#define TILE_SIZE 32 typedef struct { real4 posq; real value, temp; ATOM_PARAMETER_DATA #ifdef NEED_PADDING float padding; #endif } AtomData; /** * Compute a value based on pair interactions. */ extern "C" __global__ void computeN2Value(const real4* __restrict__ posq, const unsigned int* __restrict__ exclusions, const unsigned int* __restrict__ exclusionIndices, const unsigned int* __restrict__ exclusionRowIndices, unsigned long long* __restrict__ global_value, #ifdef USE_CUTOFF const ushort2* __restrict__ tiles, const unsigned int* __restrict__ interactionCount, real4 periodicBoxSize, real4 invPeriodicBoxSize, unsigned int maxTiles, const unsigned int* __restrict__ interactionFlags #else unsigned int numTiles #endif PARAMETER_ARGUMENTS) { unsigned int totalWarps = (blockDim.x*gridDim.x)/TILE_SIZE; unsigned int warp = (blockIdx.x*blockDim.x+threadIdx.x)/TILE_SIZE; #ifdef USE_CUTOFF unsigned int numTiles = interactionCount[0]; unsigned int pos = warp*(numTiles > maxTiles ? NUM_BLOCKS*(NUM_BLOCKS+1)/2 : numTiles)/totalWarps; unsigned int end = (warp+1)*(numTiles > maxTiles ? NUM_BLOCKS*(NUM_BLOCKS+1)/2 : numTiles)/totalWarps; #else unsigned int pos = warp*numTiles/totalWarps; unsigned int end = (warp+1)*numTiles/totalWarps; #endif real energy = 0; unsigned int lasty = 0xFFFFFFFF; __shared__ AtomData localData[THREAD_BLOCK_SIZE]; __shared__ unsigned int exclusionRange[2*WARPS_PER_GROUP]; __shared__ int exclusionIndex[WARPS_PER_GROUP]; do { // Extract the coordinates of this tile const unsigned int tgx = threadIdx.x & (TILE_SIZE-1); const unsigned int tbx = threadIdx.x - tgx; const unsigned int localGroupIndex = threadIdx.x/TILE_SIZE; unsigned int x, y; real value = 0; if (pos < end) { #ifdef USE_CUTOFF if (numTiles <= maxTiles) { ushort2 tileIndices = tiles[pos]; x = tileIndices.x; y = tileIndices.y; } else #endif { y = (unsigned int) floor(NUM_BLOCKS+0.5f-SQRT((NUM_BLOCKS+0.5f)*(NUM_BLOCKS+0.5f)-2*pos)); x = (pos-y*NUM_BLOCKS+y*(y+1)/2); if (x < y || x >= NUM_BLOCKS) { // Occasionally happens due to roundoff error. y += (x < y ? -1 : 1); x = (pos-y*NUM_BLOCKS+y*(y+1)/2); } } unsigned int atom1 = x*TILE_SIZE + tgx; real4 posq1 = posq[atom1]; LOAD_ATOM1_PARAMETERS // Locate the exclusion data for this tile. #ifdef USE_EXCLUSIONS if (tgx < 2) exclusionRange[2*localGroupIndex+tgx] = exclusionRowIndices[x+tgx]; if (tgx == 0) exclusionIndex[localGroupIndex] = -1; for (unsigned int i = exclusionRange[2*localGroupIndex]+tgx; i < exclusionRange[2*localGroupIndex+1]; i += TILE_SIZE) if (exclusionIndices[i] == y) exclusionIndex[localGroupIndex] = i*TILE_SIZE; bool hasExclusions = (exclusionIndex[localGroupIndex] > -1); #else bool hasExclusions = false; #endif if (pos >= end) ; // This warp is done. else if (x == y) { // This tile is on the diagonal. const unsigned int localAtomIndex = threadIdx.x; localData[localAtomIndex].posq = posq1; LOAD_LOCAL_PARAMETERS_FROM_1 #ifdef USE_EXCLUSIONS unsigned int excl = exclusions[exclusionIndex[localGroupIndex]+tgx]; #endif for (unsigned int j = 0; j < TILE_SIZE; j++) { #ifdef USE_EXCLUSIONS bool isExcluded = !(excl & 0x1); #endif int atom2 = tbx+j; real4 posq2 = localData[atom2].posq; real3 delta = make_real3(posq2.x-posq1.x, posq2.y-posq1.y, posq2.z-posq1.z); #ifdef USE_PERIODIC delta.x -= floor(delta.x*invPeriodicBoxSize.x+0.5f)*periodicBoxSize.x; delta.y -= floor(delta.y*invPeriodicBoxSize.y+0.5f)*periodicBoxSize.y; delta.z -= floor(delta.z*invPeriodicBoxSize.z+0.5f)*periodicBoxSize.z; #endif real r2 = delta.x*delta.x + delta.y*delta.y + delta.z*delta.z; #ifdef USE_CUTOFF if (r2 < CUTOFF_SQUARED) { #endif real invR = RSQRT(r2); real r = RECIP(invR); LOAD_ATOM2_PARAMETERS atom2 = y*TILE_SIZE+j; real tempValue1 = 0; real tempValue2 = 0; #ifdef USE_EXCLUSIONS if (!isExcluded && atom1 < NUM_ATOMS && atom2 < NUM_ATOMS && atom1 != atom2) { #else if (atom1 < NUM_ATOMS && atom2 < NUM_ATOMS && atom1 != atom2) { #endif COMPUTE_VALUE } value += tempValue1; #ifdef USE_CUTOFF } #endif #ifdef USE_EXCLUSIONS excl >>= 1; #endif } } else { // This is an off-diagonal tile. if (lasty != y) { unsigned int j = y*TILE_SIZE + tgx; localData[threadIdx.x].posq = posq[j]; const unsigned int localAtomIndex = threadIdx.x; LOAD_LOCAL_PARAMETERS_FROM_GLOBAL } localData[threadIdx.x].value = 0; #ifdef USE_CUTOFF unsigned int flags = (numTiles <= maxTiles ? interactionFlags[pos] : 0xFFFFFFFF); if (!hasExclusions && flags != 0xFFFFFFFF) { if (flags == 0) { // No interactions in this tile. } else { // Compute only a subset of the interactions in this tile. for (unsigned int j = 0; j < TILE_SIZE; j++) { if ((flags&(1<> tgx) | (excl << (TILE_SIZE - tgx)); #endif unsigned int tj = tgx; for (unsigned int j = 0; j < TILE_SIZE; j++) { #ifdef USE_EXCLUSIONS bool isExcluded = !(excl & 0x1); #endif int atom2 = tbx+tj; real4 posq2 = localData[atom2].posq; real3 delta = make_real3(posq2.x-posq1.x, posq2.y-posq1.y, posq2.z-posq1.z); #ifdef USE_PERIODIC delta.x -= floor(delta.x*invPeriodicBoxSize.x+0.5f)*periodicBoxSize.x; delta.y -= floor(delta.y*invPeriodicBoxSize.y+0.5f)*periodicBoxSize.y; delta.z -= floor(delta.z*invPeriodicBoxSize.z+0.5f)*periodicBoxSize.z; #endif real r2 = delta.x*delta.x + delta.y*delta.y + delta.z*delta.z; #ifdef USE_CUTOFF if (r2 < CUTOFF_SQUARED) { #endif real invR = RSQRT(r2); real r = RECIP(invR); LOAD_ATOM2_PARAMETERS atom2 = y*TILE_SIZE+tj; real tempValue1 = 0; real tempValue2 = 0; #ifdef USE_EXCLUSIONS if (!isExcluded && atom1 < NUM_ATOMS && atom2 < NUM_ATOMS) { #else if (atom1 < NUM_ATOMS && atom2 < NUM_ATOMS) { #endif COMPUTE_VALUE } value += tempValue1; localData[tbx+tj].value += tempValue2; #ifdef USE_CUTOFF } #endif #ifdef USE_EXCLUSIONS excl >>= 1; #endif tj = (tj + 1) & (TILE_SIZE - 1); } } } } // Write results. if (pos < end) { const unsigned int offset = x*TILE_SIZE + tgx; atomicAdd(&global_value[offset], static_cast((long long) (value*0xFFFFFFFF))); } if (pos < end && x != y) { const unsigned int offset = y*TILE_SIZE + tgx; atomicAdd(&global_value[offset], static_cast((long long) (localData[threadIdx.x].value*0xFFFFFFFF))); } lasty = y; pos++; } while (pos < end); }