1 // SPDX-License-Identifier: BSD-3-Clause
2 
3 /*============================================================================
4 
5 This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
6 Package, Release 3a, by John R. Hauser.
7 
8 Copyright 2011, 2012, 2013, 2014 The Regents of the University of California.
9 All rights reserved.
10 
11 Redistribution and use in source and binary forms, with or without
12 modification, are permitted provided that the following conditions are met:
13 
14  1. Redistributions of source code must retain the above copyright notice,
15     this list of conditions, and the following disclaimer.
16 
17  2. Redistributions in binary form must reproduce the above copyright notice,
18     this list of conditions, and the following disclaimer in the documentation
19     and/or other materials provided with the distribution.
20 
21  3. Neither the name of the University nor the names of its contributors may
22     be used to endorse or promote products derived from this software without
23     specific prior written permission.
24 
25 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
26 EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
27 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
28 DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
29 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
31 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
32 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
33 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 
36 =============================================================================*/
37 
38 #include <stdbool.h>
39 #include <stdint.h>
40 #include "platform.h"
41 #include "internals.h"
42 #include "specialize.h"
43 #include "softfloat.h"
44 
45 /*----------------------------------------------------------------------------
46 | Interpreting the unsigned integer formed from concatenating `uiA64' and
47 | `uiA0' as an 80-bit extended floating-point value, and likewise interpreting
48 | the unsigned integer formed from concatenating `uiB64' and `uiB0' as another
49 | 80-bit extended floating-point value, and assuming at least on of these
50 | floating-point values is a NaN, returns the bit pattern of the combined NaN
51 | result.  If either original floating-point value is a signaling NaN, the
52 | invalid exception is raised.
53 *----------------------------------------------------------------------------*/
54 struct uint128
softfloat_propagateNaNExtF80UI(uint_fast16_t uiA64,uint_fast64_t uiA0,uint_fast16_t uiB64,uint_fast64_t uiB0)55  softfloat_propagateNaNExtF80UI(
56      uint_fast16_t uiA64,
57      uint_fast64_t uiA0,
58      uint_fast16_t uiB64,
59      uint_fast64_t uiB0
60  )
61 {
62     bool isSigNaNA, isSigNaNB;
63     uint_fast64_t uiNonsigA0, uiNonsigB0;
64     uint_fast16_t uiMagA64, uiMagB64;
65     struct uint128 uiZ;
66 
67     /*------------------------------------------------------------------------
68     *------------------------------------------------------------------------*/
69     isSigNaNA = softfloat_isSigNaNExtF80UI( uiA64, uiA0 );
70     isSigNaNB = softfloat_isSigNaNExtF80UI( uiB64, uiB0 );
71     /*------------------------------------------------------------------------
72     | Make NaNs non-signaling.
73     *------------------------------------------------------------------------*/
74     uiNonsigA0 = uiA0 | UINT64_C( 0xC000000000000000 );
75     uiNonsigB0 = uiB0 | UINT64_C( 0xC000000000000000 );
76     /*------------------------------------------------------------------------
77     *------------------------------------------------------------------------*/
78     if ( isSigNaNA | isSigNaNB ) {
79         softfloat_raiseFlags( softfloat_flag_invalid );
80         if ( isSigNaNA ) {
81             if ( isSigNaNB ) goto returnLargerMag;
82             if ( isNaNExtF80UI( uiB64, uiB0 ) ) goto returnB;
83             goto returnA;
84         } else {
85             if ( isNaNExtF80UI( uiA64, uiA0 ) ) goto returnA;
86             goto returnB;
87         }
88     }
89  returnLargerMag:
90     uiMagA64 = uiA64 & 0x7FFF;
91     uiMagB64 = uiB64 & 0x7FFF;
92     if ( uiMagA64 < uiMagB64 ) goto returnB;
93     if ( uiMagB64 < uiMagA64 ) goto returnA;
94     if ( uiNonsigA0 < uiNonsigB0 ) goto returnB;
95     if ( uiNonsigB0 < uiNonsigA0 ) goto returnA;
96     if ( uiA64 < uiB64 ) goto returnA;
97  returnB:
98     uiZ.v64 = uiB64;
99     uiZ.v0  = uiNonsigB0;
100     return uiZ;
101  returnA:
102     uiZ.v64 = uiA64;
103     uiZ.v0  = uiNonsigA0;
104     return uiZ;
105 
106 }
107 
108