一部の CPU ルーチンが、GPU を使用して一部の計算を高速化する関数を呼び出せるようにするコードをコンパイルしようとしています。GPU コードは Thrust、具体的には reduce と device_ptr を使用します。nvcc を使用してスタンドアロンとして GPU コードをビルドすると、問題は発生しません。ただし、GPU コードを CPU C++ コードと統合しようとすると、最終的な「ラッパー」をコンパイルするときに次のコンパイラ エラーが発生します。
nvcc -O2 -c NLC_2D_TFIM.cpp -lcuda -lcudart -lcublas -lcusparse -L../CUDA/Lanczos/sort/sort/gnu/release -lmgpusort
In file included from /usr/local/cuda/bin/../include/thrust/pair.h:265:0,
from /usr/local/cuda/bin/../include/thrust/tuple.h:35,
from /usr/local/cuda/bin/../include/thrust/detail/functional/actor.h:29,
from /usr/local/cuda/bin/../include/thrust/detail/functional/placeholder.h:20,
from /usr/local/cuda/bin/../include/thrust/functional.h:26,
from /usr/local/cuda/bin/../include/thrust/system/detail/error_category.inl:22,
from /usr/local/cuda/bin/../include/thrust/system/error_code.h:516,
from /usr/local/cuda/bin/../include/thrust/system/cuda_error.h:26,
from /usr/local/cuda/bin/../include/thrust/detail/backend/cuda/malloc.inl:26,
from /usr/local/cuda/bin/../include/thrust/detail/backend/cuda/malloc.h:50,
from /usr/local/cuda/bin/../include/thrust/detail/backend/dispatch/malloc.h:22,
from /usr/local/cuda/bin/../include/thrust/detail/device_malloc.inl:23,
from /usr/local/cuda/bin/../include/thrust/device_malloc.h:102,
from /usr/local/cuda/bin/../include/thrust/detail/backend/internal_allocator.h:22,
from /usr/local/cuda/bin/../include/thrust/detail/uninitialized_array.h:23,
from /usr/local/cuda/bin/../include/thrust/detail/backend/cuda/copy_cross_space.inl:20,
from /usr/local/cuda/bin/../include/thrust/detail/backend/cuda/copy_cross_space.h:57,
from /usr/local/cuda/bin/../include/thrust/detail/backend/cuda/dispatch/copy.h:23,
from /usr/local/cuda/bin/../include/thrust/detail/backend/cuda/copy.h:21,
from /usr/local/cuda/bin/../include/thrust/detail/backend/dispatch/copy.h:24,
from /usr/local/cuda/bin/../include/thrust/detail/backend/copy.inl:20,
from /usr/local/cuda/bin/../include/thrust/detail/backend/copy.h:44,
from /usr/local/cuda/bin/../include/thrust/detail/copy.inl:20,
from /usr/local/cuda/bin/../include/thrust/detail/copy.h:39,
from /usr/local/cuda/bin/../include/thrust/detail/reference_base.inl:18,
from /usr/local/cuda/bin/../include/thrust/detail/reference_base.h:138,
from /usr/local/cuda/bin/../include/thrust/device_reference.h:27,
from /usr/local/cuda/bin/../include/thrust/detail/device_ptr.inl:23,
from /usr/local/cuda/bin/../include/thrust/device_ptr.h:181,
from ../CUDA/Lanczos/hamiltonian.h:32,
from ../CUDA/Lanczos/lanczos.h:8,
from NLC_2D_TFIM.cpp:17:
/usr/local/cuda/bin/../include/thrust/detail/pair.inl: In function ‘bool thrust::operator<(const thrust::pair<T1, T2>&, const thrust::pair<T1, T2>&)’:
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:22: error: ‘.’ cannot appear in a constant-expression
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:46: error: ‘.’ cannot appear in a constant-expression
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:36: error: parse error in template argument list
