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 The Regents of the University of California.
8 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
f128_mul(float128_t a,float128_t b)44 float128_t f128_mul( float128_t a, float128_t b )
45 {
46 union ui128_f128 uA;
47 uint_fast64_t uiA64, uiA0;
48 bool signA;
49 int_fast32_t expA;
50 struct uint128 sigA;
51 union ui128_f128 uB;
52 uint_fast64_t uiB64, uiB0;
53 bool signB;
54 int_fast32_t expB;
55 struct uint128 sigB;
56 bool signZ;
57 uint_fast64_t magBits;
58 struct exp32_sig128 normExpSig;
59 int_fast32_t expZ;
60 uint64_t sig256Z[4];
61 uint_fast64_t sigZExtra;
62 struct uint128 sigZ;
63 struct uint128_extra sig128Extra;
64 struct uint128 uiZ;
65 union ui128_f128 uZ;
66
67 /*------------------------------------------------------------------------
68 *------------------------------------------------------------------------*/
69 uA.f = a;
70 uiA64 = uA.ui.v64;
71 uiA0 = uA.ui.v0;
72 signA = signF128UI64( uiA64 );
73 expA = expF128UI64( uiA64 );
74 sigA.v64 = fracF128UI64( uiA64 );
75 sigA.v0 = uiA0;
76 uB.f = b;
77 uiB64 = uB.ui.v64;
78 uiB0 = uB.ui.v0;
79 signB = signF128UI64( uiB64 );
80 expB = expF128UI64( uiB64 );
81 sigB.v64 = fracF128UI64( uiB64 );
82 sigB.v0 = uiB0;
83 signZ = signA ^ signB;
84 /*------------------------------------------------------------------------
85 *------------------------------------------------------------------------*/
86 if ( expA == 0x7FFF ) {
87 if (
88 (sigA.v64 | sigA.v0) || ((expB == 0x7FFF) && (sigB.v64 | sigB.v0))
89 ) {
90 goto propagateNaN;
91 }
92 magBits = expB | sigB.v64 | sigB.v0;
93 goto infArg;
94 }
95 if ( expB == 0x7FFF ) {
96 if ( sigB.v64 | sigB.v0 ) goto propagateNaN;
97 magBits = expA | sigA.v64 | sigA.v0;
98 goto infArg;
99 }
100 /*------------------------------------------------------------------------
101 *------------------------------------------------------------------------*/
102 if ( ! expA ) {
103 if ( ! (sigA.v64 | sigA.v0) ) goto zero;
104 normExpSig = softfloat_normSubnormalF128Sig( sigA.v64, sigA.v0 );
105 expA = normExpSig.exp;
106 sigA = normExpSig.sig;
107 }
108 if ( ! expB ) {
109 if ( ! (sigB.v64 | sigB.v0) ) goto zero;
110 normExpSig = softfloat_normSubnormalF128Sig( sigB.v64, sigB.v0 );
111 expB = normExpSig.exp;
112 sigB = normExpSig.sig;
113 }
114 /*------------------------------------------------------------------------
115 *------------------------------------------------------------------------*/
116 expZ = expA + expB - 0x4000;
117 sigA.v64 |= UINT64_C( 0x0001000000000000 );
118 sigB = softfloat_shortShiftLeft128( sigB.v64, sigB.v0, 16 );
119 softfloat_mul128To256M( sigA.v64, sigA.v0, sigB.v64, sigB.v0, sig256Z );
120 sigZExtra = sig256Z[indexWord( 4, 1 )] | (sig256Z[indexWord( 4, 0 )] != 0);
121 sigZ =
122 softfloat_add128(
123 sig256Z[indexWord( 4, 3 )], sig256Z[indexWord( 4, 2 )],
124 sigA.v64, sigA.v0
125 );
126 if ( UINT64_C( 0x0002000000000000 ) <= sigZ.v64 ) {
127 ++expZ;
128 sig128Extra =
129 softfloat_shortShiftRightJam128Extra(
130 sigZ.v64, sigZ.v0, sigZExtra, 1 );
131 sigZ = sig128Extra.v;
132 sigZExtra = sig128Extra.extra;
133 }
134 return
135 softfloat_roundPackToF128( signZ, expZ, sigZ.v64, sigZ.v0, sigZExtra );
136 /*------------------------------------------------------------------------
137 *------------------------------------------------------------------------*/
138 propagateNaN:
139 uiZ = softfloat_propagateNaNF128UI( uiA64, uiA0, uiB64, uiB0 );
140 goto uiZ;
141 /*------------------------------------------------------------------------
142 *------------------------------------------------------------------------*/
143 infArg:
144 if ( ! magBits ) {
145 softfloat_raiseFlags( softfloat_flag_invalid );
146 uiZ.v64 = defaultNaNF128UI64;
147 uiZ.v0 = defaultNaNF128UI0;
148 goto uiZ;
149 }
150 uiZ.v64 = packToF128UI64( signZ, 0x7FFF, 0 );
151 goto uiZ0;
152 /*------------------------------------------------------------------------
153 *------------------------------------------------------------------------*/
154 zero:
155 uiZ.v64 = packToF128UI64( signZ, 0, 0 );
156 uiZ0:
157 uiZ.v0 = 0;
158 uiZ:
159 uZ.ui = uiZ;
160 return uZ.f;
161
162 }
163
164