ilogb
int ilogb(double);
#define ilogb(x) __tg_simple(x, ilogb)
PROTO_NORMAL(ilogb);
if (spread + ilogb(r) > -1023) {
DEF_STD(ilogb);
LDBL_MAYBE_CLONE(ilogb);
return scalb(x,(double) -ilogb(x));
ATF_TC_WITHOUT_HEAD(ilogb);
ATF_TC_BODY(ilogb, tc)
ATF_CHECK_EQ(FP_ILOGB0, ilogb(0));
ATF_CHECK_EQ(FP_ILOGBNAN, ilogb(NAN));
ATF_CHECK_EQ(INT_MAX, ilogb(INFINITY));
i = ilogb(d);
ATF_TP_ADD_TC(tp, ilogb);