686 lines
24 KiB
C
686 lines
24 KiB
C
#include <R_ext/RS.h>
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#include <R_ext/Boolean.h>
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#include <R.h>
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#include <Rinternals.h>
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#include <Rmath.h>
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#include <R_ext/Rdynload.h>
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#include <sys/time.h>
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#include <stdbool.h>
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#include <math.h>
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#include "CCubes.h"
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#ifdef _OPENMP
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#undef match
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#include <omp.h>
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#endif
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#include "real.h"
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#include "cl_setup.h"
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#include "clccubes.h"
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#include "config.h"
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#include "logging.h"
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SEXP CCubes(SEXP tt) {
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// $ export BITS_PER_WORD=32 in the Terminal, before running R
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// 32 bits per word, in bit shifting representation
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char *bits_per_word = getenv("BITS_PER_WORD"); // Read from the PATH
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int BITS_PER_WORD = bits_per_word ? atoi(bits_per_word) : 32;
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if (BITS_PER_WORD != 8 && BITS_PER_WORD != 16 && BITS_PER_WORD != 32 && BITS_PER_WORD != 64) {
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BITS_PER_WORD = 32; // Default to 32
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}
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// $ export PRINT_INFO=1 in the Terminal, before running R
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char *print_info = getenv("PRINT_INFO"); // Read from the PATH
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Rboolean PRINT_INFO = print_info && print_info[0] == '1';
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int multiplier = 0;
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struct timeval start, end;
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double elapsed_time;
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config_set_int("log", LOG_LEVEL_WARN);
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config_set_int("log:clccubes", LOG_LEVEL_WARN);
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config_set_int("log:ccubes", LOG_LEVEL_DEBUG);
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config_set_int("log:cl", LOG_LEVEL_DEBUG);
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char log[100] = {0};
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sprintf(log, "log-ccubes");
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config_set_string("out", log);
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if (PRINT_INFO) {
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Rprintf("--- START ---\n");
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gettimeofday(&start, NULL); // Start time
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}
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int *p_tt = INTEGER(tt);
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int ttrows = nrows(tt); // number of rows in the data matrix
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int ninputs = ncols(tt) - 1; // number of inputs (columns - 1, the last one is the outcome)
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// calculate the number of positive output rows (the ON set)
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int posrows = 0;
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for (int r = 0; r < ttrows; r++) {
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posrows += p_tt[ninputs * ttrows + r];
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}
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// calculate the number of negative output rows (the OFF set)
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int negrows = ttrows - posrows;
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if (negrows == 0) {
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// if there are no negative output rows, no PIs can be found
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// all inputs will be completely minimized
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return(R_NilValue);
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}
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// split the minterms in the ON and OFF set matrices
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int ON_set[posrows * ninputs];
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int OFF_set[ninputs * negrows];
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int rowpos = 0, rowneg = 0;
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int max_value = 0;
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for (int r = 0; r < ttrows; r++) {
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if (p_tt[ninputs * ttrows + r] == 1) { // positive
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for (int c = 0; c < ninputs; c++) {
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int value = p_tt[c * ttrows + r];
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ON_set[c * posrows + rowpos] = value;
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if (value > max_value) {
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max_value = value;
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}
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}
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rowpos += 1;
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}
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else { // negative
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for (int c = 0; c < ninputs; c++) {
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int value = p_tt[c * ttrows + r];
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OFF_set[c * negrows + rowneg] = value;
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if (value > max_value) {
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max_value = value;
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}
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}
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rowneg += 1;
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}
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}
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int value_bit_width = 0;
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while (max_value > 0) {
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max_value >>= 1; // Shift right until no bits remain
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value_bit_width++;
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}
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// calculate the number of values (biggest number) for each input
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int nofvalues[ninputs];
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int nofpi[ninputs];
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for (int i = 0; i < ninputs; i++) {
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nofvalues[i] = 0; // initialize
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nofpi[i] = 0; // initialize
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for (int r = 0; r < ttrows; r++) {
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if (nofvalues[i] < p_tt[i * ttrows + r]) {
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nofvalues[i] = p_tt[i * ttrows + r];
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}
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}
