lib/u64.h

   1 /* uint64_t-like operations that work even on hosts lacking uint64_t
   2
   3    Copyright (C) 2006, 2009-2011 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 /* Return X rotated left by N bits, where 0 < N < 64.  */
  23 #define u64rol(x, n) u64or (u64shl (x, n), u64shr (x, 64 - n))
  24
  25 #ifdef UINT64_MAX
  26
  27 /* Native implementations are trivial.  See below for comments on what
  28    these operations do.  */
  29 typedef uint64_t u64;
  30 # define u64hilo(hi, lo) ((u64) (((u64) (hi) << 32) + (lo)))
  31 # define u64init(hi, lo) u64hilo (hi, lo)
  32 # define u64lo(x) ((u64) (x))
  33 # define u64lt(x, y) ((x) < (y))
  34 # define u64and(x, y) ((x) & (y))
  35 # define u64or(x, y) ((x) | (y))
  36 # define u64xor(x, y) ((x) ^ (y))
  37 # define u64plus(x, y) ((x) + (y))
  38 # define u64shl(x, n) ((x) << (n))
  39 # define u64shr(x, n) ((x) >> (n))
  40
  41 #else
  42
  43 /* u64 is a 64-bit unsigned integer value.
  44    u64init (HI, LO), is like u64hilo (HI, LO), but for use in
  45    initializer contexts.  */
  46 # ifdef WORDS_BIGENDIAN
  47 typedef struct { uint32_t hi, lo; } u64;
  48 #  define u64init(hi, lo) { hi, lo }
  49 # else
  50 typedef struct { uint32_t lo, hi; } u64;
  51 #  define u64init(hi, lo) { lo, hi }
  52 # endif
  53
  54 /* Given the high and low-order 32-bit quantities HI and LO, return a u64
  55    value representing (HI << 32) + LO.  */
  56 static inline u64
  57 u64hilo (uint32_t hi, uint32_t lo)
  58 {
  59   u64 r;
  60   r.hi = hi;
  61   r.lo = lo;
  62   return r;
  63 }
  64
  65 /* Return a u64 value representing LO.  */
  66 static inline u64
  67 u64lo (uint32_t lo)
  68 {
  69   u64 r;
  70   r.hi = 0;
  71   r.lo = lo;
  72   return r;
  73 }
  74
  75 /* Return X < Y.  */
  76 static inline int
  77 u64lt (u64 x, u64 y)
  78 {
  79   return x.hi < y.hi || (x.hi == y.hi && x.lo < y.lo);
  80 }
  81
  82 /* Return X & Y.  */
  83 static inline u64
  84 u64and (u64 x, u64 y)
  85 {
  86   u64 r;
  87   r.hi = x.hi & y.hi;
  88   r.lo = x.lo & y.lo;
  89   return r;
  90 }
  91
  92 /* Return X | Y.  */
  93 static inline u64
  94 u64or (u64 x, u64 y)
  95 {
  96   u64 r;
  97   r.hi = x.hi | y.hi;
  98   r.lo = x.lo | y.lo;
  99   return r;
 100 }
 101
 102 /* Return X ^ Y.  */
 103 static inline u64
 104 u64xor (u64 x, u64 y)
 105 {
 106   u64 r;
 107   r.hi = x.hi ^ y.hi;
 108   r.lo = x.lo ^ y.lo;
 109   return r;
 110 }
 111
 112 /* Return X + Y.  */
 113 static inline u64
 114 u64plus (u64 x, u64 y)
 115 {
 116   u64 r;
 117   r.lo = x.lo + y.lo;
 118   r.hi = x.hi + y.hi + (r.lo < x.lo);
 119   return r;
 120 }
 121
 122 /* Return X << N.  */
 123 static inline u64
 124 u64shl (u64 x, int n)
 125 {
 126   u64 r;
 127   if (n < 32)
 128     {
 129       r.hi = (x.hi << n) | (x.lo >> (32 - n));
 130       r.lo = x.lo << n;
 131     }
 132   else
 133     {
 134       r.hi = x.lo << (n - 32);
 135       r.lo = 0;
 136     }
 137   return r;
 138 }
 139
 140 /* Return X >> N.  */
 141 static inline u64
 142 u64shr (u64 x, int n)
 143 {
 144   u64 r;
 145   if (n < 32)
 146     {
 147       r.hi = x.hi >> n;
 148       r.lo = (x.hi << (32 - n)) | (x.lo >> n);
 149     }
 150   else
 151     {
 152       r.hi = 0;
 153       r.lo = x.hi >> (n - 32);
 154     }
 155   return r;
 156 }
 157
 158 #endif