EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

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

/* @(#)e_fmod.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: e_fmod.c,v 1.11 2002/05/26 22:01:49 wiz Exp $");\r
#endif\r
\r
/*\r
 * __ieee754_fmod(x,y)\r
 * Return x mod y in exact arithmetic\r
 * Method: shift and subtract\r
 */\r
\r
#include "math.h"\r
#include "math_private.h"\r
\r
#if defined(_MSC_VER)           /* Handle Microsoft VC++ compiler specifics. */\r
  // unary minus operator applied to unsigned type, result still unsigned\r
  #pragma warning ( disable : 4146 )\r
#endif\r
\r
static const double one = 1.0, Zero[] = {0.0, -0.0,};\r
\r
double\r
__ieee754_fmod(double x, double y)\r
{\r
  int32_t n,hx,hy,hz,ix,iy,sx,i;\r
  u_int32_t lx,ly,lz;\r
\r
  EXTRACT_WORDS(hx,lx,x);\r
  EXTRACT_WORDS(hy,ly,y);\r
  sx = hx&0x80000000;   /* sign of x */\r
  hx ^=sx;    /* |x| */\r
  hy &= 0x7fffffff; /* |y| */\r
\r
    /* purge off exception values */\r
  if((hy|ly)==0||(hx>=0x7ff00000)|| /* y=0,or x not finite */\r
    ((hy|((ly|-ly)>>31))>0x7ff00000)) /* or y is NaN */\r
      return (x*y)/(x*y);\r
  if(hx<=hy) {\r
      if((hx<hy)||(lx<ly)) return x;  /* |x|<|y| return x */\r
      if(lx==ly)\r
    return Zero[(u_int32_t)sx>>31]; /* |x|=|y| return x*0*/\r
  }\r
\r
    /* determine ix = ilogb(x) */\r
  if(hx<0x00100000) { /* subnormal x */\r
      if(hx==0) {\r
    for (ix = -1043, i=lx; i>0; i<<=1) ix -=1;\r
      } else {\r
    for (ix = -1022,i=(hx<<11); i>0; i<<=1) ix -=1;\r
      }\r
  } else ix = (hx>>20)-1023;\r
\r
    /* determine iy = ilogb(y) */\r
  if(hy<0x00100000) { /* subnormal y */\r
      if(hy==0) {\r
    for (iy = -1043, i=ly; i>0; i<<=1) iy -=1;\r
      } else {\r
    for (iy = -1022,i=(hy<<11); i>0; i<<=1) iy -=1;\r
      }\r
  } else iy = (hy>>20)-1023;\r
\r
    /* set up {hx,lx}, {hy,ly} and align y to x */\r
  if(ix >= -1022)\r
      hx = 0x00100000|(0x000fffff&hx);\r
  else {    /* subnormal x, shift x to normal */\r
      n = -1022-ix;\r
      if(n<=31) {\r
          hx = (hx<<n)|(lx>>(32-n));\r
          lx <<= n;\r
      } else {\r
    hx = lx<<(n-32);\r
    lx = 0;\r
      }\r
  }\r
  if(iy >= -1022)\r
      hy = 0x00100000|(0x000fffff&hy);\r
  else {    /* subnormal y, shift y to normal */\r
      n = -1022-iy;\r
      if(n<=31) {\r
          hy = (hy<<n)|(ly>>(32-n));\r
          ly <<= n;\r
      } else {\r
    hy = ly<<(n-32);\r
    ly = 0;\r
      }\r
  }\r
\r
    /* fix point fmod */\r
  n = ix - iy;\r
  while(n--) {\r
      hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;\r
      if(hz<0){hx = hx+hx+(lx>>31); lx = lx+lx;}\r
      else {\r
        if((hz|lz)==0)    /* return sign(x)*0 */\r
        return Zero[(u_int32_t)sx>>31];\r
        hx = hz+hz+(lz>>31); lx = lz+lz;\r
      }\r
  }\r
  hz=hx-hy;lz=lx-ly; if(lx<ly) hz -= 1;\r
  if(hz>=0) {hx=hz;lx=lz;}\r
\r
    /* convert back to floating value and restore the sign */\r
  if((hx|lx)==0)      /* return sign(x)*0 */\r
      return Zero[(u_int32_t)sx>>31];\r
  while(hx<0x00100000) {    /* normalize x */\r
      hx = hx+hx+(lx>>31); lx = lx+lx;\r
      iy -= 1;\r
  }\r
  if(iy>= -1022) {  /* normalize output */\r
      hx = ((hx-0x00100000)|((iy+1023)<<20));\r
      INSERT_WORDS(x,hx|sx,lx);\r
  } else {    /* subnormal output */\r
      n = -1022 - iy;\r
      if(n<=20) {\r
    lx = (lx>>n)|((u_int32_t)hx<<(32-n));\r
    hx >>= n;\r
      } else if (n<=31) {\r
    lx = (hx<<(32-n))|(lx>>n); hx = sx;\r
      } else {\r
    lx = hx>>(n-32); hx = sx;\r
      }\r
      INSERT_WORDS(x,hx|sx,lx);\r
      x *= one;   /* create necessary signal */\r
  }\r
  return x;   /* exact output */\r
}\r