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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
/* Copyright (C) 2007-2013 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
#include "bid_internal.h"
/*
* Takes a BID32 as input and converts it to a BID64 and returns it.
*/
TYPE0_FUNCTION_ARGTYPE1_NORND (UINT64, bid32_to_bid64, UINT32, x)
UINT64 res;
UINT32 sign_x;
int exponent_x;
UINT32 coefficient_x;
if (!unpack_BID32 (&sign_x, &exponent_x, &coefficient_x, x)) {
// Inf, NaN, 0
if (((x) & 0x78000000) == 0x78000000) {
if (((x) & 0x7e000000) == 0x7e000000) { // sNaN
#ifdef SET_STATUS_FLAGS
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
}
res = (coefficient_x & 0x000fffff);
res *= 1000000000;
res |= ((((UINT64) coefficient_x) << 32) & 0xfc00000000000000ull);
BID_RETURN (res);
}
}
res =
very_fast_get_BID64_small_mantissa (((UINT64) sign_x) << 32,
exponent_x +
DECIMAL_EXPONENT_BIAS -
DECIMAL_EXPONENT_BIAS_32,
(UINT64) coefficient_x);
BID_RETURN (res);
} // convert_bid32_to_bid64
/*
* Takes a BID64 as input and converts it to a BID32 and returns it.
*/
#if DECIMAL_CALL_BY_REFERENCE
void
bid64_to_bid32 (UINT32 * pres,
UINT64 *
px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
_EXC_INFO_PARAM) {
UINT64 x;
#else
UINT32
bid64_to_bid32 (UINT64 x _RND_MODE_PARAM _EXC_FLAGS_PARAM
_EXC_MASKS_PARAM _EXC_INFO_PARAM) {
#endif
UINT128 Q;
UINT64 sign_x, coefficient_x, remainder_h, carry, Stemp;
UINT32 res;
int_float tempx;
int exponent_x, bin_expon_cx, extra_digits, rmode = 0, amount;
unsigned status = 0;
#if DECIMAL_CALL_BY_REFERENCE
#if !DECIMAL_GLOBAL_ROUNDING
_IDEC_round rnd_mode = *prnd_mode;
#endif
x = *px;
#endif
// unpack arguments, check for NaN or Infinity, 0
if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) {
if (((x) & 0x7800000000000000ull) == 0x7800000000000000ull) {
res = (coefficient_x & 0x0003ffffffffffffull);
res /= 1000000000ull;
res |= ((coefficient_x >> 32) & 0xfc000000);
#ifdef SET_STATUS_FLAGS
if ((x & SNAN_MASK64) == SNAN_MASK64) // sNaN
__set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
BID_RETURN (res);
}
exponent_x =
exponent_x - DECIMAL_EXPONENT_BIAS + DECIMAL_EXPONENT_BIAS_32;
if (exponent_x < 0)
exponent_x = 0;
if (exponent_x > DECIMAL_MAX_EXPON_32)
exponent_x = DECIMAL_MAX_EXPON_32;
res = (sign_x >> 32) | (exponent_x << 23);
BID_RETURN (res);
}
exponent_x =
exponent_x - DECIMAL_EXPONENT_BIAS + DECIMAL_EXPONENT_BIAS_32;
// check number of digits
if (coefficient_x >= 10000000) {
tempx.d = (float) coefficient_x;
bin_expon_cx = ((tempx.i >> 23) & 0xff) - 0x7f;
extra_digits = estimate_decimal_digits[bin_expon_cx] - 7;
// add test for range
if (coefficient_x >= power10_index_binexp[bin_expon_cx])
extra_digits++;
#ifndef IEEE_ROUND_NEAREST_TIES_AWAY
#ifndef IEEE_ROUND_NEAREST
rmode = rnd_mode;
if (sign_x && (unsigned) (rmode - 1) < 2)
rmode = 3 - rmode;
#else
rmode = 0;
#endif
#else
rmode = 0;
#endif
exponent_x += extra_digits;
if ((exponent_x < 0) && (exponent_x + MAX_FORMAT_DIGITS_32 >= 0)) {
status = UNDERFLOW_EXCEPTION;
if (exponent_x == -1)
if (coefficient_x + round_const_table[rmode][extra_digits] >=
power10_table_128[extra_digits + 7].w[0])
status = 0;
extra_digits -= exponent_x;
exponent_x = 0;
}
coefficient_x += round_const_table[rmode][extra_digits];
__mul_64x64_to_128 (Q, coefficient_x,
reciprocals10_64[extra_digits]);
// now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128
amount = short_recip_scale[extra_digits];
coefficient_x = Q.w[1] >> amount;
#ifndef IEEE_ROUND_NEAREST_TIES_AWAY
#ifndef IEEE_ROUND_NEAREST
if (rmode == 0) //ROUNDING_TO_NEAREST
#endif
if (coefficient_x & 1) {
// check whether fractional part of initial_P/10^extra_digits
// is exactly .5
// get remainder
remainder_h = Q.w[1] << (64 - amount);
if (!remainder_h && (Q.w[0] < reciprocals10_64[extra_digits]))
coefficient_x--;
}
#endif
#ifdef SET_STATUS_FLAGS
{
status |= INEXACT_EXCEPTION;
// get remainder
remainder_h = Q.w[1] << (64 - amount);
switch (rmode) {
case ROUNDING_TO_NEAREST:
case ROUNDING_TIES_AWAY:
// test whether fractional part is 0
if (remainder_h == 0x8000000000000000ull
&& (Q.w[0] < reciprocals10_64[extra_digits]))
status = EXACT_STATUS;
break;
case ROUNDING_DOWN:
case ROUNDING_TO_ZERO:
if (!remainder_h && (Q.w[0] < reciprocals10_64[extra_digits]))
status = EXACT_STATUS;
break;
default:
// round up
__add_carry_out (Stemp, carry, Q.w[0],
reciprocals10_64[extra_digits]);
if ((remainder_h >> (64 - amount)) + carry >=
(((UINT64) 1) << amount))
status = EXACT_STATUS;
}
if (status != EXACT_STATUS)
__set_status_flags (pfpsf, status);
}
#endif
}
res =
get_BID32 ((UINT32) (sign_x >> 32),
exponent_x, coefficient_x, rnd_mode, pfpsf);
BID_RETURN (res);
}
|
