86 lines
2.5 KiB
C++
86 lines
2.5 KiB
C++
/*
|
|
open source routing machine
|
|
Copyright (C) Dennis Luxen, others 2010
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU AFFERO General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
any later version.
|
|
|
|
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. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Affero General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
or see http://www.gnu.org/licenses/agpl.txt.
|
|
*/
|
|
|
|
#include "CRC32.h"
|
|
|
|
CRC32::CRC32() : crc(0) {
|
|
crcFunction = detectBestCRC32C();
|
|
}
|
|
|
|
unsigned CRC32::SoftwareBasedCRC32(char *str, unsigned len, unsigned crc) {
|
|
boost::crc_optimal<32, 0x1EDC6F41, 0x0, 0x0, true, true> CRC32_Processor;
|
|
CRC32_Processor.process_bytes( str, len);
|
|
return CRC32_Processor.checksum();
|
|
}
|
|
|
|
unsigned CRC32::SSEBasedCRC32( char *str, unsigned len, unsigned crc) {
|
|
unsigned q=len/sizeof(unsigned),
|
|
r=len%sizeof(unsigned),
|
|
*p=(unsigned*)str/*, crc*/;
|
|
|
|
//crc=0;
|
|
while (q--) {
|
|
__asm__ __volatile__(
|
|
".byte 0xf2, 0xf, 0x38, 0xf1, 0xf1;"
|
|
:"=S"(crc)
|
|
:"0"(crc), "c"(*p)
|
|
);
|
|
++p;
|
|
}
|
|
|
|
str=(char*)p;
|
|
while (r--) {
|
|
__asm__ __volatile__(
|
|
".byte 0xf2, 0xf, 0x38, 0xf1, 0xf1;"
|
|
:"=S"(crc)
|
|
:"0"(crc), "c"(*str)
|
|
);
|
|
++str;
|
|
}
|
|
return crc;
|
|
}
|
|
|
|
CRC32::CRC32CFunctionPtr CRC32::detectBestCRC32C() {
|
|
static const int SSE42_BIT = 20;
|
|
unsigned ecx = cpuid(1);
|
|
bool hasSSE42 = ecx & (1 << SSE42_BIT);
|
|
if (hasSSE42) {
|
|
std::cout << "sse based" << std::endl;
|
|
return &CRC32::SSEBasedCRC32; //crc32 hardware accelarated;
|
|
} else {
|
|
std::cout << "softbased" << std::endl;
|
|
return &CRC32::SoftwareBasedCRC32; //crc32cSlicingBy8;
|
|
}
|
|
}
|
|
|
|
unsigned CRC32::cpuid(unsigned functionInput) {
|
|
unsigned eax;
|
|
unsigned ebx;
|
|
unsigned ecx;
|
|
unsigned edx;
|
|
asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (functionInput));
|
|
return ecx;
|
|
}
|
|
|
|
unsigned CRC32::operator()(char *str, unsigned len){
|
|
crc =((*this).*(crcFunction))(str, len, crc);
|
|
return crc;
|
|
}
|