s_lround.c - vx32 - Local 9vx git repository for patches.
 (HTM) git clone git://r-36.net/vx32
 (DIR) Log
 (DIR) Files
 (DIR) Refs
       ---
       s_lround.c (2452B)
       ---
            1 /*-
            2  * Copyright (c) 2005 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 <fenv.h>
           28 #include <math.h>
           29 #include <limits.h>
           30 
           31 #ifndef type
           32 #define type                double
           33 #define        roundit                round
           34 #define dtype                long
           35 #define        DTYPE_MIN        LONG_MIN
           36 #define        DTYPE_MAX        LONG_MAX
           37 #define        fn                lround
           38 #endif
           39 
           40 /*
           41  * If type has more precision than dtype, the endpoints dtype_(min|max) are
           42  * of the form xxx.5; they are "out of range" because lround() rounds away
           43  * from 0.  On the other hand, if type has less precision than dtype, then
           44  * all values that are out of range are integral, so we might as well assume
           45  * that everything is in range.  (The correct condition in this case is
           46  * harder to express.)  At compile time, INRANGE(x) should reduce to two
           47  * floating-point comparisons in the former case, or TRUE otherwise.
           48  */
           49 static const double dtype_min = DTYPE_MIN - 0.5;
           50 static const double dtype_max = DTYPE_MAX + 0.5;
           51 #define        INRANGE(x)        (dtype_max - DTYPE_MAX != 0.5 || \
           52                          ((x) > dtype_min && (x) < dtype_max))
           53 
           54 dtype
           55 fn(type x)
           56 {
           57 
           58         if (INRANGE(x)) {
           59                 x = roundit(x);
           60                 return ((dtype)x);
           61         } else {
           62                 feraiseexcept(FE_INVALID);
           63                 return (DTYPE_MAX);
           64         }
           65 }