blob: 8c0cef91e1568e392c1034c1230a285c7384da45 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
// See LICENSE.SoftFloat for license details.
#include <stdbool.h>
#include <stdint.h>
#include "platform.h"
#include "internals.h"
#include "specialize.h"
#include "softfloat.h"
float32_t f32_roundToInt( float32_t a, int_fast8_t roundingMode, bool exact )
{
union ui32_f32 uA;
uint_fast32_t uiA;
int_fast16_t expA;
uint_fast32_t uiZ;
bool signA;
uint_fast32_t lastBitMask, roundBitsMask;
union ui32_f32 uZ;
uA.f = a;
uiA = uA.ui;
expA = expF32UI( uiA );
if ( 0x96 <= expA ) {
if ( ( expA == 0xFF ) && fracF32UI( uiA ) ) {
uiZ = softfloat_propagateNaNF32UI( uiA, 0 );
goto uiZ;
}
return a;
}
if ( expA <= 0x7E ) {
if ( ! (uint32_t) ( uiA<<1 ) ) return a;
if ( exact ) softfloat_raiseFlags( softfloat_flag_inexact );
signA = signF32UI( uiA );
switch ( roundingMode ) {
case softfloat_round_nearest_even:
if ( ( expA == 0x7E ) && fracF32UI( uiA ) ) {
uiZ = packToF32UI( signA, 0x7F, 0 );
goto uiZ;
}
break;
case softfloat_round_min:
uiZ = signA ? 0xBF800000 : 0;
goto uiZ;
case softfloat_round_max:
uiZ = signA ? 0x80000000 : 0x3F800000;
goto uiZ;
case softfloat_round_nearest_maxMag:
if ( expA == 0x7E ) {
uiZ = packToF32UI( signA, 0x7F, 0 );
goto uiZ;
}
break;
}
uiZ = packToF32UI( signA, 0, 0 );
goto uiZ;
}
lastBitMask = (uint_fast32_t) 1<<( 0x96 - expA );
roundBitsMask = lastBitMask - 1;
uiZ = uiA;
if ( roundingMode == softfloat_round_nearest_maxMag ) {
uiZ += lastBitMask>>1;
} else if ( roundingMode == softfloat_round_nearest_even ) {
uiZ += lastBitMask>>1;
if ( ! ( uiZ & roundBitsMask ) ) uiZ &= ~ lastBitMask;
} else if ( roundingMode != softfloat_round_minMag ) {
if ( signF32UI( uiZ ) ^ ( roundingMode == softfloat_round_max ) ) {
uiZ += roundBitsMask;
}
}
uiZ &= ~ roundBitsMask;
if ( exact && ( uiZ != uiA ) ) {
softfloat_raiseFlags( softfloat_flag_inexact );
}
uiZ:
uZ.ui = uiZ;
return uZ.f;
}
|
