newlib/libm/math/sf_ceil.c

   1 /* sf_ceil.c -- float version of s_ceil.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 "fdlibm.h"
  17
  18 #ifdef __STDC__
  19 static const float huge = 1.0e30;
  20 #else
  21 static float huge = 1.0e30;
  22 #endif
  23
  24 #ifdef __STDC__
  25         float ceilf(float x)
  26 #else
  27         float ceilf(x)
  28         float x;
  29 #endif
  30 {
  31         __int32_t i0,j0;
  32         __uint32_t i,ix;
  33         GET_FLOAT_WORD(i0,x);
  34         ix = (i0&0x7fffffff);
  35         j0 = (ix>>23)-0x7f;
  36         if(j0<23) {
  37             if(j0<0) {  /* raise inexact if x != 0 */
  38                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
  39                     if(i0<0) {i0=0x80000000;}
  40                     else if(!FLT_UWORD_IS_ZERO(ix)) { i0=0x3f800000;}
  41                 }
  42             } else {
  43                 i = (0x007fffff)>>j0;
  44                 if((i0&i)==0) return x; /* x is integral */
  45                 if(huge+x>(float)0.0) { /* raise inexact flag */
  46                     if(i0>0) i0 += (0x00800000)>>j0;
  47                     i0 &= (~i);
  48                 }
  49             }
  50         } else {
  51             if(!FLT_UWORD_IS_FINITE(ix)) return x+x; /* inf or NaN */
  52             else return x;              /* x is integral */
  53         }
  54         SET_FLOAT_WORD(x,i0);
  55         return x;
  56 }
  57
  58 #ifdef _DOUBLE_IS_32BITS
  59
  60 #ifdef __STDC__
  61         double ceil(double x)
  62 #else
  63         double ceil(x)
  64         double x;
  65 #endif
  66 {
  67         return (double) ceilf((float) x);
  68 }
  69
  70 #endif /* defined(_DOUBLE_IS_32BITS) */