我用下面的代码对比了blitz++、armadillo、boost::MultiArray(借用自an old post)
#include <iostream>
using namespace std;
#include <windows.h>
#define _SCL_SECURE_NO_WARNINGS
#define BOOST_DISABLE_ASSERTS
#include <boost/multi_array.hpp>
#include <blitz/array.h>
#include <armadillo>
int main(int argc, char* argv[])
{
const int X_SIZE = 1000;
const int Y_SIZE = 1000;
const int ITERATIONS = 100;
unsigned int startTime = 0;
unsigned int endTime = 0;
// Create the boost array
//------------------Measure boost Loop------------------------------------------
{
typedef boost::multi_array<double, 2> ImageArrayType;
ImageArrayType boostMatrix(boost::extents[X_SIZE][Y_SIZE]);
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
for (int x = 0; x < X_SIZE; ++x)
{
for (int y = 0; y < Y_SIZE; ++y)
{
boostMatrix[x][y] = 1.0001;
}
}
}
endTime = ::GetTickCount();
printf("[Boost Loop] Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
}
//------------------Measure blitz Loop-------------------------------------------
{
blitz::Array<double, 2> blitzArray( X_SIZE, Y_SIZE );
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
for (int x = 0; x < X_SIZE; ++x)
{
for (int y = 0; y < Y_SIZE; ++y)
{
blitzArray(x,y) = 1.0001;
}
}
}
endTime = ::GetTickCount();
printf("[Blitz Loop] Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
}
//------------------Measure armadillo loop----------------------------------------
{
arma::mat matArray( X_SIZE, Y_SIZE );
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
for (int y = 0; y < Y_SIZE; ++y)
{
for (int x = 0; x < X_SIZE; ++x)
{
matArray(x,y) = 1.0001;
}
}
}
endTime = ::GetTickCount();
printf("[arma Loop] Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
}
//------------------Measure native loop----------------------------------------
// Create the native array
{
double *nativeMatrix = new double [X_SIZE * Y_SIZE];
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
for (int y = 0; y < Y_SIZE*X_SIZE; ++y)
{
nativeMatrix[y] = 1.0001;
}
}
endTime = ::GetTickCount();
printf("[Native Loop]Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
delete[] nativeMatrix;
}
//------------------Measure boost computation-----------------------------------
{
typedef boost::multi_array<double, 2> ImageArrayType;
ImageArrayType boostMatrix(boost::extents[X_SIZE][Y_SIZE]);
for (int x = 0; x < X_SIZE; ++x)
{
for (int y = 0; y < Y_SIZE; ++y)
{
boostMatrix[x][y] = 1.0001;
}
}
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
for (int x = 0; x < X_SIZE; ++x)
{
for (int y = 0; y < Y_SIZE; ++y)
{
boostMatrix[x][y] += boostMatrix[x][y] * 0.5;
}
}
}
endTime = ::GetTickCount();
printf("[Boost computation] Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
}
//------------------Measure blitz computation-----------------------------------
{
blitz::Array<double, 2> blitzArray( X_SIZE, Y_SIZE );
blitzArray = 1.0001;
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
blitzArray += blitzArray*0.5;
}
endTime = ::GetTickCount();
printf("[Blitz computation] Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
}
//------------------Measure armadillo computation-------------------------------
{
arma::mat matArray( X_SIZE, Y_SIZE );
matArray.fill(1.0001);
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
//matArray.fill(1.0001);
matArray += matArray*0.5;
}
endTime = ::GetTickCount();
printf("[arma computation] Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
}
//------------------Measure native computation------------------------------------------
// Create the native array
{
double *nativeMatrix = new double [X_SIZE * Y_SIZE];
for (int y = 0; y < Y_SIZE*X_SIZE; ++y)
{
nativeMatrix[y] = 1.0001;
}
startTime = ::GetTickCount();
for (int i = 0; i < ITERATIONS; ++i)
{
for (int y = 0; y < Y_SIZE*X_SIZE; ++y)
{
nativeMatrix[y] += nativeMatrix[y] * 0.5;
}
}
endTime = ::GetTickCount();
printf("[Native computation]Elapsed time: %6.3f seconds\n", (endTime - startTime) / 1000.0);
delete[] nativeMatrix;
}
return 0;
}
在windows，VS2010上，结果是
[Boost Loop] Elapsed time: 1.217 seconds
[Blitz Loop] Elapsed time: 0.046 seconds
[arma Loop] Elapsed time: 0.078 seconds
[Native Loop]Elapsed time: 0.172 seconds
[Boost computation] Elapsed time: 2.152 seconds
[Blitz computation] Elapsed time: 0.156 seconds
[arma computation] Elapsed time: 0.078 seconds
[Native computation]Elapsed time: 0.078 seconds
在windows，intel c++上，结果是
[Boost Loop] Elapsed time: 0.468 seconds
[Blitz Loop] Elapsed time: 0.125 seconds
[arma Loop] Elapsed time: 0.046 seconds
[Native Loop]Elapsed time: 0.047 seconds
[Boost computation] Elapsed time: 0.796 seconds
[Blitz computation] Elapsed time: 0.109 seconds
[arma computation] Elapsed time: 0.078 seconds
[Native computation]Elapsed time: 0.062 seconds
有些奇怪:
(1) with VS2010, native computation (including loop) is faster than native loop
(2) blitz loop behave so different under VS2010 and intel C++.
