gonzui

    1: /* s_ceilf.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 "math.h"
   17: #include "math_private.h"
   18: 
   19: static const float huge = 1.0e30;
   20: 
   21: float
   22: ceilf(float x)
   23: {
   24:         int32_t i0,jj0;
   25:         u_int32_t i;
   26: 
   27:         GET_FLOAT_WORD(i0,x);
   28:         jj0 = ((i0>>23)&0xff)-0x7f;
   29:         if(jj0<23) {
   30:             if(jj0<0) {        /* raise inexact if x != 0 */
   31:                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
   32:                     if(i0<0) {i0=0x80000000;} 
   33:                     else if(i0!=0) { i0=0x3f800000;}
   34:                 }
   35:             } else {
   36:                 i = (0x007fffff)>>jj0;
   37:                 if((i0&i)==0) return x; /* x is integral */
   38:                 if(huge+x>(float)0.0) {       /* raise inexact flag */
   39:                     if(i0>0) i0 += (0x00800000)>>jj0;
   40:                     i0 &= (~i);
   41:                 }
   42:             }
   43:         } else {
   44:             if(jj0==0x80) return x+x;  /* inf or NaN */
   45:             else return x;             /* x is integral */
   46:         }
   47:         SET_FLOAT_WORD(x,i0);
   48:         return x;
   49: }