From 5a17f58adf391c94cace31eb9f0613e1a952f2bd Mon Sep 17 00:00:00 2001
From: kmazouzi <kamel.mazouzi@univ-fcomte.fr>
Date: Wed, 23 Mar 2016 00:10:27 +0100
Subject: [PATCH] add jacobi for openacc

---
 openacc/Makefile |   28 +++++++++++++++++++
 openacc/jacobi.c |   75 +++++++++++++++++++++++++++++++++++++++++++++++++
 openacc/timer.h  |   82 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 185 insertions(+)
 create mode 100644 openacc/Makefile
 create mode 100644 openacc/jacobi.c
 create mode 100644 openacc/timer.h

diff --git a/openacc/Makefile b/openacc/Makefile
new file mode 100644
index 0000000..1fdee41
--- /dev/null
+++ b/openacc/Makefile
@@ -0,0 +1,28 @@
+
+CC=gcc
+
+CFLAGS=-O3   -std=c99 -Wall
+LDFLAG= -lm
+
+OMPFLAG=-fopenmp -D_OMP
+
+PGCC=pgcc
+PGCFLAGS=-acc -ta=nvidia -Minfo
+
+
+NAME=jacobi
+
+default: seq omp
+
+seq:
+	$(CC) $(CFLAGS) $(NAME).c -o $(NAME).seq.exe $(LDFLAG)
+
+omp:
+	$(CC) $(CFLAGS) $(OMPFLAG) $(NAME).c -o $(NAME).omp.exe $(LDFLAG)
+
+
+gpu:
+	$(PGCC) $(PGCFLAGS) $(NAME).c  -o $(NAME).pgi.exe
+
+clean: 
+	rm -f  *.exe
diff --git a/openacc/jacobi.c b/openacc/jacobi.c
new file mode 100644
index 0000000..5e21f42
--- /dev/null
+++ b/openacc/jacobi.c
@@ -0,0 +1,75 @@
+#include <math.h>
+#include <string.h>
+#include <stdlib.h>
+
+#ifdef _OMP
+#include <omp.h>
+#endif 
+
+#include <stdio.h>
+// #include <openacc.h>
+#include "timer.h"
+#define NN 4096
+#define NM 4096
+
+double A[NN][NM];
+double Anew[NN][NM];
+
+int main(int argc, char** argv)
+{
+    const int n = NN;
+    const int m = NM;
+    const int iter_max = 200;
+    
+    const double tol = 1.0e-6;
+    double error     = 1.0;
+    
+    memset(A, 0, n * m * sizeof(double));
+    memset(Anew, 0, n * m * sizeof(double));
+        
+    for (int j = 0; j < n; j++)
+    {
+        A[j][0]    = 1.0;
+        Anew[j][0] = 1.0;
+    }
+    
+    printf("Jacobi relaxation Calculation: %d x %d mesh\n", n, m);
+    
+    StartTimer();
+    int iter = 0;
+ 
+{
+    while ( error > tol && iter < iter_max )
+    {
+        error = 0.0;
+
+#ifdef _OMP
+#pragma omp parallel for reduction (max:error)       
+#endif 
+        for( int j = 1; j < n-1; j++)
+        {
+            for( int i = 1; i < m-1; i++ )
+            {
+                Anew[j][i] = 0.25 * ( A[j][i+1] + A[j][i-1]
+                                    + A[j-1][i] + A[j+1][i]);
+                error = fmax( error, fabs(Anew[j][i] - A[j][i]));
+            }
+        }
+        
+        for( int j = 1; j < n-1; j++)
+        {
+            for( int i = 1; i < m-1; i++ )
+            {
+                A[j][i] = Anew[j][i];    
+            }
+        }
+
+        if(iter % 10 == 0) printf("%5d, %0.6f\n", iter, error);
+        
+        iter++;
+    }
+}
+    double runtime = GetTimer();
+ 
+    printf(" total: %f s\n", runtime / 1000);
+}
diff --git a/openacc/timer.h b/openacc/timer.h
new file mode 100644
index 0000000..18738ef
--- /dev/null
+++ b/openacc/timer.h
@@ -0,0 +1,82 @@
+/*
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef TIMER_H
+#define TIMER_H
+
+#include <stdlib.h>
+
+#ifdef WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#else
+#include <sys/time.h>
+
+/* RR: Apparently if no BSD or mac, this is missing */ 
+#ifndef __USE_BSD
+# define timersub(a, b, result)						      \
+  do {									      \
+    (result)->tv_sec = (a)->tv_sec - (b)->tv_sec;			      \
+    (result)->tv_usec = (a)->tv_usec - (b)->tv_usec;			      \
+    if ((result)->tv_usec < 0) {					      \
+      --(result)->tv_sec;						      \
+      (result)->tv_usec += 1000000;					      \
+    }									      \
+  } while (0)
+#endif	/* BSD */
+
+
+#endif
+
+
+
+#ifdef WIN32
+double PCFreq = 0.0;
+__int64 timerStart = 0;
+#else
+struct timeval timerStart;
+#endif
+
+void StartTimer()
+{
+#ifdef WIN32
+    LARGE_INTEGER li;
+    if(!QueryPerformanceFrequency(&li))
+        printf("QueryPerformanceFrequency failed!\n");
+
+    PCFreq = (double)li.QuadPart/1000.0;
+
+    QueryPerformanceCounter(&li);
+    timerStart = li.QuadPart;
+#else
+    gettimeofday(&timerStart, NULL);
+#endif
+}
+
+// time elapsed in ms
+double GetTimer()
+{
+#ifdef WIN32
+    LARGE_INTEGER li;
+    QueryPerformanceCounter(&li);
+    return (double)(li.QuadPart-timerStart)/PCFreq;
+#else
+    struct timeval timerStop, timerElapsed;
+    gettimeofday(&timerStop, NULL);
+    timersub(&timerStop, &timerStart, &timerElapsed);
+    return timerElapsed.tv_sec*1000.0+timerElapsed.tv_usec/1000.0;
+#endif
+}
+
+#endif // TIMER_H
-- 
1.7.10.4