aaron/ispc
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Add volume rendering example. (~2.3x speedup from SIMD vs serial code.)

Browse Source
This commit is contained in:
Matt Pharr
2011-08-17 12:05:37 +01:00
parent fce183c244
commit ecaa57c7c6
14 changed files with 1691 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

251
examples/volume_rendering/volume.cpp Normal file
View File

@@ -0,0 +1,251 @@
/*
Copyright (c) 2011, Intel Corporation
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of Intel Corporation nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef _MSC_VER
#define _CRT_SECURE_NO_WARNINGS
#define NOMINMAX
#pragma warning (disable: 4244)
#pragma warning (disable: 4305)
#endif
#include <stdio.h>
#include <algorithm>
#include "../timing.h"
#include "../cpuid.h"
#include "volume_ispc.h"
using namespace ispc;
extern void volume_serial(float density[], int nVoxels[3],
const float raster2camera[4][4],
const float camera2world[4][4],
int width, int height, float image[]);
/* Write a PPM image file with the image */
static void
writePPM(float *buf, int width, int height, const char *fn) {
FILE *fp = fopen(fn, "wb");
fprintf(fp, "P6\n");
fprintf(fp, "%d %d\n", width, height);
fprintf(fp, "255\n");
for (int i = 0; i < width*height; ++i) {
float v = buf[i] * 255.f;
if (v < 0.f) v = 0.f;
else if (v > 255.f) v = 255.f;
unsigned char c = (unsigned char)v;
for (int j = 0; j < 3; ++j)
fputc(c, fp);
}
fclose(fp);
printf("Wrote image file %s\n", fn);
}
// Make sure that the vector ISA used during compilation is supported by
// the processor. The ISPC_TARGET_* macro is set in the ispc-generated
// header file that we include above.
static void
ensureTargetISAIsSupported() {
#if defined(ISPC_TARGET_SSE2)
bool isaSupported = CPUSupportsSSE2();
const char *target = "SSE2";
#elif defined(ISPC_TARGET_SSE4)
bool isaSupported = CPUSupportsSSE4();
const char *target = "SSE4";
#elif defined(ISPC_TARGET_AVX)
bool isaSupported = CPUSupportsAVX();
const char *target = "AVX";
#else
#error "Unknown ISPC_TARGET_* value"
#endif
if (!isaSupported) {
fprintf(stderr, "***\n*** Error: the ispc-compiled code uses the %s instruction "
"set, which isn't\n*** supported by this computer's CPU!\n", target);
fprintf(stderr, "***\n*** Please modify the "
#ifdef _MSC_VER
"MSVC project file "
#else
"Makefile "
#endif
"to select another target (e.g. sse2)\n***\n");
exit(1);
}
}
/* Load image and viewing parameters from a camera data file.
FIXME: we should add support to be able to specify viewing parameters
in the program here directly. */
static void
loadCamera(const char *fn, int *width, int *height, float raster2camera[4][4],
float camera2world[4][4]) {
FILE *f = fopen(fn, "r");
if (!f) {
perror(fn);
exit(1);
}
if (fscanf(f, "%d %d", width, height) != 2) {
fprintf(stderr, "Unexpected end of file in camera file\n");
exit(1);
}
for (int i = 0; i < 4; ++i) {
for (int j = 0; j < 4; ++j) {
if (fscanf(f, "%f", &raster2camera[i][j]) != 1) {
fprintf(stderr, "Unexpected end of file in camera file\n");
exit(1);
}
}
}
for (int i = 0; i < 4; ++i) {
for (int j = 0; j < 4; ++j) {
if (fscanf(f, "%f", &camera2world[i][j]) != 1) {
fprintf(stderr, "Unexpected end of file in camera file\n");
exit(1);
}
}
}
fclose(f);
}
/* Load a volume density file. Expects the number of x, y, and z samples
as the first three values (as integer strings), then x*y*z
floating-point values (also as strings) to give the densities. */
static float *
loadVolume(const char *fn, int n[3]) {
FILE *f = fopen(fn, "r");
if (!f) {
perror(fn);
exit(1);
}
if (fscanf(f, "%d %d %d", &n[0], &n[1], &n[2]) != 3) {
fprintf(stderr, "Couldn't find resolution at start of density file\n");
exit(1);
}
int count = n[0] * n[1] * n[2];
float *v = new float[count];
for (int i = 0; i < count; ++i) {
if (fscanf(f, "%f", &v[i]) != 1) {
fprintf(stderr, "Unexpected end of file at %d'th density value\n", i);
exit(1);
}
}
return v;
}
int main(int argc, char *argv[]) {
if (argc != 3) {
fprintf(stderr, "usage: volume <camera.dat> <volume_density.vol>\n");
return 1;
}
ensureTargetISAIsSupported();
extern void TasksInit();
TasksInit();
//
// Load viewing data and the volume density data
//
int width, height;
float raster2camera[4][4], camera2world[4][4];
loadCamera(argv[1], &width, &height, raster2camera, camera2world);
float *image = new float[width*height];
int n[3];
float *density = loadVolume(argv[2], n);
//
// Compute the image using the ispc implementation; report the minimum
// time of three runs.
//
double minISPC = 1e30;
for (int i = 0; i < 3; ++i) {
reset_and_start_timer();
volume_ispc(density, n, raster2camera, camera2world,
width, height, image);
double dt = get_elapsed_mcycles();
minISPC = std::min(minISPC, dt);
}
printf("[volume ispc 1 core]:\t\t[%.3f] million cycles\n", minISPC);
writePPM(image, width, height, "volume-ispc-1core.ppm");
// Clear out the buffer
for (int i = 0; i < width * height; ++i)
image[i] = 0.;
//
// Compute the image using the ispc implementation that also uses
// tasks; report the minimum time of three runs.
//
double minISPCtasks = 1e30;
for (int i = 0; i < 3; ++i) {
reset_and_start_timer();
volume_ispc_tasks(density, n, raster2camera, camera2world,
width, height, image);
double dt = get_elapsed_mcycles();
minISPCtasks = std::min(minISPCtasks, dt);
}
printf("[volume ispc + tasks]:\t\t[%.3f] million cycles\n", minISPCtasks);
writePPM(image, width, height, "volume-ispc-tasks.ppm");
// Clear out the buffer
for (int i = 0; i < width * height; ++i)
image[i] = 0.;
//
// And run the serial implementation 3 times, again reporting the
// minimum time.
//
double minSerial = 1e30;
for (int i = 0; i < 3; ++i) {
reset_and_start_timer();
volume_serial(density, n, raster2camera, camera2world,
width, height, image);
double dt = get_elapsed_mcycles();
minSerial = std::min(minSerial, dt);
}
printf("[volume serial]:\t\t[%.3f] millon cycles\n", minSerial);
writePPM(image, width, height, "volume-serial.ppm");
printf("\t\t\t\t(%.2fx speedup from ISPC serial, %.2fx from ISPC+tasks)\n",
minSerial/minISPC, minSerial / minISPCtasks);
return 0;
}