forked from OSchip/llvm-project
28 lines
919 B
C
28 lines
919 B
C
//===-- ffsdi2.c - Implement __ffsdi2 -------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements __ffsdi2 for the compiler_rt library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#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.
|
|
|
|
COMPILER_RT_ABI si_int __ffsdi2(di_int a) {
|
|
dwords x;
|
|
x.all = a;
|
|
if (x.s.low == 0) {
|
|
if (x.s.high == 0)
|
|
return 0;
|
|
return __builtin_ctz(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
|
|
}
|
|
return __builtin_ctz(x.s.low) + 1;
|
|
}
|