ilogbl
int ilogbl(long double);
j = ilogbl(g);
j = ilogbl(g);
__strong_alias(ilogbl,ilogb)
if (spread + ilogbl(r.hi) > -16383)
__strong_alias(ilogbl,ilogb)
ATF_CHECK(ilogbl(-INFINITY) == INT_MAX);
ATF_CHECK(ilogbl(1024) == 10);
ATF_CHECK(ilogbl(NAN) == FP_ILOGBNAN);
ATF_CHECK(ilogbl(0) == FP_ILOGB0);
ATF_CHECK(ilogbl(-0.) == FP_ILOGB0);
ATF_CHECK(ilogbl(INFINITY) == INT_MAX);