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
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
|
/**************************************************************************/
/* */
/* OCaml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 2002 Institut National de Recherche en Informatique et */
/* en Automatique. */
/* */
/* All rights reserved. This file is distributed under the terms of */
/* the GNU Lesser General Public License version 2.1, with the */
/* special exception on linking described in the file LICENSE. */
/* */
/**************************************************************************/
/* Software emulation of 64-bit integer arithmetic, for C compilers
that do not support it. */
#ifndef CAML_INT64_EMUL_H
#define CAML_INT64_EMUL_H
#ifdef CAML_INTERNALS
#include <math.h>
#ifdef ARCH_BIG_ENDIAN
#define I64_literal(hi,lo) { hi, lo }
#else
#define I64_literal(hi,lo) { lo, hi }
#endif
#define I64_split(x,hi,lo) (hi = (x).h, lo = (x).l)
/* Unsigned comparison */
static int I64_ucompare(uint64_t x, uint64_t y)
{
if (x.h > y.h) return 1;
if (x.h < y.h) return -1;
if (x.l > y.l) return 1;
if (x.l < y.l) return -1;
return 0;
}
#define I64_ult(x, y) (I64_ucompare(x, y) < 0)
/* Signed comparison */
static int I64_compare(int64_t x, int64_t y)
{
if ((int32_t)x.h > (int32_t)y.h) return 1;
if ((int32_t)x.h < (int32_t)y.h) return -1;
if (x.l > y.l) return 1;
if (x.l < y.l) return -1;
return 0;
}
/* Negation */
static int64_t I64_neg(int64_t x)
{
int64_t res;
res.l = -x.l;
res.h = ~x.h;
if (res.l == 0) res.h++;
return res;
}
/* Addition */
static int64_t I64_add(int64_t x, int64_t y)
{
int64_t res;
res.l = x.l + y.l;
res.h = x.h + y.h;
if (res.l < x.l) res.h++;
return res;
}
/* Subtraction */
static int64_t I64_sub(int64_t x, int64_t y)
{
int64_t res;
res.l = x.l - y.l;
res.h = x.h - y.h;
if (x.l < y.l) res.h--;
return res;
}
/* Multiplication */
static int64_t I64_mul(int64_t x, int64_t y)
{
int64_t res;
uint32_t prod00 = (x.l & 0xFFFF) * (y.l & 0xFFFF);
uint32_t prod10 = (x.l >> 16) * (y.l & 0xFFFF);
uint32_t prod01 = (x.l & 0xFFFF) * (y.l >> 16);
uint32_t prod11 = (x.l >> 16) * (y.l >> 16);
res.l = prod00;
res.h = prod11 + (prod01 >> 16) + (prod10 >> 16);
prod01 = prod01 << 16; res.l += prod01; if (res.l < prod01) res.h++;
prod10 = prod10 << 16; res.l += prod10; if (res.l < prod10) res.h++;
res.h += x.l * y.h + x.h * y.l;
return res;
}
#define I64_is_zero(x) (((x).l | (x).h) == 0)
#define I64_is_negative(x) ((int32_t) (x).h < 0)
#define I64_is_min_int(x) ((x).l == 0 && (x).h == 0x80000000U)
#define I64_is_minus_one(x) (((x).l & (x).h) == 0xFFFFFFFFU)
/* Bitwise operations */
static int64_t I64_and(int64_t x, int64_t y)
{
int64_t res;
res.l = x.l & y.l;
res.h = x.h & y.h;
return res;
}
static int64_t I64_or(int64_t x, int64_t y)
{
int64_t res;
res.l = x.l | y.l;
res.h = x.h | y.h;
return res;
}
static int64_t I64_xor(int64_t x, int64_t y)
{
int64_t res;
res.l = x.l ^ y.l;
res.h = x.h ^ y.h;
return res;
}
/* Shifts */
