libquadmath/math/ceilq.c

   1 /* ceilq.c -- __float128 version of s_ceil.c.
   2  * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
   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 "quadmath-imp.h"
  17
  18 static const __float128 huge = 1.0e4930Q;
  19
  20 __float128
  21 ceilq (__float128 x)
  22 {
  23         int64_t i0,i1,j0;
  24         uint64_t i,j;
  25         GET_FLT128_WORDS64(i0,i1,x);
  26         j0 = ((i0>>48)&0x7fff)-0x3fff;
  27         if(j0<48) {
  28             if(j0<0) {  /* raise inexact if x != 0 */
  29                 if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
  30                     if(i0<0) {i0=0x8000000000000000ULL;i1=0;}
  31                     else if((i0|i1)!=0) { i0=0x3fff000000000000ULL;i1=0;}
  32                 }
  33             } else {
  34                 i = (0x0000ffffffffffffULL)>>j0;
  35                 if(((i0&i)|i1)==0) return x; /* x is integral */
  36                 if(huge+x>0.0) {        /* raise inexact flag */
  37                     if(i0>0) i0 += (0x0001000000000000LL)>>j0;
  38                     i0 &= (~i); i1=0;
  39                 }
  40             }
  41         } else if (j0>111) {
  42             if(j0==0x4000) return x+x;  /* inf or NaN */
  43             else return x;              /* x is integral */
  44         } else {
  45             i = -1ULL>>(j0-48);
  46             if((i1&i)==0) return x;     /* x is integral */
  47             if(huge+x>0.0) {            /* raise inexact flag */
  48                 if(i0>0) {
  49                     if(j0==48) i0+=1;
  50                     else {
  51                         j = i1+(1LL<<(112-j0));
  52                         if(j<i1) i0 +=1 ;       /* got a carry */
  53                         i1=j;
  54                     }
  55                 }
  56                 i1 &= (~i);
  57             }
  58         }
  59         SET_FLT128_WORDS64(x,i0,i1);
  60         return x;
  61 }