|  | // Ceres Solver - A fast non-linear least squares minimizer | 
|  | // Copyright 2023 Google Inc. All rights reserved. | 
|  | // http://ceres-solver.org/ | 
|  | // | 
|  | // Redistribution and use in source and binary forms, with or without | 
|  | // modification, are permitted provided that the following conditions are met: | 
|  | // | 
|  | // * Redistributions of source code must retain the above copyright notice, | 
|  | //   this list of conditions and the following disclaimer. | 
|  | // * Redistributions in binary form must reproduce the above copyright notice, | 
|  | //   this list of conditions and the following disclaimer in the documentation | 
|  | //   and/or other materials provided with the distribution. | 
|  | // * Neither the name of Google Inc. nor the names of its contributors may be | 
|  | //   used to endorse or promote products derived from this software without | 
|  | //   specific prior written permission. | 
|  | // | 
|  | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | 
|  | // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | 
|  | // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | 
|  | // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | 
|  | // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | 
|  | // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | 
|  | // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | 
|  | // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | 
|  | // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | 
|  | // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | 
|  | // POSSIBILITY OF SUCH DAMAGE. | 
|  | // | 
|  | // Author: yangfan34@lenovo.com (Lenovo Research Device+ Lab - Shanghai) | 
|  | // | 
|  | // Optimization for simple blas functions used in the Schur Eliminator. | 
|  | // These are fairly basic implementations which already yield a significant | 
|  | // speedup in the eliminator performance. | 
|  |  | 
|  | #ifndef CERES_INTERNAL_SMALL_BLAS_GENERIC_H_ | 
|  | #define CERES_INTERNAL_SMALL_BLAS_GENERIC_H_ | 
|  |  | 
|  | namespace ceres::internal { | 
|  |  | 
|  | // The following macros are used to share code | 
|  | #define CERES_GEMM_OPT_NAIVE_HEADER       \ | 
|  | double cvec4[4] = {0.0, 0.0, 0.0, 0.0}; \ | 
|  | const double* pa = a;                   \ | 
|  | const double* pb = b;                   \ | 
|  | const int span = 4;                     \ | 
|  | int col_r = col_a & (span - 1);         \ | 
|  | int col_m = col_a - col_r; | 
|  |  | 
|  | #define CERES_GEMM_OPT_STORE_MAT1X4 \ | 
|  | if (kOperation > 0) {             \ | 
|  | c[0] += cvec4[0];               \ | 
|  | c[1] += cvec4[1];               \ | 
|  | c[2] += cvec4[2];               \ | 
|  | c[3] += cvec4[3];               \ | 
|  | } else if (kOperation < 0) {      \ | 
|  | c[0] -= cvec4[0];               \ | 
|  | c[1] -= cvec4[1];               \ | 
|  | c[2] -= cvec4[2];               \ | 
|  | c[3] -= cvec4[3];               \ | 
|  | } else {                          \ | 
|  | c[0] = cvec4[0];                \ | 
|  | c[1] = cvec4[1];                \ | 
|  | c[2] = cvec4[2];                \ | 
|  | c[3] = cvec4[3];                \ | 
|  | }                                 \ | 
|  | c += 4; | 
|  |  | 
|  | // Matrix-Matrix Multiplication | 
|  | // Figure out 1x4 of Matrix C in one batch | 
|  | // | 
|  | // c op a * B; | 
|  | // where op can be +=, -=, or =, indicated by kOperation. | 
|  | // | 
|  | //  Matrix C              Matrix A                   Matrix B | 
|  | // | 
|  | //  C0, C1, C2, C3   op   A0, A1, A2, A3, ...    *   B0, B1, B2, B3 | 
|  | //                                                   B4, B5, B6, B7 | 
|  | //                                                   B8, B9, Ba, Bb | 
|  | //                                                   Bc, Bd, Be, Bf | 
|  | //                                                   . , . , . , . | 
|  | //                                                   . , . , . , . | 
|  | //                                                   . , . , . , . | 
|  | // | 
|  | // unroll for loops | 
