1353358Sdim//===-- powidf2.cpp - Implement __powidf2 ---------------------------------===//
2353358Sdim//
3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4353358Sdim// See https://llvm.org/LICENSE.txt for license information.
5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6353358Sdim//
7353358Sdim//===----------------------------------------------------------------------===//
8353358Sdim//
9353358Sdim// This file implements __powidf2 for the compiler_rt library.
10353358Sdim//
11353358Sdim//===----------------------------------------------------------------------===//
12276789Sdim
13276789Sdim#include "int_lib.h"
14276789Sdim
15353358Sdim// Returns: a ^ b
16276789Sdim
17353358SdimCOMPILER_RT_ABI double __powidf2(double a, si_int b) {
18353358Sdim  const int recip = b < 0;
19353358Sdim  double r = 1;
20353358Sdim  while (1) {
21353358Sdim    if (b & 1)
22353358Sdim      r *= a;
23353358Sdim    b /= 2;
24353358Sdim    if (b == 0)
25353358Sdim      break;
26353358Sdim    a *= a;
27353358Sdim  }
28353358Sdim  return recip ? 1 / r : r;
29276789Sdim}
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