lib/libm/src/w_scalbf.c

   1 /* w_scalbf.c -- float version of w_scalb.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  */
  15
  16 #include <sys/cdefs.h>
  17 #if defined(LIBM_SCCS) && !defined(lint)
  18 __RCSID("$NetBSD: w_scalbf.c,v 1.6 2002/05/26 22:02:02 wiz Exp $");
  19 #endif
  20
  21 /*
  22  * wrapper scalbf(float x, float fn) is provide for
  23  * passing various standard test suite. One
  24  * should use scalbn() instead.
  25  */
  26
  27 #include "math.h"
  28 #include "math_private.h"
  29
  30 #include <errno.h>
  31
  32 #ifdef _SCALB_INT
  33 float
  34 scalbf(float x, int fn)         /* wrapper scalbf */
  35 #else
  36 float
  37 scalbf(float x, float fn)               /* wrapper scalbf */
  38 #endif
  39 {
  40 #ifdef _IEEE_LIBM
  41         return __ieee754_scalbf(x,fn);
  42 #else
  43         float z;
  44         z = __ieee754_scalbf(x,fn);
  45         if(_LIB_VERSION == _IEEE_) return z;
  46         if(!(finitef(z)||isnanf(z))&&finitef(x)) {
  47             /* scalbf overflow */
  48             return (float)__kernel_standard((double)x,(double)fn,132);
  49         }
  50         if(z==(float)0.0&&z!=x) {
  51             /* scalbf underflow */
  52             return (float)__kernel_standard((double)x,(double)fn,133);
  53         }
  54 #ifndef _SCALB_INT
  55         if(!finitef(fn)) errno = ERANGE;
  56 #endif
  57         return z;
  58 #endif
  59 }