|  | // utilize the data resided in cache | 
|  | // NOTE: col_a means the columns of A | 
|  | static inline void MMM_mat1x4(const int col_a, | 
|  | const double* a, | 
|  | const double* b, | 
|  | const int col_stride_b, | 
|  | double* c, | 
|  | const int kOperation) { | 
|  | CERES_GEMM_OPT_NAIVE_HEADER | 
|  | double av = 0.0; | 
|  | int bi = 0; | 
|  |  | 
|  | #define CERES_GEMM_OPT_MMM_MAT1X4_MUL \ | 
|  | av = pa[k];                         \ | 
|  | pb = b + bi;                        \ | 
|  | cvec4[0] += av * pb[0];             \ | 
|  | cvec4[1] += av * pb[1];             \ | 
|  | cvec4[2] += av * pb[2];             \ | 
|  | cvec4[3] += av * pb[3];             \ | 
|  | pb += 4;                            \ | 
|  | bi += col_stride_b;                 \ | 
|  | k++; | 
|  |  | 
|  | for (int k = 0; k < col_m;) { | 
|  | CERES_GEMM_OPT_MMM_MAT1X4_MUL | 
|  | CERES_GEMM_OPT_MMM_MAT1X4_MUL | 
|  | CERES_GEMM_OPT_MMM_MAT1X4_MUL | 
|  | CERES_GEMM_OPT_MMM_MAT1X4_MUL | 
|  | } | 
|  |  | 
|  | for (int k = col_m; k < col_a;) { | 
|  | CERES_GEMM_OPT_MMM_MAT1X4_MUL | 
|  | } | 
|  |  | 
|  | CERES_GEMM_OPT_STORE_MAT1X4 | 
|  |  | 
|  | #undef CERES_GEMM_OPT_MMM_MAT1X4_MUL | 
|  | } | 
|  |  | 
|  | // Matrix Transpose-Matrix multiplication | 
|  | // Figure out 1x4 of Matrix C in one batch | 
|  | // | 
|  | // c op a' * B; | 
|  | // where op can be +=, -=, or = indicated by kOperation. | 
|  | // | 
|  | //                        Matrix A | 
|  | // | 
|  | //                        A0 | 
|  | //                        A1 | 
|  | //                        A2 | 
|  | //                        A3 | 
|  | //                        . | 
|  | //                        . | 
|  | //                        . | 
|  | // | 
|  | //  Matrix C              Matrix A'                  Matrix B | 
|  | // | 
|  | //  C0, C1, C2, C3   op   A0, A1, A2, A3, ...    *   B0, B1, B2, B3 | 
|  | //                                                   B4, B5, B6, B7 | 
|  | //                                                   B8, B9, Ba, Bb | 
|  | //                                                   Bc, Bd, Be, Bf | 
|  | //                                                   . , . , . , . | 
|  | //                                                   . , . , . , . | 
|  | //                                                   . , . , . , . | 
|  | // | 
|  | // unroll for loops | 
|  | // utilize the data resided in cache | 
|  | // NOTE: col_a means the columns of A' | 
|  | static inline void MTM_mat1x4(const int col_a, | 
|  | const double* a, | 
|  | const int col_stride_a, | 
|  | const double* b, | 
|  | const int col_stride_b, | 
|  | double* c, | 
|  | const int kOperation) { | 
|  | CERES_GEMM_OPT_NAIVE_HEADER | 
|  | double av = 0.0; | 
|  | int ai = 0; | 
|  | int bi = 0; | 
|  |  | 
|  | #define CERES_GEMM_OPT_MTM_MAT1X4_MUL \ | 
|  | av = pa[ai];                        \ | 
|  | pb = b + bi;                        \ | 
|  | cvec4[0] += av * pb[0];             \ | 
|  | cvec4[1] += av * pb[1];             \ | 
|  | cvec4[2] += av * pb[2];             \ | 
|  | cvec4[3] += av * pb[3];             \ | 
|  | pb += 4;                            \ | 
|  | ai += col_stride_a;                 \ | 
|  | bi += col_stride_b; | 
|  |  | 
|  | for (int k = 0; k < col_m; k += span) { | 
|  | CERES_GEMM_OPT_MTM_MAT1X4_MUL | 
|  | CERES_GEMM_OPT_MTM_MAT1X4_MUL | 
|  | CERES_GEMM_OPT_MTM_MAT1X4_MUL | 
|  | CERES_GEMM_OPT_MTM_MAT1X4_MUL | 
|  | } | 
|  |  | 
|  | for (int k = col_m; k < col_a; k++) { | 
|  | CERES_GEMM_OPT_MTM_MAT1X4_MUL | 
|  | } | 
|  |  | 
|  | CERES_GEMM_OPT_STORE_MAT1X4 | 
|  |  | 
|  | #undef CERES_GEMM_OPT_MTM_MAT1X4_MUL | 
|  | } | 
|  |  | 
|  | // Matrix-Vector Multiplication | 
|  | // Figure out 4x1 of vector c in one batch | 
|  | // | 
|  | // c op A * b; | 
|  | // where op can be +=, -=, or =, indicated by kOperation. | 
|  | // | 
|  | //  Vector c              Matrix A                   Vector b | 
|  | // | 
|  | //  C0               op   A0, A1, A2, A3, ...    *   B0 | 
|  | //  C1                    A4, A5, A6, A7, ...        B1 | 
