gonzui

    1: /****************************************************************
    2: 
    3: The author of this software is David M. Gay.
    4: 
    5: Copyright (C) 1998, 2000 by Lucent Technologies
    6: All Rights Reserved
    7: 
    8: Permission to use, copy, modify, and distribute this software and
    9: its documentation for any purpose and without fee is hereby
   10: granted, provided that the above copyright notice appear in all
   11: copies and that both that the copyright notice and this
   12: permission notice and warranty disclaimer appear in supporting
   13: documentation, and that the name of Lucent or any of its entities
   14: not be used in advertising or publicity pertaining to
   15: distribution of the software without specific, written prior
   16: permission.
   17: 
   18: LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
   19: INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
   20: IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
   21: SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   22: WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
   23: IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
   24: ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
   25: THIS SOFTWARE.
   26: 
   27: ****************************************************************/
   28: 
   29: /* Please send bug reports to David M. Gay (dmg at acm dot org,
   30:  * with " at " changed at "@" and " dot " changed to ".").      */
   31: 
   32: #include "gdtoaimp.h"
   33: 
   34:  float
   35: #ifdef KR_headers
   36: strtof(s, sp) CONST char *s; char **sp;
   37: #else
   38: strtof(CONST char *s, char **sp)
   39: #endif
   40: {
   41:         static FPI fpi0 = { 24, 1-127-24+1,  254-127-24+1, 1, SI };
   42:         ULong bits[1];
   43:         Long exp;
   44:         int k;
   45:         union { ULong L[1]; float f; } u;
   46: #ifdef Honor_FLT_ROUNDS
   47: #include "gdtoa_fltrnds.h"
   48: #else
   49: #define fpi &fpi0
   50: #endif
   51: 
   52:         k = strtodg(s, sp, fpi, &exp, bits);
   53:         switch(k & STRTOG_Retmask) {
   54:           case STRTOG_NoNumber:
   55:           case STRTOG_Zero:
   56:                 u.L[0] = 0;
   57:                 break;
   58: 
   59:           case STRTOG_Normal:
   60:           case STRTOG_NaNbits:
   61:                 u.L[0] = (bits[0] & 0x7fffff) | ((exp + 0x7f + 23) << 23);
   62:                 break;
   63: 
   64:           case STRTOG_Denormal:
   65:                 u.L[0] = bits[0];
   66:                 break;
   67: 
   68:           case STRTOG_NoMemory:
   69:                 /*errno = ERANGE*/;
   70:                 /* FALLTHROUGH */
   71:           case STRTOG_Infinite:
   72:                 u.L[0] = 0x7f800000;
   73:                 break;
   74: 
   75:           case STRTOG_NaN:
   76:                 u.L[0] = f_QNAN;
   77:           }
   78:         if (k & STRTOG_Neg)
   79:                 u.L[0] |= 0x80000000L;
   80:         return u.f;
   81:         }