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