isl_mat: keep track of the actual number of columns in a row

We need this number to perform extensions after dropping columns.

diff --git a/isl_mat.c b/isl_mat.c
index 5c925ae..c1ba26e 100644 (file)
--- a/isl_mat.c
+++ b/isl_mat.c
@@ -29,6 +29,7 @@ struct isl_mat *isl_mat_alloc(struct isl_ctx *ctx,
        mat->ref = 1;
        mat->n_row = n_row;
        mat->n_col = n_col;
+       mat->max_col = n_col;
        mat->flags = 0;
 
        return mat;
@@ -47,10 +48,13 @@ struct isl_mat *isl_mat_extend(struct isl_mat *mat,
        if (!mat)
                return NULL;
 
-       if (mat->n_col >= n_col && mat->n_row >= n_row)
+       if (mat->max_col >= n_col && mat->n_row >= n_row) {
+               if (mat->n_col < n_col)
+                       mat->n_col = n_col;
                return mat;
+       }
 
-       if (mat->n_col < n_col) {
+       if (mat->max_col < n_col) {
                struct isl_mat *new_mat;
 
                new_mat = isl_mat_alloc(mat->ctx, n_row, n_col);
@@ -68,7 +72,7 @@ struct isl_mat *isl_mat_extend(struct isl_mat *mat,
 
        assert(mat->ref == 1);
        old = mat->block.data;
-       mat->block = isl_blk_extend(mat->ctx, mat->block, n_row * mat->n_col);
+       mat->block = isl_blk_extend(mat->ctx, mat->block, n_row * mat->max_col);
        if (isl_blk_is_error(mat->block))
                goto error;
        mat->row = isl_realloc_array(mat->ctx, mat->row, isl_int *, n_row);
@@ -78,8 +82,10 @@ struct isl_mat *isl_mat_extend(struct isl_mat *mat,
        for (i = 0; i < mat->n_row; ++i)
                mat->row[i] = mat->block.data + (mat->row[i] - old);
        for (i = mat->n_row; i < n_row; ++i)
-               mat->row[i] = mat->block.data + i * mat->n_col;
+               mat->row[i] = mat->block.data + i * mat->max_col;
        mat->n_row = n_row;
+       if (mat->n_col < n_col)
+               mat->n_col = n_col;
 
        return mat;
 error:

diff --git a/isl_mat.h b/isl_mat.h
index 3671db1..ed82ec2 100644 (file)
--- a/isl_mat.h
+++ b/isl_mat.h
@@ -26,6 +26,9 @@ struct isl_mat {
 
        isl_int **row;
 
+       /* actual size of the rows in memory; n_col <= max_col */
+       unsigned max_col;
+
        struct isl_blk block;
 };