b6cbf7203b
This patch imports the unmodified current version of NetBSD libc. The NetBSD includes are in /nbsd_include, while the libc code itself is split between lib/nbsd_libc and common/lib/libc.
82 lines
2.6 KiB
C
82 lines
2.6 KiB
C
/* $NetBSD: popcount64.c,v 1.5 2009/08/05 15:04:15 joerg Exp $ */
|
|
/*-
|
|
* Copyright (c) 2009 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by Joerg Sonnenberger.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
|
|
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__RCSID("$NetBSD: popcount64.c,v 1.5 2009/08/05 15:04:15 joerg Exp $");
|
|
|
|
#if !defined(_KERNEL) && !defined(_STANDALONE)
|
|
#include <limits.h>
|
|
#include <strings.h>
|
|
#else
|
|
#include <lib/libkern/libkern.h>
|
|
#include <machine/limits.h>
|
|
#endif
|
|
|
|
/*
|
|
* If uint64_t is larger than size_t, the follow assumes that
|
|
* splitting into 32bit halfes is faster.
|
|
*
|
|
* The native pocount64 version is based on the same ideas as popcount32(3),
|
|
* see popcount32.c for comments.
|
|
*/
|
|
|
|
#if SIZE_MAX < 0xffffffffffffffffULL
|
|
unsigned int
|
|
popcount64(uint64_t v)
|
|
{
|
|
return popcount32((uint32_t)(v >> 32)) +
|
|
popcount32((uint32_t)(v & 0xffffffffULL));
|
|
}
|
|
#else
|
|
unsigned int
|
|
popcount64(uint64_t v)
|
|
{
|
|
unsigned int c;
|
|
|
|
v = v - ((v >> 1) & 0x5555555555555555ULL);
|
|
v = (v & 0x3333333333333333ULL) + ((v >> 2) & 0x3333333333333333ULL);
|
|
v = ((v + (v >> 4)) & 0x0f0f0f0f0f0f0f0fULL) * 0x0101010101010101ULL;
|
|
c = v >> 56;
|
|
|
|
return c;
|
|
}
|
|
#endif
|
|
|
|
#if ULONG_MAX == 0xffffffffffffffffULL
|
|
__strong_alias(popcountl, popcount64)
|
|
#endif
|
|
|
|
#if ULLONG_MAX == 0xffffffffffffffffULL
|
|
__strong_alias(popcountll, popcount64)
|
|
#endif
|
|
|