sheet3

sheet3/6/.vscode/settings.json

@@ -0,0 +1,6 @@
+{
+    "files.associations": {
+        "ostream": "cpp",
+        "iostream": "cpp"
+    }
+}

sheet3/6/Makefile

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+#
+# use GNU-Compiler tools
+COMPILER=GCC_
+# alternatively from the shell
+# export COMPILER=GCC_
+# or, alternatively from the shell
+# make COMPILER=GCC_
+
+# use Intel compilers
+#COMPILER=ICC_
+
+# use PGI compilers
+# COMPILER=PGI_
+
+LIBS = -lopenblas   
+
+SOURCES = main.cpp mylib.cpp benchmark.cpp
+OBJECTS = $(SOURCES:.cpp=.o)
+
+PROGRAM	= main.${COMPILER}
+
+# uncomment the next to lines for debugging and detailed performance analysis
+CXXFLAGS += -g
+LINKFLAGS += -g
+# do not use -pg with PGI compilers
+
+ifndef COMPILER
+  COMPILER=GCC_
+endif
+
+include ../${COMPILER}default.mk

sheet3/6/benchmark.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+#include <vector>   
+#include <cmath>
+using namespace std;
+#include <cblas.h>
+
+// Inner product
+double benchmark_A(const vector<double> &x, const vector<double> &y)
+{
+   
+   
+    return cblas_ddot(x.size(),x.data(),1,y.data(),1);
+
+}
+
+//Matrix-vector product
+vector<double> benchmark_B(const vector<double> &A, const vector<double> &x)
+{
+    unsigned int N = x.size();
+    unsigned int M = A.size() / N;
+    vector<double> b(M, 0.0);
+
+    cblas_dgemv(CblasRowMajor,CblasNoTrans,M,N,1,A.data(),N,x.data(),1,0.0,b.data(),1);
+
+    return b;
+}
+
+
+//Matrix-Matrix product
+vector<double> benchmark_C(const vector<double> &A, const vector<double> &B, unsigned int M)
+{
+    unsigned int L = A.size()/M;
+    unsigned int N = B.size()/L;
+    vector<double> C(M*N,0.0);
+    
+    cblas_dgemm(CblasRowMajor,CblasNoTrans,CblasNoTrans,M,N,L,1.0,A.data(),L,B.data(),N,0.0,C.data(),N);
+
+    return C;
+
+}
+
+
+

sheet3/6/benchmark.h

@@ -0,0 +1,21 @@
+#ifndef BENCHMARK_H
+#define BENCHMARK_H
+
+
+#include <vector>
+using namespace std;
+
+double benchmark_A(const vector<double> &x,
+                   const vector<double> &y);
+
+vector<double> benchmark_B(const vector<double> &A,
+                                const vector<double> &x);
+
+vector<double> benchmark_C(const vector<double> &A,
+                                const vector<double> &B,
+                                unsigned int M);
+
+
+
+
+#endif 

sheet3/6/main.cpp

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+#include "mylib.h"
+#include <cassert>
+#include <chrono>           // timing
+#include <cmath>            // sqrt()
+#include <cstdlib>          // atoi()
+#include <cstring>          // strncmp()
+#include <ctime>
+#include <iostream>
+#include <sstream>
+#include "benchmark.h"
+using namespace std;
+using namespace std::chrono;  // timing
+
+int main(int argc, char **argv)
+{
+    const unsigned int NA = 1400000;     
+    const unsigned int NLOOPSA = 10000;     
+    //const unsigned int NLOOPS = 10;  
+    
+    const unsigned int MC = 1000;
+    int const NLOOPSC = 1000;
+// ---------- Benchmark A ----------
+
+{
+    
+    
+    vector<double> xA(NA), yA(NA);
+    for (unsigned int i = 0; i < NA; ++i)
+    {
+        double xi= (i % 219) + 1;
+        xA[i] = xi;
+        yA[i] = 1.0 / xi;
+    }
+
+    auto tA1 = system_clock::now();
+    double sA = 0.0, sumA = 0.0;
+    for (unsigned int loop = 0; loop < NLOOPSA; ++loop)
+    {
+        sA = benchmark_A(xA, yA);
+        sumA += sA;
+    }
+    auto tA2 = system_clock::now();
+
+    auto durA = duration_cast<microseconds>(tA2 - tA1);
+    double tA = static_cast<double>(durA.count()) / 1e6 / NLOOPSA; //duration per loop seconds
+
+    cout << "\n===== Benchmark A =====\n";
+    cout << "<xA,yA> = "  << sA << endl;
+    cout << "Timing in sec. : " << tA << endl;
+    cout << "GFLOPS         : " << 2.0 * NA / tA / 1024 / 1024 / 1024 << endl;
+    cout << "GiByte/s       : "
+         << 2.0 * NA * sizeof(xA[0]) / tA / 1024 / 1024 / 1024 << endl;
+}
+
+// ---------- Benchmark B----------
+
+{
+    const unsigned int MB = 1700;
+    const unsigned int NB = MB;
+    const unsigned int NLOOPSB = 10000;//50;
+
+    vector<double> AB(MB * NB);
+    vector<double> xB(NB);
+
+    for (unsigned int i = 0; i < MB; ++i)
+        for (unsigned int j = 0; j < NB; ++j)
+            AB[i * NB + j] = (i+j) %219 +1;
+
+    for (unsigned int j = 0; j < NB; ++j)
+    {
+        
+        xB[j] = 1.0 / AB[17*NB+j];
+    }
+
+    vector<double> bB;
+    auto tB1 = system_clock::now();
+    double guardB = 0.0;
+    for (unsigned int loop = 0; loop < NLOOPSB; ++loop)
+    {
+        bB = benchmark_B(AB, xB);
+        guardB += bB[17];
+    }
+    auto tB2 = system_clock::now();
+
+    auto durB = duration_cast<microseconds>(tB2 - tB1);
+    double tB = static_cast<double>(durB.count()) / 1e6 / NLOOPSB;
+
+    double flopsB = 2.0 * MB * NB;  
+    double bytesB = (MB * NB + NB  + MB)  * sizeof(double);
+
+    cout << "\n===== Benchmark B =====\n";
+    cout << guardB << endl;
+    cout << "bytes: " << bytesB << endl;
+    cout << "Timing in sec. : " << tB << endl;
+    cout << "GFLOPS         : " << flopsB / tB / 1024 / 1024 / 1024 << endl;
+    cout << "GiByte/s       : " << bytesB / tB / 1024 / 1024 / 1024 << endl;
+}
+
+// ---------- Benchmark C ----------
+
+{
+    
+    const unsigned int LC = MC;
+    const unsigned int NC = MC;
+
+   
+    vector<double> AC(MC * LC), BC(LC * NC);
+
+    for (unsigned int i = 0; i < MC; ++i)
+        for (unsigned int j = 0; j < LC; ++j)
+            AC[i * LC + j] = (i+j) %219 +1;
+
+    for (unsigned int i = 0; i < LC; ++i)
+        for (unsigned int j = 0; j < NC; ++j)
+            BC[i * NC + j] = (i+j) %219 +1;
+
+    vector<double> CC;
+    auto tC1 = system_clock::now();
+    double guardC = 0.0;
+    for (unsigned int loop = 0; loop < NLOOPSC; ++loop)
+    {
+        CC = benchmark_C(AC, BC, MC);
+        guardC += CC[0];
+    }
+    auto tC2 = system_clock::now();
+
+    auto durC = duration_cast<microseconds>(tC2 - tC1);
+    double tC = static_cast<double>(durC.count()) / 1e6 / NLOOPSC;
+
+    double flopsC = 2.0 * MC * LC * NC;
+    double bytesC = (MC * LC  + LC * NC  + MC * NC)* sizeof(double);
+
+    cout << "\n===== Benchmark C =====\n";
+    cout << "bytes: " << bytesC << endl;
+    cout << "Timing in sec. : " << tC << endl;
+    cout << "GFLOPS         : " << flopsC / tC / 1024 / 1024 / 1024 << endl;
+    cout << "GiByte/s       : " << bytesC / tC / 1024 / 1024 / 1024 << endl;
+}
+
+
+return 0;
+}  // memory for x and y will be deallocated by their destructors

