Actual source code: baijsolvnat6.c

  1: #include <../src/mat/impls/baij/seq/baij.h>
  2: #include <petsc/private/kernels/blockinvert.h>

  4: PetscErrorCode MatSolve_SeqBAIJ_6_NaturalOrdering_inplace(Mat A, Vec bb, Vec xx)
  5: {
  6:   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ *)A->data;
  7:   PetscInt           i, nz, idx, idt, jdx;
  8:   const PetscInt    *diag = a->diag, *vi, n = a->mbs, *ai = a->i, *aj = a->j;
  9:   const MatScalar   *aa = a->a, *v;
 10:   PetscScalar       *x, s1, s2, s3, s4, s5, s6, x1, x2, x3, x4, x5, x6;
 11:   const PetscScalar *b;

 13:   VecGetArrayRead(bb, &b);
 14:   VecGetArray(xx, &x);
 15:   /* forward solve the lower triangular */
 16:   idx  = 0;
 17:   x[0] = b[idx];
 18:   x[1] = b[1 + idx];
 19:   x[2] = b[2 + idx];
 20:   x[3] = b[3 + idx];
 21:   x[4] = b[4 + idx];
 22:   x[5] = b[5 + idx];
 23:   for (i = 1; i < n; i++) {
 24:     v   = aa + 36 * ai[i];
 25:     vi  = aj + ai[i];
 26:     nz  = diag[i] - ai[i];
 27:     idx = 6 * i;
 28:     s1  = b[idx];
 29:     s2  = b[1 + idx];
 30:     s3  = b[2 + idx];
 31:     s4  = b[3 + idx];
 32:     s5  = b[4 + idx];
 33:     s6  = b[5 + idx];
 34:     while (nz--) {
 35:       jdx = 6 * (*vi++);
 36:       x1  = x[jdx];
 37:       x2  = x[1 + jdx];
 38:       x3  = x[2 + jdx];
 39:       x4  = x[3 + jdx];
 40:       x5  = x[4 + jdx];
 41:       x6  = x[5 + jdx];
 42:       s1 -= v[0] * x1 + v[6] * x2 + v[12] * x3 + v[18] * x4 + v[24] * x5 + v[30] * x6;
 43:       s2 -= v[1] * x1 + v[7] * x2 + v[13] * x3 + v[19] * x4 + v[25] * x5 + v[31] * x6;
 44:       s3 -= v[2] * x1 + v[8] * x2 + v[14] * x3 + v[20] * x4 + v[26] * x5 + v[32] * x6;
 45:       s4 -= v[3] * x1 + v[9] * x2 + v[15] * x3 + v[21] * x4 + v[27] * x5 + v[33] * x6;
 46:       s5 -= v[4] * x1 + v[10] * x2 + v[16] * x3 + v[22] * x4 + v[28] * x5 + v[34] * x6;
 47:       s6 -= v[5] * x1 + v[11] * x2 + v[17] * x3 + v[23] * x4 + v[29] * x5 + v[35] * x6;
 48:       v += 36;
 49:     }
 50:     x[idx]     = s1;
 51:     x[1 + idx] = s2;
 52:     x[2 + idx] = s3;
 53:     x[3 + idx] = s4;
 54:     x[4 + idx] = s5;
 55:     x[5 + idx] = s6;
 56:   }
 57:   /* backward solve the upper triangular */
 58:   for (i = n - 1; i >= 0; i--) {
 59:     v   = aa + 36 * diag[i] + 36;
 60:     vi  = aj + diag[i] + 1;
 61:     nz  = ai[i + 1] - diag[i] - 1;
 62:     idt = 6 * i;
 63:     s1  = x[idt];
 64:     s2  = x[1 + idt];
 65:     s3  = x[2 + idt];
 66:     s4  = x[3 + idt];
 67:     s5  = x[4 + idt];
 68:     s6  = x[5 + idt];
 69:     while (nz--) {
 70:       idx = 6 * (*vi++);
 71:       x1  = x[idx];
 72:       x2  = x[1 + idx];
 73:       x3  = x[2 + idx];
 74:       x4  = x[3 + idx];
 75:       x5  = x[4 + idx];
 76:       x6  = x[5 + idx];
 77:       s1 -= v[0] * x1 + v[6] * x2 + v[12] * x3 + v[18] * x4 + v[24] * x5 + v[30] * x6;
 78:       s2 -= v[1] * x1 + v[7] * x2 + v[13] * x3 + v[19] * x4 + v[25] * x5 + v[31] * x6;
 79:       s3 -= v[2] * x1 + v[8] * x2 + v[14] * x3 + v[20] * x4 + v[26] * x5 + v[32] * x6;
 80:       s4 -= v[3] * x1 + v[9] * x2 + v[15] * x3 + v[21] * x4 + v[27] * x5 + v[33] * x6;
 81:       s5 -= v[4] * x1 + v[10] * x2 + v[16] * x3 + v[22] * x4 + v[28] * x5 + v[34] * x6;
 82:       s6 -= v[5] * x1 + v[11] * x2 + v[17] * x3 + v[23] * x4 + v[29] * x5 + v[35] * x6;
 83:       v += 36;
 84:     }
 85:     v          = aa + 36 * diag[i];
 86:     x[idt]     = v[0] * s1 + v[6] * s2 + v[12] * s3 + v[18] * s4 + v[24] * s5 + v[30] * s6;
 87:     x[1 + idt] = v[1] * s1 + v[7] * s2 + v[13] * s3 + v[19] * s4 + v[25] * s5 + v[31] * s6;
 88:     x[2 + idt] = v[2] * s1 + v[8] * s2 + v[14] * s3 + v[20] * s4 + v[26] * s5 + v[32] * s6;
 89:     x[3 + idt] = v[3] * s1 + v[9] * s2 + v[15] * s3 + v[21] * s4 + v[27] * s5 + v[33] * s6;
 90:     x[4 + idt] = v[4] * s1 + v[10] * s2 + v[16] * s3 + v[22] * s4 + v[28] * s5 + v[34] * s6;
 91:     x[5 + idt] = v[5] * s1 + v[11] * s2 + v[17] * s3 + v[23] * s4 + v[29] * s5 + v[35] * s6;
 92:   }

