xref: /libCEED/include/ceed/jit-source/cuda/cuda-ref-basis-tensor.h (revision d310b3d31eeeddd20725517a3a61881a36d919f0)
1 // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED:  http://github.com/ceed
7 
8 #include <ceed.h>
9 
10 //------------------------------------------------------------------------------
11 // Tensor Basis Kernels
12 //------------------------------------------------------------------------------
13 
14 //------------------------------------------------------------------------------
15 // Interp
16 //------------------------------------------------------------------------------
17 extern "C" __global__ void Interp(const CeedInt num_elem, const CeedInt transpose, const CeedScalar *__restrict__ interp_1d,
18                                   const CeedScalar *__restrict__ u, CeedScalar *__restrict__ v) {
19   const CeedInt i = threadIdx.x;
20 
21   __shared__ CeedScalar s_mem[BASIS_Q_1D * BASIS_P_1D + 2 * BASIS_BUF_LEN];
22   CeedScalar           *s_interp_1d = s_mem;
23   CeedScalar           *s_buffer_1  = s_mem + BASIS_Q_1D * BASIS_P_1D;
24   CeedScalar           *s_buffer_2  = s_buffer_1 + BASIS_BUF_LEN;
25   for (CeedInt k = i; k < BASIS_Q_1D * BASIS_P_1D; k += blockDim.x) {
26     s_interp_1d[k] = interp_1d[k];
27   }
28 
29   const CeedInt P             = transpose ? BASIS_Q_1D : BASIS_P_1D;
30   const CeedInt Q             = transpose ? BASIS_P_1D : BASIS_Q_1D;
31   const CeedInt stride_0      = transpose ? 1 : BASIS_P_1D;
32   const CeedInt stride_1      = transpose ? BASIS_P_1D : 1;
33   const CeedInt u_stride      = transpose ? BASIS_NUM_QPTS : BASIS_NUM_NODES;
34   const CeedInt v_stride      = transpose ? BASIS_NUM_NODES : BASIS_NUM_QPTS;
35   const CeedInt u_comp_stride = num_elem * (transpose ? BASIS_NUM_QPTS : BASIS_NUM_NODES);
36   const CeedInt v_comp_stride = num_elem * (transpose ? BASIS_NUM_NODES : BASIS_NUM_QPTS);
37   const CeedInt u_size        = transpose ? BASIS_NUM_QPTS : BASIS_NUM_NODES;
38 
39   // Apply basis element by element
40   for (CeedInt elem = blockIdx.x; elem < num_elem; elem += gridDim.x) {
41     for (CeedInt comp = 0; comp < BASIS_NUM_COMP; comp++) {
42       const CeedScalar *cur_u = u + elem * u_stride + comp * u_comp_stride;
43       CeedScalar       *cur_v = v + elem * v_stride + comp * v_comp_stride;
44       for (CeedInt k = i; k < u_size; k += blockDim.x) {
45         s_buffer_1[k] = cur_u[k];
46       }
47       CeedInt pre  = u_size;
48       CeedInt post = 1;
49       for (CeedInt d = 0; d < BASIS_DIM; d++) {
50         __syncthreads();
51         // Update bufferfers used
52         pre /= P;
53         const CeedScalar *in  = d % 2 ? s_buffer_2 : s_buffer_1;
54         CeedScalar       *out = d == BASIS_DIM - 1 ? cur_v : (d % 2 ? s_buffer_1 : s_buffer_2);
55 
56         // Contract along middle index
57         const CeedInt writeLen = pre * post * Q;
58         for (CeedInt k = i; k < writeLen; k += blockDim.x) {
59           const CeedInt c = k % post;
60           const CeedInt j = (k / post) % Q;
61           const CeedInt a = k / (post * Q);
62 
63           CeedScalar vk = 0;
64           for (CeedInt b = 0; b < P; b++) vk += s_interp_1d[j * stride_0 + b * stride_1] * in[(a * P + b) * post + c];
65 
66           out[k] = vk;
67         }
68 
69         post *= Q;
70       }
71     }
72   }
73 }
74 
75 //------------------------------------------------------------------------------
76 // Grad
77 //------------------------------------------------------------------------------
78 extern "C" __global__ void Grad(const CeedInt num_elem, const CeedInt transpose, const CeedScalar *__restrict__ interp_1d,
79                                 const CeedScalar *__restrict__ grad_1d, const CeedScalar *__restrict__ u, CeedScalar *__restrict__ v) {
80   const CeedInt i = threadIdx.x;
81 
82   __shared__ CeedScalar s_mem[2 * (BASIS_Q_1D * BASIS_P_1D + BASIS_BUF_LEN)];
83   CeedScalar           *s_interp_1d = s_mem;
84   CeedScalar           *s_grad_1d   = s_interp_1d + BASIS_Q_1D * BASIS_P_1D;
85   CeedScalar           *s_buffer_1  = s_grad_1d + BASIS_Q_1D * BASIS_P_1D;
86   CeedScalar           *s_buffer_2  = s_buffer_1 + BASIS_BUF_LEN;
87   for (CeedInt k = i; k < BASIS_Q_1D * BASIS_P_1D; k += blockDim.x) {
88     s_interp_1d[k] = interp_1d[k];
89     s_grad_1d[k]   = grad_1d[k];
90   }
91 
92   const CeedInt P             = transpose ? BASIS_Q_1D : BASIS_P_1D;
93   const CeedInt Q             = transpose ? BASIS_P_1D : BASIS_Q_1D;
94   const CeedInt stride_0      = transpose ? 1 : BASIS_P_1D;
95   const CeedInt stride_1      = transpose ? BASIS_P_1D : 1;
96   const CeedInt u_stride      = transpose ? BASIS_NUM_QPTS : BASIS_NUM_NODES;
