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
f64_mul(float64_t a,float64_t b)45 float64_t f64_mul( float64_t a, float64_t b )
46 {
47 union ui64_f64 uA;
48 uint_fast64_t uiA;
49 bool signA;
50 int_fast16_t expA;
51 uint_fast64_t sigA;
52 union ui64_f64 uB;
53 uint_fast64_t uiB;
54 bool signB;
55 int_fast16_t expB;
56 uint_fast64_t sigB;
57 bool signZ;
58 uint_fast64_t magBits;
59 struct exp16_sig64 normExpSig;
60 int_fast16_t expZ;
61 #ifdef SOFTFLOAT_FAST_INT64
62 struct uint128 sig128Z;
63 #else
64 uint32_t sig128Z[4];
65 #endif
66 uint_fast64_t sigZ, uiZ;
67 union ui64_f64 uZ;
68
69 /*------------------------------------------------------------------------
70 *------------------------------------------------------------------------*/
71 uA.f = a;
72 uiA = uA.ui;
73 signA = signF64UI( uiA );
74 expA = expF64UI( uiA );
75 sigA = fracF64UI( uiA );
76 uB.f = b;
77 uiB = uB.ui;
78 signB = signF64UI( uiB );
79 expB = expF64UI( uiB );
80 sigB = fracF64UI( uiB );
81 signZ = signA ^ signB;
82 /*------------------------------------------------------------------------
83 *------------------------------------------------------------------------*/
84 if ( expA == 0x7FF ) {
85 if ( sigA || ((expB == 0x7FF) && sigB) ) goto propagateNaN;
86 magBits = expB | sigB;
87 goto infArg;
88 }
89 if ( expB == 0x7FF ) {
90 if ( sigB ) goto propagateNaN;
91 magBits = expA | sigA;
92 goto infArg;
93 }
94 /*------------------------------------------------------------------------
95 *------------------------------------------------------------------------*/
96 if ( ! expA ) {
97 if ( ! sigA ) goto zero;
98 normExpSig = softfloat_normSubnormalF64Sig( sigA );
99 expA = normExpSig.exp;
100 sigA = normExpSig.sig;
101 }
102 if ( ! expB ) {
103 if ( ! sigB ) goto zero;
104 normExpSig = softfloat_normSubnormalF64Sig( sigB );
105 expB = normExpSig.exp;
106 sigB = normExpSig.sig;
107 }
108 /*------------------------------------------------------------------------
109 *------------------------------------------------------------------------*/
110 expZ = expA + expB - 0x3FF;
111 sigA = (sigA | UINT64_C( 0x0010000000000000 ))<<10;
112 sigB = (sigB | UINT64_C( 0x0010000000000000 ))<<11;
113 #ifdef SOFTFLOAT_FAST_INT64
114 sig128Z = softfloat_mul64To128( sigA, sigB );
115 sigZ = sig128Z.v64 | (sig128Z.v0 != 0);
116 #else
117 softfloat_mul64To128M( sigA, sigB, sig128Z );
118 sigZ =
119 (uint64_t) sig128Z[indexWord( 4, 3 )]<<32 | sig128Z[indexWord( 4, 2 )];
120 if ( sig128Z[indexWord( 4, 1 )] || sig128Z[indexWord( 4, 0 )] ) sigZ |= 1;
121 #endif
122 if ( sigZ < UINT64_C( 0x4000000000000000 ) ) {
123 --expZ;
124 sigZ <<= 1;
125 }
126 return softfloat_roundPackToF64( signZ, expZ, sigZ );
127 /*------------------------------------------------------------------------
128 *------------------------------------------------------------------------*/
129 propagateNaN:
130 uiZ = softfloat_propagateNaNF64UI( uiA, uiB );
131 goto uiZ;
132 /*------------------------------------------------------------------------
133 *------------------------------------------------------------------------*/
134 infArg:
135 if ( ! magBits ) {
136 softfloat_raiseFlags( softfloat_flag_invalid );
137 uiZ = defaultNaNF64UI;
138 } else {
139 uiZ = packToF64UI( signZ, 0x7FF, 0 );
140 }
141 goto uiZ;
142 /*------------------------------------------------------------------------
143 *------------------------------------------------------------------------*/
144 zero:
145 uiZ = packToF64UI( signZ, 0, 0 );
146 uiZ:
147 uZ.ui = uiZ;
148 return uZ.f;
149
150 }
151
152