xref: /aosp_15_r20/external/compiler-rt/lib/builtins/powitf2.c (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot /* ===-- powitf2.cpp - Implement __powitf2 ---------------------------------===
2*7c3d14c8STreehugger Robot  *
3*7c3d14c8STreehugger Robot  *                     The LLVM Compiler Infrastructure
4*7c3d14c8STreehugger Robot  *
5*7c3d14c8STreehugger Robot  * This file is dual licensed under the MIT and the University of Illinois Open
6*7c3d14c8STreehugger Robot  * Source Licenses. See LICENSE.TXT for details.
7*7c3d14c8STreehugger Robot  *
8*7c3d14c8STreehugger Robot  * ===----------------------------------------------------------------------===
9*7c3d14c8STreehugger Robot  *
10*7c3d14c8STreehugger Robot  * This file implements __powitf2 for the compiler_rt library.
11*7c3d14c8STreehugger Robot  *
12*7c3d14c8STreehugger Robot  * ===----------------------------------------------------------------------===
13*7c3d14c8STreehugger Robot  */
14*7c3d14c8STreehugger Robot 
15*7c3d14c8STreehugger Robot #include "int_lib.h"
16*7c3d14c8STreehugger Robot 
17*7c3d14c8STreehugger Robot #if _ARCH_PPC
18*7c3d14c8STreehugger Robot 
19*7c3d14c8STreehugger Robot /* Returns: a ^ b */
20*7c3d14c8STreehugger Robot 
21*7c3d14c8STreehugger Robot COMPILER_RT_ABI long double
__powitf2(long double a,si_int b)22*7c3d14c8STreehugger Robot __powitf2(long double a, si_int b)
23*7c3d14c8STreehugger Robot {
24*7c3d14c8STreehugger Robot     const int recip = b < 0;
25*7c3d14c8STreehugger Robot     long double r = 1;
26*7c3d14c8STreehugger Robot     while (1)
27*7c3d14c8STreehugger Robot     {
28*7c3d14c8STreehugger Robot         if (b & 1)
29*7c3d14c8STreehugger Robot             r *= a;
30*7c3d14c8STreehugger Robot         b /= 2;
31*7c3d14c8STreehugger Robot         if (b == 0)
32*7c3d14c8STreehugger Robot             break;
33*7c3d14c8STreehugger Robot         a *= a;
34*7c3d14c8STreehugger Robot     }
35*7c3d14c8STreehugger Robot     return recip ? 1/r : r;
36*7c3d14c8STreehugger Robot }
37*7c3d14c8STreehugger Robot 
38*7c3d14c8STreehugger Robot #endif
39