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// add 1 because if the biggest number is 2 then it has three levels: 0, 1 and 2
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nofvalues[i] += 1;
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if (nofvalues[i] == 1) {
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// no input ever has less than two values
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nofvalues[i] = 2;
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}
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}
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// preallocating for an estimated large number of 10000 found PIs
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// this number will be iteratively increased when the found PIs reach the upper limit
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int estimPI = 250000;
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// the index of the PIs, in descending order of their number of covered ON-set minterms
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int *p_covered = R_Calloc(estimPI, int);
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// many PIs will have the same coverage, but they don't necessarily cover the same minterms
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// to employ row dominance when solving the PI chart, we need to compare the coverage of the
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// current PI with the coverage of the previous PIs. If this PI survives the comparison, its
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// coverage has to be added in the p_covered vector, and its order in the p_covered
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// vector, at the last index of the PI coverage with the same number of minterms
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int last_index[posrows]; // descending order
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// p_pichart = malloc(estimPI * posrows * sizeof(int));
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// memset(p_pichart, false, estimPI * posrows * sizeof(int));
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int *p_pichart = (int *) R_Calloc(estimPI * posrows, int);
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// prefixing (int *) prefills in all values with 0s
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int pichart_words = (posrows + BITS_PER_WORD - 1) / BITS_PER_WORD; // Words needed per PI chart columns
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unsigned int *p_pichart_pos = (unsigned int *) R_Calloc(estimPI * pichart_words, unsigned int);
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int implicant_words = (ninputs + BITS_PER_WORD - 1) / BITS_PER_WORD; // Words needed per PI representation
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unsigned int *p_implicants_pos = (unsigned int *) R_Calloc(estimPI * implicant_words, unsigned int);
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unsigned int *p_implicants_val = (unsigned int *) R_Calloc(estimPI * implicant_words, unsigned int);
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int prevfoundPI = 0; // the number of previously found PIs
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int foundPI = 0;
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int prevsolmin = 0; // the minimum number of PIs that solve the PI chart
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int solmin = 0;
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// the positions of the PIs solving the PI chart
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// a vector which can never be lengthier than the number of ON minterms (posrows)
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int previndices[posrows];
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int indices[posrows];
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for (int i = 0; i < posrows; i++) {
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previndices[i] = 0;
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indices[i] = 0;
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last_index[i] = 0;
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}
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Rboolean ON_set_covered = false;
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if (PRINT_INFO) {
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Rprintf("ON-set minterms: %d\n", posrows);
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#ifdef _OPENMP
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Rprintf("OpenMP enabled, %d workers\n", omp_get_max_threads());
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#endif
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}
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int stop_counter = 0; // to stop if two consecutive levels of complexity yield no PIs
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int k;
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for (k = 1; k <= ninputs; k++) {
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if (PRINT_INFO) {
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Rprintf("---k: %d\n", k);
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}
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int n_tasks = 512;
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struct ccubes_context *ctx = NULL;
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for (int task = 0; task < nchoosek(ninputs, k); task+=n_tasks) {
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bool *coverage;
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unsigned int *fixed_bits;
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unsigned int *value_bits;
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unsigned int *pichart_values;
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ctx = ccubes_do_tasks(n_tasks,
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task,
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k,
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ninputs,
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posrows,
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negrows,
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implicant_words,
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value_bit_width,
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pichart_words,
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estimPI,
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nofvalues,
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ON_set,
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OFF_set,
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p_implicants_pos,
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p_implicants_val,
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last_index,
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p_covered,
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p_pichart_pos,
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coverage,
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fixed_bits,
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value_bits,
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pichart_values
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);
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if (ctx == NULL) {
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log_error("ccubes", "ccubes_do_tasks failed");
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}
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for (int i = 0; i < n_tasks; i++) {
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log_debug("ccubes", "Task %d", i);
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log_debug_raw("ccubes", "coverage[%d]:", i);
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for (int j = 0; j < posrows; j++) {
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log_debug_raw("ccubes", " %d",
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ctx->h_coverage[i * posrows + j]);
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}
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log_debug_raw("ccubes", "\n");
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log_debug_raw("ccubes", "fixed_bits[%d]:", i);
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for (int j = 0; j < implicant_words; j++) {
