HAVE_Y1
 
 /* Define to 1 if you have the `y1f' function. */
 #undef HAVE_Y1F
 
+/* Define to 1 if you have the `y1f128' function. */
+#undef HAVE_Y1F128
+
 /* Define to 1 if you have the `yn' function. */
 #undef HAVE_YN
 
 /* Define to 1 if you have the `ynf' function. */
 #undef HAVE_YNF
 
+/* Define to 1 if you have the `ynf128' function. */
+#undef HAVE_YNF128
+
 /* Define to 1 if you have the `ynl' function. */
 #undef HAVE_YNL
 
@@ -1006,6 +1198,9 @@
 /* Define to 1 if the target supports weakref */
 #undef SUPPORTS_WEAKREF
 
+/* Define if IEC 60559 *f128 APIs should be used for _Float128. */
+#undef USE_IEC_60559
+
 /* Enable extensions on AIX 3, Interix.  */
 #ifndef _ALL_SOURCE
 # undef _ALL_SOURCE

libgfortran/configure.ac

@@ -356,7 +356,7 @@ else
    getcwd localtime_r gmtime_r getpwuid_r ttyname_r clock_gettime \
    getgid getpid getuid geteuid umask getegid \
    secure_getenv __secure_getenv mkostemp strnlen strndup newlocale \
-   freelocale uselocale strerror_l)
+   freelocale uselocale strerror_l strtof128 strfromf128)
 fi
 
 # Check strerror_r, cannot be above as versions with two and three arguments exist
@@ -582,24 +582,101 @@ GCC_CHECK_MATH_INLINE_BUILTIN_FALLBACK2([copysignl], [long double])
 GCC_CHECK_MATH_INLINE_BUILTIN_FALLBACK1([fabs], [double])
 GCC_CHECK_MATH_INLINE_BUILTIN_FALLBACK1([fabsl], [long double])
 
+GCC_CHECK_MATH_FUNC([acosf128])
+GCC_CHECK_MATH_FUNC([acoshf128])
+GCC_CHECK_MATH_FUNC([asinf128])
+GCC_CHECK_MATH_FUNC([asinhf128])
+GCC_CHECK_MATH_FUNC([atan2f128])
+GCC_CHECK_MATH_FUNC([atanf128])
+GCC_CHECK_MATH_FUNC([atanhf128])
+GCC_CHECK_MATH_FUNC([cargf128])
+GCC_CHECK_MATH_FUNC([ceilf128])
+GCC_CHECK_MATH_FUNC([copysignf128])
+GCC_CHECK_MATH_FUNC([cosf128])
+GCC_CHECK_MATH_FUNC([ccosf128])
+GCC_CHECK_MATH_FUNC([coshf128])
+GCC_CHECK_MATH_FUNC([ccoshf128])
+GCC_CHECK_MATH_FUNC([expf128])
+GCC_CHECK_MATH_FUNC([cexpf128])
+GCC_CHECK_MATH_FUNC([fabsf128])
+GCC_CHECK_MATH_FUNC([cabsf128])
+GCC_CHECK_MATH_FUNC([floorf128])
+GCC_CHECK_MATH_FUNC([fmaf128])
+GCC_CHECK_MATH_FUNC([fmodf128])
+GCC_CHECK_MATH_FUNC([frexpf128])
+GCC_CHECK_MATH_FUNC([hypotf128])
+GCC_CHECK_MATH_FUNC([ldexpf128])
+GCC_CHECK_MATH_FUNC([logf128])
+GCC_CHECK_MATH_FUNC([clogf128])
+GCC_CHECK_MATH_FUNC([log10f128])
+GCC_CHECK_MATH_FUNC([clog10f128])
+GCC_CHECK_MATH_FUNC([nextafterf128])
+GCC_CHECK_MATH_FUNC([powf128])
+GCC_CHECK_MATH_FUNC([cpowf128])
+GCC_CHECK_MATH_FUNC([roundf128])
+GCC_CHECK_MATH_FUNC([lroundf128])
+GCC_CHECK_MATH_FUNC([llroundf128])
+GCC_CHECK_MATH_FUNC([scalbnf128])
+GCC_CHECK_MATH_FUNC([sinf128])
+GCC_CHECK_MATH_FUNC([csinf128])
+GCC_CHECK_MATH_FUNC([sinhf128])
+GCC_CHECK_MATH_FUNC([csinhf128])
+GCC_CHECK_MATH_FUNC([sqrtf128])
+GCC_CHECK_MATH_FUNC([csqrtf128])
+GCC_CHECK_MATH_FUNC([tanf128])
+GCC_CHECK_MATH_FUNC([ctanf128])
+GCC_CHECK_MATH_FUNC([tanhf128])
+GCC_CHECK_MATH_FUNC([ctanhf128])
+GCC_CHECK_MATH_FUNC([truncf128])
+GCC_CHECK_MATH_FUNC([erff128])
+GCC_CHECK_MATH_FUNC([erfcf128])
+GCC_CHECK_MATH_FUNC([j0f128])
+GCC_CHECK_MATH_FUNC([j1f128])
+GCC_CHECK_MATH_FUNC([jnf128])
+GCC_CHECK_MATH_FUNC([y0f128])
+GCC_CHECK_MATH_FUNC([y1f128])
+GCC_CHECK_MATH_FUNC([ynf128])
+GCC_CHECK_MATH_FUNC([tgammaf128])
+GCC_CHECK_MATH_FUNC([lgammaf128])
+
+GCC_CHECK_MATH_FUNC([cacosf128])
+GCC_CHECK_MATH_FUNC([cacoshf128])
+GCC_CHECK_MATH_FUNC([casinf128])
+GCC_CHECK_MATH_FUNC([casinhf128])
+GCC_CHECK_MATH_FUNC([catanf128])
+GCC_CHECK_MATH_FUNC([catanhf128])
+
 # Check whether the system has a working stat()
 LIBGFOR_CHECK_WORKING_STAT
 
