code: def log1p(ctx, x):
      if not x:
          return ctx.zero
      if ctx.mag(x) < -ctx.prec:
          return x - 0.5 * x**2
      return ctx.log(ctx.fadd(1, x, prec=2 * ctx.prec))
  
imports: from ..libmp.backend import xrange
  import math
  import cmath
label_desc: Use image node_id 21 for calling a global function with example usage: log1p(ctx, x) and returns: ctx, ctx, unknown