要使用 intel c++ 编译器编译 blitz++，blitz/intel/文件夹中需要一个名为 bzconfig.h 的文件。但是没有。我只是复制 blitz/ms/bzconfig.h 中的那个。这可能会给出非最佳配置。任何人都可以告诉我如何使用 intel c++ 编译器编译 blitz++？在手册中，它说运行 bzconfig 脚本以获取正确的 bzconfig.h。但我不明白这是什么意思。
非常感谢!
添加一些我的结论:
1. Boost multi array is the slowest.
2. With intel c++ compiler, native pointers are very fast.
3. With intel c++ compiler, armadillo can achieve the performance of native pointers.
4. Also test eigen, it is x0% slower than armadillo in my simple cases.
5. Curious about blitz++'s behavior in intel c++ compiler with proper configuration.
Please see my question.
最佳答案
简答:./configure CXX=icpc，通过阅读 Blitz++ 用户指南找到。
长答案:
To compile blitz++ with intel c++ compiler, a file called bzconfig.h is required in blitz/intel/ folder. But there isn't.
是的，是的。 Blitz++ 应该自己生成文件。根据 blitz-0.10.tar.gz 中包含的 Blitz++ 用户指南 blitz.pdf，“安装”部分，
Blitz++ uses GNU Autoconf, which handles rewriting Makefiles for various platforms and compilers.
更准确地说，Blitz++ 使用 GNU autotools 工具链(automake、autoconf、configure)，可以生成 makefile、配置脚本、头文件等。 bzconfig.h 文件应该是由 Blitz++ 自带的 configure 脚本生成的，可以直接使用。
I just copy the one in blitz/ms/bzconfig.h in. That may give an non-optimal configuration.
如果“非最佳”对您来说意味着“不工作”，那么是的。 :-)
您需要一个准确代表您的编译器的 intel/bzconfig.h。
Anyone can tell me how to compile blitz++ with intel c++ compiler?
阅读并遵循精美的手册，尤其是上面提到的“安装”部分。
go into the ‘blitz-VERSION’ directory, and type:
./configure CXX=[compiler]where [compiler] is one of xlc++, icpc, pathCC, xlC, cxx, aCC, CC, g++, KCC, pgCC or FCC. (If you do not choose a C++ compiler, the configure script will attempt to find an appropriate compiler for the current platform.)
你做过吗？对于英特尔编译器，您需要使用
./configure CXX=icpc.
In the manual, it said run bzconfig script to get the right bzconfig.h. But I don't understand what it means.
我假设“它”是指“那个”。 “手动”是什么意思？我的 Blitz++ 用户指南没有提到 bzconfig。您确定您使用的是与您的 Blitz++ 版本对应的手册吗？
PS:在blitz-0.10的内容中寻找“bzconfig” ，看起来“bzconfig”不再是 Blitz++ 的一部分，而是曾经是:
找到 . -name bzconfig -> 没有结果
找到 . -print0 | xargs -0 grep -a -i -n -e bzconfig:
./blitz/compiler.h:44: #error In <blitz/config.h>: A working template implementation is required by Blitz++ (you may need to rerun the compiler/bzconfig script)
这需要更新。
./blitz/gnu/bzconfig.h:4:/* blitz/gnu/bzconfig.h. Generated automatically at end of configure. */
./configure.ac:159:# autoconf replacement of bzconfig
你有它，这些 bzconfig.h 文件应该由 configure 生成。
./ChangeLog.1:1787: will now replace the old file that was generate with the bzconfig
这可能是切换到 autoconf 的变化。
./INSTALL:107: 2. Go into the compiler subdirectory and run the bzconfig
这需要更新。这就是让你寻找 bzconfig 的原因吗？
./README:27:compiler Compiler tests (used with obsolete bzconfig script)
需要更新，不再包含compiler目录。
关于c++ - 比较 blitz++、 Armadillo 、boost::MultiArray，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14414906/