EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

[mirror_edk2.git] / StdLib / LibC / Math / s_frexp.c

/* @(#)s_frexp.c 5.1 93/09/24 */\r
/*\r
 * ====================================================\r
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.\r
 *\r
 * Developed at SunPro, a Sun Microsystems, Inc. business.\r
 * Permission to use, copy, modify, and distribute this\r
 * software is freely granted, provided that this notice\r
 * is preserved.\r
 * ====================================================\r
 */\r
#include  <LibConfig.h>\r
#include  <sys/EfiCdefs.h>\r
#if defined(LIBM_SCCS) && !defined(lint)\r
__RCSID("$NetBSD: s_frexp.c,v 1.12 2002/05/26 22:01:56 wiz Exp $");\r
#endif\r
\r
/*\r
 * for non-zero x\r
 *  x = frexp(arg,&exp);\r
 * return a double fp quantity x such that 0.5 <= |x| <1.0\r
 * and the corresponding binary exponent "exp". That is\r
 *  arg = x*2^exp.\r
 * If arg is inf, 0.0, or NaN, then frexp(arg,&exp) returns arg\r
 * with *exp=0.\r
 */\r
\r
#include "math.h"\r
#include "math_private.h"\r
\r
static const double\r
two54 =  1.80143985094819840000e+16; /* 0x43500000, 0x00000000 */\r
\r
double\r
frexp(double x, int *eptr)\r
{\r
  int32_t hx, ix, lx;\r
  EXTRACT_WORDS(hx,lx,x);\r
  ix = 0x7fffffff&hx;\r
  *eptr = 0;\r
  if(ix>=0x7ff00000||((ix|lx)==0)) return x;  /* 0,inf,nan */\r
  if (ix<0x00100000) {    /* subnormal */\r
      x *= two54;\r
      GET_HIGH_WORD(hx,x);\r
      ix = hx&0x7fffffff;\r
      *eptr = -54;\r
  }\r
  *eptr += (ix>>20)-1022;\r
  hx = (hx&0x800fffff)|0x3fe00000;\r
  SET_HIGH_WORD(x,hx);\r
  return x;\r
}\r