/* -------------------------------------------------------------------------- * * OpenMM * * -------------------------------------------------------------------------- * * This is part of the OpenMM molecular simulation toolkit originating from * * Simbios, the NIH National Center for Physics-Based Simulation of * * Biological Structures at Stanford, funded under the NIH Roadmap for * * Medical Research, grant U54 GM072970. See https://simtk.org. * * * * Portions copyright (c) 2009 Stanford University and the Authors. * * Authors: Scott Le Grand, Peter Eastman * * Contributors: * * * * Permission is hereby granted, free of charge, to any person obtaining a * * copy of this software and associated documentation files (the "Software"), * * to deal in the Software without restriction, including without limitation * * the rights to use, copy, modify, merge, publish, distribute, sublicense, * * and/or sell copies of the Software, and to permit persons to whom the * * Software is furnished to do so, subject to the following conditions: * * * * The above copyright notice and this permission notice shall be included in * * all copies or substantial portions of the Software. * * * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * * THE AUTHORS, CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE * * USE OR OTHER DEALINGS IN THE SOFTWARE. * * -------------------------------------------------------------------------- */ /** * This file contains the kernels for evalauating nonbonded forces. It is included * several times in kCalculateCDLJForces.cu with different #defines to generate * different versions of the kernels. */ __global__ void METHOD_NAME(kCalculateCDLJ, Forces_kernel)(unsigned int* workUnit, unsigned int numWorkUnits) { extern __shared__ Atom sA[]; unsigned int totalWarps = cSim.nonbond_blocks*cSim.nonbond_threads_per_block/GRID; unsigned int warp = (blockIdx.x*blockDim.x+threadIdx.x)/GRID; unsigned int pos = warp*numWorkUnits/totalWarps; unsigned int end = (warp+1)*numWorkUnits/totalWarps; #ifdef USE_CUTOFF float3* tempBuffer = (float3*) &sA[cSim.nonbond_threads_per_block]; #endif unsigned int lasty = 0xFFFFFFFF; while (pos < end) { // Extract cell coordinates from appropriate work unit unsigned int x = workUnit[pos]; unsigned int y = ((x >> 2) & 0x7fff) << GRIDBITS; bool bExclusionFlag = (x & 0x1); x = (x >> 17) << GRIDBITS; float4 apos; // Local atom x, y, z, q float3 af; // Local atom fx, fy, fz float dx; float dy; float dz; float r2; float invR; float sig; float sig2; float sig6; float eps; float dEdR; unsigned int tgx = threadIdx.x & (GRID - 1); unsigned int tbx = threadIdx.x - tgx; unsigned int tj = tgx; Atom* psA = &sA[tbx]; unsigned int i = x + tgx; apos = cSim.pPosq[i]; float2 a = cSim.pAttr[i]; af.x = 0.0f; af.y = 0.0f; af.z = 0.0f; if (x == y) // Handle diagonals uniquely at 50% efficiency { // Read fixed atom data into registers and GRF sA[threadIdx.x].x = apos.x; sA[threadIdx.x].y = apos.y; sA[threadIdx.x].z = apos.z; sA[threadIdx.x].q = apos.w; sA[threadIdx.x].sig = a.x; sA[threadIdx.x].eps = a.y; apos.w *= cSim.epsfac; if (!bExclusionFlag) { for (unsigned int j = 0; j < GRID; j++) { dx = psA[j].x - apos.x; dy = psA[j].y - apos.y; dz = psA[j].z - apos.z; #ifdef USE_PERIODIC dx -= floor(dx/cSim.periodicBoxSizeX+0.5f)*cSim.periodicBoxSizeX; dy -= floor(dy/cSim.periodicBoxSizeY+0.5f)*cSim.periodicBoxSizeY; dz -= floor(dz/cSim.periodicBoxSizeZ+0.5f)*cSim.periodicBoxSizeZ; #endif r2 = dx * dx + dy * dy + dz * dz; invR = 1.0f / sqrt(r2); sig = a.x + psA[j].sig; sig2 = invR * sig; sig2 *= sig2; sig6 = sig2 * sig2 * sig2; eps = a.y * psA[j].eps; dEdR = eps * (12.0f * sig6 - 6.0f) * sig6; #ifdef USE_CUTOFF dEdR += apos.w * psA[j].q * (invR - 2.0f * cSim.reactionFieldK * r2); #else dEdR += apos.w * psA[j].q * invR; #endif dEdR *= invR * invR; #ifdef USE_CUTOFF if (r2 > cSim.nonbondedCutoffSqr) { dEdR = 0.0f; } #endif dx *= dEdR; dy *= dEdR; dz *= dEdR; af.x -= dx; af.y -= dy; af.z -= dz; } } else // bExclusion { unsigned int xi = x>>GRIDBITS; unsigned int cell = xi+xi*cSim.paddedNumberOfAtoms/GRID-xi*(xi+1)/2; unsigned int excl = cSim.pExclusion[cSim.pExclusionIndex[cell]+tgx]; for (unsigned int j = 0; j < GRID; j++) { dx = psA[j].x - apos.x; dy = psA[j].y - apos.y; dz = psA[j].z - apos.z; #ifdef USE_PERIODIC dx -= floor(dx/cSim.periodicBoxSizeX+0.5f)*cSim.periodicBoxSizeX; dy -= floor(dy/cSim.periodicBoxSizeY+0.5f)*cSim.periodicBoxSizeY; dz -= floor(dz/cSim.periodicBoxSizeZ+0.5f)*cSim.periodicBoxSizeZ; #endif r2 = dx * dx + dy * dy + dz * dz; invR = 1.0f / sqrt(r2); sig = a.x + psA[j].sig; sig2 = invR * sig; sig2 *= sig2; sig6 = sig2 * sig2 * sig2; eps = a.y * psA[j].eps; dEdR = eps * (12.0f * sig6 - 6.0f) * sig6; #ifdef USE_CUTOFF dEdR += apos.w * psA[j].q * (invR - 2.0f * cSim.reactionFieldK * r2); #else dEdR += apos.w * psA[j].q * invR; #endif dEdR *= invR * invR; #ifdef USE_CUTOFF if (!(excl & 0x1) || r2 > cSim.nonbondedCutoffSqr) #else if (!(excl & 0x1)) #endif { dEdR = 0.0f; } dx *= dEdR; dy *= dEdR; dz *= dEdR; af.x -= dx; af.y -= dy; af.z -= dz; excl >>= 1; } } // Write results float4 of; #ifdef USE_OUTPUT_BUFFER_PER_WARP unsigned int offset = x + tgx + warp*cSim.stride; of = cSim.pForce4a[offset]; of.x += af.x; of.y += af.y; of.z += af.z; cSim.pForce4a[offset] = of; #else of.x = af.x; of.y = af.y; of.z = af.z; of.w = 0.0f; unsigned int offset = x + tgx + (x >> GRIDBITS) * cSim.stride; cSim.pForce4a[offset] = of; #endif } else // 100% utilization { // Read fixed atom data into registers and GRF if (lasty != y) { unsigned int j = y + tgx; float4 temp = cSim.pPosq[j]; float2 temp1 = cSim.pAttr[j]; sA[threadIdx.x].x = temp.x; sA[threadIdx.x].y = temp.y; sA[threadIdx.x].z = temp.z; sA[threadIdx.x].q = temp.w; sA[threadIdx.x].sig = temp1.x; sA[threadIdx.x].eps = temp1.y; } sA[threadIdx.x].fx = 0.0f; sA[threadIdx.x].fy = 0.0f; sA[threadIdx.x].fz = 0.0f; apos.w *= cSim.epsfac; if (!bExclusionFlag) { #ifdef USE_CUTOFF unsigned int flags = cSim.pInteractionFlag[pos]; if (flags == 0) { // No interactions in this block. } else if (flags == 0xFFFFFFFF) #endif { // Compute all interactions within this block. for (unsigned int j = 0; j < GRID; j++) { dx = psA[tj].x - apos.x; dy = psA[tj].y - apos.y; dz = psA[tj].z - apos.z; #ifdef USE_PERIODIC dx -= floor(dx/cSim.periodicBoxSizeX+0.5f)*cSim.periodicBoxSizeX; dy -= floor(dy/cSim.periodicBoxSizeY+0.5f)*cSim.periodicBoxSizeY; dz -= floor(dz/cSim.periodicBoxSizeZ+0.5f)*cSim.periodicBoxSizeZ; #endif r2 = dx * dx + dy * dy + dz * dz; invR = 1.0f / sqrt(r2); sig = a.x + psA[tj].sig; sig2 = invR * sig; sig2 *= sig2; sig6 = sig2 * sig2 * sig2; eps = a.y * psA[tj].eps; dEdR = eps * (12.0f * sig6 - 6.0f) * sig6; #ifdef USE_CUTOFF dEdR += apos.w * psA[tj].q * (invR - 2.0f * cSim.reactionFieldK * r2); #else dEdR += apos.w * psA[tj].q * invR; #endif dEdR *= invR * invR; #ifdef USE_CUTOFF if (r2 > cSim.nonbondedCutoffSqr) { dEdR = 0.0f; } #endif dx *= dEdR; dy *= dEdR; dz *= dEdR; af.x -= dx; af.y -= dy; af.z -= dz; psA[tj].fx += dx; psA[tj].fy += dy; psA[tj].fz += dz; tj = (tj + 1) & (GRID - 1); } } #ifdef USE_CUTOFF else { // Compute only a subset of the interactions in this block. for (unsigned int j = 0; j < GRID; j++) { if ((flags&(1< cSim.nonbondedCutoffSqr) { dEdR = 0.0f; } #endif dx *= dEdR; dy *= dEdR; dz *= dEdR; af.x -= dx; af.y -= dy; af.z -= dz; tempBuffer[threadIdx.x].x = dx; tempBuffer[threadIdx.x].y = dy; tempBuffer[threadIdx.x].z = dz; // Sum the forces on atom j. if (tgx % 2 == 0) { tempBuffer[threadIdx.x].x += tempBuffer[threadIdx.x+1].x; tempBuffer[threadIdx.x].y += tempBuffer[threadIdx.x+1].y; tempBuffer[threadIdx.x].z += tempBuffer[threadIdx.x+1].z; } if (tgx % 4 == 0) { tempBuffer[threadIdx.x].x += tempBuffer[threadIdx.x+2].x; tempBuffer[threadIdx.x].y += tempBuffer[threadIdx.x+2].y; tempBuffer[threadIdx.x].z += tempBuffer[threadIdx.x+2].z; } if (tgx % 8 == 0) { tempBuffer[threadIdx.x].x += tempBuffer[threadIdx.x+4].x; tempBuffer[threadIdx.x].y += tempBuffer[threadIdx.x+4].y; tempBuffer[threadIdx.x].z += tempBuffer[threadIdx.x+4].z; } if (tgx % 16 == 0) { tempBuffer[threadIdx.x].x += tempBuffer[threadIdx.x+8].x; tempBuffer[threadIdx.x].y += tempBuffer[threadIdx.x+8].y; tempBuffer[threadIdx.x].z += tempBuffer[threadIdx.x+8].z; } if (tgx == 0) { psA[j].fx += tempBuffer[threadIdx.x].x + tempBuffer[threadIdx.x+16].x; psA[j].fy += tempBuffer[threadIdx.x].y + tempBuffer[threadIdx.x+16].y; psA[j].fz += tempBuffer[threadIdx.x].z + tempBuffer[threadIdx.x+16].z; } } } } #endif } else // bExclusion { // Read fixed atom data into registers and GRF unsigned int xi = x>>GRIDBITS; unsigned int yi = y>>GRIDBITS; unsigned int cell = xi+yi*cSim.paddedNumberOfAtoms/GRID-yi*(yi+1)/2; unsigned int excl = cSim.pExclusion[cSim.pExclusionIndex[cell]+tgx]; excl = (excl >> tgx) | (excl << (GRID - tgx)); for (unsigned int j = 0; j < GRID; j++) { dx = psA[tj].x - apos.x; dy = psA[tj].y - apos.y; dz = psA[tj].z - apos.z; #ifdef USE_PERIODIC dx -= floor(dx/cSim.periodicBoxSizeX+0.5f)*cSim.periodicBoxSizeX; dy -= floor(dy/cSim.periodicBoxSizeY+0.5f)*cSim.periodicBoxSizeY; dz -= floor(dz/cSim.periodicBoxSizeZ+0.5f)*cSim.periodicBoxSizeZ; #endif r2 = dx * dx + dy * dy + dz * dz; invR = 1.0f / sqrt(r2); sig = a.x + psA[tj].sig; sig2 = invR * sig; sig2 *= sig2; sig6 = sig2 * sig2 * sig2; eps = a.y * psA[tj].eps; dEdR = eps * (12.0f * sig6 - 6.0f) * sig6; #ifdef USE_CUTOFF dEdR += apos.w * psA[tj].q * (invR - 2.0f * cSim.reactionFieldK * r2); #else dEdR += apos.w * psA[tj].q * invR; #endif dEdR *= invR * invR; #ifdef USE_CUTOFF if (!(excl & 0x1) || r2 > cSim.nonbondedCutoffSqr) #else if (!(excl & 0x1)) #endif { dEdR = 0.0f; } dx *= dEdR; dy *= dEdR; dz *= dEdR; af.x -= dx; af.y -= dy; af.z -= dz; psA[tj].fx += dx; psA[tj].fy += dy; psA[tj].fz += dz; excl >>= 1; tj = (tj + 1) & (GRID - 1); } } // Write results float4 of; #ifdef USE_OUTPUT_BUFFER_PER_WARP unsigned int offset = x + tgx + warp*cSim.stride; of = cSim.pForce4a[offset]; of.x += af.x; of.y += af.y; of.z += af.z; cSim.pForce4a[offset] = of; offset = y + tgx + warp*cSim.stride; of = cSim.pForce4a[offset]; of.x += sA[threadIdx.x].fx; of.y += sA[threadIdx.x].fy; of.z += sA[threadIdx.x].fz; cSim.pForce4a[offset] = of; #else of.x = af.x; of.y = af.y; of.z = af.z; of.w = 0.0f; unsigned int offset = x + tgx + (y >> GRIDBITS) * cSim.stride; cSim.pForce4a[offset] = of; of.x = sA[threadIdx.x].fx; of.y = sA[threadIdx.x].fy; of.z = sA[threadIdx.x].fz; offset = y + tgx + (x >> GRIDBITS) * cSim.stride; cSim.pForce4a[offset] = of; #endif lasty = y; } pos++; } }