问题描述
请帮帮我.我有以下代码
Please, help me. I have the following code
...
#include <accelmath.h>
#include <openacc.h>
const long int G=100000;
const unsigned int GL=100000;
const long int K=G;
const int LE=1.0f;
struct Particle
{
float x;
float rs;
};
Particle particles[GL];
int sort[GL];
int ind01[GL];
long int MAX_ELEMENT=1;
int POSITION1;
int POSITION0;
int LIFE=0;
bool start=true;
int mini;
int count0;
int count1;
int GL1;
int js;
#pragma acc declare device_resident(ind01,POSITION0,POSITION1,mini,GL1,js,MAX_ELEMENT,count0,count1,K)
#pragma acc declare create(LIFE,particles,sort)
void function_device()
{
#pragma acc update host(LIFE,particles) async
std::cout<<"LIFE before="<<LIFE<<std::endl;
#pragma acc update device(LIFE,particles) async
#pragma acc parallel num_gangs(1) vector_length(1) present(particles) async
{
count0=0;
count1=0;
if(LIFE<K)
{
particles[LIFE].x=5.0;
particles[LIFE].rs=MAX_ELEMENT;
++MAX_ELEMENT;
++LIFE;
}
}
#pragma acc loop vector reduction(+:count0,count1)
for(int i=0; i<LIFE; ++i)
{
if(particles[i].x>=LE)
{
sort[i]=1;
count1=count1+1;
}
else
{
sort[i]=0;
count0=count0+1;
}
}
#pragma acc parallel num_gangs(1) vector_length(1)
{
GL1=LIFE-1;
count0=GL1;
count1=0;
}
#pragma acc loop seq
for(int i=0; i<LIFE; ++i)
{
if(sort[i]==1)
{
ind01[count1++]=i;
}
else
{
ind01[count0--]=i;
}
}
#pragma acc parallel num_gangs(1) vector_length(1)
{
mini=GL1-count0;
if(count1<mini) mini=count1;
js=0;
}
...
#pragma acc update host(LIFE) async
}
int main(int argc, char **argv)
{
acc_init(acc_device_nvidia);
int step=1;
while(start==true || LIFE>0)
{
std::cout<<" LIFE="<<LIFE<<std::endl;
start=false;
function_device();
std::cout<<"MAIN LOOP # "<<step<<std::endl;
++step;
}
}
在我填写了在gpu上分配的数组之后:
After i have filled in the array allocated on the gpu:
particles[LIFE].x=5.0;
但打印输出:
#pragma acc update host(LIFE,particles) async
std::cout<<"LIFE after injector="<<LIFE<<std::endl;
for(int i=0; i<LIFE; ++i) std::cout<<" particles: "<<particles[i]<<std::endl;
和:
#pragma acc update host(LIFE,sort) async
std::cout<<"LIFE after 1="<<LIFE<<" c0="<<count0<<" c1="<<count1<<std::endl;
for(int i=0; i<LIFE; ++i) std::cout<<"sort: "<<sort[i]<<std::endl;
是LIFE = 1时，数组仅包含0，就好像我没有用5.0f填充数组粒子.如何填写粒子"数组?我可以在gpu上正确启动串行代码吗?
is LIFE=1 the arrays contain only 0, as if i did not fill the array particles with 5.0f. How to fill in the array "particles"? Do i correctly launch a serial code on the gpu:
#pragma acc parallel num_gangs(1) vector_length(1)
{
mini=GL1-count0;
if(count1<mini) mini=count1;
js=0;
}
如果在使用openacc指令时出现错误，请显示出来.为什么
If there are mistakes in the usage of openacc directives, please, show them. Why the
#pragma acc update host(LIFE) async
如果没有异步指令，指令将无法正常工作?
directive does not work without async?
推荐答案
我更新了您的代码以使其正常工作.您有几个孤立的循环需要在它们上进行并行"处理，再加上一些变量是全局变量，因此您需要使用atomic.在原子中使用在声明创建"中定义的变量时，确实遇到了编译器问题，因此需要将一些变量移至数据区域.我将报告给我们的工程师.
I updated your code to get it to work. You had a few orphaned loops which needed "parallel" on them plus since several of the variables are globals, you need to use atomic. I did encounter a compiler issue when using variables defined in the "declare create" in an atomic so needed to move a few of the variables to a data region. I'll report this to our engineers.
请注意，当LIFE达到G时，我也处于终止状态，否则它似乎进入了无限循环.
Note that I also put in a terminating condition when LIFE reached G, otherwise it seemed to enter an infinite loop.
#include <iostream>
#include <accelmath.h>
#include <openacc.h>
const long int G=100000;
const unsigned int GL=100000;
const long int K=G;
const int LE=1.0f;
struct Particle
{
float x;
float rs;
};
Particle particles[GL];
int sort[GL];
int ind01[GL];
int MAX_ELEMENT;
int POSITION1;
int POSITION0;
int LIFE;
bool start=true;
int mini;
int GL1;
int js;
int count0;
int count1;
#pragma acc declare device_resident(ind01,POSITION0,POSITION1,mini,GL1,js)
#pragma acc declare create(particles,sort)
void function_device()
{
#pragma acc parallel num_gangs(1) vector_length(1) present(particles)
{
#pragma acc atomic write
count0=0;
#pragma acc atomic write
count1=0;
if(LIFE<K)
{
particles[LIFE].x=5.0;
particles[LIFE].rs=MAX_ELEMENT;
#pragma acc atomic update
++MAX_ELEMENT;
#pragma acc atomic update
++LIFE;
}
}
#pragma acc parallel loop
for(int i=0; i<LIFE; ++i)
{
if(particles[i].x>=LE)
{
sort[i]=1;
#pragma acc atomic update
count1=count1+1;
}
else
{
sort[i]=0;
#pragma acc atomic update
count0=count0+1;
}
}
#pragma acc parallel num_gangs(1) vector_length(1)
{
GL1=LIFE-1;
count0=GL1;
count1=0;
}
#pragma acc parallel loop
for(int i=0; i<LIFE; ++i)
{
int cnt;
if(sort[i]==1)
{
#pragma acc atomic capture
{
cnt = count1++;
}
ind01[cnt]=i;
}
else
{
#pragma acc atomic capture
{
cnt = count0--;
}
ind01[cnt]=i;
}
}
#pragma acc parallel num_gangs(1) vector_length(1)
{
mini=GL1-count0;
if(count1<mini) mini=count1;
js=0;
}
}
int main(int argc, char **argv)
{
acc_init(acc_device_nvidia);
int step=1;
LIFE=0;
MAX_ELEMENT=1;
#pragma acc data copyin(LIFE,MAX_ELEMENT,count0,count1)
{
while(start==true || (LIFE>0 && LIFE < G ))
{
std::cout<<" LIFE="<<LIFE<<std::endl;
start=false;
function_device();
#pragma acc update self(LIFE)
std::cout<<"MAIN LOOP # "<<step<<std::endl;
++step;
}
}
}
这篇关于无法填充在gpu上分配的数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！