 # Check whether __mingw_snprintf() is present
 LIBGFOR_CHECK_MINGW_SNPRINTF
 
+have_iec_60559_libc_support=no
+if test "x$ac_cv_func_strtof128$ac_cv_func_strfromf128" = xyesyes \
+   && test "x$gcc_cv_math_func_sinf128$gcc_cv_math_func_cacosf128" = xyesyes; then
+  have_iec_60559_libc_support=yes
+fi
+
 # Check whether libquadmath should be used
 AC_ARG_ENABLE(libquadmath-support,
 AS_HELP_STRING([--disable-libquadmath-support],
   [disable libquadmath support for Fortran]),
 ENABLE_LIBQUADMATH_SUPPORT=$enableval,
-ENABLE_LIBQUADMATH_SUPPORT=yes)
+if test "x$have_iec_60559_libc_support" = xyes; then
+  ENABLE_LIBQUADMATH_SUPPORT=default
+else
+  ENABLE_LIBQUADMATH_SUPPORT=yes
+fi)
 enable_libquadmath_support=
 if test "${ENABLE_LIBQUADMATH_SUPPORT}" = "no" ; then
   enable_libquadmath_support=no
+elif test "${ENABLE_LIBQUADMATH_SUPPORT}" = "default" ; then
+  enable_libquadmath_support=default
 fi
 
-# Check whether we have a __float128 type, depends on enable_libquadmath_support
+# Check whether we have a _Float128 type, depends on enable_libquadmath_support
+# and have_iec_60559_libc_support.
 LIBGFOR_CHECK_FLOAT128
 
 # Check for GNU libc feenableexcept

libgfortran/generated/bessel_r16.c

@@ -29,7 +29,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 
 #if defined(GFC_REAL_16_IS_FLOAT128)
+#if defined(GFC_REAL_16_USE_IEC_60559)
+#define MATHFUNC(funcname) funcname ## f128
+#else
 #define MATHFUNC(funcname) funcname ## q
+#endif
 #else
 #define MATHFUNC(funcname) funcname ## l
 #endif

libgfortran/generated/bessel_r17.c

@@ -30,6 +30,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #if defined(POWER_IEEE128)
 #define MATHFUNC(funcname) __ ## funcname ## ieee128
+#elif defined(GFC_REAL_17_USE_IEC_60559)
+#define MATHFUNC(funcname) funcname ## f128
 #else
 #define MATHFUNC(funcname) funcname ## q
 #endif

libgfortran/generated/norm2_r16.c

@@ -30,7 +30,11 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #if defined (HAVE_GFC_REAL_16) && defined (HAVE_GFC_REAL_16) && (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_SQRTL)) && (defined(GFC_REAL_16_IS_FLOAT128) || defined(HAVE_FABSL))
 
