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, 2015 The Regents of the University of
8California.  All 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
44float32_t f32_mul( float32_t a, float32_t b )
45{
46    union ui32_f32 uA;
47    uint_fast32_t uiA;
48    bool signA;
49    int_fast16_t expA;
50    uint_fast32_t sigA;
51    union ui32_f32 uB;
52    uint_fast32_t uiB;
53    bool signB;
54    int_fast16_t expB;
55    uint_fast32_t sigB;
56    bool signZ;
57    uint_fast32_t magBits;
58    struct exp16_sig32 normExpSig;
59    int_fast16_t expZ;
60    uint_fast32_t sigZ, uiZ;
61    union ui32_f32 uZ;
62
63    /*------------------------------------------------------------------------
64    *------------------------------------------------------------------------*/
65    uA.f = a;
66    uiA = uA.ui;
67    signA = signF32UI( uiA );
68    expA  = expF32UI( uiA );
69    sigA  = fracF32UI( uiA );
70    uB.f = b;
71    uiB = uB.ui;
72    signB = signF32UI( uiB );
73    expB  = expF32UI( uiB );
74    sigB  = fracF32UI( uiB );
75    signZ = signA ^ signB;
76    /*------------------------------------------------------------------------
77    *------------------------------------------------------------------------*/
78    if ( expA == 0xFF ) {
79        if ( sigA || ((expB == 0xFF) && sigB) ) goto propagateNaN;
80        magBits = expB | sigB;
81        goto infArg;
82    }
83    if ( expB == 0xFF ) {
84        if ( sigB ) goto propagateNaN;
85        magBits = expA | sigA;
86        goto infArg;
87    }
88    /*------------------------------------------------------------------------
89    *------------------------------------------------------------------------*/
90    if ( ! expA ) {
91        if ( ! sigA ) goto zero;
92        normExpSig = softfloat_normSubnormalF32Sig( sigA );
93        expA = normExpSig.exp;
94        sigA = normExpSig.sig;
95    }
96    if ( ! expB ) {
97        if ( ! sigB ) goto zero;
98        normExpSig = softfloat_normSubnormalF32Sig( sigB );
99        expB = normExpSig.exp;
100        sigB = normExpSig.sig;
101    }
102    /*------------------------------------------------------------------------
103    *------------------------------------------------------------------------*/
104    expZ = expA + expB - 0x7F;
105    sigA = (sigA | 0x00800000)<<7;
106    sigB = (sigB | 0x00800000)<<8;
107    sigZ = softfloat_shortShiftRightJam64( (uint_fast64_t) sigA * sigB, 32 );
108    if ( sigZ < 0x40000000 ) {
109        --expZ;
110        sigZ <<= 1;
111    }
112    return softfloat_roundPackToF32( signZ, expZ, sigZ );
113    /*------------------------------------------------------------------------
114    *------------------------------------------------------------------------*/
115 propagateNaN:
116    uiZ = softfloat_propagateNaNF32UI( uiA, uiB );
117    goto uiZ;
118    /*------------------------------------------------------------------------
119    *------------------------------------------------------------------------*/
120 infArg:
121    if ( ! magBits ) {
122        softfloat_raiseFlags( softfloat_flag_invalid );
123        uiZ = defaultNaNF32UI;
124    } else {
125        uiZ = packToF32UI( signZ, 0xFF, 0 );
126    }
127    goto uiZ;
128    /*------------------------------------------------------------------------
129    *------------------------------------------------------------------------*/
130 zero:
131    uiZ = packToF32UI( signZ, 0, 0 );
132 uiZ:
133    uZ.ui = uiZ;
134    return uZ.f;
135
136}
137
138