| Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame^] | 1 | //===-- powidf2.cpp - Implement __powidf2 ---------------------------------===// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file implements __powidf2 for the compiler_rt library. |
| 11 | // |
| 12 | //===----------------------------------------------------------------------===// |
| 13 | |
| 14 | #include "int_lib.h" |
| 15 | |
| 16 | // Returns: a ^ b |
| 17 | |
| 18 | double |
| 19 | __powidf2(double a, si_int b) |
| 20 | { |
| 21 | const int recip = b < 0; |
| 22 | double r = 1; |
| 23 | while (1) |
| 24 | { |
| 25 | if (b & 1) |
| 26 | r *= a; |
| 27 | b /= 2; |
| 28 | if (b == 0) |
| 29 | break; |
| 30 | a *= a; |
| 31 | } |
| 32 | return recip ? 1/r : r; |
| 33 | } |