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glibc  2.9
s_modf.c
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00001 /* Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
00002    This file is part of the GNU C Library.
00003 
00004    The GNU C Library is free software; you can redistribute it and/or
00005    modify it under the terms of the GNU Lesser General Public
00006    License as published by the Free Software Foundation; either
00007    version 2.1 of the License, or (at your option) any later version.
00008 
00009    The GNU C Library is distributed in the hope that it will be useful,
00010    but WITHOUT ANY WARRANTY; without even the implied warranty of
00011    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012    Lesser General Public License for more details.
00013 
00014    You should have received a copy of the GNU Lesser General Public
00015    License along with the GNU C Library; if not, write to the Free
00016    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00017    02111-1307 USA.  */
00018 
00019 #include <math.h>
00020 #include "mathimpl.h"
00021 
00022 #ifndef SUFF
00023 #define SUFF
00024 #endif
00025 #ifndef float_type
00026 #define float_type double
00027 #endif
00028 
00029 #define CONCATX(a,b) __CONCAT(a,b)
00030 #define s(name) CONCATX(name,SUFF)
00031 #define m81(func) __m81_u(s(func))
00032 
00033 float_type
00034 s(__modf) (float_type x, float_type *iptr)
00035 {
00036   float_type x_int, result;
00037   unsigned long x_cond;
00038 
00039   __asm ("fintrz%.x %1, %0" : "=f" (x_int) : "f" (x));
00040   *iptr = x_int;
00041   x_cond = __m81_test (x);
00042   if (x_cond & __M81_COND_INF)
00043     {
00044       result = 0;
00045       if (x_cond & __M81_COND_NEG)
00046        result = -result;
00047     }
00048   else if (x_cond & __M81_COND_ZERO)
00049     result = x;
00050   else
00051     result = x - x_int;
00052   return result;
00053 }
00054 
00055 #define weak_aliasx(a,b) weak_alias(a,b)
00056 weak_aliasx(s(__modf), s(modf))