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
44void
45 softfloat_addF128M(
46     const uint32_t *aWPtr,
47     const uint32_t *bWPtr,
48     uint32_t *zWPtr,
49     bool negateB
50 )
51{
52    uint32_t uiA96;
53    int32_t expA;
54    uint32_t uiB96;
55    int32_t expB;
56    uint32_t uiZ96;
57    bool signZ, signB;
58    const uint32_t *tempPtr;
59    uint32_t sig96A, sig96B;
60    int32_t expDiff;
61    uint_fast8_t
62     (*addCarryMRoutinePtr)(
63         uint_fast8_t,
64         const uint32_t *,
65         const uint32_t *,
66         uint_fast8_t,
67         uint32_t *
68     );
69    uint32_t extSigZ[5], wordSigZ;
70    uint_fast8_t carry;
71    void (*roundPackRoutinePtr)( bool, int32_t, uint32_t *, uint32_t * );
72
73    /*------------------------------------------------------------------------
74    *------------------------------------------------------------------------*/
75    uiA96 = aWPtr[indexWordHi( 4 )];
76    expA = expF128UI96( uiA96 );
77    uiB96 = bWPtr[indexWordHi( 4 )];
78    expB = expF128UI96( uiB96 );
79    /*------------------------------------------------------------------------
80    *------------------------------------------------------------------------*/
81    if ( (expA == 0x7FFF) || (expB == 0x7FFF) ) {
82        if ( softfloat_tryPropagateNaNF128M( aWPtr, bWPtr, zWPtr ) ) return;
83        uiZ96 = uiA96;
84        if ( expB == 0x7FFF ) {
85            uiZ96 = uiB96 ^ packToF128UI96( negateB, 0, 0 );
86            if ( (expA == 0x7FFF) && (uiZ96 != uiA96) ) {
87                softfloat_invalidF128M( zWPtr );
88                return;
89            }
90        }
91        zWPtr[indexWordHi( 4 )] = uiZ96;
92        zWPtr[indexWord( 4, 2 )] = 0;
93        zWPtr[indexWord( 4, 1 )] = 0;
94        zWPtr[indexWord( 4, 0 )] = 0;
95        return;
96    }
97    /*------------------------------------------------------------------------
98    *------------------------------------------------------------------------*/
99    signZ = signF128UI96( uiA96 );
100    signB = signF128UI96( uiB96 ) ^ negateB;
101    negateB = (signZ != signB);
102    if ( (uint32_t) (uiA96<<1) < (uint32_t) (uiB96<<1) ) {
103        signZ = signB;
104        expA = expB;
105        expB = expF128UI96( uiA96 );
106        tempPtr = aWPtr;
107        aWPtr = bWPtr;
108        bWPtr = tempPtr;
109        uiA96 = uiB96;
110        uiB96 = bWPtr[indexWordHi( 4 )];
111    }
112    sig96A = fracF128UI96( uiA96 );
113    sig96B = fracF128UI96( uiB96 );
114    if ( expA ) {
115        --expA;
116        sig96A |= 0x00010000;
117        if ( expB ) {
118            --expB;
119            sig96B |= 0x00010000;
120        }
121    }
122    /*------------------------------------------------------------------------
123    *------------------------------------------------------------------------*/
124    addCarryMRoutinePtr =
125        negateB ? softfloat_addComplCarryM : softfloat_addCarryM;
126    expDiff = expA - expB;
127    if ( expDiff ) {
128        /*--------------------------------------------------------------------
129        *--------------------------------------------------------------------*/
130        extSigZ[indexWordHi( 5 )] = sig96B;
131        extSigZ[indexWord( 5, 3 )] = bWPtr[indexWord( 4, 2 )];
132        extSigZ[indexWord( 5, 2 )] = bWPtr[indexWord( 4, 1 )];
133        extSigZ[indexWord( 5, 1 )] = bWPtr[indexWord( 4, 0 )];
134        extSigZ[indexWord( 5, 0 )] = 0;
135        softfloat_shiftRightJam160M( extSigZ, expDiff, extSigZ );
136        sig96B = extSigZ[indexWordHi( 5 )];
137        carry = 0;
138        if ( negateB ) {
139            sig96B = ~sig96B;
140            wordSigZ = extSigZ[indexWordLo( 5 )];
141            extSigZ[indexWordLo( 5 )] = -wordSigZ;
142            carry = ! wordSigZ;
143        }
144        carry =
145            (*addCarryMRoutinePtr)(
146                3,
147                &aWPtr[indexMultiwordLo( 4, 3 )],
148                &extSigZ[indexMultiword( 5, 3, 1 )],
149                carry,
150                &extSigZ[indexMultiword( 5, 3, 1 )]
151            );
152        wordSigZ = sig96A + sig96B + carry;
153    } else {
154        /*--------------------------------------------------------------------
155        *--------------------------------------------------------------------*/
156        extSigZ[indexWordLo( 5 )] = 0;
157        carry =
158            (*addCarryMRoutinePtr)(
159                3,
160                &aWPtr[indexMultiwordLo( 4, 3 )],
161                &bWPtr[indexMultiwordLo( 4, 3 )],
162                negateB,
163                &extSigZ[indexMultiword( 5, 3, 1 )]
164            );
165        if ( negateB ) {
166            wordSigZ = sig96A + ~sig96B + carry;
167            if ( wordSigZ & 0x80000000 ) {
168                signZ = ! signZ;
169                carry =
170                    softfloat_addComplCarry96M(
171                        &bWPtr[indexMultiwordLo( 4, 3 )],
172                        &aWPtr[indexMultiwordLo( 4, 3 )],
173                        1,
174                        &extSigZ[indexMultiword( 5, 3, 1 )]
175                    );
176                wordSigZ = sig96B + ~sig96A + carry;
177            } else {
178                if (
179                    ! wordSigZ && ! extSigZ[indexWord( 5, 3 )]
180                        && ! (  extSigZ[indexWord( 5, 2 )]
181                              | extSigZ[indexWord( 5, 1 )]
182                              | extSigZ[indexWord( 5, 0 )]
183                             )
184                ) {
185                    signZ = (softfloat_roundingMode == softfloat_round_min);
186                    zWPtr[indexWordHi( 4 )] = packToF128UI96( signZ, 0, 0 );
187                    zWPtr[indexWord( 4, 2 )] = 0;
188                    zWPtr[indexWord( 4, 1 )] = 0;
189                    zWPtr[indexWord( 4, 0 )] = 0;
190                    return;
191                }
192            }
193        } else {
194            wordSigZ = sig96A + sig96B + carry;
195        }
196    }
197    extSigZ[indexWordHi( 5 )] = wordSigZ;
198    /*------------------------------------------------------------------------
199    *------------------------------------------------------------------------*/
200    roundPackRoutinePtr = softfloat_normRoundPackMToF128M;
201    if ( 0x00010000 <= wordSigZ ) {
202        if ( 0x00020000 <= wordSigZ ) {
203            ++expA;
204            softfloat_shortShiftRightJam160M( extSigZ, 1, extSigZ );
205        }
206        roundPackRoutinePtr = softfloat_roundPackMToF128M;
207    }
208    (*roundPackRoutinePtr)( signZ, expA, extSigZ, zWPtr );
209
210}
211
212