w_log.c 793 B

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  1. /*
  2. * ====================================================
  3. * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  4. *
  5. * Developed at SunPro, a Sun Microsystems, Inc. business.
  6. * Permission to use, copy, modify, and distribute this
  7. * software is freely granted, provided that this notice
  8. * is preserved.
  9. * ====================================================
  10. */
  11. /*
  12. * wrapper log(x)
  13. */
  14. #include "math.h"
  15. #include "math_private.h"
  16. double log(double x) /* wrapper log */
  17. {
  18. #ifdef _IEEE_LIBM
  19. return __ieee754_log(x);
  20. #else
  21. double z;
  22. z = __ieee754_log(x);
  23. if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z;
  24. if(x==0.0)
  25. return __kernel_standard(x,x,16); /* log(0) */
  26. else
  27. return __kernel_standard(x,x,17); /* log(x<0) */
  28. #endif
  29. }
  30. libm_hidden_def(log)