1    :  // Copyright 2011 Google Inc.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // Utility functions to align and test alignment.
  16    :  
  17    :  #ifndef SYZYGY_COMMON_ALIGN_H_
  18    :  #define SYZYGY_COMMON_ALIGN_H_
  19    :  
  20  m :  namespace common {
  21    :  
  22    :  // @returns true iff @p value is a power of two.
  23  m :  bool IsPowerOfTwo(size_t value);
  24    :  
  25    :  // @param value the value to round up.
  26    :  // @param alignment the alignment boundary to round @p value up to.
  27    :  // @pre alignment != 0.
  28    :  // @returns @p value rounded up to the nearest higher multiple of @p alignment.
  29  m :  size_t AlignUp(size_t value, size_t alignment);
  30    :  
  31    :  // @param value the value to round up.
  32    :  // @param alignment the alignment boundary to round @p value up to.
  33    :  // @pre alignment != 0.
  34    :  // @returns @p value rounded down to the nearest lower multiple of @p alignment.
  35  m :  size_t AlignDown(size_t value, size_t alignment);
  36    :  
  37    :  // @param value the value to test.
  38    :  // @param alignment the alignment boundary to test.
  39    :  // @pre alignment != 0.
  40    :  // @returns true iff value is an even multiple of alignment.
  41  m :  bool IsAligned(size_t value, size_t alignment);
  42    :  
  43  m :  }  // namespace common
  44    :  
  45    :  #endif  // SYZYGY_COMMON_ALIGN_H_