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log_debug_raw("ccubes", " %d",
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ctx->h_fixed_bits[i * implicant_words + j]);
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}
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log_debug_raw("ccubes", "\n");
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log_debug_raw("ccubes", "value_bits[%d]:", i);
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for (int j = 0; j < implicant_words; j++) {
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log_debug_raw("ccubes", " %d",
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ctx->h_value_bits[i * implicant_words + j]);
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}
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log_debug_raw("ccubes", "\n");
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log_debug_raw("ccubes", "pichart_values[%d]:", i);
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for (int j = 0; j < pichart_words; j++) {
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log_debug_raw("ccubes", " %d",
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ctx->h_pichart_values[i * pichart_words + j]);
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}
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log_debug_raw("ccubes", "\n");
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}
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}
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#ifdef _OPENMP
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#pragma omp parallel for schedule(dynamic)
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#endif
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for (int task = 0; task < nchoosek(ninputs, k); task++) {
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int tempk[k];
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int x = 0;
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int start_point = task;
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// fill the combination for the current task
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for (int i = 0; i < k; i++) {
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while (nchoosek(ninputs - (x + 1), k - (i + 1)) <= start_point) {
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start_point -= nchoosek(ninputs - (x + 1), k - (i + 1));
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x++;
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}
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tempk[i] = x;
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x++;
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}
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// allocate vectors of decimal row numbers for the positive and negative rows
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int decpos[posrows];
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int decneg[negrows];
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// create the vector of multiple bases, useful when calculating the decimal representation
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// of a particular combination of columns, for each row
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int mbase[k];
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mbase[0] = 1; // the first number is _always_ equal to 1, irrespective of the number of values in a certain input
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// calculate the vector of multiple bases, for example if we have k = 3 (three inputs) with
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// 2, 3 and 2 values then mbase will be [1, 2, 6] from: 1, 1 * 2 = 2, 2 * 3 = 6
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for (int i = 1; i < k; i++) {
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mbase[i] = mbase[i - 1] * nofvalues[tempk[i - 1]];
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}
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// calculate decimal numbers, using mbase, fills in decpos and decneg
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for (int r = 0; r < posrows; r++) {
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decpos[r] = 0;
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for (int c = 0; c < k; c++) {
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decpos[r] += ON_set[tempk[c] * posrows + r] * mbase[c];
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}
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}
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for (int r = 0; r < negrows; r++) {
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decneg[r] = 0;
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for (int c = 0; c < k; c++) {
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decneg[r] += OFF_set[tempk[c] * negrows + r] * mbase[c];
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}
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}
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int possible_rows[posrows];
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Rboolean possible_cover[posrows];
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possible_cover[0] = true; // Rboolean flag, to be set with false if found among the OFF set
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int found = 0;
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// identifies all unique decimal rows, for the selected combination of k inputs
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for (int r = 0; r < posrows; r++) {
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int prev = 0;
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Rboolean unique = true; // Rboolean flag, assume the row is unique
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while (prev < found && unique) {
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unique = decpos[possible_rows[prev]] != decpos[r];
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prev++;
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}
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if (unique) {
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possible_rows[found] = r;
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possible_cover[found] = true;
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found++;
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}
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}
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if (found > 0) {
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// some of the ON set numbers are possible PIs (not found in the OFF set)
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int frows[found];
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// verify if this is a possible PI
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// (if the same decimal number is not found in the OFF set)
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for (int i = found - 1; i >= 0; i--) {
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int j = 0;
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while (j < negrows && possible_cover[i]) {
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if (decpos[possible_rows[i]] == decneg[j]) {
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possible_cover[i] = false;
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found--;
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}
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j++;
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}
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if (possible_cover[i]) {
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frows[found - i - 1] = possible_rows[i];
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}
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}
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// Rprintf("task: %d; rows: %d\n", task, found);
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for (int f = 0; f < found; f++) {
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// create a temporary vector of length k, containing the values from the initial ON set
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// plus 1 (because 0 now signals a minimization, it becomes 1, and 1 becomes 2 etc.
