1 
2 /*============================================================================
3 
4 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
5 Package, Release 3e, by John R. Hauser.
6 
7 Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017 The Regents of the
8 University of California.  All rights reserved.
9 
10 Redistribution and use in source and binary forms, with or without
11 modification, are permitted provided that the following conditions are met:
12 
13  1. Redistributions of source code must retain the above copyright notice,
14     this list of conditions, and the following disclaimer.
15 
16  2. Redistributions in binary form must reproduce the above copyright notice,
17     this list of conditions, and the following disclaimer in the documentation
18     and/or other materials provided with the distribution.
19 
20  3. Neither the name of the University nor the names of its contributors may
21     be used to endorse or promote products derived from this software without
22     specific prior written permission.
23 
24 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
25 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
26 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
27 DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
28 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
29 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 
35 =============================================================================*/
36 
37 #include <stdbool.h>
38 #include <stdint.h>
39 #include "platform.h"
40 #include "internals.h"
41 #include "specialize.h"
42 #include "softfloat.h"
43 
44 uint_fast32_t
softfloat_roundToUI32(bool sign,uint_fast64_t sig,uint_fast8_t roundingMode,bool exact)45  softfloat_roundToUI32(
46      bool sign, uint_fast64_t sig, uint_fast8_t roundingMode, bool exact )
47 {
48     uint_fast16_t roundIncrement, roundBits;
49     uint_fast32_t z;
50 
51     /*------------------------------------------------------------------------
52     *------------------------------------------------------------------------*/
53     roundIncrement = 0x800;
54     if (
55         (roundingMode != softfloat_round_near_maxMag)
56             && (roundingMode != softfloat_round_near_even)
57     ) {
58         roundIncrement = 0;
59         if ( sign ) {
60             if ( !sig ) return 0;
61             if ( roundingMode == softfloat_round_min ) goto invalid;
62 #ifdef SOFTFLOAT_ROUND_ODD
63             if ( roundingMode == softfloat_round_odd ) goto invalid;
64 #endif
65         } else {
66             if ( roundingMode == softfloat_round_max ) roundIncrement = 0xFFF;
67         }
68     }
69     roundBits = sig & 0xFFF;
70     sig += roundIncrement;
71     if ( sig & UINT64_C( 0xFFFFF00000000000 ) ) goto invalid;
72     z = sig>>12;
73     if (
74         (roundBits == 0x800) && (roundingMode == softfloat_round_near_even)
75     ) {
76         z &= ~(uint_fast32_t) 1;
77     }
78     if ( sign && z ) goto invalid;
79     if ( roundBits ) {
80 #ifdef SOFTFLOAT_ROUND_ODD
81         if ( roundingMode == softfloat_round_odd ) z |= 1;
82 #endif
83         if ( exact ) softfloat_exceptionFlags |= softfloat_flag_inexact;
84     }
85     return z;
86     /*------------------------------------------------------------------------
87     *------------------------------------------------------------------------*/
88  invalid:
89     softfloat_raiseFlags( softfloat_flag_invalid );
90     return sign ? ui32_fromNegOverflow : ui32_fromPosOverflow;
91 
92 }
93 
94