code: def mpf_mod(s, t, prec, rnd=round_fast):
      ssign, sman, sexp, sbc = s
      tsign, tman, texp, tbc = t
      if ((not sman) and sexp) or ((not tman) and texp):
          return fnan
      # Important special case: do nothing if t is larger
      if ssign == tsign and texp > sexp + sbc:
          return s
      # Another important special case: this allows us to do e.g. x % 1.0
      # to find the fractional part of x, and it will work when x is huge.
      if tman == 1 and sexp > texp + tbc:
          return fzero
      base = min(sexp, texp)
      sman = (-1) ** ssign * sman
      tman = (-1) ** tsign * tman
      man = (sman << (sexp - base)) % (tman << (texp - base))
      if man >= 0:
          sign = 0
      else:
          man = -man
          sign = 1
      return normalize(sign, man, base, bitcount(man), prec, rnd)
  
imports: import math
  from bisect import bisect
  import sys
  from .backend import MPZ, MPZ_TYPE, MPZ_ZERO, MPZ_ONE, MPZ_TWO, MPZ_FIVE, BACKEND, STRICT, HASH_MODULUS, HASH_BITS, gmpy, sage, sage_utils
  from .libintmath import giant_steps, trailtable, bctable, lshift, rshift, bitcount, trailing, sqrt_fixed, numeral, isqrt, isqrt_fast, sqrtrem, bin_to_radix
label_desc: Use image node_id 50 for calling a global function with example usage: mpf_mod(s, t, prec, rnd) and returns: normalize, fnan, s, fzero