|  | //  C2                    A8, A9, Aa, Ab, ...        B2 | 
|  | //  C3                    Ac, Ad, Ae, Af, ...        B3 | 
|  | //                                                   . | 
|  | //                                                   . | 
|  | //                                                   . | 
|  | // | 
|  | // unroll for loops | 
|  | // utilize the data resided in cache | 
|  | // NOTE: col_a means the columns of A | 
|  | static inline void MVM_mat4x1(const int col_a, | 
|  | const double* a, | 
|  | const int col_stride_a, | 
|  | const double* b, | 
|  | double* c, | 
|  | const int kOperation) { | 
|  | CERES_GEMM_OPT_NAIVE_HEADER | 
|  | double bv = 0.0; | 
|  |  | 
|  | // clang-format off | 
|  | #define CERES_GEMM_OPT_MVM_MAT4X1_MUL       \ | 
|  | bv = *pb;                                 \ | 
|  | cvec4[0] += *(pa                   ) * bv; \ | 
|  | cvec4[1] += *(pa + col_stride_a    ) * bv; \ | 
|  | cvec4[2] += *(pa + col_stride_a * 2) * bv; \ | 
|  | cvec4[3] += *(pa + col_stride_a * 3) * bv; \ | 
|  | pa++;                                     \ | 
|  | pb++; | 
|  | // clang-format on | 
|  |  | 
|  | for (int k = 0; k < col_m; k += span) { | 
|  | CERES_GEMM_OPT_MVM_MAT4X1_MUL | 
|  | CERES_GEMM_OPT_MVM_MAT4X1_MUL | 
|  | CERES_GEMM_OPT_MVM_MAT4X1_MUL | 
|  | CERES_GEMM_OPT_MVM_MAT4X1_MUL | 
|  | } | 
|  |  | 
|  | for (int k = col_m; k < col_a; k++) { | 
|  | CERES_GEMM_OPT_MVM_MAT4X1_MUL | 
|  | } | 
|  |  | 
|  | CERES_GEMM_OPT_STORE_MAT1X4 | 
|  |  | 
|  | #undef CERES_GEMM_OPT_MVM_MAT4X1_MUL | 
|  | } | 
|  |  | 
|  | // Matrix Transpose-Vector multiplication | 
|  | // Figure out 4x1 of vector c in one batch | 
|  | // | 
|  | // c op A' * b; | 
|  | // where op can be +=, -=, or =, indicated by kOperation. | 
|  | // | 
|  | //                        Matrix A | 
|  | // | 
|  | //                        A0, A4, A8, Ac | 
|  | //                        A1, A5, A9, Ad | 
|  | //                        A2, A6, Aa, Ae | 
|  | //                        A3, A7, Ab, Af | 
|  | //                        . , . , . , . | 
|  | //                        . , . , . , . | 
|  | //                        . , . , . , . | 
|  | // | 
|  | //  Vector c              Matrix A'                  Vector b | 
|  | // | 
|  | //  C0               op   A0, A1, A2, A3, ...    *   B0 | 
|  | //  C1                    A4, A5, A6, A7, ...        B1 | 
|  | //  C2                    A8, A9, Aa, Ab, ...        B2 | 
|  | //  C3                    Ac, Ad, Ae, Af, ...        B3 | 
|  | //                                                   . | 
|  | //                                                   . | 
|  | //                                                   . | 
|  | // | 
|  | // unroll for loops | 
|  | // utilize the data resided in cache | 
|  | // NOTE: col_a means the columns of A' | 
|  | static inline void MTV_mat4x1(const int col_a, | 
|  | const double* a, | 
|  | const int col_stride_a, | 
|  | const double* b, | 
|  | double* c, | 
|  | const int kOperation) { | 
|  | CERES_GEMM_OPT_NAIVE_HEADER | 
|  | double bv = 0.0; | 
|  |  | 
|  | #define CERES_GEMM_OPT_MTV_MAT4X1_MUL \ | 
|  | bv = *pb;                           \ | 
|  | cvec4[0] += pa[0] * bv;             \ | 
|  | cvec4[1] += pa[1] * bv;             \ | 
|  | cvec4[2] += pa[2] * bv;             \ | 
|  | cvec4[3] += pa[3] * bv;             \ | 
|  | pa += col_stride_a;                 \ | 
|  | pb++; | 
|  |  | 
|  | for (int k = 0; k < col_m; k += span) { | 
|  | CERES_GEMM_OPT_MTV_MAT4X1_MUL | 
|  | CERES_GEMM_OPT_MTV_MAT4X1_MUL | 
|  | CERES_GEMM_OPT_MTV_MAT4X1_MUL | 
|  | CERES_GEMM_OPT_MTV_MAT4X1_MUL | 
|  | } | 
|  |  | 
|  | for (int k = col_m; k < col_a; k++) { | 
|  | CERES_GEMM_OPT_MTV_MAT4X1_MUL | 
|  | } | 
|  |  | 
|  | CERES_GEMM_OPT_STORE_MAT1X4 | 
|  |  | 
|  | #undef CERES_GEMM_OPT_MTV_MAT4X1_MUL | 
|  | } | 
|  |  | 
|  | #undef CERES_GEMM_OPT_NAIVE_HEADER | 
|  | #undef CERES_GEMM_OPT_STORE_MAT1X4 | 
|  |  | 
|  | }  // namespace ceres::internal | 
|  |  | 
|  | #endif  // CERES_INTERNAL_SMALL_BLAS_GENERIC_H_ |