llvm-project/polly/lib/External/isl/isl_local.c

75 lines
1.9 KiB
C

/*
* Copyright 2014 Ecole Normale Superieure
*
* Use of this software is governed by the MIT license
*
* Written by Sven Verdoolaege,
* Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France
*/
#include <isl_mat_private.h>
#include <isl_seq.h>
/* Given a matrix "div" representing local variables,
* does the variable at position "pos" have an explicit representation?
*/
isl_bool isl_local_div_is_known(__isl_keep isl_mat *div, int pos)
{
if (!div)
return isl_bool_error;
if (pos < 0 || pos >= div->n_row)
isl_die(isl_mat_get_ctx(div), isl_error_invalid,
"position out of bounds", return isl_bool_error);
return !isl_int_is_zero(div->row[pos][0]);
}
/* Compare two matrices representing local variables, defined over
* the same space.
*
* Return -1 if "div1" is "smaller" than "div2", 1 if "div1" is "greater"
* than "div2" and 0 if they are equal.
*
* The order is fairly arbitrary. We do "prefer" divs that only involve
* earlier dimensions in the sense that we consider matrices where
* the first differing div involves earlier dimensions to be smaller.
*/
int isl_local_cmp(__isl_keep isl_mat *div1, __isl_keep isl_mat *div2)
{
int i;
int cmp;
int known1, known2;
int last1, last2;
int n_col;
if (div1 == div2)
return 0;
if (!div1)
return -1;
if (!div2)
return 1;
if (div1->n_row != div2->n_row)
return div1->n_row - div2->n_row;
n_col = isl_mat_cols(div1);
for (i = 0; i < div1->n_row; ++i) {
known1 = isl_local_div_is_known(div1, i);
known2 = isl_local_div_is_known(div2, i);
if (!known1 && !known2)
continue;
if (!known1)
return 1;
if (!known2)
return -1;
last1 = isl_seq_last_non_zero(div1->row[i] + 1, n_col - 1);
last2 = isl_seq_last_non_zero(div2->row[i] + 1, n_col - 1);
if (last1 != last2)
return last1 - last2;
cmp = isl_seq_cmp(div1->row[i], div2->row[i], n_col);
if (cmp != 0)
return cmp;
}
return 0;
}