This file is indexed.

/usr/include/m4ri/strassen.h is in libm4ri-dev 20130416-6.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
/**
 * \file strassen.h
 *
 * \brief Matrix operations using Strassen's formulas including
 * Winograd's improvements.
 *
 * \author Gregory Bard <bard@fordham.edu>
 * \author Martin Albrecht <M.R.Albrecht@rhul.ac.uk>
 */

#ifndef M4RI_STRASSEN_H
#define M4RI_STRASSEN_H

/*******************************************************************
*
*                 M4RI: Linear Algebra over GF(2)
*
*    Copyright (C) 2008 Martin Albrecht <M.R.Albrecht@rhul.ac.uk>
*    Copyright (C) 2008 Clement Pernet <pernet@math.washington.edu>
*
*  Distributed under the terms of the GNU General Public License (GPL)
*  version 2 or higher.
*
*    This code is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
*    General Public License for more details.
*
*  The full text of the GPL is available at:
*
*                  http://www.gnu.org/licenses/
*
********************************************************************/

#include <math.h>
#include <m4ri/mzd.h>
#include <m4ri/brilliantrussian.h>

/**
 * \brief Matrix multiplication via the Strassen-Winograd matrix
 * multiplication algorithm, i.e. compute C = AB.
 * 
 * This is the wrapper function including bounds checks. See
 * _mzd_mul_even for implementation details.
 *
 * \param C Preallocated product matrix, may be NULL for automatic creation.
 * \param A Input matrix A
 * \param B Input matrix B
 * \param cutoff Minimal dimension for Strassen recursion.
 */

mzd_t *mzd_mul(mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * \brief Matrix multiplication and in-place addition via the
 * Strassen-Winograd matrix multiplication algorithm, i.e. compute 
 * C = C+ AB.
 * 
 * This is the wrapper function including bounds checks. See
 * _mzd_addmul_even for implementation details.
 *
 * \param C product matrix
 * \param A Input matrix A
 * \param B Input matrix B
 * \param cutoff Minimal dimension for Strassen recursion.
 */

mzd_t *mzd_addmul(mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * \brief Matrix multiplication via the Strassen-Winograd matrix
 * multiplication algorithm, i.e. compute C = AB.
 * 
 * This is the actual implementation. Any matrix where either the
 * number of rows or the number of columns is smaller than cutoff is
 * processed using the M4RM algorithm.
 *
 * \param C Preallocated product matrix, may be NULL for automatic creation.
 * \param A Input matrix A
 * \param B Input matrix B
 * \param cutoff Minimal dimension for Strassen recursion.
 *
 * \note This implementation is heavily inspired by the function
 * strassen_window_multiply_c in Sage 3.0; For reference see
 * http://www.sagemath.org
 */

mzd_t *_mzd_mul_even(mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * \brief Matrix multiplication and in-place addition via the
 * Strassen-Winograd matrix multiplication algorithm, i.e. compute 
 * C = C+ AB.
 * 
 * This is the actual implementation. Any matrix where either the
 * number of rows or the number of columns is smaller than cutoff is
 * processed using the M4RM algorithm.
 *
 * \param C Preallocated product matrix, may be NULL for automatic creation.
 * \param A Input matrix A
 * \param B Input matrix B
 * \param cutoff Minimal dimension for Strassen recursion.
 *
 * \note This implementation is heavily inspired by the function
 * strassen_window_multiply_c in Sage 3.0; For reference see
 * http://www.sagemath.org
 */

mzd_t *_mzd_addmul_even(mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * \brief Matrix multiplication and in-place addition via the
 * Strassen-Winograd matrix multiplication algorithm, i.e. compute 
 * C = C + AB.
 * 
 * The matrices A and B are respectively m x k and k x n, and can be not
 * aligned on the m4ri_radix grid.
 * 
 * \param C Preallocated product matrix, may be NULL for automatic creation.
 * \param A Input matrix A
 * \param B Input matrix B
 * \param cutoff Minimal dimension for Strassen recursion.
 *
 */

mzd_t *_mzd_addmul (mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * C = A*B + C for matrices with offsets != 0
 *
 * This is scratch code.
 *
 * \internal
 */

mzd_t *_mzd_addmul_weird_weird (mzd_t *C, mzd_t const *A, mzd_t const *B);

/**
 * C = A*B + C for A with offset == 0 and B with offset != 0.
 *
 * This is scratch code.
 *
 * \internal
 */

mzd_t *_mzd_addmul_weird_even (mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * C = A*B + C for A with offset != 0 and B with offset == 0.
 *
 * This is scratch code.
 *
 * \internal
 */

mzd_t *_mzd_addmul_even_weird (mzd_t *C, mzd_t const *A, mzd_t const *B, int cutoff);

/**
 * The default cutoff for Strassen-Winograd multiplication. It should
 * hold hold that 2 * (n^2)/8 fits into the L2 cache.
 */

#ifndef __M4RI_STRASSEN_MUL_CUTOFF
#define __M4RI_STRASSEN_MUL_CUTOFF MIN(((int)sqrt((double)(4 * __M4RI_CPU_L3_CACHE))), 4096)
#endif

#endif // M4RI_STRASSEN_H