From e7cf1f47c93df3ca04026a0ee4e5124beade5d1f Mon Sep 17 00:00:00 2001
From: Neil Gershenfeld <gersh@cba.mit.edu>
Date: Wed, 19 Jun 2019 21:17:12 -0400
Subject: [PATCH] wip
---
MPI/mpipi.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/MPI/mpipi.c b/MPI/mpipi.c
index cf4343d..e1fd6e6 100755
--- a/MPI/mpipi.c
+++ b/MPI/mpipi.c
@@ -8,11 +8,10 @@
#include <mpi.h>
#include <sys/time.h>
-#define NPTS 100000000
-#define NLOOP 10
+#define NPTS 1000000000
void main(int argc, char** argv) {
- int rank,nproc,i,istart,iend,loop,N;
+ int rank,nproc,i,istart,iend;
unsigned long int start_time,end_time;
struct timeval start,end;
double sum,pi,mflops;
@@ -25,24 +24,22 @@ void main(int argc, char** argv) {
istart = 1 + NPTS*((rank+0.0)/nproc);
iend = NPTS*((rank+1.0)/nproc);
sum = 0.0;
- for (loop = 0; loop < NLOOP; ++loop)
- for (i = istart; i <= iend; ++i)
- sum += 0.5/((i-0.75)*(i-0.25));
+ for (i = istart; i <= iend; ++i)
+ sum += 0.5/((i-0.75)*(i-0.25));
MPI_Reduce(&sum,&pi,1,MPI_DOUBLE,MPI_SUM,0,MPI_COMM_WORLD);
gettimeofday(&end, NULL);
start_time = start.tv_sec * 1e6 + start.tv_usec;
end_time = end.tv_sec * 1e6 + end.tv_usec;
- mflops = NLOOP*(NPTS*(5.0/(end_time-start_time)));
- printf("processes = %d, NPTS = %d, NLOOP = %d, pi = %f\n",nproc,NPTS,NLOOP,pi/NLOOP);
+ mflops = NPTS*(5.0/(end_time-start_time));
+ printf("processes = %d, NPTS = %d, pi = %f\n",nproc,NPTS,pi);
printf("time = %f, estimated MFlops = %f\n",(end_time-start_time)/1.0e6,mflops);
}
else {
istart = 1 + NPTS*((rank+0.0)/nproc);
iend = NPTS*((rank+1.0)/nproc);
sum = 0.0;
- for (loop = 0; loop < NLOOP; ++loop)
- for (i = istart; i <= iend; ++i)
- sum += 0.5/((i-0.75)*(i-0.25));
+ for (i = istart; i <= iend; ++i)
+ sum += 0.5/((i-0.75)*(i-0.25));
MPI_Reduce(&sum,&pi,1,MPI_DOUBLE,MPI_SUM,0,MPI_COMM_WORLD);
}
MPI_Finalize();
--
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