homework-jianmu/source/os/src/osLz4.c

74 lines
1.8 KiB
C

/*
* Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
*
* This program is free software: you can use, redistribute, and/or modify
* it under the terms of the GNU Affero General Public License, version 3
* or later ("AGPL"), as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define _DEFAULT_SOURCE
#include "os.h"
#ifdef WINDOWS
/*
* windows implementation
*/
unsigned char _MyBitScanForward64(unsigned long *ret, uint64_t x) {
unsigned long x0 = (unsigned long)x, top, bottom;
_BitScanForward(&top, (unsigned long)(x >> 32));
_BitScanForward(&bottom, x0);
*ret = x0 ? bottom : 32 + top;
return x != 0;
}
unsigned char _MyBitScanReverse64(unsigned long *ret, uint64_t x) {
unsigned long x1 = (unsigned long)(x >> 32), top, bottom;
_BitScanReverse(&top, x1);
_BitScanReverse(&bottom, (unsigned long)x);
*ret = x1 ? top + 32 : bottom;
return x != 0;
}
int32_t BUILDIN_CLZL(uint64_t val) {
unsigned long r = 0;
#ifdef _WIN64
_BitScanReverse64(&r, val);
#else
_MyBitScanReverse64(&r, val);
#endif
return (int)(63 - r);
}
int32_t BUILDIN_CLZ(uint32_t val) {
unsigned long r = 0;
_BitScanReverse(&r, val);
return (int)(31 - r);
}
int32_t BUILDIN_CTZL(uint64_t val) {
unsigned long r = 0;
#ifdef _WIN64
_BitScanForward64(&r, val);
#else
_MyBitScanForward64(&r, val);
#endif
return (int)(r);
}
int32_t BUILDIN_CTZ(uint32_t val) {
unsigned long r = 0;
_BitScanForward(&r, val);
return (int)(r);
}
#endif