HelenOS sources

FP_ZERO            97 uspace/lib/c/include/math.h #define fpclassify(x)  __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, (x))
FP_ZERO            97 uspace/lib/posix/include/libc/math.h #define fpclassify(x)  __builtin_fpclassify(FP_NAN, FP_INFINITE, FP_NORMAL, FP_SUBNORMAL, FP_ZERO, (x))