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

35 lines
820 B
C

/* ===-- powidf2.cpp - Implement __powidf2 ---------------------------------===
*
* The LLVM Compiler Infrastructure
*
* This file is dual licensed under the MIT and the University of Illinois Open
* Source Licenses. See LICENSE.TXT for details.
*
* ===----------------------------------------------------------------------===
*
* 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;
}