src/math/logbl.c

   1 #include <math.h>
   2 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   3 long double logbl(long double x)
   4 {
   5         return logb(x);
   6 }
   7 #else
   8 long double logbl(long double x)
   9 {
  10         if (!isfinite(x))
  11                 return x * x;
  12         if (x == 0)
  13                 return -1/(x*x);
  14         return ilogbl(x);
  15 }
  16 #endif