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[/] [openrisc/] [trunk/] [gnu-dev/] [or1k-gcc/] [libquadmath/] [math/] [remainderq.c] - Blame information for rev 775

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Line No. Rev Author Line
1 740 jeremybenn
/* e_fmodl.c -- long double version of e_fmod.c.
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 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
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 */
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/*
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 * ====================================================
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 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
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 *
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 * Developed at SunPro, a Sun Microsystems, Inc. business.
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 * Permission to use, copy, modify, and distribute this
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 * software is freely granted, provided that this notice
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 * is preserved.
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 * ====================================================
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 */
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/* remainderq(x,p)
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 * Return :
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 *      returns  x REM p  =  x - [x/p]*p as if in infinite
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 *      precise arithmetic, where [x/p] is the (infinite bit)
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 *      integer nearest x/p (in half way case choose the even one).
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 * Method :
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 *      Based on fmodq() return x-[x/p]chopped*p exactlp.
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 */
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#include "quadmath-imp.h"
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static const __float128 zero = 0.0Q;
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__float128
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remainderq (__float128 x, __float128 p)
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{
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  int64_t hx,hp;
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  uint64_t sx,lx,lp;
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  __float128 p_half;
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  GET_FLT128_WORDS64(hx,lx,x);
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  GET_FLT128_WORDS64(hp,lp,p);
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  sx = hx&0x8000000000000000ULL;
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  hp &= 0x7fffffffffffffffLL;
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  hx &= 0x7fffffffffffffffLL;
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  /* purge off exception values */
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  if((hp|lp)==0) return (x*p)/(x*p);     /* p = 0 */
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  if((hx>=0x7fff000000000000LL)||                       /* x not finite */
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    ((hp>=0x7fff000000000000LL)&&                       /* p is NaN */
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    (((hp-0x7fff000000000000LL)|lp)!=0)))
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      return (x*p)/(x*p);
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  if (hp<=0x7ffdffffffffffffLL) x = fmodq (x,p+p);      /* now x < 2p */
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  if (((hx-hp)|(lx-lp))==0) return zero*x;
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  x  = fabsq(x);
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  p  = fabsq(p);
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  if (hp<0x0002000000000000LL) {
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      if(x+x>p) {
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          x-=p;
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          if(x+x>=p) x -= p;
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      }
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  } else {
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      p_half = 0.5Q*p;
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      if(x>p_half) {
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          x-=p;
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          if(x>=p_half) x -= p;
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      }
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  }
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  GET_FLT128_MSW64(hx,x);
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  SET_FLT128_MSW64(x,hx^sx);
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  return x;
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}

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