xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/powitf2.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1*0b57cec5SDimitry Andric //===-- powitf2.cpp - Implement __powitf2 ---------------------------------===//
2*0b57cec5SDimitry Andric //
3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*0b57cec5SDimitry Andric //
7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
8*0b57cec5SDimitry Andric //
9*0b57cec5SDimitry Andric // This file implements __powitf2 for the compiler_rt library.
10*0b57cec5SDimitry Andric //
11*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===//
12*0b57cec5SDimitry Andric 
13*0b57cec5SDimitry Andric #include "int_lib.h"
14*0b57cec5SDimitry Andric 
15*0b57cec5SDimitry Andric #if _ARCH_PPC
16*0b57cec5SDimitry Andric 
17*0b57cec5SDimitry Andric // Returns: a ^ b
18*0b57cec5SDimitry Andric 
19*0b57cec5SDimitry Andric COMPILER_RT_ABI long double __powitf2(long double a, si_int b) {
20*0b57cec5SDimitry Andric   const int recip = b < 0;
21*0b57cec5SDimitry Andric   long double r = 1;
22*0b57cec5SDimitry Andric   while (1) {
23*0b57cec5SDimitry Andric     if (b & 1)
24*0b57cec5SDimitry Andric       r *= a;
25*0b57cec5SDimitry Andric     b /= 2;
26*0b57cec5SDimitry Andric     if (b == 0)
27*0b57cec5SDimitry Andric       break;
28*0b57cec5SDimitry Andric     a *= a;
29*0b57cec5SDimitry Andric   }
30*0b57cec5SDimitry Andric   return recip ? 1 / r : r;
31*0b57cec5SDimitry Andric }
32*0b57cec5SDimitry Andric 
33*0b57cec5SDimitry Andric #endif
34