Open Broadcaster Software
Free, open source software for live streaming and recording
util_uint128.h
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1 /*
2  * Copyright (c) 2015 Hugh Bailey <obs.jim@gmail.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #pragma once
18 
19 struct util_uint128 {
20  union {
21  uint32_t i32[4];
22  struct {
23  uint64_t low;
24  uint64_t high;
25  };
26  };
27 };
28 
29 typedef struct util_uint128 util_uint128_t;
30 
31 static inline util_uint128_t util_add128(util_uint128_t a, util_uint128_t b)
32 {
33  util_uint128_t out;
34  uint64_t val;
35 
36  val = (a.low & 0xFFFFFFFFULL) + (b.low & 0xFFFFFFFFULL);
37  out.i32[0] = (uint32_t)(val & 0xFFFFFFFFULL);
38  val >>= 32;
39 
40  val += (a.low >> 32) + (b.low >> 32);
41  out.i32[1] = (uint32_t)val;
42  val >>= 32;
43 
44  val += (a.high & 0xFFFFFFFFULL) + (b.high & 0xFFFFFFFFULL);
45  out.i32[2] = (uint32_t)(val & 0xFFFFFFFFULL);
46  val >>= 32;
47 
48  val += (a.high >> 32) + (b.high >> 32);
49  out.i32[3] = (uint32_t)val;
50 
51  return out;
52 }
53 
54 static inline util_uint128_t util_lshift64_internal_32(uint64_t a)
55 {
56  util_uint128_t val;
57  val.low = a << 32;
58  val.high = a >> 32;
59  return val;
60 }
61 
62 static inline util_uint128_t util_lshift64_internal_64(uint64_t a)
63 {
64  util_uint128_t val;
65  val.low = 0;
66  val.high = a;
67  return val;
68 }
69 
70 static inline util_uint128_t util_mul64_64(uint64_t a, uint64_t b)
71 {
72  util_uint128_t out;
73  uint64_t m;
74 
75  m = (a & 0xFFFFFFFFULL) * (b & 0xFFFFFFFFULL);
76  out.low = m;
77  out.high = 0;
78 
79  m = (a >> 32) * (b & 0xFFFFFFFFULL);
80  out = util_add128(out, util_lshift64_internal_32(m));
81 
82  m = (a & 0xFFFFFFFFULL) * (b >> 32);
83  out = util_add128(out, util_lshift64_internal_32(m));
84 
85  m = (a >> 32) * (b >> 32);
86  out = util_add128(out, util_lshift64_internal_64(m));
87 
88  return out;
89 }
90 
91 static inline util_uint128_t util_div128_32(util_uint128_t a, uint32_t b)
92 {
93  util_uint128_t out;
94  uint64_t val = 0;
95 
96  for (int i = 3; i >= 0; i--) {
97  val = (val << 32) | a.i32[i];
98  if (val < b) {
99  out.i32[i] = 0;
100  continue;
101  }
102 
103  out.i32[i] = (uint32_t)(val / b);
104  val = val % b;
105  }
106 
107  return out;
108 }
util_uint128::high
uint64_t high
Definition: util_uint128.h:24
util_uint128
Definition: util_uint128.h:19
util_uint128::low
uint64_t low
Definition: util_uint128.h:23
util_uint128::i32
uint32_t i32[4]
Definition: util_uint128.h:21