1
2/*============================================================================
3
4This C source file is part of the SoftFloat IEEE Floating-Point Arithmetic
5Package, Release 3e, by John R. Hauser.
6
7Copyright 2011, 2012, 2013, 2014 The Regents of the University of California.
8All rights reserved.
9
10Redistribution and use in source and binary forms, with or without
11modification, 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
24THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS", AND ANY
25EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
26WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ARE
27DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
28DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
29(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
31ON 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
33SOFTWARE, 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
44extFloat80_t
45 softfloat_addMagsExtF80(
46     uint_fast16_t uiA64,
47     uint_fast64_t uiA0,
48     uint_fast16_t uiB64,
49     uint_fast64_t uiB0,
50     bool signZ
51 )
52{
53    int_fast32_t expA;
54    uint_fast64_t sigA;
55    int_fast32_t expB;
56    uint_fast64_t sigB;
57    int_fast32_t expDiff;
58    uint_fast16_t uiZ64;
59    uint_fast64_t uiZ0, sigZ, sigZExtra;
60    struct exp32_sig64 normExpSig;
61    int_fast32_t expZ;
62    struct uint64_extra sig64Extra;
63    struct uint128 uiZ;
64    union { struct extFloat80M s; extFloat80_t f; } uZ;
65
66    /*------------------------------------------------------------------------
67    *------------------------------------------------------------------------*/
68    expA = expExtF80UI64( uiA64 );
69    sigA = uiA0;
70    expB = expExtF80UI64( uiB64 );
71    sigB = uiB0;
72    /*------------------------------------------------------------------------
73    *------------------------------------------------------------------------*/
74    expDiff = expA - expB;
75    if ( ! expDiff ) {
76        if ( expA == 0x7FFF ) {
77            if ( (sigA | sigB) & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) {
78                goto propagateNaN;
79            }
80            uiZ64 = uiA64;
81            uiZ0  = uiA0;
82            goto uiZ;
83        }
84        sigZ = sigA + sigB;
85        sigZExtra = 0;
86        if ( ! expA ) {
87            normExpSig = softfloat_normSubnormalExtF80Sig( sigZ );
88            expZ = normExpSig.exp + 1;
89            sigZ = normExpSig.sig;
90            goto roundAndPack;
91        }
92        expZ = expA;
93        goto shiftRight1;
94    }
95    /*------------------------------------------------------------------------
96    *------------------------------------------------------------------------*/
97    if ( expDiff < 0 ) {
98        if ( expB == 0x7FFF ) {
99            if ( sigB & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN;
100            uiZ64 = packToExtF80UI64( signZ, 0x7FFF );
101            uiZ0  = uiB0;
102            goto uiZ;
103        }
104        expZ = expB;
105        if ( ! expA ) {
106            ++expDiff;
107            sigZExtra = 0;
108            if ( ! expDiff ) goto newlyAligned;
109        }
110        sig64Extra = softfloat_shiftRightJam64Extra( sigA, 0, -expDiff );
111        sigA = sig64Extra.v;
112        sigZExtra = sig64Extra.extra;
113    } else {
114        if ( expA == 0x7FFF ) {
115            if ( sigA & UINT64_C( 0x7FFFFFFFFFFFFFFF ) ) goto propagateNaN;
116            uiZ64 = uiA64;
117            uiZ0  = uiA0;
118            goto uiZ;
119        }
120        expZ = expA;
121        if ( ! expB ) {
122            --expDiff;
123            sigZExtra = 0;
124            if ( ! expDiff ) goto newlyAligned;
125        }
126        sig64Extra = softfloat_shiftRightJam64Extra( sigB, 0, expDiff );
127        sigB = sig64Extra.v;
128        sigZExtra = sig64Extra.extra;
129    }
130 newlyAligned:
131    sigZ = sigA + sigB;
132    if ( sigZ & UINT64_C( 0x8000000000000000 ) ) goto roundAndPack;
133    /*------------------------------------------------------------------------
134    *------------------------------------------------------------------------*/
135 shiftRight1:
136    sig64Extra = softfloat_shortShiftRightJam64Extra( sigZ, sigZExtra, 1 );
137    sigZ = sig64Extra.v | UINT64_C( 0x8000000000000000 );
138    sigZExtra = sig64Extra.extra;
139    ++expZ;
140 roundAndPack:
141    return
142        softfloat_roundPackToExtF80(
143            signZ, expZ, sigZ, sigZExtra, extF80_roundingPrecision );
144    /*------------------------------------------------------------------------
145    *------------------------------------------------------------------------*/
146 propagateNaN:
147    uiZ = softfloat_propagateNaNExtF80UI( uiA64, uiA0, uiB64, uiB0 );
148    uiZ64 = uiZ.v64;
149    uiZ0  = uiZ.v0;
150 uiZ:
151    uZ.s.signExp = uiZ64;
152    uZ.s.signif  = uiZ0;
153    return uZ.f;
154
155}
156
157