Edward O'Callaghan | 0898ee9 | 2009-08-05 19:57:20 +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 | */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 14 | |
| 15 | #include "int_lib.h" |
| 16 | |
Edward O'Callaghan | 0898ee9 | 2009-08-05 19:57:20 +0000 | [diff] [blame^] | 17 | /* Returns: a ^ b */ |
Daniel Dunbar | b3a6901 | 2009-06-26 16:47:03 +0000 | [diff] [blame] | 18 | |
| 19 | double |
| 20 | __powidf2(double a, si_int b) |
| 21 | { |
| 22 | const int recip = b < 0; |
| 23 | double r = 1; |
| 24 | while (1) |
| 25 | { |
| 26 | if (b & 1) |
| 27 | r *= a; |
| 28 | b /= 2; |
| 29 | if (b == 0) |
| 30 | break; |
| 31 | a *= a; |
| 32 | } |
| 33 | return recip ? 1/r : r; |
| 34 | } |