 #if defined(GFC_REAL_16_IS_FLOAT128)
+#if defined(GFC_REAL_16_USE_IEC_60559)
+#define MATHFUNC(funcname) funcname ## f128
+#else
 #define MATHFUNC(funcname) funcname ## q
+#endif
 #else
 #define MATHFUNC(funcname) funcname ## l
 #endif

libgfortran/generated/norm2_r17.c

@@ -31,6 +31,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #if defined(POWER_IEEE128)
 #define MATHFUNC(funcname) __ ## funcname ## ieee128
+#elif defined(GFC_REAL_17_USE_IEC_60559)
+#define MATHFUNC(funcname) funcname ## f128
 #else
 #define MATHFUNC(funcname) funcname ## q
 #endif

libgfortran/ieee/issignaling_fallback.h

@@ -197,11 +197,11 @@ __issignalingl (long double x)
 
 #if defined(GFC_REAL_16_IS_FLOAT128)
 
-/* We have a __float128 type.  */
+/* We have a _Float128 type.  */
 
 typedef union
 {
-  __float128 value;
+  _Float128 value;
   struct
   {
 #if __FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__
@@ -215,7 +215,7 @@ typedef union
 } ieee854_float128_shape_type;
 
 static inline int
-__issignalingf128 (__float128 x)
+__issignalingf128 (_Float128 x)
 {
   uint64_t hxi, lxi;
   ieee854_float128_shape_type u;
@@ -237,7 +237,7 @@ __issignalingf128 (__float128 x)
 #if defined(GFC_REAL_16_IS_FLOAT128)
 # define issignaling(X) \
   _Generic ((X), \
-	    __float128: __issignalingf128, \
+	    _Float128: __issignalingf128, \
 	    float: __issignalingf, \
 	    double: __issignaling, \
 	    long double: __issignalingl)(X)

libgfortran/intrinsics/cshift0.c

@@ -132,7 +132,7 @@ cshift0 (gfc_array_char * ret, const gfc_array_char * array,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -162,7 +162,7 @@ cshift0 (gfc_array_char * ret, const gfc_array_char * array,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)

libgfortran/intrinsics/erfc_scaled.c

@@ -52,11 +52,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #ifdef GFC_REAL_16_IS_FLOAT128
 
-# define _THRESH -106.566990228185312813205074546585730Q
+# ifdef GFC_REAL_16_USE_IEC_60559
-# define _M_2_SQRTPI M_2_SQRTPIq
+#  define _THRESH -106.566990228185312813205074546585730F128
-# define _INF __builtin_infq()
+#  define _M_2_SQRTPI M_2_SQRTPIf128
-# define _ERFC(x) erfcq(x)
+#  define _INF __builtin_inff128()
-# define _EXP(x) expq(x)
+#  define _ERFC(x) erfcf128(x)
+#  define _EXP(x) expf128(x)
+# else
+#  define _THRESH -106.566990228185312813205074546585730Q
+#  define _M_2_SQRTPI M_2_SQRTPIq
+#  define _INF __builtin_infq()
+#  define _ERFC(x) erfcq(x)
+#  define _EXP(x) expq(x)
+# endif
 
 #else
 
@@ -139,12 +147,15 @@ ERFC_SCALED(16)
 /* For quadruple-precision, netlib's implementation is
    not accurate enough.  We provide another one.  */
 