static int64_t I64_lsl(int64_t x, int s)
{
int64_t res;
s = s & 63;
if (s == 0) return x;
if (s < 32) {
res.l = x.l << s;
res.h = (x.h << s) | (x.l >> (32 - s));
} else {
res.l = 0;
res.h = x.l << (s - 32);
}
return res;
}
static int64_t I64_lsr(int64_t x, int s)
{
int64_t res;
s = s & 63;
if (s == 0) return x;
if (s < 32) {
res.l = (x.l >> s) | (x.h << (32 - s));
res.h = x.h >> s;
} else {
res.l = x.h >> (s - 32);
res.h = 0;
}
return res;
}
static int64_t I64_asr(int64_t x, int s)
{
int64_t res;
s = s & 63;
if (s == 0) return x;
if (s < 32) {
res.l = (x.l >> s) | (x.h << (32 - s));
res.h = (int32_t) x.h >> s;
} else {
res.l = (int32_t) x.h >> (s - 32);
res.h = (int32_t) x.h >> 31;
}
return res;
}
/* Division and modulus */
#define I64_SHL1(x) x.h = (x.h << 1) | (x.l >> 31); x.l <<= 1
#define I64_SHR1(x) x.l = (x.l >> 1) | (x.h << 31); x.h >>= 1
static void I64_udivmod(uint64_t modulus, uint64_t divisor,
uint64_t * quo, uint64_t * mod)
{
int64_t quotient, mask;
int cmp;
quotient.h = 0; quotient.l = 0;
mask.h = 0; mask.l = 1;
while ((int32_t) divisor.h >= 0) {
cmp = I64_ucompare(divisor, modulus);
I64_SHL1(divisor);
I64_SHL1(mask);
if (cmp >= 0) break;
}
while (mask.l | mask.h) {
if (I64_ucompare(modulus, divisor) >= 0) {
quotient.h |= mask.h; quotient.l |= mask.l;
modulus = I64_sub(modulus, divisor);
}
I64_SHR1(mask);
I64_SHR1(divisor);
}
*quo = quotient;
*mod = modulus;
}
static int64_t I64_div(int64_t x, int64_t y)
{
int64_t q, r;
int32_t sign;
sign = x.h ^ y.h;
if ((int32_t) x.h < 0) x = I64_neg(x);
if ((int32_t) y.h < 0) y = I64_neg(y);
I64_udivmod(x, y, &q, &r);
if (sign < 0) q = I64_neg(q);
return q;
}
static int64_t I64_mod(int64_t x, int64_t y)
{
int64_t q, r;
int32_t sign;
sign = x.h;
if ((int32_t) x.h < 0) x = I64_neg(x);
if ((int32_t) y.h < 0) y = I64_neg(y);
I64_udivmod(x, y, &q, &r);
if (sign < 0) r = I64_neg(r);
return r;
}
/* Coercions */
static int64_t I64_of_int32(int32_t x)
{
int64_t res;
res.l = x;
res.h = x >> 31;
return res;
}
#define I64_to_int32(x) ((int32_t) (x).l)
/* Note: we assume sizeof(intnat) = 4 here, which is true otherwise
autoconfiguration would have selected native 64-bit integers */
#define I64_of_intnat I64_of_int32
#define I64_to_intnat I64_to_int32
static double I64_to_double(int64_t x)
{
double res;
int32_t sign = x.h;
if (sign < 0) x = I64_neg(x);
res = ldexp((double) x.h, 32) + x.l;
if (sign < 0) res = -res;
return res;
}
static int64_t I64_of_double(double f)
{
int64_t res;
double frac, integ;
int neg;
neg = (f < 0);
f = fabs(f);
frac = modf(ldexp(f, -32), &integ);
res.h = (uint32_t) integ;
res.l = (uint32_t) ldexp(frac, 32);
if (neg) res = I64_neg(res);
return res;
}
static int64_t I64_bswap(int64_t x)
{
int64_t res;
res.h = (((x.l & 0x000000FF) << 24) |
((x.l & 0x0000FF00) << 8) |
((x.l & 0x00FF0000) >> 8) |
((x.l & 0xFF000000) >> 24));
res.l = (((x.h & 0x000000FF) << 24) |
((x.h & 0x0000FF00) << 8) |
((x.h & 0x00FF0000) >> 8) |
((x.h & 0xFF000000) >> 24));
return res;
}
#endif /* CAML_INTERNALS */
#endif /* CAML_INT64_EMUL_H */
|