97   const CeedInt v_stride      = transpose ? BASIS_NUM_NODES : BASIS_NUM_QPTS;
98   const CeedInt u_comp_stride = num_elem * (transpose ? BASIS_NUM_QPTS : BASIS_NUM_NODES);
99   const CeedInt v_comp_stride = num_elem * (transpose ? BASIS_NUM_NODES : BASIS_NUM_QPTS);
100   const CeedInt u_dim_stride  = transpose ? num_elem * BASIS_NUM_QPTS * BASIS_NUM_COMP : 0;
101   const CeedInt v_dim_stride  = transpose ? 0 : num_elem * BASIS_NUM_QPTS * BASIS_NUM_COMP;
102 
103   // Apply basis element by element
104   for (CeedInt elem = blockIdx.x; elem < num_elem; elem += gridDim.x) {
105     for (CeedInt comp = 0; comp < BASIS_NUM_COMP; comp++) {
106       // dim*dim contractions for grad
107       for (CeedInt dim_1 = 0; dim_1 < BASIS_DIM; dim_1++) {
108         CeedInt           pre   = transpose ? BASIS_NUM_QPTS : BASIS_NUM_NODES;
109         CeedInt           post  = 1;
110         const CeedScalar *cur_u = u + elem * u_stride + dim_1 * u_dim_stride + comp * u_comp_stride;
111         CeedScalar       *cur_v = v + elem * v_stride + dim_1 * v_dim_stride + comp * v_comp_stride;
112         for (CeedInt dim_2 = 0; dim_2 < BASIS_DIM; dim_2++) {
113           __syncthreads();
114           // Update bufferfers used
115           pre /= P;
116           const CeedScalar *op  = dim_1 == dim_2 ? s_grad_1d : s_interp_1d;
117           const CeedScalar *in  = dim_2 == 0 ? cur_u : (dim_2 % 2 ? s_buffer_2 : s_buffer_1);
118           CeedScalar       *out = dim_2 == BASIS_DIM - 1 ? cur_v : (dim_2 % 2 ? s_buffer_1 : s_buffer_2);
119 
120           // Contract along middle index
121           const CeedInt writeLen = pre * post * Q;
122           for (CeedInt k = i; k < writeLen; k += blockDim.x) {
123             const CeedInt c   = k % post;
124             const CeedInt j   = (k / post) % Q;
125             const CeedInt a   = k / (post * Q);
126             CeedScalar    v_k = 0;
127             for (CeedInt b = 0; b < P; b++) v_k += op[j * stride_0 + b * stride_1] * in[(a * P + b) * post + c];
128 
129             if (transpose && dim_2 == BASIS_DIM - 1) out[k] += v_k;
130             else out[k] = v_k;
131           }
132 
133           post *= Q;
134         }
135       }
136     }
137   }
138 }
139 
140 //------------------------------------------------------------------------------
141 // 1D quadrature weights
142 //------------------------------------------------------------------------------
143 __device__ void Weight1d(const CeedInt num_elem, const CeedScalar *q_weight_1d, CeedScalar *w) {
144   const CeedInt i = threadIdx.x;
145   if (i < BASIS_Q_1D) {
146     const size_t elem = blockIdx.x;
147     if (elem < num_elem) w[elem * BASIS_Q_1D + i] = q_weight_1d[i];
148   }
149 }
150 
151 //------------------------------------------------------------------------------
152 // 2D quadrature weights
153 //------------------------------------------------------------------------------
154 __device__ void Weight2d(const CeedInt num_elem, const CeedScalar *q_weight_1d, CeedScalar *w) {
155   const CeedInt i = threadIdx.x;
156   const CeedInt j = threadIdx.y;
157   if (i < BASIS_Q_1D && j < BASIS_Q_1D) {
158     const size_t elem = blockIdx.x;
159     if (elem < num_elem) {
160       const size_t ind = (elem * BASIS_Q_1D + j) * BASIS_Q_1D + i;
161       w[ind]           = q_weight_1d[i] * q_weight_1d[j];
162     }
163   }
164 }
165 
166 //------------------------------------------------------------------------------
167 // 3D quadrature weights
168 //------------------------------------------------------------------------------
169 __device__ void Weight3d(const CeedInt num_elem, const CeedScalar *q_weight_1d, CeedScalar *w) {
170   const CeedInt i = threadIdx.x;
171   const CeedInt j = threadIdx.y;
172   if (i < BASIS_Q_1D && j < BASIS_Q_1D) {
173     const size_t elem = blockIdx.x;
174     if (elem < num_elem) {
175       for (CeedInt k = 0; k < BASIS_Q_1D; k++) {
176         const size_t ind = ((elem * BASIS_Q_1D + k) * BASIS_Q_1D + j) * BASIS_Q_1D + i;
177         w[ind]           = q_weight_1d[i] * q_weight_1d[j] * q_weight_1d[k];
178       }
179     }
180   }
181 }
182 
183 //------------------------------------------------------------------------------
184 // Quadrature weights
185 //------------------------------------------------------------------------------
186 extern "C" __global__ void Weight(const CeedInt num_elem, const CeedScalar *__restrict__ q_weight_1d, CeedScalar *__restrict__ v) {
187   if (BASIS_DIM == 1) Weight1d(num_elem, q_weight_1d, v);
188   else if (BASIS_DIM == 2) Weight2d(num_elem, q_weight_1d, v);
189   else if (BASIS_DIM == 3) Weight3d(num_elem, q_weight_1d, v);
190 }
191 
192 //------------------------------------------------------------------------------
193