 94:   VecRestoreArrayRead(bb, &b);
 95:   VecRestoreArray(xx, &x);
 96:   PetscLogFlops(2.0 * 36 * (a->nz) - 6.0 * A->cmap->n);
 97:   return 0;
 98: }

100: PetscErrorCode MatSolve_SeqBAIJ_6_NaturalOrdering(Mat A, Vec bb, Vec xx)
101: {
102:   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ *)A->data;
103:   const PetscInt     n = a->mbs, *vi, *ai = a->i, *aj = a->j, *adiag = a->diag;
104:   PetscInt           i, k, nz, idx, jdx, idt;
105:   const PetscInt     bs = A->rmap->bs, bs2 = a->bs2;
106:   const MatScalar   *aa = a->a, *v;
107:   PetscScalar       *x;
108:   const PetscScalar *b;
109:   PetscScalar        s1, s2, s3, s4, s5, s6, x1, x2, x3, x4, x5, x6;

111:   VecGetArrayRead(bb, &b);
112:   VecGetArray(xx, &x);
113:   /* forward solve the lower triangular */
114:   idx  = 0;
115:   x[0] = b[idx];
116:   x[1] = b[1 + idx];
117:   x[2] = b[2 + idx];
118:   x[3] = b[3 + idx];
119:   x[4] = b[4 + idx];
120:   x[5] = b[5 + idx];
121:   for (i = 1; i < n; i++) {
122:     v   = aa + bs2 * ai[i];
123:     vi  = aj + ai[i];
124:     nz  = ai[i + 1] - ai[i];
125:     idx = bs * i;
126:     s1  = b[idx];
127:     s2  = b[1 + idx];
128:     s3  = b[2 + idx];
129:     s4  = b[3 + idx];
130:     s5  = b[4 + idx];
131:     s6  = b[5 + idx];
132:     for (k = 0; k < nz; k++) {
133:       jdx = bs * vi[k];
134:       x1  = x[jdx];
135:       x2  = x[1 + jdx];
136:       x3  = x[2 + jdx];
137:       x4  = x[3 + jdx];
138:       x5  = x[4 + jdx];
139:       x6  = x[5 + jdx];
140:       s1 -= v[0] * x1 + v[6] * x2 + v[12] * x3 + v[18] * x4 + v[24] * x5 + v[30] * x6;
141:       s2 -= v[1] * x1 + v[7] * x2 + v[13] * x3 + v[19] * x4 + v[25] * x5 + v[31] * x6;
142:       s3 -= v[2] * x1 + v[8] * x2 + v[14] * x3 + v[20] * x4 + v[26] * x5 + v[32] * x6;
143:       s4 -= v[3] * x1 + v[9] * x2 + v[15] * x3 + v[21] * x4 + v[27] * x5 + v[33] * x6;
144:       s5 -= v[4] * x1 + v[10] * x2 + v[16] * x3 + v[22] * x4 + v[28] * x5 + v[34] * x6;
145:       s6 -= v[5] * x1 + v[11] * x2 + v[17] * x3 + v[23] * x4 + v[29] * x5 + v[35] * x6;
146:       v += bs2;
147:     }