-# define _THRESH -106.566990228185312813205074546585730Q
+# define _THRESH GFC_REAL_17_LITERAL(-106.566990228185312813205074546585730)
-# define _M_2_SQRTPI M_2_SQRTPIq
+# define _M_2_SQRTPI GFC_REAL_17_LITERAL(M_2_SQRTPI)
 # define _INF __builtin_inff128()
 # ifdef POWER_IEEE128
 #  define _ERFC(x) __erfcieee128(x)
 #  define _EXP(x) __expieee128(x)
+# elif defined(GFC_REAL_17_USE_IEC_60559)
+#  define _ERFC(x) erfcf128(x)
+#  define _EXP(x) expf128(x)
 # else
 #  define _ERFC(x) erfcq(x)
 #  define _EXP(x) expq(x)

libgfortran/intrinsics/pack_generic.c

@@ -307,7 +307,7 @@ pack (gfc_array_char *ret, const gfc_array_char *array,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -339,7 +339,7 @@ pack (gfc_array_char *ret, const gfc_array_char *array,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)

libgfortran/intrinsics/spread_generic.c

@@ -320,7 +320,7 @@ spread (gfc_array_char *ret, const gfc_array_char *source,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -352,7 +352,7 @@ spread (gfc_array_char *ret, const gfc_array_char *source,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -524,7 +524,7 @@ spread_scalar (gfc_array_char *ret, const char *source,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -556,7 +556,7 @@ spread_scalar (gfc_array_char *ret, const char *source,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)

libgfortran/intrinsics/trigd.c

@@ -261,6 +261,24 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 #endif /* HAVE_FABSL && HAVE_FMODL && HAVE_COPYSIGNL */
 
+#elif defined(GFC_REAL_16_USE_IEC_60559)
+
+#if defined(HAVE_FABSF128) && defined(HAVE_FMODF128) && defined(HAVE_COPYSIGNF128)
+
+#ifdef HAVE_SINF128
+#define ENABLE_SIND
+#endif
+
+#ifdef HAVE_COSF128
+#define ENABLE_COSD
+#endif
+
+#ifdef HAVE_TANF128
+#define ENABLE_TAND
+#endif
+
+#endif /* HAVE_FABSF128 && HAVE_FMODF128 && HAVE_COPYSIGNF128 */
+
 #else
 
 /* libquadmath: HAVE_*Q are never defined.  They must be available.  */

libgfortran/intrinsics/unpack_generic.c

@@ -265,7 +265,7 @@ unpack1 (gfc_array_char *ret, const gfc_array_char *vector,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -297,7 +297,7 @@ unpack1 (gfc_array_char *ret, const gfc_array_char *vector,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -486,7 +486,7 @@ unpack0 (gfc_array_char *ret, const gfc_array_char *vector,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -518,7 +518,7 @@ unpack0 (gfc_array_char *ret, const gfc_array_char *vector,
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)

libgfortran/io/read.c

@@ -186,7 +186,11 @@ convert_real (st_parameter_dt *dtp, void *dest, const char *buffer, int length)
 #if defined(HAVE_GFC_REAL_16)
 # if defined(GFC_REAL_16_IS_FLOAT128)
     case 16:
+#  if defined(GFC_REAL_16_USE_IEC_60559)
+      *((GFC_REAL_16*) dest) = strtof128 (buffer, &endptr);
+#  else
       *((GFC_REAL_16*) dest) = __qmath_(strtoflt128) (buffer, &endptr);
+#  endif
       break;
 # elif defined(HAVE_STRTOLD)
     case 16:
@@ -199,6 +203,8 @@ convert_real (st_parameter_dt *dtp, void *dest, const char *buffer, int length)
     case 17:
 # if defined(POWER_IEEE128)
       *((GFC_REAL_17*) dest) = __strtoieee128 (buffer, &endptr);
+# elif defined(GFC_REAL_17_USE_IEC_60559)
+      *((GFC_REAL_17*) dest) = strtof128 (buffer, &endptr);
 # else
       *((GFC_REAL_17*) dest) = __qmath_(strtoflt128) (buffer, &endptr);
 # endif
@@ -272,7 +278,14 @@ convert_infnan (st_parameter_dt *dtp, void *dest, const char *buffer,
 #if defined(HAVE_GFC_REAL_16)
 # if defined(GFC_REAL_16_IS_FLOAT128)
     case 16:
+#  if defined(GFC_REAL_16_USE_IEC_60559)
+      if (is_inf)
+	*((GFC_REAL_16*) dest) = plus ? __builtin_inff128 () : -__builtin_inff128 ();
+      else
+	*((GFC_REAL_16*) dest) = plus ? __builtin_nanf128 ("") : -__builtin_nanf128 ("");
+#  else
       *((GFC_REAL_16*) dest) = __qmath_(strtoflt128) (buffer, NULL);
+#  endif
       break;
 # else
     case 16:

