+#elif defined(USE_QUADMATH) && defined(I_QUADMATH)
+# include <quadmath.h>
+# define NV_DIG FLT128_DIG
+# define NV_MANT_DIG FLT128_MANT_DIG
+# define NV_MIN FLT128_MIN
+# define NV_MAX FLT128_MAX
+# define NV_MIN_EXP FLT128_MIN_EXP
+# define NV_MAX_EXP FLT128_MAX_EXP
+# define NV_EPSILON FLT128_EPSILON
+# define NV_MIN_10_EXP FLT128_MIN_10_EXP
+# define NV_MAX_10_EXP FLT128_MAX_10_EXP
+# define NV_INF HUGE_VALQ
+# define NV_NAN nanq("0")
+# define Perl_acos acosq
+# define Perl_asin asinq
+# define Perl_atan atanq
+# define Perl_atan2 atan2q
+# define Perl_ceil ceilq
+# define Perl_cos cosq
+# define Perl_cosh coshq
+# define Perl_exp expq
+/* no Perl_fabs, but there's PERL_ABS */
+# define Perl_floor floorq
+# define Perl_fmod fmodq
+# define Perl_log logq
+# define Perl_log10 log10q
+# define Perl_pow powq
+# define Perl_sin sinq
+# define Perl_sinh sinhq
+# define Perl_sqrt sqrtq
+# define Perl_tan tanq
+# define Perl_tanh tanhq
+# define Perl_modf(x,y) modfq(x,y)
+# define Perl_frexp(x,y) frexpq(x,y)
+# define Perl_ldexp(x, y) ldexpq(x,y)
+# define Perl_isinf(x) isinfq(x)
+# define Perl_isnan(x) isnanq(x)
+# define Perl_isfinite(x) !(isnanq(x) || isinfq(x))