1/* ===-- powidf2.cpp - Implement __powidf2 ---------------------------------===
2 *
3 *                     The LLVM Compiler Infrastructure
4 *
5 * This file is dual licensed under the MIT and the University of Illinois Open
6 * Source Licenses. See LICENSE.TXT for details.
7 *
8 * ===----------------------------------------------------------------------===
9 *
10 * This file implements __powidf2 for the compiler_rt library.
11 *
12 * ===----------------------------------------------------------------------===
13 */
14
15#include "int_lib.h"
16
17/* Returns: a ^ b */
18
19COMPILER_RT_ABI double
20__powidf2(double a, si_int b)
21{
22    const int recip = b < 0;
23    double r = 1;
24    while (1)
25    {
26        if (b & 1)
27            r *= a;
28        b /= 2;
29        if (b == 0)
30            break;
31        a *= a;
32    }
33    return recip ? 1/r : r;
34}
35