Actual source code: bvorthogcuda.cu
slepc-3.18.0 2022-10-01
1: /*
2: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
3: SLEPc - Scalable Library for Eigenvalue Problem Computations
4: Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain
6: This file is part of SLEPc.
7: SLEPc is distributed under a 2-clause BSD license (see LICENSE).
8: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
9: */
10: /*
11: BV orthogonalization routines (CUDA)
12: */
14: #include <slepc/private/bvimpl.h>
15: #include <slepcblaslapack.h>
16: #include <slepccublas.h>
18: /*
19: BV_CleanCoefficients_CUDA - Sets to zero all entries of column j of the bv buffer
20: */
21: PetscErrorCode BV_CleanCoefficients_CUDA(BV bv,PetscInt j,PetscScalar *h)
22: {
23: PetscScalar *d_hh,*d_a;
24: PetscInt i;
26: if (!h) {
27: VecCUDAGetArray(bv->buffer,&d_a);
28: PetscLogGpuTimeBegin();
29: d_hh = d_a + j*(bv->nc+bv->m);
30: cudaMemset(d_hh,0,(bv->nc+j)*sizeof(PetscScalar));
31: PetscLogGpuTimeEnd();
32: VecCUDARestoreArray(bv->buffer,&d_a);
33: } else { /* cpu memory */
34: for (i=0;i<bv->nc+j;i++) h[i] = 0.0;
35: }
36: return 0;
37: }
39: /*
40: BV_AddCoefficients_CUDA - Add the contents of the scratch (0-th column) of the bv buffer
41: into column j of the bv buffer
42: */
43: PetscErrorCode BV_AddCoefficients_CUDA(BV bv,PetscInt j,PetscScalar *h,PetscScalar *c)
44: {
45: PetscScalar *d_h,*d_c,sone=1.0;
46: PetscInt i;
47: PetscCuBLASInt idx=0,one=1;
48: cublasHandle_t cublasv2handle;
50: if (!h) {
51: PetscCUBLASGetHandle(&cublasv2handle);
52: VecCUDAGetArray(bv->buffer,&d_c);
53: d_h = d_c + j*(bv->nc+bv->m);
54: PetscCuBLASIntCast(bv->nc+j,&idx);
55: PetscLogGpuTimeBegin();
56: cublasXaxpy(cublasv2handle,idx,&sone,d_c,one,d_h,one);
57: PetscLogGpuTimeEnd();
58: PetscLogGpuFlops(1.0*(bv->nc+j));
59: VecCUDARestoreArray(bv->buffer,&d_c);
60: } else { /* cpu memory */
61: for (i=0;i<bv->nc+j;i++) h[i] += c[i];
62: PetscLogFlops(1.0*(bv->nc+j));
63: }
64: return 0;
65: }
67: /*
68: BV_SetValue_CUDA - Sets value in row j (counted after the constraints) of column k
69: of the coefficients array
70: */
71: PetscErrorCode BV_SetValue_CUDA(BV bv,PetscInt j,PetscInt k,PetscScalar *h,PetscScalar value)
72: {
73: PetscScalar *d_h,*a;
75: if (!h) {
76: VecCUDAGetArray(bv->buffer,&a);
77: PetscLogGpuTimeBegin();
78: d_h = a + k*(bv->nc+bv->m) + bv->nc+j;
79: cudaMemcpy(d_h,&value,sizeof(PetscScalar),cudaMemcpyHostToDevice);
80: PetscLogCpuToGpu(sizeof(PetscScalar));
81: PetscLogGpuTimeEnd();
82: VecCUDARestoreArray(bv->buffer,&a);
83: } else { /* cpu memory */
84: h[bv->nc+j] = value;
85: }
86: return 0;
87: }
89: /*
90: BV_SquareSum_CUDA - Returns the value h'*h, where h represents the contents of the
91: coefficients array (up to position j)
92: */
93: PetscErrorCode BV_SquareSum_CUDA(BV bv,PetscInt j,PetscScalar *h,PetscReal *sum)
94: {
95: const PetscScalar *d_h;
96: PetscScalar dot;
97: PetscInt i;
98: PetscCuBLASInt idx=0,one=1;
99: cublasHandle_t cublasv2handle;
101: if (!h) {
102: PetscCUBLASGetHandle(&cublasv2handle);
103: VecCUDAGetArrayRead(bv->buffer,&d_h);
104: PetscCuBLASIntCast(bv->nc+j,&idx);
105: PetscLogGpuTimeBegin();
106: cublasXdotc(cublasv2handle,idx,d_h,one,d_h,one,&dot);
107: PetscLogGpuTimeEnd();
108: PetscLogGpuFlops(2.0*(bv->nc+j));
109: *sum = PetscRealPart(dot);
110: VecCUDARestoreArrayRead(bv->buffer,&d_h);
111: } else { /* cpu memory */
112: *sum = 0.0;
113: for (i=0;i<bv->nc+j;i++) *sum += PetscRealPart(h[i]*PetscConj(h[i]));
