xref: /aosp_15_r20/external/compiler-rt/lib/builtins/powisf2.c (revision 7c3d14c8b49c529e04be81a3ce6f5cc23712e4c6)
1*7c3d14c8STreehugger Robot /*===-- powisf2.cpp - Implement __powisf2 ---------------------------------===
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 __powisf2 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 /* Returns: a ^ b */
18*7c3d14c8STreehugger Robot 
19*7c3d14c8STreehugger Robot COMPILER_RT_ABI float
__powisf2(float a,si_int b)20*7c3d14c8STreehugger Robot __powisf2(float a, si_int b)
21*7c3d14c8STreehugger Robot {
22*7c3d14c8STreehugger Robot     const int recip = b < 0;
23*7c3d14c8STreehugger Robot     float r = 1;
24*7c3d14c8STreehugger Robot     while (1)
25*7c3d14c8STreehugger Robot     {
26*7c3d14c8STreehugger Robot         if (b & 1)
27*7c3d14c8STreehugger Robot             r *= a;
28*7c3d14c8STreehugger Robot         b /= 2;
29*7c3d14c8STreehugger Robot         if (b == 0)
30*7c3d14c8STreehugger Robot             break;
31*7c3d14c8STreehugger Robot         a *= a;
32*7c3d14c8STreehugger Robot     }
33*7c3d14c8STreehugger Robot     return recip ? 1/r : r;
34*7c3d14c8STreehugger Robot }
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