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int tempc[k];
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// using bit shifting, store the fixed bits and value bits
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unsigned int fixed_bits[implicant_words];
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unsigned int value_bits[implicant_words];
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for (int i = 0; i < implicant_words; i++) {
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fixed_bits[i] = 0U;
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value_bits[i] = 0U;
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}
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for (int c = 0; c < k; c++) {
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int value = ON_set[tempk[c] * posrows + frows[f]];
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tempc[c] = value + 1;
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int word_index = tempk[c] / BITS_PER_WORD;
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int bit_index = tempk[c] % BITS_PER_WORD;
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fixed_bits[word_index] |= 1U << bit_index;
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value_bits[word_index] |= (unsigned int)value << (bit_index * value_bit_width);
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}
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// check if the current PI is not redundant
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Rboolean redundant = false;
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int i = 0;
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while (i < prevfoundPI && !redundant) {
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// /*
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// - ck contains the complexity level for each of the previously found non-redundant PIs
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// - indx is a matrix containing the indexes of the columns where the values were stored
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// - a redundant PI is one for which all values from a previous PI are exactly the same:
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// 0 0 1 2 0, let's say previously found PI
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// which means a corresponding ck = 2 and a corresponding indx = [3, 4]
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// 0 0 1 2 1 is redundant because on both columns 3 and 4 the values are equal
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// therefore sumeq = 2 and it will be equal to v = 2 when reaching the complexity level ck = 2
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// */
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Rboolean is_subset = true; // Assume it's a subset unless proven otherwise
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for (int w = 0; w < implicant_words; w++) {
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// If the new PI has values on positions outside the existing PI’s fixed positions, it’s not a subset
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if ((fixed_bits[w] & p_implicants_pos[i * implicant_words + w]) != p_implicants_pos[i * implicant_words + w]) {
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is_subset = false;
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break;
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}
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// then compare the value bits, if one or more values on those positions are different, it’s not a subset
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if ((value_bits[w] & p_implicants_val[i * implicant_words + w]) != p_implicants_val[i * implicant_words + w]) {
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is_subset = false;
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break;
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}
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}
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redundant = is_subset;
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i++;
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}
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if (redundant) continue;
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Rboolean coverage[posrows];
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int covsum = 0;
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unsigned int pichart_values[pichart_words];
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for (int w = 0; w < pichart_words; w++) {
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pichart_values[w] = 0U;
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}
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for (int r = 0; r < posrows; r++) {
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coverage[r] = decpos[r] == decpos[frows[f]];
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if (coverage[r]) {
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int word_index = r / BITS_PER_WORD;
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int bit_index = r % BITS_PER_WORD;
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pichart_values[word_index] |= (1U << bit_index);
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}
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covsum += coverage[r];
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}
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// verify row dominance
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int rd = 0;
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while (rd < last_index[covsum - 1] && !redundant) {
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bool dominated = true;
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for (int w = 0; w < pichart_words; w++) {
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if ((pichart_values[w] & p_pichart_pos[p_covered[rd] * pichart_words + w]) != pichart_values[w]) {
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dominated = false;
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break;
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}
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}
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redundant = dominated;
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rd++;
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}
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if (redundant) continue;
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// Rprintf("It is a prime implicant\n");
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// This operation first gets a new index to push in the global array in a concurrent way
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// Then adds the result there.
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// We could synchronize only the index and let the copy operation happen in parallel BUT this
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// creates a false sharing problem and the performance is down by several factors.
