File: ffsdi2.c

package info (click to toggle)
swiftlang 6.1.3-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 2,791,532 kB
  • sloc: cpp: 9,901,743; ansic: 2,201,431; asm: 1,091,827; python: 308,252; objc: 82,166; f90: 80,126; lisp: 38,358; pascal: 25,559; sh: 20,429; ml: 5,058; perl: 4,745; makefile: 4,484; awk: 3,535; javascript: 3,018; xml: 918; fortran: 664; cs: 573; ruby: 396
file content (27 lines) | stat: -rw-r--r-- 900 bytes parent folder | download | duplicates (33) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
 
//===-- 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 int __ffsdi2(di_int a) {
  dwords x;
  x.all = a;
  if (x.s.low == 0) {
    if (x.s.high == 0)
      return 0;
    return ctzsi(x.s.high) + (1 + sizeof(si_int) * CHAR_BIT);
  }
  return ctzsi(x.s.low) + 1;
}