isl_basic_map: put inequalities before equalities

When confronted with a list of inequalities that need to be
turned into equalities, we want to handle the inequalities
in the same order in which we handle inequalities that can
be removed.  Eventually, we would want to do these at the
same time.

1 files changed, 27 insertions, 25 deletions

diff --git a/isl_map.c b/isl_map.c
index 0aa529bc..a9898c81 100644
--- a/isl_map.c
+++ b/isl_map.c
@@ -222,14 +222,14 @@ static struct isl_basic_map *basic_map_init(struct isl_ctx *ctx,
 	int i;
 	size_t row_size = 1 + isl_dim_total(bmap->dim) + extra;
 
-	bmap->block = isl_blk_alloc(ctx, (n_eq + n_ineq) * row_size);
+	bmap->block = isl_blk_alloc(ctx, (n_ineq + n_eq) * row_size);
 	if (isl_blk_is_error(bmap->block)) {
 		free(bmap);
 		return NULL;
 	}
 
-	bmap->eq = isl_alloc_array(ctx, isl_int *, n_eq + n_ineq);
-	if (!bmap->eq) {
+	bmap->ineq = isl_alloc_array(ctx, isl_int *, n_ineq + n_eq);
+	if (!bmap->ineq) {
 		isl_blk_free(ctx, bmap->block);
 		free(bmap);
 		return NULL;
@@ -241,7 +241,7 @@ static struct isl_basic_map *basic_map_init(struct isl_ctx *ctx,
 	} else {
 		bmap->block2 = isl_blk_alloc(ctx, extra * (1 + row_size));
 		if (isl_blk_is_error(bmap->block2)) {
-			free(bmap->eq);
+			free(bmap->ineq);
 			isl_blk_free(ctx, bmap->block);
 			free(bmap);
 			return NULL;
@@ -250,15 +250,15 @@ static struct isl_basic_map *basic_map_init(struct isl_ctx *ctx,
 		bmap->div = isl_alloc_array(ctx, isl_int *, extra);
 		if (!bmap->div) {
 			isl_blk_free(ctx, bmap->block2);
-			free(bmap->eq);
+			free(bmap->ineq);
 			isl_blk_free(ctx, bmap->block);
 			free(bmap);
 			return NULL;
 		}
 	}
 
-	for (i = 0; i < n_eq + n_ineq; ++i)
-		bmap->eq[i] = bmap->block.data + i * row_size;
+	for (i = 0; i < n_ineq + n_eq; ++i)
+		bmap->ineq[i] = bmap->block.data + i * row_size;
 
 	for (i = 0; i < extra; ++i)
 		bmap->div[i] = bmap->block2.data + i * (1 + row_size);
@@ -268,7 +268,7 @@ static struct isl_basic_map *basic_map_init(struct isl_ctx *ctx,
 	bmap->ref = 1;
 	bmap->flags = 0;
 	bmap->c_size = n_eq + n_ineq;
-	bmap->ineq = bmap->eq + n_eq;
+	bmap->eq = bmap->ineq + n_ineq;
 	bmap->extra = extra;
 	bmap->n_eq = 0;
 	bmap->n_ineq = 0;
@@ -434,7 +434,7 @@ void isl_basic_map_free(struct isl_basic_map *bmap)
 	isl_ctx_deref(bmap->ctx);
 	free(bmap->div);
 	isl_blk_free(bmap->ctx, bmap->block2);
-	free(bmap->eq);
+	free(bmap->ineq);
 	isl_blk_free(bmap->ctx, bmap->block);
 	isl_vec_free(bmap->ctx, bmap->sample);
 	isl_dim_free(bmap->dim);
@@ -453,22 +453,25 @@ int isl_basic_map_alloc_equality(struct isl_basic_map *bmap)
 		return -1;
 	ctx = bmap->ctx;
 	isl_assert(ctx, bmap->n_eq + bmap->n_ineq < bmap->c_size, return -1);
-	isl_assert(ctx, bmap->eq + bmap->n_eq <= bmap->ineq, return -1);
-	if (bmap->eq + bmap->n_eq == bmap->ineq) {
+	isl_assert(ctx, (bmap->eq - bmap->ineq) + bmap->n_eq <= bmap->c_size,
+			return -1);
+	ISL_F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED_DIVS);
+	if ((bmap->eq - bmap->ineq) + bmap->n_eq == bmap->c_size) {
 		isl_int *t;
 		int j = isl_basic_map_alloc_inequality(bmap);
 		if (j < 0)
 			return -1;
-		t = bmap->ineq[0];
-		bmap->ineq[0] = bmap->ineq[j];
-		bmap->ineq[j] = t;
+		t = bmap->ineq[j];
+		bmap->ineq[j] = bmap->ineq[bmap->n_ineq - 1];
+		bmap->ineq[bmap->n_ineq - 1] = bmap->eq[-1];
+		bmap->eq[-1] = t;
+		bmap->n_eq++;
 		bmap->n_ineq--;
-		bmap->ineq++;
-	} else
-		isl_seq_clr(bmap->eq[bmap->n_eq] +
-		      1 + isl_basic_map_total_dim(bmap),
+		bmap->eq--;
+		return 0;
+	}
+	isl_seq_clr(bmap->eq[bmap->n_eq] + 1 + isl_basic_map_total_dim(bmap),
 		      bmap->extra - bmap->n_div);
-	ISL_F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED_DIVS);
 	return bmap->n_eq++;
 }
 
@@ -513,12 +516,12 @@ void isl_basic_map_inequality_to_equality(
 	isl_int *t;
 
 	t = bmap->ineq[pos];
-	bmap->ineq[pos] = bmap->ineq[0];
-	bmap->ineq[0] = bmap->eq[bmap->n_eq];
-	bmap->eq[bmap->n_eq] = t;
+	bmap->ineq[pos] = bmap->ineq[bmap->n_ineq - 1];
+	bmap->ineq[bmap->n_ineq - 1] = bmap->eq[-1];
+	bmap->eq[-1] = t;
 	bmap->n_eq++;
 	bmap->n_ineq--;
-	bmap->ineq++;
+	bmap->eq--;
 	ISL_F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
 	ISL_F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED_DIVS);
 	ISL_F_CLR(bmap, ISL_BASIC_MAP_ALL_EQUALITIES);
@@ -530,8 +533,7 @@ int isl_basic_map_alloc_inequality(struct isl_basic_map *bmap)
 	if (!bmap)
 		return -1;
 	ctx = bmap->ctx;
-	isl_assert(ctx, (bmap->ineq - bmap->eq) + bmap->n_ineq < bmap->c_size,
-			return -1);
+	isl_assert(ctx, bmap->n_ineq < bmap->eq - bmap->ineq, return -1);
 	ISL_F_CLR(bmap, ISL_BASIC_MAP_NO_IMPLICIT);
 	ISL_F_CLR(bmap, ISL_BASIC_MAP_NO_REDUNDANT);
 	ISL_F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);