libgfortran/io/transfer128.c

@@ -65,7 +65,9 @@ export_proto(transfer_complex128_write);
    write_float; the pointer assignment with USED attribute make sure
    that there is a non-weakref dependence if the quadmath functions
    are used. That avoids segfault when libquadmath is statically linked.  */
-# if !defined(HAVE_GFC_REAL_17) || !defined(POWER_IEEE128)
+# if (defined(HAVE_GFC_REAL_17) && !defined(POWER_IEEE128) \
+      && !defined(GFC_REAL_17_USE_IEC_60559)) \
+     || (!defined(HAVE_GFC_REAL_17) && !defined(GFC_REAL_16_USE_IEC_60559))
 static void __attribute__((used)) *tmp1 = strtoflt128;
 static void __attribute__((used)) *tmp2 = quadmath_snprintf;
 # endif

libgfortran/io/write_float.def

@@ -837,18 +837,60 @@ snprintf (buffer, size, "%+-#.*e", (prec), (val))
 #define DTOA2L(prec,val) \
 snprintf (buffer, size, "%+-#.*Le", (prec), (val))
 
+#if defined(GFC_REAL_16_USE_IEC_60559) || defined(GFC_REAL_17_USE_IEC_60559)
+/* strfromf128 unfortunately doesn't allow +, - and # modifiers
+   nor .* (only allows .number).  For +, work around it by adding
+   leading + manually for !signbit values.  For - I don't see why
+   we need it, when we don't specify field minimum width.
+   For #, add . if it is missing.  Assume size is at least 2.  */
+static int
+gfor_strfromf128 (char *buffer, size_t size, int kind, int prec, _Float128 val)
+{
+  int ret, n = 0;
+  char fmt[sizeof (int) * 3 + 5];
+  snprintf (fmt, sizeof fmt, "%%.%d%c", prec, kind);
+  if (!__builtin_signbit (val))
+    {
+      n = 1;
+      buffer[0] = '+';
+    }
+  ret = strfromf128 (buffer + n, size - n, fmt, val) + n;
+  if ((size_t) ret < size - 1)
+    {
+      size_t s = strcspn (buffer, ".e");
+      if (buffer[s] != '.')
+	{
+	  if (buffer[s] == '\0')
+	    buffer[s + 1] = '\0';
+	  else
+	    memmove (buffer + s + 1, buffer + s, ret + 1 - s);
+	  buffer[s] = '.';
+	  ++ret;
+	}
+    }
+  return ret;
+}
+#endif
 
 #if defined(HAVE_GFC_REAL_17)
 # if defined(POWER_IEEE128)
 #  define DTOA2Q(prec,val) \
 __snprintfieee128 (buffer, size, "%+-#.*Le", (prec), (val))
+# elif defined(GFC_REAL_17_USE_IEC_60559)
+#  define DTOA2Q(prec,val) \
+gfor_strfromf128 (buffer, size, 'e', (prec), (val))
 # else
 #  define DTOA2Q(prec,val) \
 quadmath_snprintf (buffer, size, "%+-#.*Qe", (prec), (val))
 # endif
 #elif defined(GFC_REAL_16_IS_FLOAT128)
-# define DTOA2Q(prec,val) \
+# if defined(GFC_REAL_16_USE_IEC_60559)
+#  define DTOA2Q(prec,val) \
+gfor_strfromf128 (buffer, size, 'e', (prec), (val))
+# else
+#  define DTOA2Q(prec,val) \
 quadmath_snprintf (buffer, size, "%+-#.*Qe", (prec), (val))
+# endif
 #endif
 