114: PetscLogFlops(2.0*(bv->nc+j));
115: }
116: return 0;
117: }
119: /* pointwise multiplication */
120: __global__ void PointwiseMult_kernel(PetscInt xcount,PetscScalar *a,const PetscScalar *b,PetscInt n)
121: {
122: PetscInt x;
124: x = xcount*gridDim.x*blockDim.x+blockIdx.x*blockDim.x+threadIdx.x;
125: if (x<n) a[x] *= PetscRealPart(b[x]);
126: }
128: /* pointwise division */
129: __global__ void PointwiseDiv_kernel(PetscInt xcount,PetscScalar *a,const PetscScalar *b,PetscInt n)
130: {
131: PetscInt x;
133: x = xcount*gridDim.x*blockDim.x+blockIdx.x*blockDim.x+threadIdx.x;
134: if (x<n) a[x] /= PetscRealPart(b[x]);
135: }
137: /*
138: BV_ApplySignature_CUDA - Computes the pointwise product h*omega, where h represents
139: the contents of the coefficients array (up to position j) and omega is the signature;
140: if inverse=TRUE then the operation is h/omega
141: */
142: PetscErrorCode BV_ApplySignature_CUDA(BV bv,PetscInt j,PetscScalar *h,PetscBool inverse)
143: {
144: PetscScalar *d_h;
145: const PetscScalar *d_omega,*omega;
146: PetscInt i,xcount;
147: dim3 blocks3d, threads3d;
149: if (!(bv->nc+j)) return 0;
150: if (!h) {
151: VecCUDAGetArray(bv->buffer,&d_h);
152: VecCUDAGetArrayRead(bv->omega,&d_omega);
153: SlepcKernelSetGrid1D(bv->nc+j,&blocks3d,&threads3d,&xcount);
154: PetscLogGpuTimeBegin();
155: if (inverse) {
156: for (i=0;i<xcount;i++) PointwiseDiv_kernel<<<blocks3d,threads3d>>>(i,d_h,d_omega,bv->nc+j);
157: } else {
158: for (i=0;i<xcount;i++) PointwiseMult_kernel<<<blocks3d,threads3d>>>(i,d_h,d_omega,bv->nc+j);
159: }
160: cudaGetLastError();
161: PetscLogGpuTimeEnd();
162: PetscLogGpuFlops(1.0*(bv->nc+j));
163: VecCUDARestoreArrayRead(bv->omega,&d_omega);
164: VecCUDARestoreArray(bv->buffer,&d_h);
165: } else {
166: VecGetArrayRead(bv->omega,&omega);
167: if (inverse) for (i=0;i<bv->nc+j;i++) h[i] /= PetscRealPart(omega[i]);
168: else for (i=0;i<bv->nc+j;i++) h[i] *= PetscRealPart(omega[i]);
169: VecRestoreArrayRead(bv->omega,&omega);
170: PetscLogFlops(1.0*(bv->nc+j));
171: }
172: return 0;
173: }
175: /*
176: BV_SquareRoot_CUDA - Returns the square root of position j (counted after the constraints)
177: of the coefficients array
178: */
179: PetscErrorCode BV_SquareRoot_CUDA(BV bv,PetscInt j,PetscScalar *h,PetscReal *beta)
180: {
181: const PetscScalar *d_h;
182: PetscScalar hh;
184: if (!h) {
185: VecCUDAGetArrayRead(bv->buffer,&d_h);
186: PetscLogGpuTimeBegin();
187: cudaMemcpy(&hh,d_h+bv->nc+j,sizeof(PetscScalar),cudaMemcpyDeviceToHost);
188: PetscLogGpuToCpu(sizeof(PetscScalar));
189: PetscLogGpuTimeEnd();
190: BV_SafeSqrt(bv,hh,beta);
191: VecCUDARestoreArrayRead(bv->buffer,&d_h);
192: } else BV_SafeSqrt(bv,h[bv->nc+j],beta);
193: return 0;
194: }
196: /*
197: BV_StoreCoefficients_CUDA - Copy the contents of the coefficients array to an array dest
198: provided by the caller (only values from l to j are copied)
199: */
200: PetscErrorCode BV_StoreCoefficients_CUDA(BV bv,PetscInt j,PetscScalar *h,PetscScalar *dest)
201: {
202: const PetscScalar *d_h,*d_a;
203: PetscInt i;
205: if (!h) {
206: VecCUDAGetArrayRead(bv->buffer,&d_a);
207: PetscLogGpuTimeBegin();
208: d_h = d_a + j*(bv->nc+bv->m)+bv->nc;
209: cudaMemcpy(dest-bv->l,d_h,(j-bv->l)*sizeof(PetscScalar),cudaMemcpyDeviceToHost);
210: PetscLogGpuToCpu((j-bv->l)*sizeof(PetscScalar));
211: PetscLogGpuTimeEnd();
212: VecCUDARestoreArrayRead(bv->buffer,&d_a);
213: } else {
214: for (i=bv->l;i<j;i++) dest[i-bv->l] = h[bv->nc+i];
215: }
216: return 0;
217: }