1214152Sed/* ===-- powidf2.cpp - Implement __powidf2 ---------------------------------===
2214152Sed *
3214152Sed *                     The LLVM Compiler Infrastructure
4214152Sed *
5222656Sed * This file is dual licensed under the MIT and the University of Illinois Open
6222656Sed * Source Licenses. See LICENSE.TXT for details.
7214152Sed *
8214152Sed * ===----------------------------------------------------------------------===
9214152Sed *
10214152Sed * This file implements __powidf2 for the compiler_rt library.
11214152Sed *
12214152Sed * ===----------------------------------------------------------------------===
13214152Sed */
14214152Sed
15214152Sed#include "int_lib.h"
16214152Sed
17214152Sed/* Returns: a ^ b */
18214152Sed
19222656SedCOMPILER_RT_ABI double
20214152Sed__powidf2(double a, si_int b)
21214152Sed{
22214152Sed    const int recip = b < 0;
23214152Sed    double r = 1;
24214152Sed    while (1)
25214152Sed    {
26214152Sed        if (b & 1)
27214152Sed            r *= a;
28214152Sed        b /= 2;
29214152Sed        if (b == 0)
30214152Sed            break;
31214152Sed        a *= a;
32214152Sed    }
33214152Sed    return recip ? 1/r : r;
34214152Sed}
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