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[emacs.git] / lib / u64.h
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1 /* uint64_t-like operations that work even on hosts lacking uint64_t
3 Copyright (C) 2006, 2009-2017 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Paul Eggert. */
20 #include <stdint.h>
22 #ifndef _GL_INLINE_HEADER_BEGIN
23 #error "Please include config.h first."
24 #endif
25 _GL_INLINE_HEADER_BEGIN
26 #ifndef _GL_U64_INLINE
27 # define _GL_U64_INLINE _GL_INLINE
28 #endif
30 /* Return X rotated left by N bits, where 0 < N < 64. */
31 #define u64rol(x, n) u64or (u64shl (x, n), u64shr (x, 64 - n))
33 #ifdef UINT64_MAX
35 /* Native implementations are trivial. See below for comments on what
36 these operations do. */
37 typedef uint64_t u64;
38 # define u64hilo(hi, lo) ((u64) (((u64) (hi) << 32) + (lo)))
39 # define u64init(hi, lo) u64hilo (hi, lo)
40 # define u64lo(x) ((u64) (x))
41 # define u64size(x) u64lo (x)
42 # define u64lt(x, y) ((x) < (y))
43 # define u64and(x, y) ((x) & (y))
44 # define u64or(x, y) ((x) | (y))
45 # define u64xor(x, y) ((x) ^ (y))
46 # define u64plus(x, y) ((x) + (y))
47 # define u64shl(x, n) ((x) << (n))
48 # define u64shr(x, n) ((x) >> (n))
50 #else
52 /* u64 is a 64-bit unsigned integer value.
53 u64init (HI, LO), is like u64hilo (HI, LO), but for use in
54 initializer contexts. */
55 # ifdef WORDS_BIGENDIAN
56 typedef struct { uint32_t hi, lo; } u64;
57 # define u64init(hi, lo) { hi, lo }
58 # else
59 typedef struct { uint32_t lo, hi; } u64;
60 # define u64init(hi, lo) { lo, hi }
61 # endif
63 /* Given the high and low-order 32-bit quantities HI and LO, return a u64
64 value representing (HI << 32) + LO. */
65 _GL_U64_INLINE u64
66 u64hilo (uint32_t hi, uint32_t lo)
68 u64 r;
69 r.hi = hi;
70 r.lo = lo;
71 return r;
74 /* Return a u64 value representing LO. */
75 _GL_U64_INLINE u64
76 u64lo (uint32_t lo)
78 u64 r;
79 r.hi = 0;
80 r.lo = lo;
81 return r;
84 /* Return a u64 value representing SIZE. */
85 _GL_U64_INLINE u64
86 u64size (size_t size)
88 u64 r;
89 r.hi = size >> 31 >> 1;
90 r.lo = size;
91 return r;
94 /* Return X < Y. */
95 _GL_U64_INLINE int
96 u64lt (u64 x, u64 y)
98 return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
101 /* Return X & Y. */
102 _GL_U64_INLINE u64
103 u64and (u64 x, u64 y)
105 u64 r;
106 r.hi = x.hi & y.hi;
107 r.lo = x.lo & y.lo;
108 return r;
111 /* Return X | Y. */
112 _GL_U64_INLINE u64
113 u64or (u64 x, u64 y)
115 u64 r;
116 r.hi = x.hi | y.hi;
117 r.lo = x.lo | y.lo;
118 return r;
121 /* Return X ^ Y. */
122 _GL_U64_INLINE u64
123 u64xor (u64 x, u64 y)
125 u64 r;
126 r.hi = x.hi ^ y.hi;
127 r.lo = x.lo ^ y.lo;
128 return r;
131 /* Return X + Y. */
132 _GL_U64_INLINE u64
133 u64plus (u64 x, u64 y)
135 u64 r;
136 r.lo = x.lo + y.lo;
137 r.hi = x.hi + y.hi + (r.lo < x.lo);
138 return r;
141 /* Return X << N. */
142 _GL_U64_INLINE u64
143 u64shl (u64 x, int n)
145 u64 r;
146 if (n < 32)
148 r.hi = (x.hi << n) | (x.lo >> (32 - n));
149 r.lo = x.lo << n;
151 else
153 r.hi = x.lo << (n - 32);
154 r.lo = 0;
156 return r;
159 /* Return X >> N. */
160 _GL_U64_INLINE u64
161 u64shr (u64 x, int n)
163 u64 r;
164 if (n < 32)
166 r.hi = x.hi >> n;
167 r.lo = (x.hi << (32 - n)) | (x.lo >> n);
169 else
171 r.hi = 0;
172 r.lo = x.hi >> (n - 32);
174 return r;
177 #endif
179 _GL_INLINE_HEADER_END