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:36: error: ‘.’ cannot appear in a constant-expression
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:58: error: ‘.’ cannot appear in a constant-expression
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:69: error: ‘.’ cannot appear in a constant-expression
/usr/local/cuda/bin/../include/thrust/detail/pair.inl:72:12: error: parse error in template argument list
make: *** [NLC_2D_TFIM.o] Error 1
NLC_2D_TFIMs を使用する別のモジュール ( Graphs) で動作しますstd::pairが、これらのいずれも GPU と対話するモジュールに渡されません。すべてのヘッダーはstd、ではなく名前空間として使用しますthrust。GPU ハンドラーに渡すすべてのパラメーターは、通常の C 配列、ints などです。
上記の行は次のとおりです。
#include"lanczos.h"
使用するもの:
#include"hamiltonian.h"
そしてそこから：
#include<thrust/device_ptr.h>
「NLC_2D_TFIM.cuラッパー」のコードは次のとおりです。
ReadGraphsFromFile(fileGraphs, "rectanglegraphs.dat", TypeFlag); //graphs the information generated by the Graphs module
double J=1.;
for(int hh=1; hh<10; hh++) {
h = hh;
//Create some storage for things to be used in GPU functions
d_hamiltonian* HamilLancz = (d_hamiltonian*)malloc(HowMany*sizeof(d_hamiltonian));
parameters* data = (parameters*)malloc(HowMany*sizeof(parameters));
double** groundstates = (double**)malloc(HowMany*sizeof(double*));
double** eigenvalues = (double**)malloc(HowMany*sizeof(double*));
int* NumElem = (int*)malloc(HowMany*sizeof(int));
int** Bonds = (int**)malloc(HowMany*sizeof(int*));
//Go through each graph we read in earlier
unsigned int i = 1;
while ( i<fileGraphs.size() && fileGraphs.at(i)->Order < 14) { //skip the zeroth graph
//CPU gets the energy for smaller graphs
GENHAM HV(fileGraphs.at(i)->Order, J, h, fileGraphs.at(i)->AdjacencyList, TypeFlag);
LANCZOS lancz(HV.Vdim); //dimension of reduced Hilbert space (Sz sector)
HV.SparseHamJQ(); //generates sparse matrix Hamiltonian for Lanczos
energy = lancz.Diag(HV, 1, prm.valvec_, eVec);
i++;
}
if( argv[0] == "--gpu" || argv[0] == "-g" )
{
while ( i < fileGraphs.size() )
{
i += 30;
for( int j = 0; j < HowMany; j++)
{
Bonds[ j ] = (int*)malloc(sizeof(int)*3*fileGraphs.at(i - j)->Order);
for(unsigned int k = 0; k < fileGraphs.at(i - j)->Order; k++)
{
Bonds[ j ][ k ] = k;
Bonds[ j ][ k + fileGraphs.at(i - j)->Order ] = fileGraphs.at(i - j)->AdjacencyList.at(2*k).second;
Bonds[ j ][ k + 2*fileGraphs.at(i - j)->Order ] = fileGraphs.at(i - j)->AdjacencyList.at(2*k + 1).second;
}
data[ j ].Sz = 0;
data[ j ].dimension = 2;
data[ j ].J1 = J;
data[ j ].J2 = h;
data[ j ].modelType = 2;
eigenvalues[ j ] = (double*)malloc(sizeof(double));
}
//Calls the CPU functions which will talk to the GPU, including Thrust
ConstructSparseMatrix(HowMany, Bonds, HamilLancz, data, NumElem, 1);
lanczos(HowMany, NumElem, HamilLancz, groundstates, eigenvalues, 200, 1, 1e-12);
したがってstd::pair、GPU に渡される には何もありません。スラスト呼び出しは次のとおりです。
for(int i = 0; i < howMany; i++)
{
thrust::device_ptr<int> red_ptr(d_H[i].set);
numElem[i] = thrust::reduce(red_ptr, red_ptr + rawSize[i]);
}