lib/u64.h

   1 /* uint64_t-like operations that work even on hosts lacking uint64_t
   2
   3    Copyright (C) 2006, 2009-2012 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 _GL_INLINE_HEADER_BEGIN
  23 #ifndef _GL_U64_INLINE
  24 # define _GL_U64_INLINE _GL_INLINE
  25 #endif
  26
  27 /* Return X rotated left by N bits, where 0 < N < 64.  */
  28 #define u64rol(x, n) u64or (u64shl (x, n), u64shr (x, 64 - n))
  29
  30 #ifdef UINT64_MAX
  31
  32 /* Native implementations are trivial.  See below for comments on what
  33    these operations do.  */
  34 typedef uint64_t u64;
  35 # define u64hilo(hi, lo) ((u64) (((u64) (hi) << 32) + (lo)))
  36 # define u64init(hi, lo) u64hilo (hi, lo)
  37 # define u64lo(x) ((u64) (x))
  38 # define u64size(x) u64lo (x)
  39 # define u64lt(x, y) ((x) < (y))
  40 # define u64and(x, y) ((x) & (y))
  41 # define u64or(x, y) ((x) | (y))
  42 # define u64xor(x, y) ((x) ^ (y))
  43 # define u64plus(x, y) ((x) + (y))
  44 # define u64shl(x, n) ((x) << (n))
  45 # define u64shr(x, n) ((x) >> (n))
  46
  47 #else
  48
  49 /* u64 is a 64-bit unsigned integer value.
  50    u64init (HI, LO), is like u64hilo (HI, LO), but for use in
  51    initializer contexts.  */
  52 # ifdef WORDS_BIGENDIAN
  53 typedef struct { uint32_t hi, lo; } u64;
  54 #  define u64init(hi, lo) { hi, lo }
  55 # else
  56 typedef struct { uint32_t lo, hi; } u64;
  57 #  define u64init(hi, lo) { lo, hi }
  58 # endif
  59
  60 /* Given the high and low-order 32-bit quantities HI and LO, return a u64
  61    value representing (HI << 32) + LO.  */
  62 _GL_U64_INLINE u64
  63 u64hilo (uint32_t hi, uint32_t lo)
  64 {
  65   u64 r;
  66   r.hi = hi;
  67   r.lo = lo;
  68   return r;
  69 }
  70
  71 /* Return a u64 value representing LO.  */
  72 _GL_U64_INLINE u64
  73 u64lo (uint32_t lo)
  74 {
  75   u64 r;
  76   r.hi = 0;
  77   r.lo = lo;
  78   return r;
  79 }
  80
  81 /* Return a u64 value representing SIZE.  */
  82 _GL_U64_INLINE u64
  83 u64size (size_t size)
  84 {
  85   u64 r;
  86   r.hi = size >> 31 >> 1;
  87   r.lo = size;
  88   return r;
  89 }
  90
  91 /* Return X < Y.  */
  92 _GL_U64_INLINE int
  93 u64lt (u64 x, u64 y)
  94 {
  95   return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
  96 }
  97
  98 /* Return X & Y.  */
  99 _GL_U64_INLINE u64
 100 u64and (u64 x, u64 y)
 101 {
 102   u64 r;
 103   r.hi = x.hi & y.hi;
 104   r.lo = x.lo & y.lo;
 105   return r;
 106 }
 107
 108 /* Return X | Y.  */
 109 _GL_U64_INLINE u64
 110 u64or (u64 x, u64 y)
 111 {
 112   u64 r;
 113   r.hi = x.hi | y.hi;
 114   r.lo = x.lo | y.lo;
 115   return r;
 116 }
 117
 118 /* Return X ^ Y.  */
 119 _GL_U64_INLINE u64
 120 u64xor (u64 x, u64 y)
 121 {
 122   u64 r;
 123   r.hi = x.hi ^ y.hi;
 124   r.lo = x.lo ^ y.lo;
 125   return r;
 126 }
 127
 128 /* Return X + Y.  */
 129 _GL_U64_INLINE u64
 130 u64plus (u64 x, u64 y)
 131 {
 132   u64 r;
 133   r.lo = x.lo + y.lo;
 134   r.hi = x.hi + y.hi + (r.lo < x.lo);
 135   return r;
 136 }
 137
 138 /* Return X << N.  */
 139 _GL_U64_INLINE u64
 140 u64shl (u64 x, int n)
 141 {
 142   u64 r;
 143   if (n < 32)
 144     {
 145       r.hi = (x.hi << n) | (x.lo >> (32 - n));
 146       r.lo = x.lo << n;
 147     }
 148   else
 149     {
 150       r.hi = x.lo << (n - 32);
 151       r.lo = 0;
 152     }
 153   return r;
 154 }
 155
 156 /* Return X >> N.  */
 157 _GL_U64_INLINE u64
 158 u64shr (u64 x, int n)
 159 {
 160   u64 r;
 161   if (n < 32)
 162     {
 163       r.hi = x.hi >> n;
 164       r.lo = (x.hi << (32 - n)) | (x.lo >> n);
 165     }
 166   else
 167     {
 168       r.hi = 0;
 169       r.lo = x.hi >> (n - 32);
 170     }
 171   return r;
 172 }
 173
 174 #endif
 175
 176 _GL_INLINE_HEADER_END