sheet3/6/mylib.cpp

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+#include "mylib.h"
+#include <cassert>       // assert()
+#include <cmath>
+#include <vector>
+
+#ifdef __INTEL_CLANG_COMPILER
+#pragma message(" ##########  Use of MKL  ###############")
+#include <mkl.h>
+#else
+#pragma message(" ##########  Use of CBLAS  ###############")
+//extern "C"
+//{
+#include <cblas.h>               // cBLAS Library
+#include <lapacke.h>             // Lapack
+//}
+#endif
+
+using namespace std;
+
+double scalar(vector<double> const &x, vector<double> const &y)
+{
+    assert(x.size() == y.size()); // switch off via compile flag: -DNDEBUG
+    size_t const N = x.size();
+    double sum = 0.0;
+    for (size_t i = 0; i < N; ++i)
+    {
+        sum += x[i] * y[i];
+        //sum += exp(x[i])*log(y[i]);
+    }
+    return sum;
+}
+
+
+double scalar_cblas(vector<double> const &x, vector<double> const &y)
+{
+    int const asize = static_cast<int>(size(x));
+    int const bsize = static_cast<int>(size(y));
+    assert(asize == bsize); // switch off via compile flag: -DNDEBUG
+	return cblas_ddot(asize,x.data(),1,y.data(),1);    
+    //assert(x.size() == y.size()); // switch off via compile flag: -DNDEBUG
+	//return cblas_ddot(x.size(),x.data(),1,y.data(),1);
+}
+
+float scalar_cblas(vector<float> const &x, vector<float> const &y)
+{
+    int const asize = static_cast<int>(size(x));
+    int const bsize = static_cast<int>(size(y));
+    assert(asize == bsize); // switch off via compile flag: -DNDEBUG
+	return cblas_sdot(asize,x.data(),1,y.data(),1);    
+    //assert(x.size() == y.size()); // switch off via compile flag: -DNDEBUG
+	//return cblas_ddot(x.size(),x.data(),1,y.data(),1);
+}
+
+
+double norm(vector<double> const &x)
+{
+    size_t const N = x.size();
+    double sum = 0.0;
+    for (size_t i = 0; i < N; ++i)
+    {
+        sum += x[i] * x[i];
+    }
+    return std::sqrt(sum);
+}
+

sheet3/6/mylib.h

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+#ifndef FILE_MYLIB
+#define FILE_MYLIB
+#include <vector>
+
+/** 	Inner product
+	@param[in] x	vector
+	@param[in] y	vector
+	@return 	    resulting Euclidian inner product <x,y>
+*/
+double scalar(std::vector<double> const &x, std::vector<double> const &y);
+
+/** 	Inner product using BLAS routines
+	@param[in] x	vector
+	@param[in] y	vector
+	@return 	    resulting Euclidian inner product <x,y>
+*/
+double scalar_cblas(std::vector<double> const &x, std::vector<double> const &y);
+float scalar_cblas(std::vector<float> const &x, std::vector<float> const &y);
+
+
+/** 	L_2 Norm of a vector
+	@param[in] x	vector
+	@return 	    resulting Euclidian norm <x,y>
+*/
+double norm(std::vector<double> const &x);
+
+
+
+
+#endif