runtime/util/align.h

   1 /* Copyright (C) 1999-2005 Henry Cejtin, Matthew Fluet, Suresh
   2  *    Jagannathan, and Stephen Weeks.
   3  * Copyright (C) 1997-2000 NEC Research Institute.
   4  *
   5  * MLton is released under a BSD-style license.
   6  * See the file MLton-LICENSE for details.
   7  */
   8
   9 static inline bool isAligned (size_t a, size_t b) {
  10   return 0 == a % b;
  11 }
  12
  13 static inline bool isAlignedMax (uintmax_t a, uintmax_t b) {
  14   return 0 == a % b;
  15 }
  16
  17 static inline size_t alignDown (size_t a, size_t b) {
  18   assert (b >= 1 && b == (b & -b));
  19   a &= -b;
  20   assert (isAligned (a, b));
  21   return a;
  22 }
  23
  24 static inline uintmax_t alignMaxDown (uintmax_t a, uintmax_t b) {
  25   assert (b >= 1 && b == (b & -b));
  26   a &= -b;
  27   assert (isAlignedMax (a, b));
  28   return a;
  29 }
  30
  31 static inline size_t align (size_t a, size_t b) {
  32   assert (b >= 1 && b == (b & -b));
  33   a += b - 1;
  34   a &= -b;
  35   assert (isAligned (a, b));
  36   return a;
  37 }
  38
  39 static inline uintmax_t alignMax (uintmax_t a, uintmax_t b) {
  40   assert (b >= 1 && b == (b & -b));
  41   a += b - 1;
  42   a &= -b;
  43   assert (isAlignedMax (a, b));
  44   return a;
  45 }