 #define FDTOA(suff,prec,val) TOKENPASTE(FDTOA2,suff)(prec,val)
@@ -865,13 +907,21 @@ snprintf (buffer, size, "%+-#.*Lf", (prec), (val))
 # if defined(POWER_IEEE128)
 #  define FDTOA2Q(prec,val) \
 __snprintfieee128 (buffer, size, "%+-#.*Lf", (prec), (val))
+# elif defined(GFC_REAL_17_USE_IEC_60559)
+#  define FDTOA2Q(prec,val) \
+gfor_strfromf128 (buffer, size, 'f', (prec), (val))
 # else
 # define FDTOA2Q(prec,val) \
 quadmath_snprintf (buffer, size, "%+-#.*Qf", (prec), (val))
 # endif
 #elif defined(GFC_REAL_16_IS_FLOAT128)
-# define FDTOA2Q(prec,val) \
+# if defined(GFC_REAL_16_USE_IEC_60559)
+#  define FDTOA2Q(prec,val) \
+gfor_strfromf128 (buffer, size, 'f', (prec), (val))
+# else
+#  define FDTOA2Q(prec,val) \
 quadmath_snprintf (buffer, size, "%+-#.*Qf", (prec), (val))
+# endif
 #endif
 
 

libgfortran/kinds-override.h

@@ -26,18 +26,26 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 /* Ensure that TFmode is available under.  */
 
 #if defined(GFC_REAL_16_IS_FLOAT128) && !defined(HAVE_FLOAT128)
-# error "Where has __float128 gone?"
+# error "Where has _Float128 gone?"
 #endif
 
 /* Keep these conditions on one line so grep can filter it out.  */
 #if defined(__powerpc64__)  && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__  && __SIZEOF_LONG_DOUBLE__ == 16
-typedef __float128 GFC_REAL_17;
+typedef _Float128 GFC_REAL_17;
-typedef _Complex float __attribute__((mode(KC))) GFC_COMPLEX_17;
+typedef _Complex _Float128 GFC_COMPLEX_17;
 #define HAVE_GFC_REAL_17
 #define HAVE_GFC_COMPLEX_17
+#define GFC_REAL_17_IS_FLOAT128
+#ifdef USE_IEC_60559
+#define GFC_REAL_17_USE_IEC_60559
+#define GFC_REAL_17_HUGE 1.18973149535723176508575932662800702e4932f128
+#define GFC_REAL_17_LITERAL_SUFFIX f128
+#define GFC_REAL_17_LITERAL(X) (X ## f128)
+#else
 #define GFC_REAL_17_HUGE 1.18973149535723176508575932662800702e4932q
 #define GFC_REAL_17_LITERAL_SUFFIX q
 #define GFC_REAL_17_LITERAL(X) (X ## q)
+#endif
 #define GFC_REAL_17_DIGITS 113
 #define GFC_REAL_17_RADIX 2
 #endif

libgfortran/libgfortran.h

@@ -58,8 +58,8 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 
 /* If we're support quad-precision floating-point type, include the
    header to our support library.  */
-#ifdef HAVE_FLOAT128
+#if defined(HAVE_FLOAT128) && !defined(USE_IEC_60559)
-#  include "quadmath_weak.h"
+# include "quadmath_weak.h"
 #endif
 
 #ifdef __MINGW32__
@@ -322,6 +322,8 @@ typedef GFC_UINTEGER_4 gfc_char4_t;
 # ifdef HAVE_GFC_REAL_16
 #  ifdef GFC_REAL_16_IS_LONG_DOUBLE
 #   define GFC_REAL_16_INFINITY __builtin_infl ()
+#  elif defined GFC_REAL_16_USE_IEC_60559
+#   define GFC_REAL_16_INFINITY __builtin_inff128 ()
 #  else
 #   define GFC_REAL_16_INFINITY __builtin_infq ()
 #  endif
@@ -343,6 +345,8 @@ typedef GFC_UINTEGER_4 gfc_char4_t;
 # ifdef HAVE_GFC_REAL_16
 #  ifdef GFC_REAL_16_IS_LONG_DOUBLE
 #   define GFC_REAL_16_QUIET_NAN __builtin_nanl ("")
+#  elif defined GFC_REAL_16_USE_IEC_60559
+#   define GFC_REAL_16_QUIET_NAN __builtin_nanf128 ("")
 #  else
 #   define GFC_REAL_16_QUIET_NAN nanq ("")
 #  endif

