--- glibc-2.27/bits/floatn-common.h.0134~	2018-02-01 17:17:18.000000000 +0100
+++ glibc-2.27/bits/floatn-common.h	2018-03-03 02:32:16.924822310 +0100
@@ -28,6 +28,7 @@
    where the same definitions, or definitions based only on the macros
    in bits/floatn.h, are appropriate for all glibc configurations.  */
 
+#ifndef __clang__ /* FIXME reinvestigate with clang 7 */
 /* Defined to 1 if the current compiler invocation provides a
    floating-point type with the right format for this type, and this
    glibc includes corresponding *fN or *fNx interfaces for it.  */
@@ -36,6 +37,7 @@
 #define __HAVE_FLOAT64 1
 #define __HAVE_FLOAT32X 1
 #define __HAVE_FLOAT128X 0
+#endif
 
 /* Defined to 1 if the corresponding __HAVE_<type> macro is 1 and the
    type is the first with its format in the sequence of (the default
--- glibc-2.27/sysdeps/ieee754/ldbl-128/bits/floatn.h.0134~	2018-02-01 17:17:18.000000000 +0100
+++ glibc-2.27/sysdeps/ieee754/ldbl-128/bits/floatn.h	2018-03-03 02:32:16.924822310 +0100
@@ -26,7 +26,11 @@
    floating-point type with the IEEE 754 binary128 format, and this
    glibc includes corresponding *f128 interfaces for it.  */
 #ifndef __NO_LONG_DOUBLE_MATH
-# define __HAVE_FLOAT128 1
+# if defined(__clang__)
+#  define __HAVE_FLOAT128 0
+# else
+#  define __HAVE_FLOAT128 1
+# endif
 #else
 /* glibc does not support _Float128 for platforms where long double is
    normally binary128 when building with long double as binary64.
--- glibc-2.27/sysdeps/x86/bits/floatn.h.0134~	2018-02-01 17:17:18.000000000 +0100
+++ glibc-2.27/sysdeps/x86/bits/floatn.h	2018-03-03 02:34:50.472771373 +0100
@@ -26,9 +26,9 @@
    glibc includes corresponding *f128 interfaces for it.  The required
    libgcc support was added some time after the basic compiler
    support, for x86_64 and x86.  */
-#if (defined __x86_64__							\
+#if (!defined(__clang__) && (defined __x86_64__				\
      ? __GNUC_PREREQ (4, 3)						\
-     : (defined __GNU__ ? __GNUC_PREREQ (4, 5) : __GNUC_PREREQ (4, 4)))
+     : (defined __GNU__ ? __GNUC_PREREQ (4, 5) : __GNUC_PREREQ (4, 4))))
 # define __HAVE_FLOAT128 1
 #else
 # define __HAVE_FLOAT128 0
@@ -42,6 +42,7 @@
 # define __HAVE_DISTINCT_FLOAT128 0
 #endif
 
+#ifndef __clang__ /* FIXME reinvestigate with clang 7 */
 /* Defined to 1 if the current compiler invocation provides a
    floating-point type with the right format for _Float64x, and this
    glibc includes corresponding *f64x interfaces for it.  */
@@ -52,6 +53,7 @@
    the format of _Float128, which must be different from that of long
    double.  */
 #define __HAVE_FLOAT64X_LONG_DOUBLE 1
+#endif
 
 #ifndef __ASSEMBLER__
 
@@ -68,7 +70,7 @@
 
 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1.  */
 # if __HAVE_FLOAT128
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus || defined __clang__
 /* Add a typedef for older GCC compilers which don't natively support
    _Complex _Float128.  */
 typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__)));
@@ -82,7 +84,7 @@ typedef _Complex float __cfloat128 __att
 # if __HAVE_FLOAT128
 
 /* The type _Float128 exists only since GCC 7.0.  */
-#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus
+#  if !__GNUC_PREREQ (7, 0) || defined __cplusplus || defined __clang__
 typedef __float128 _Float128;
 #  endif