149:     x[idx]     = s1;
150:     x[1 + idx] = s2;
151:     x[2 + idx] = s3;
152:     x[3 + idx] = s4;
153:     x[4 + idx] = s5;
154:     x[5 + idx] = s6;
155:   }

157:   /* backward solve the upper triangular */
158:   for (i = n - 1; i >= 0; i--) {
159:     v   = aa + bs2 * (adiag[i + 1] + 1);
160:     vi  = aj + adiag[i + 1] + 1;
161:     nz  = adiag[i] - adiag[i + 1] - 1;
162:     idt = bs * i;
163:     s1  = x[idt];
164:     s2  = x[1 + idt];
165:     s3  = x[2 + idt];
166:     s4  = x[3 + idt];
167:     s5  = x[4 + idt];
168:     s6  = x[5 + idt];
169:     for (k = 0; k < nz; k++) {
170:       idx = bs * vi[k];
171:       x1  = x[idx];
172:       x2  = x[1 + idx];
173:       x3  = x[2 + idx];
174:       x4  = x[3 + idx];
175:       x5  = x[4 + idx];
176:       x6  = x[5 + idx];
177:       s1 -= v[0] * x1 + v[6] * x2 + v[12] * x3 + v[18] * x4 + v[24] * x5 + v[30] * x6;
178:       s2 -= v[1] * x1 + v[7] * x2 + v[13] * x3 + v[19] * x4 + v[25] * x5 + v[31] * x6;
179:       s3 -= v[2] * x1 + v[8] * x2 + v[14] * x3 + v[20] * x4 + v[26] * x5 + v[32] * x6;
180:       s4 -= v[3] * x1 + v[9] * x2 + v[15] * x3 + v[21] * x4 + v[27] * x5 + v[33] * x6;
181:       s5 -= v[4] * x1 + v[10] * x2 + v[16] * x3 + v[22] * x4 + v[28] * x5 + v[34] * x6;
182:       s6 -= v[5] * x1 + v[11] * x2 + v[17] * x3 + v[23] * x4 + v[29] * x5 + v[35] * x6;
183:       v += bs2;
184:     }
185:     /* x = inv_diagonal*x */
186:     x[idt]     = v[0] * s1 + v[6] * s2 + v[12] * s3 + v[18] * s4 + v[24] * s5 + v[30] * s6;
187:     x[1 + idt] = v[1] * s1 + v[7] * s2 + v[13] * s3 + v[19] * s4 + v[25] * s5 + v[31] * s6;
188:     x[2 + idt] = v[2] * s1 + v[8] * s2 + v[14] * s3 + v[20] * s4 + v[26] * s5 + v[32] * s6;
189:     x[3 + idt] = v[3] * s1 + v[9] * s2 + v[15] * s3 + v[21] * s4 + v[27] * s5 + v[33] * s6;
190:     x[4 + idt] = v[4] * s1 + v[10] * s2 + v[16] * s3 + v[22] * s4 + v[28] * s5 + v[34] * s6;
191:     x[5 + idt] = v[5] * s1 + v[11] * s2 + v[17] * s3 + v[23] * s4 + v[29] * s5 + v[35] * s6;
192:   }

194:   VecRestoreArrayRead(bb, &b);
195:   VecRestoreArray(xx, &x);
196:   PetscLogFlops(2.0 * bs2 * (a->nz) - bs * A->cmap->n);
197:   return 0;
198: }