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#ifdef _OPENMP
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#pragma omp critical
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#endif
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{
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// push the PI information to the global arrays
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for (int i = foundPI; i > last_index[covsum - 1]; i--) {
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p_covered[i] = p_covered[i - 1];
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}
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p_covered[last_index[covsum - 1]] = foundPI;
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for (int l = 1; l < covsum; l++) {
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last_index[l - 1] += 1;
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}
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for (int w = 0; w < implicant_words; w++) {
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p_implicants_pos[implicant_words * foundPI + w] = fixed_bits[w];
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p_implicants_val[implicant_words * foundPI + w] = value_bits[w];
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}
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// populate the PI chart
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for (int r = 0; r < posrows; r++) {
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for (int w = 0; w < pichart_words; w++) {
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p_pichart_pos[foundPI * pichart_words + w] = pichart_values[w];
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}
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p_pichart[posrows * foundPI + r] = coverage[r];
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}
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++foundPI;
|
||
|
||
// when needed, increase allocated memory
|
||
if (foundPI / estimPI > 0.9) {
|
||
int old_size = estimPI;
|
||
estimPI += 100000;
|
||
p_pichart = R_Realloc(p_pichart, posrows * estimPI, int);
|
||
p_pichart_pos = R_Realloc(p_pichart_pos, estimPI, unsigned int);
|
||
p_implicants_val = R_Realloc(p_implicants_val, ninputs * estimPI, unsigned int);
|
||
p_implicants_pos = R_Realloc(p_implicants_pos, ninputs * estimPI, unsigned int);
|
||
p_covered = R_Realloc(p_covered, estimPI, int);
|
||
|
||
for (unsigned int i = old_size; i < posrows * estimPI; i++) {
|
||
p_pichart[i] = 0;
|
||
}
|
||
for (unsigned int i = old_size; i < estimPI; i++) {
|
||
p_pichart_pos[i] = 0U;
|
||
}
|
||
for (unsigned int i = old_size; i < ninputs * estimPI; i++) {
|
||
p_implicants_val[i] = 0U;
|
||
p_implicants_pos[i] = 0U;
|
||
}
|
||
|
||
if (PRINT_INFO) {
|
||
multiplier++;
|
||
Rprintf("%dx ", multiplier);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
nofpi[k - 1] = foundPI;
|
||
|
||
if (foundPI > 0 && !ON_set_covered) {
|
||
Rboolean test_coverage = true;
|
||
|
||
int r = 0;
|
||
while (r < posrows && test_coverage) {
|
||
|
||
Rboolean minterm_covered = false;
|
||
int c = 0;
|
||
|
||
while (c < foundPI && !minterm_covered) {
|
||
minterm_covered = p_pichart[c * posrows + r];
|
||
c++;
|
||
}
|
||
|
||
test_coverage = minterm_covered;
|
||
r++;
|
||
}
|
||
|
||
ON_set_covered = test_coverage;
|
||
}
|
||
|
||
if (ON_set_covered) {
|
||
// Rprintf("posrows: %d; foundPI: %d\n", posrows, foundPI);
|
||
|
||
|
||
if (PRINT_INFO) {
|
||
gettimeofday(&end, NULL); // End time
|
||
elapsed_time = (end.tv_sec - start.tv_sec) + (end.tv_usec - start.tv_usec) / 1e6;
|
||
