lib/u64.h

   1 /* uint64_t-like operations that work even on hosts lacking uint64_t
   2
   3    Copyright (C) 2006, 2009-2017 Free Software Foundation, Inc.
   4
   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.
   9
  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.
  14
  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/>.  */
  17
  18 /* Written by Paul Eggert.  */
  19
  20 #include <stdint.h>
  21
  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
  29
  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))
  32
  33 #ifdef UINT64_MAX
  34
  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))
  49
  50 #else
  51
  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
  62
  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)
  67 {
  68   u64 r;
  69   r.hi = hi;
  70   r.lo = lo;
  71   return r;
  72 }
  73
  74 /* Return a u64 value representing LO.  */
  75 _GL_U64_INLINE u64
  76 u64lo (uint32_t lo)
  77 {
  78   u64 r;
  79   r.hi = 0;
  80   r.lo = lo;
  81   return r;
  82 }
  83
  84 /* Return a u64 value representing SIZE.  */
  85 _GL_U64_INLINE u64
  86 u64size (size_t size)
  87 {
  88   u64 r;
  89   r.hi = size >> 31 >> 1;
  90   r.lo = size;
  91   return r;
  92 }
  93
  94 /* Return X < Y.  */
  95 _GL_U64_INLINE int
  96 u64lt (u64 x, u64 y)
  97 {
  98   return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
  99 }
 100
 101 /* Return X & Y.  */
 102 _GL_U64_INLINE u64
 103 u64and (u64 x, u64 y)
 104 {
 105   u64 r;
 106   r.hi = x.hi & y.hi;
 107   r.lo = x.lo & y.lo;
 108   return r;
 109 }
 110
 111 /* Return X | Y.  */
 112 _GL_U64_INLINE u64
 113 u64or (u64 x, u64 y)
 114 {
 115   u64 r;
 116   r.hi = x.hi | y.hi;
 117   r.lo = x.lo | y.lo;
 118   return r;
 119 }
 120
 121 /* Return X ^ Y.  */
 122 _GL_U64_INLINE u64
 123 u64xor (u64 x, u64 y)
 124 {
 125   u64 r;
 126   r.hi = x.hi ^ y.hi;
 127   r.lo = x.lo ^ y.lo;
 128   return r;
 129 }
 130
 131 /* Return X + Y.  */
 132 _GL_U64_INLINE u64
 133 u64plus (u64 x, u64 y)
 134 {
 135   u64 r;
 136   r.lo = x.lo + y.lo;
 137   r.hi = x.hi + y.hi + (r.lo < x.lo);
 138   return r;
 139 }
 140
 141 /* Return X << N.  */
 142 _GL_U64_INLINE u64
 143 u64shl (u64 x, int n)
 144 {
 145   u64 r;
 146   if (n < 32)
 147     {
 148       r.hi = (x.hi << n) | (x.lo >> (32 - n));
 149       r.lo = x.lo << n;
 150     }
 151   else
 152     {
 153       r.hi = x.lo << (n - 32);
 154       r.lo = 0;
 155     }
 156   return r;
 157 }
 158
 159 /* Return X >> N.  */
 160 _GL_U64_INLINE u64
 161 u64shr (u64 x, int n)
 162 {
 163   u64 r;
 164   if (n < 32)
 165     {
 166       r.hi = x.hi >> n;
 167       r.lo = (x.hi << (32 - n)) | (x.lo >> n);
 168     }
 169   else
 170     {
 171       r.hi = 0;
 172       r.lo = x.hi >> (n - 32);
 173     }
 174   return r;
 175 }
 176
 177 #endif
 178
 179 _GL_INLINE_HEADER_END