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Reduction finished and hopefully fixes CI regression fail on single precisoin and force

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This commit is contained in:
Peter Boyle
2019-08-14 15:18:34 +01:00
parent 96ac56cace
commit 3e49dc8a67
2 changed files with 119 additions and 73 deletions
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69
Grid/lattice/Lattice_reduction_gpu.h
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@ -82,13 +82,11 @@ __device__ void reduceBlock(volatile sobj *sdata, sobj mySum, const Iterator tid
__syncthreads();
}
template <class vobj, class Iterator>
__device__ void reduceBlocks(const LatticeView<vobj> g_idata, typename vobj::scalar_object *g_odata, Iterator n) {
typedef typename vobj::scalar_type scalar_type;
typedef typename vobj::vector_type vector_type;
typedef typename vobj::scalar_object sobj;
constexpr Iterator nsimd = sizeof(vector_type)/sizeof(scalar_type);
template <class vobj, class sobj, class Iterator>
__device__ void reduceBlocks(const vobj *g_idata, sobj *g_odata, Iterator n)
{
constexpr Iterator nsimd = vobj::Nsimd();
Iterator blockSize = blockDim.x;
@ -109,13 +107,16 @@ __device__ void reduceBlocks(const LatticeView<vobj> g_idata, typename vobj::sca
Iterator lane = i % nsimd;
Iterator ss = i / nsimd;
auto tmp = extractLane(lane,g_idata[ss]);
mySum += tmp;
sobj tmpD;
tmpD=tmp;
mySum +=tmpD;
if (i + blockSize < n) {
lane = (i+blockSize) % nsimd;
ss = (i+blockSize) / nsimd;
tmp = extractLane(lane,g_idata[ss]);
mySum += tmp;
tmpD = tmp;
mySum += tmpD;
}
i += gridSize;
}
@ -126,9 +127,8 @@ __device__ void reduceBlocks(const LatticeView<vobj> g_idata, typename vobj::sca
if (tid == 0) g_odata[blockIdx.x] = sdata[0];
}
template <class vobj, class Iterator>
__global__ void reduceKernel(const LatticeView<vobj> lat, typename vobj::scalar_object *buffer, Iterator n) {
typedef typename vobj::scalar_object sobj;
template <class vobj, class sobj,class Iterator>
__global__ void reduceKernel(const vobj *lat, sobj *buffer, Iterator n) {
Iterator blockSize = blockDim.x;
@ -179,32 +179,26 @@ __global__ void reduceKernel(const LatticeView<vobj> lat, typename vobj::scalar_
}
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////
// Possibly promote to double and sum
/////////////////////////////////////////////////////////////////////////////////////////////////////////
template <class vobj>
inline typename vobj::scalar_object sum_gpu(const Lattice<vobj> &lat)
inline typename vobj::scalar_objectD sumD_gpu(const vobj *lat, Integer osites)
{
typedef typename vobj::scalar_objectD sobj;
typedef decltype(lat) Iterator;
LatticeView<vobj> lat_v = lat.View();
typedef typename vobj::scalar_object sobj;
typedef decltype(lat_v.begin()) Iterator;
Iterator size = lat.Grid()->lSites();
Iterator numThreads, numBlocks;
Integer nsimd= vobj::Nsimd();
Integer size = osites*nsimd;
Integer numThreads, numBlocks;
getNumBlocksAndThreads(size, sizeof(sobj), numThreads, numBlocks);
Iterator smemSize = numThreads * sizeof(sobj);
/*
std::cout << GridLogDebug << "Starting reduction with:" << std::endl;
std::cout << GridLogDebug << "\tsize = " << size << std::endl;
std::cout << GridLogDebug << "\tnumThreads = " << numThreads << std::endl;
std::cout << GridLogDebug << "\tnumBlocks = " << numBlocks << std::endl;
std::cout << GridLogDebug << "\tsmemSize = " << smemSize << std::endl;
*/
Integer smemSize = numThreads * sizeof(sobj);
Vector<sobj> buffer(numBlocks);
sobj *buffer_v = &buffer[0];
reduceKernel<<< numBlocks, numThreads, smemSize >>>(lat_v, buffer_v, size);
reduceKernel<<< numBlocks, numThreads, smemSize >>>(lat, buffer_v, size);
cudaDeviceSynchronize();
cudaError err = cudaGetLastError();
@ -212,10 +206,21 @@ inline typename vobj::scalar_object sum_gpu(const Lattice<vobj> &lat)
printf("Cuda error %s\n",cudaGetErrorString( err ));
exit(0);
}
auto result = buffer_v[0];
lat.Grid()->GlobalSum(result);
return result;
}
/////////////////////////////////////////////////////////////////////////////////////////////////////////
// Return as same precision as input performing reduction in double precision though
/////////////////////////////////////////////////////////////////////////////////////////////////////////
template <class vobj>
inline typename vobj::scalar_object sum_gpu(const vobj *lat, Integer osites)
{
typedef typename vobj::scalar_object sobj;
sobj result;
result = sumD_gpu(lat,osites);
return result;
}
NAMESPACE_END(Grid);