mathExtensions.c 1.1 KB

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  1. /*
  2. * Copyright 2017 Uber Technologies, Inc.
  3. *
  4. * Licensed under the Apache License, Version 2.0 (the "License");
  5. * you may not use this file except in compliance with the License.
  6. * You may obtain a copy of the License at
  7. *
  8. * http://www.apache.org/licenses/LICENSE-2.0
  9. *
  10. * Unless required by applicable law or agreed to in writing, software
  11. * distributed under the License is distributed on an "AS IS" BASIS,
  12. * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13. * See the License for the specific language governing permissions and
  14. * limitations under the License.
  15. */
  16. /** @file mathExtensions.c
  17. * @brief Math functions that should've been in math.h but aren't
  18. */
  19. #include "mathExtensions.h"
  20. /**
  21. * _ipow does integer exponentiation efficiently. Taken from StackOverflow.
  22. *
  23. * @param base the integer base
  24. * @param exp the integer exponent
  25. *
  26. * @return the exponentiated value
  27. */
  28. int _ipow(int base, int exp) {
  29. int result = 1;
  30. while (exp) {
  31. if (exp & 1) result *= base;
  32. exp >>= 1;
  33. base *= base;
  34. }
  35. return result;
  36. }