lib/u64.h

   1 /* uint64_t-like operations that work even on hosts lacking uint64_t
   2
   3    Copyright (C) 2006, 2009-2024 Free Software Foundation, Inc.
   4
   5    This file is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU Lesser General Public License as
   7    published by the Free Software Foundation; either version 2.1 of the
   8    License, or (at your option) any later version.
   9
  10    This file 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 Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 /* This file uses _GL_INLINE_HEADER_BEGIN, _GL_INLINE.  */
  21 #if !_GL_CONFIG_H_INCLUDED
  22  #error "Please include config.h first."
  23 #endif
  24
  25 #include <stdint.h>
  26
  27 _GL_INLINE_HEADER_BEGIN
  28 #ifndef _GL_U64_INLINE
  29 # define _GL_U64_INLINE _GL_INLINE
  30 #endif
  31
  32 /* Return X rotated left by N bits, where 0 < N < 64.  */
  33 #define u64rol(x, n) u64or (u64shl (x, n), u64shr (x, 64 - n))
  34
  35 #ifdef UINT64_MAX
  36
  37 /* Native implementations are trivial.  See below for comments on what
  38    these operations do.  */
  39 typedef uint64_t u64;
  40 # define u64hilo(hi, lo) ((u64) (((u64) (hi) << 32) + (lo)))
  41 # define u64init(hi, lo) u64hilo (hi, lo)
  42 # define u64lo(x) ((u64) (x))
  43 # define u64size(x) u64lo (x)
  44 # define u64lt(x, y) ((x) < (y))
  45 # define u64and(x, y) ((x) & (y))
  46 # define u64or(x, y) ((x) | (y))
  47 # define u64xor(x, y) ((x) ^ (y))
  48 # define u64plus(x, y) ((x) + (y))
  49 # define u64shl(x, n) ((x) << (n))
  50 # define u64shr(x, n) ((x) >> (n))
  51
  52 #else
  53
  54 /* u64 is a 64-bit unsigned integer value.
  55    u64init (HI, LO), is like u64hilo (HI, LO), but for use in
  56    initializer contexts.  */
  57 # ifdef WORDS_BIGENDIAN
  58 typedef struct { uint32_t hi, lo; } u64;
  59 #  define u64init(hi, lo) { hi, lo }
  60 # else
  61 typedef struct { uint32_t lo, hi; } u64;
  62 #  define u64init(hi, lo) { lo, hi }
  63 # endif
  64
  65 /* Given the high and low-order 32-bit quantities HI and LO, return a u64
  66    value representing (HI << 32) + LO.  */
  67 _GL_U64_INLINE u64
  68 u64hilo (uint32_t hi, uint32_t lo)
  69 {
  70   u64 r;
  71   r.hi = hi;
  72   r.lo = lo;
  73   return r;
  74 }
  75
  76 /* Return a u64 value representing LO.  */
  77 _GL_U64_INLINE u64
  78 u64lo (uint32_t lo)
  79 {
  80   u64 r;
  81   r.hi = 0;
  82   r.lo = lo;
  83   return r;
  84 }
  85
  86 /* Return a u64 value representing SIZE.  */
  87 _GL_U64_INLINE u64
  88 u64size (size_t size)
  89 {
  90   u64 r;
  91   r.hi = size >> 31 >> 1;
  92   r.lo = size;
  93   return r;
  94 }
  95
  96 /* Return X < Y.  */
  97 _GL_U64_INLINE int
  98 u64lt (u64 x, u64 y)
  99 {
 100   return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
 101 }
 102
 103 /* Return X & Y.  */
 104 _GL_U64_INLINE u64
 105 u64and (u64 x, u64 y)
 106 {
 107   u64 r;
 108   r.hi = x.hi & y.hi;
 109   r.lo = x.lo & y.lo;
 110   return r;
 111 }
 112
 113 /* Return X | Y.  */
 114 _GL_U64_INLINE u64
 115 u64or (u64 x, u64 y)
 116 {
 117   u64 r;
 118   r.hi = x.hi | y.hi;
 119   r.lo = x.lo | y.lo;
 120   return r;
 121 }
 122
 123 /* Return X ^ Y.  */
 124 _GL_U64_INLINE u64
 125 u64xor (u64 x, u64 y)
 126 {
 127   u64 r;
 128   r.hi = x.hi ^ y.hi;
 129   r.lo = x.lo ^ y.lo;
 130   return r;
 131 }
 132
 133 /* Return X + Y.  */
 134 _GL_U64_INLINE u64
 135 u64plus (u64 x, u64 y)
 136 {
 137   u64 r;
 138   r.lo = x.lo + y.lo;
 139   r.hi = x.hi + y.hi + (r.lo < x.lo);
 140   return r;
 141 }
 142
 143 /* Return X << N.  */
 144 _GL_U64_INLINE u64
 145 u64shl (u64 x, int n)
 146 {
 147   u64 r;
 148   if (n < 32)
 149     {
 150       r.hi = (x.hi << n) | (x.lo >> (32 - n));
 151       r.lo = x.lo << n;
 152     }
 153   else
 154     {
 155       r.hi = x.lo << (n - 32);
 156       r.lo = 0;
 157     }
 158   return r;
 159 }
 160
 161 /* Return X >> N.  */
 162 _GL_U64_INLINE u64
 163 u64shr (u64 x, int n)
 164 {
 165   u64 r;
 166   if (n < 32)
 167     {
 168       r.hi = x.hi >> n;
 169       r.lo = (x.hi << (32 - n)) | (x.lo >> n);
 170     }
 171   else
 172     {
 173       r.hi = 0;
 174       r.lo = x.hi >> (n - 32);
 175     }
 176   return r;
 177 }
 178
 179 #endif
 180
 181 _GL_INLINE_HEADER_END