SST  12.0.0
StructuralSimulationToolkit
sqrt.h
1 // Copyright 2009-2022 NTESS. Under the terms
2 // of Contract DE-NA0003525 with NTESS, the U.S.
3 // Government retains certain rights in this software.
4 //
5 // Copyright (c) 2009-2022, NTESS
6 // All rights reserved.
7 //
8 // This file is part of the SST software package. For license
9 // information, see the LICENSE file in the top level directory of the
10 // distribution.
11 
12 #ifndef SST_CORE_MATH_SQRT_H
13 #define SST_CORE_MATH_SQRT_H
14 
15 namespace SST {
16 namespace Math {
17 
18 // Implements uint32_t square root based on algorithm from:
19 // Reference: http://en.wikipedia.org/wiki/Methods_of_computing_square_roots
20 static inline uint32_t
21 square_root(const uint32_t input)
22 {
23 
24  uint32_t op = input;
25  uint32_t res = 0;
26  uint32_t one = 1uL << 30;
27 
28  while ( one > op ) {
29  one >>= 2;
30  }
31 
32  while ( one != 0 ) {
33  if ( op >= res + one ) {
34  op = op - (res + one);
35  res = res + 2 * one;
36  }
37 
38  res >>= 1;
39  one >>= 2;
40  }
41 
42  return res;
43 };
44 
45 } // namespace Math
46 } // namespace SST
47 
48 #endif // SST_CORE_MATH_SQRT_H