/* -*- Mode: C; c-basic-offset:4 ; indent-tabs-mode:nil ; -*- */
/*
* (C) 2012 by Argonne National Laboratory.
* See COPYRIGHT in top-level directory.
*/
/*
* Tests that the performance of a struct that contains a vector type
* exploits the vector type correctly
*
* If PACK_IS_NATIVE is defined, MPI_Pack stores exactly the same bytes as the
* user would pack manually; in that case, there is a consistency check.
*/
#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "mpitestconf.h"
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef MPICH
/* MPICH (as of 6/2012) packs the native bytes */
#define PACK_IS_NATIVE
#endif
static int verbose = 0;
int main(int argc, char **argv)
{
int vcount, vstride;
int32_t counts[2];
int v2stride, typesize, packsize, i, position, errs = 0;
double *outbuf, *outbuf2;
double *vsource;
MPI_Datatype vtype, stype;
MPI_Aint lb, extent;
double t0, t1;
double tspack, tvpack, tmanual;
int ntry;
int blocklengths[2];
MPI_Aint displacements[2];
MPI_Datatype typesArray[2];
MPI_Init(&argc, &argv);
/* Create a struct consisting of a two 32-bit ints, followed by a
* vector of stride 3 but count 128k (less than a few MB of data area) */
vcount = 128000;
vstride = 3;
MPI_Type_vector(vcount, 1, vstride, MPI_DOUBLE, &vtype);
vsource = (double *) malloc((vcount + 1) * (vstride + 1) * sizeof(double));
if (!vsource) {
fprintf(stderr, "Unable to allocate vsource\n");
MPI_Abort(MPI_COMM_WORLD, 1);
}
for (i = 0; i < vcount * vstride; i++) {
vsource[i] = i;
}
blocklengths[0] = 2;
MPI_Get_address(&counts[0], &displacements[0]);
blocklengths[1] = 1;
MPI_Get_address(vsource, &displacements[1]);
if (verbose) {
printf("%p = %p?\n", vsource, (void *) displacements[1]);
}
typesArray[0] = MPI_INT32_T;
typesArray[1] = vtype;
MPI_Type_create_struct(2, blocklengths, displacements, typesArray, &stype);
MPI_Type_commit(&stype);
MPI_Type_commit(&vtype);
#if defined(MPICH) && defined(PRINT_DATATYPE_INTERNALS)
/* To use MPIDU_Datatype_debug to print the datatype internals,
* you must configure MPICH with --enable-g=log */
if (verbose) {
printf("Original struct datatype:\n");
MPIDU_Datatype_debug(stype, 10);
}
#endif
MPI_Pack_size(1, stype, MPI_COMM_WORLD, &packsize);
outbuf = (double *) malloc(packsize);
outbuf2 = (double *) malloc(packsize);
if (!outbuf) {
fprintf(stderr, "Unable to allocate %ld for outbuf\n", (long) packsize);
MPI_Abort(MPI_COMM_WORLD, 1);
}
if (!outbuf2) {
fprintf(stderr, "Unable to allocate %ld for outbuf2\n", (long) packsize);
MPI_Abort(MPI_COMM_WORLD, 1);
}
position = 0;
/* Warm up the code and data */
MPI_Pack(MPI_BOTTOM, 1, stype, outbuf, packsize, &position, MPI_COMM_WORLD);
tspack = 1e12;
for (ntry = 0; ntry < 5; ntry++) {
position = 0;
t0 = MPI_Wtime();
MPI_Pack(MPI_BOTTOM, 1, stype, outbuf, packsize, &position, MPI_COMM_WORLD);
t1 = MPI_Wtime() - t0;
if (t1 < tspack)
tspack = t1;
}
MPI_Type_free(&stype);
/* An equivalent packing, using the 2 ints and the vector separately */
tvpack = 1e12;
for (ntry = 0; ntry < 5; ntry++) {
position = 0;
t0 = MPI_Wtime();
MPI_Pack(counts, 2, MPI_INT32_T, outbuf, packsize, &position, MPI_COMM_WORLD);
MPI_Pack(vsource, 1, vtype, outbuf, packsize, &position, MPI_COMM_WORLD);
t1 = MPI_Wtime() - t0;
if (t1 < tvpack)
tvpack = t1;
}
MPI_Type_free(&vtype);
/* Note that we exploit the fact that the vector type contains vblock
* instances of a contiguous type of size 24, or a single block of 24*vblock
* bytes.
*/
tmanual = 1e12;
for (ntry = 0; ntry < 5; ntry++) {
const double *restrict ppe = (const double *) vsource;
double *restrict ppo = outbuf2;
int j;
t0 = MPI_Wtime();
position = 0;
*(int32_t *) ppo = counts[0];
*(((int32_t *) ppo) + 1) = counts[1];
ppo++;
/* Some hand optimization because this file is not normally
* compiled with optimization by the test suite */
j = vcount;
while (j) {
*ppo++ = *ppe;
ppe += vstride;
*ppo++ = *ppe;
ppe += vstride;
*ppo++ = *ppe;
ppe += vstride;
*ppo++ = *ppe;
ppe += vstride;
j -= 4;
}
position += (1 + vcount);
position *= sizeof(double);
t1 = MPI_Wtime() - t0;
if (t1 < tmanual)
tmanual = t1;
/* Check on correctness */
#ifdef PACK_IS_NATIVE
if (memcmp(outbuf, outbuf2, position) != 0) {
printf("Panic(manual) - pack buffers differ\n");
for (j = 0; j < 8; j++) {
printf("%d: %llx\t%llx\n", j, (long long unsigned) outbuf[j],
(long long unsigned) outbuf2[j]);
}
}
#endif
}
if (verbose) {
printf("Bytes packed = %d\n", position);
printf("MPI_Pack time = %e (struct), = %e (vector), manual pack time = %e\n",
tspack, tvpack, tmanual);
}
if (4 * tmanual < tspack) {
errs++;
printf("MPI_Pack time using struct with vector = %e, manual pack time = %e\n", tspack,
tmanual);
printf("MPI_Pack time should be less than 4 times the manual time\n");
printf("For most informative results, be sure to compile this test with optimization\n");
}
if (4 * tmanual < tvpack) {
errs++;
printf("MPI_Pack using vector = %e, manual pack time = %e\n", tvpack, tmanual);
printf("MPI_Pack time should be less than 4 times the manual time\n");
printf("For most informative results, be sure to compile this test with optimization\n");
}
if (4 * tvpack < tspack) {
errs++;
printf("MPI_Pack using a vector = %e, using a struct with vector = %e\n", tvpack, tspack);
printf
("MPI_Pack time using vector should be about the same as the struct containing the vector\n");
printf("For most informative results, be sure to compile this test with optimization\n");
}
if (errs) {
printf(" Found %d errors\n", errs);
}
else {
printf(" No Errors\n");
}
free(vsource);
free(outbuf);
free(outbuf2);
MPI_Finalize();
return 0;
}