libgfortran/m4/mtype.m4

@@ -15,12 +15,18 @@ ifelse(kind,17,`1 /* FIXME: figure this out later.  */',dnl
 define(mathfunc_macro,`ifelse(kind,17,dnl
 `#if defined(POWER_IEEE128)
 #define MATHFUNC(funcname) __ ## funcname ## ieee128
+#elif defined(GFC_REAL_17_USE_IEC_60559)
+#define MATHFUNC(funcname) funcname ## f128
 #else
 #define MATHFUNC(funcname) funcname ## q
 #endif',dnl
 `ifelse(kind,16,dnl
 `#if defined(GFC_REAL_16_IS_FLOAT128)
+#if defined(GFC_REAL_16_USE_IEC_60559)
+#define MATHFUNC(funcname) funcname ## f128
+#else
 #define MATHFUNC(funcname) funcname ## q
+#endif
 #else
 #define MATHFUNC(funcname) funcname ## l
 #endif',dnl

libgfortran/mk-kinds-h.sh

@@ -2,8 +2,8 @@
 LC_ALL=C
 export LC_ALL
 
-if test "$#" -ne 3; then
+if test "$#" -ne 4; then
-  echo "Usage $0 int_kinds real_kinds compile"
+  echo "Usage $0 int_kinds real_kinds compile use_iec_60559"
   exit 1
 fi
 
@@ -11,6 +11,7 @@ fi
 possible_integer_kinds="$1"
 possible_real_kinds="$2"
 compile="$3"
+use_iec_60559="$4"
 
 largest=""
 smallest=""
@@ -49,7 +50,7 @@ echo ""
 
 
 # Get the kind value for long double, so we may disambiguate it
-# from __float128.
+# from _Float128.
 echo "use iso_c_binding; print *, c_long_double ; end" > tmq$$.f90
 long_double_kind=`$compile -S -fdump-parse-tree tmq$$.f90 | grep TRANSFER \
 			| sed 's/ *TRANSFER *//'`
@@ -68,10 +69,15 @@ for k in $possible_real_kinds; do
       10) ctype="long double" ; cplxtype="complex long double" ; suffix="l" ;;
       # If we have a REAL(KIND=16), it is either long double or __float128
       16) if [ $long_double_kind -ne 16 ]; then
-	    ctype="__float128"
+	    ctype="_Float128"
-	    cplxtype="_Complex float __attribute__((mode(TC)))"
+	    cplxtype="_Complex _Float128"
-	    suffix="q"
 	    echo "#define GFC_REAL_16_IS_FLOAT128"
+	    if [ x$use_iec_60559 = xyes ]; then
+	      suffix="f128"
+	      echo "#define GFC_REAL_16_USE_IEC_60559"
+	    else
+	      suffix="q"
+	    fi
 	  else
 	    ctype="long double"
 	    cplxtype="complex long double"

libgfortran/runtime/in_pack_generic.c

@@ -82,7 +82,7 @@ internal_pack (gfc_array_char * source)
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -106,7 +106,7 @@ internal_pack (gfc_array_char * source)
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)

libgfortran/runtime/in_unpack_generic.c

@@ -89,7 +89,7 @@ internal_unpack (gfc_array_char * d, const void * s)
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)
@@ -117,7 +117,7 @@ internal_unpack (gfc_array_char * d, const void * s)
 /* FIXME: This here is a hack, which will have to be removed when
    the array descriptor is reworked.  Currently, we don't store the
    kind value for the type, but only the size.  Because on targets with
-   __float128, we have sizeof(logn double) == sizeof(__float128),
+   _Float128, we have sizeof(long double) == sizeof(_Float128),
    we cannot discriminate here and have to fall back to the generic
    handling (which is suboptimal).  */
 #if !defined(GFC_REAL_16_IS_FLOAT128)