Rprintf("Time taken finding %d PIs: %f sec.\n", foundPI, elapsed_time);
|
||
gettimeofday(&start, NULL);
|
||
}
|
||
|
||
|
||
|
||
SEXP pic = PROTECT(allocMatrix(INTSXP, posrows, foundPI));
|
||
for (long long unsigned int i = 0; i < posrows * foundPI; i++) {
|
||
INTEGER(pic)[i] = p_pichart[i];
|
||
}
|
||
|
||
SEXP PIlayers = PROTECT(allocVector(INTSXP, ninputs));
|
||
for (int i = 0; i < ninputs; i++) {
|
||
INTEGER(PIlayers)[i] = nofpi[i];
|
||
}
|
||
setAttrib(pic, install("PIlayers"), PIlayers);
|
||
|
||
// if this file is run directly using SHLIB, the following line is needed
|
||
// R_ParseEvalString("library(IEEE)", R_GlobalEnv);
|
||
|
||
SEXP pkg_env = PROTECT(R_FindNamespace(mkString("IEEE")));
|
||
SEXP solvechart = PROTECT(Rf_findVarInFrame(pkg_env, Rf_install("solvechart")));
|
||
SEXP evalinR = PROTECT(R_tryEval(Rf_lang2(solvechart, pic), pkg_env, NULL));
|
||
|
||
solmin = length(evalinR);
|
||
for (int i = 0; i < solmin; i++) {
|
||
indices[i] = INTEGER(evalinR)[i] - 1; // R is 1-based
|
||
}
|
||
|
||
UNPROTECT(5);
|
||
// Rprintf("solution minima: %d\n", solmin);
|
||
|
||
|
||
if (PRINT_INFO) {
|
||
gettimeofday(&end, NULL);
|
||
elapsed_time = (end.tv_sec - start.tv_sec) + (end.tv_usec - start.tv_usec) / 1e6;
|
||
Rprintf("Time spent solving the PI chart: %f sec.\n", elapsed_time);
|
||
gettimeofday(&start, NULL);
|
||
}
|
||
|
||
if (solmin == prevsolmin) {
|
||
// the minimum number of PIs did not change in the current level of complexity
|
||
// we can safely retain the less complex PIs from the previous level
|
||
for (int i = 0; i < solmin; i++) {
|
||
indices[i] = previndices[i];
|
||
}
|
||
stop_counter += 1;
|
||
}
|
||
else {
|
||
// this means solmin is in fact smaller than the previously found solmin
|
||
// or it is the very first time a solmin was found
|
||
// only here it makes sense to overwrite prevsolmin and previndices,
|
||
// otherwise they are just as good as the ones from the previous level
|
||
|
||
prevsolmin = solmin;
|
||
for (int i = 0; i < solmin; i++) {
|
||
previndices[i] = indices[i];
|
||
}
|
||
|
||
stop_counter = 0;
|
||
}
|
||
}
|
||
|
||
prevfoundPI = foundPI;
|
||
|
||
// printf("stop_counter: %d\n", stop_counter);
|
||
|
||
// One level of complexity up, and the solution minima does not change
|
||
if (stop_counter > 0) {
|
||
// the search can stop
|
||
break;
|
||
}
|
||
}
|
||
|
||
// printf("solmin: %d\n", solmin);
|
||
if (PRINT_INFO) {
|
||
Rprintf("--- END ---\n");
|
||
}
|
||
|
||
SEXP sol = PROTECT(allocMatrix(INTSXP, solmin, ninputs));
|
||
int *p_sol = INTEGER(sol);
|
||
|
||
for (int c = 0; c < solmin; c++) {
|
||
for (int r = 0; r < ninputs; r++) {
|
||
unsigned int value = 0;
|
||
int word_index = r / BITS_PER_WORD; // Word index within the implicant
|
||
int bit_index = r % BITS_PER_WORD; // Bit position within the word
|
||
|
||
if (p_implicants_pos[indices[c] * implicant_words + word_index] & (1U << bit_index)) {
|
||
value = 1U + ((p_implicants_val[indices[c] * implicant_words + word_index] >> (bit_index * value_bit_width)) & ((1U << value_bit_width) - 1U));
|
||
}
|
||
|
||
p_sol[r * solmin + c] = value; // transposed
|
||
}
|
||
}
|
||
|
||
R_Free(p_pichart);
|
||
R_Free(p_implicants_val);
|
||
R_Free(p_implicants_pos);
|
||
R_Free(p_pichart_pos);
|
||
R_Free(p_covered);
|
||
|
||
UNPROTECT(1);
|
||
return (sol);
|
||
}
|
||
|
||
|
||
long long unsigned int nchoosek(
|
||
int n,
|
||
int k
|
||
) {
|
||
if (k == 0 || k == n) return 1;
|
||
if (k == 1) return n;
|
||
|
||
long long unsigned int result = 1;
|
||
|
||
if (k > n - k) {
|
||
k = n - k;
|
||
}
|
||
|
||
for (int i = 0; i < k; i++) {
|
||
result = result * (n - i) / (i + 1);
|
||
}
|
||
|
||
return result;
|
||
}
|