llvm-project/compiler-rt/lib/builtins/powidf2.c

30 lines
789 B
C

//===-- powidf2.cpp - Implement __powidf2 ---------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements __powidf2 for the compiler_rt library.
//
//===----------------------------------------------------------------------===//
#include "int_lib.h"
// Returns: a ^ b
COMPILER_RT_ABI double __powidf2(double a, si_int b) {
const int recip = b < 0;
double r = 1;
while (1) {
if (b & 1)
r *= a;
b /= 2;
if (b == 0)
break;
a *= a;
}
return recip ? 1 / r : r;
}