Line data    Source code

       1             : /*-
       2             :  * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
       3             :  * All rights reserved.
       4             :  *
       5             :  * Redistribution and use in source and binary forms, with or without
       6             :  * modification, are permitted provided that the following conditions
       7             :  * are met:
       8             :  * 1. Redistributions of source code must retain the above copyright
       9             :  *    notice, this list of conditions and the following disclaimer.
      10             :  * 2. Redistributions in binary form must reproduce the above copyright
      11             :  *    notice, this list of conditions and the following disclaimer in the
      12             :  *    documentation and/or other materials provided with the distribution.
      13             :  *
      14             :  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
      15             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      16             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      17             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
      18             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      19             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      20             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      21             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      22             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      23             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      24             :  * SUCH DAMAGE.
      25             :  */
      26             : 
      27             : //#include <sys/cdefs.h>
      28             : //__FBSDID("$FreeBSD$");
      29             : 
      30             : #include <fenv.h>
      31             : #include "math_private.h"
      32             : 
      33             : /*
      34             :  * We save and restore the floating-point environment to avoid raising
      35             :  * an inexact exception.  We can get away with using fesetenv()
      36             :  * instead of feclearexcept()/feupdateenv() to restore the environment
      37             :  * because the only exception defined for rint() is overflow, and
      38             :  * rounding can't overflow as long as emax >= p.
      39             :  *
      40             :  * The volatile keyword is needed below because clang incorrectly assumes
      41             :  * that rint won't raise any floating-point exceptions. Declaring ret volatile
      42             :  * is sufficient to trick the compiler into doing the right thing.
      43             :  */
      44             : #define DECL(type, fn, rint)    \
      45             : type                            \
      46             : fn(type x)                      \
      47             : {                               \
      48             :         volatile type ret;      \
      49             :         fenv_t env;             \
      50             :                                 \
      51             :         fegetenv(&env);             \
      52             :         ret = rint(x);          \
      53             :         fesetenv(&env);             \
      54             :         return (ret);           \
      55             : }
      56             : 
      57           0 : DECL(double, nearbyint, rint)
      58           0 : DECL(float, nearbyintf, rintf)