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Eldar Agalarov updated MATH-725: -------------------------------- Description: The Well PRNG's implementations have arrays iRm1, iRm2, iRm3, i1, i2, i3. All these arrays are unmodifiable, so we can replace this arrays initialization block final int w = 32; final int r = (k + w - 1) / w; this.v = new int[r]; this.index = 0; // precompute indirection index tables. These tables are used for optimizing access // they allow saving computations like "(j + r - 2) % r" with costly modulo operations iRm1 = new int[r]; iRm2 = new int[r]; i1 = new int[r]; i2 = new int[r]; i3 = new int[r]; for (int j = 0; j < r; ++j) { iRm1[j] = (j + r - 1) % r; iRm2[j] = (j + r - 2) % r; i1[j] = (j + m1) % r; i2[j] = (j + m2) % r; i3[j] = (j + m3) % r; } with inline initialized static final arrays. This is much better and faster implementation, freed from unnecessary costly calculations (such as %). Another solution: leave as is, but make all these arrays static. was: The Well PRNG's implementations have arrays iRm1, iRm2, iRm3, i1, i2, i3. All these arrays are unmodifiable, so we can replace this arrays initialization block final int w = 32; final int r = (k + w - 1) / w; this.v = new int[r]; this.index = 0; // precompute indirection index tables. These tables are used for optimizing access // they allow saving computations like "(j + r - 2) % r" with costly modulo operations iRm1 = new int[r]; iRm2 = new int[r]; i1 = new int[r]; i2 = new int[r]; i3 = new int[r]; for (int j = 0; j < r; ++j) { iRm1[j] = (j + r - 1) % r; iRm2[j] = (j + r - 2) % r; i1[j] = (j + m1) % r; i2[j] = (j + m2) % r; i3[j] = (j + m3) % r; } with inline initialized static final arrays. This is much better and faster implementation, freed from unnecessary costly calculations (such as %). If you agreed with my proposal, i can make a patch for this issue. > use initialized static final arrays, instead of initializing it in > constructors > ------------------------------------------------------------------------------- > > Key: MATH-725 > URL: https://issues.apache.org/jira/browse/MATH-725 > Project: Commons Math > Issue Type: Improvement > Affects Versions: 2.2 > Reporter: Eldar Agalarov > Priority: Minor > Original Estimate: 1h > Remaining Estimate: 1h > > The Well PRNG's implementations have arrays iRm1, iRm2, iRm3, i1, i2, i3. All > these arrays are unmodifiable, so we can replace this arrays initialization > block > final int w = 32; > final int r = (k + w - 1) / w; > this.v = new int[r]; > this.index = 0; > > // precompute indirection index tables. These tables are used for > optimizing access > // they allow saving computations like "(j + r - 2) % r" with costly > modulo operations > iRm1 = new int[r]; > iRm2 = new int[r]; > i1 = new int[r]; > i2 = new int[r]; > i3 = new int[r]; > for (int j = 0; j < r; ++j) { > iRm1[j] = (j + r - 1) % r; > iRm2[j] = (j + r - 2) % r; > i1[j] = (j + m1) % r; > i2[j] = (j + m2) % r; > i3[j] = (j + m3) % r; > } > with inline initialized static final arrays. > This is much better and faster implementation, freed from unnecessary costly > calculations (such as %). > Another solution: leave as is, but make all these arrays static. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira