| //===-- ffsti2.c - Implement __ffsti2 -------------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements __ffsti2 for the compiler_rt library. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #if __x86_64 |
| |
| #include "int_lib.h" |
| |
| // Returns: the index of the least significant 1-bit in a, or |
| // the value zero if a is zero. The least significant bit is index one. |
| |
| si_int |
| __ffsti2(ti_int a) |
| { |
| twords x; |
| x.all = a; |
| if (x.low == 0) |
| { |
| if (x.high == 0) |
| return 0; |
| return __builtin_ctzll(x.high) + (1 + sizeof(di_int) * CHAR_BIT); |
| } |
| return __builtin_ctzll(x.low) + 1; |
| } |
| |
| #endif |