isl_map_simplify.c: remove_redundant_divs: drop div constraints of re…

…dundant div The constraints are now being removed by isl_basic_map_drop_div. Performing the removal directly inside remove_redundant_divs allows isl_basic_map_drop_div to be simplified and subsequently merged with the core of isl_basic_map_drop. isl_basic_map_drop_constraints_involving drops constraints in the opposite order from isl_basic_map_drop_div, so this can result in changes because the resulting order of the remaining constraints may be different. Signed-off-by: Sven Verdoolaege <[email protected]>
opencompl · Aug 28, 2018 · bb78067 · bb78067
1 parent dfc4fe2
commit bb78067
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Showing 3 changed files with 11 additions and 4 deletions.
diff --git a/isl_map.c b/isl_map.c
@@ -2833,6 +2833,9 @@ isl_bool isl_set_involves_dims(__isl_keep isl_set *set,
 /* Drop all constraints in bmap that involve any of the dimensions
  * first to first+n-1.
  * This function only performs the actual removal of constraints.
+ *
+ * This function should not call finalize since it is used by
+ * remove_redundant_divs, which in turn is called by isl_basic_map_finalize.
  */
 __isl_give isl_basic_map *isl_basic_map_drop_constraints_involving(
 	__isl_take isl_basic_map *bmap, unsigned first, unsigned n)

diff --git a/isl_map_simplify.c b/isl_map_simplify.c
@@ -1463,9 +1463,11 @@ static __isl_give isl_basic_map *remove_redundant_divs(
 	__isl_take isl_basic_map *bmap)
 {
 	int i;
+	int v_div;
 
-	if (!bmap)
-		return NULL;
+	v_div = isl_basic_map_var_offset(bmap, isl_dim_div);
+	if (v_div < 0)
+		return isl_basic_map_free(bmap);
 
 	for (i = bmap->n_div-1; i >= 0; --i) {
 		isl_bool redundant;
@@ -1475,6 +1477,8 @@ static __isl_give isl_basic_map *remove_redundant_divs(
 			return isl_basic_map_free(bmap);
 		if (!redundant)
 			continue;
+		bmap = isl_basic_map_drop_constraints_involving(bmap,
+								v_div + i, 1);
 		bmap = isl_basic_map_drop_div(bmap, i);
 	}
 	return bmap;

diff --git a/test_inputs/codegen/unroll4.c b/test_inputs/codegen/unroll4.c
@@ -2,14 +2,14 @@
   write_shared_A(3, ((t1 + 3) % 4) + 1, ((t2 + 31) % 32) + 1);
   if (t2 >= 1 && t2 <= 2 && t1 % 3 == 0)
     write_shared_A(3, (-t1 / 3) + 4, t2 + 32);
-  if (((-((t1 + 3) % 4) + t2 + 30) % 32) + t1 >= ((t1 + 3) % 4) + ((t2 + 1) % 2) - 4 * ((-t1 + 4) / 4) + 1)
+  if (((t1 + 3) % 4) + 1 >= t2 || t2 >= ((t1 + 3) % 4) + ((t2 + 1) % 2) + 2)
     write_shared_A(3, ((t1 + 3) % 4) + 5, -((((t1 + 3) % 4) - t2 + 33) % 32) + t1 + 4 * ((-t1 + 4) / 4) + 32);
   if (t1 >= 1 && t2 >= t1 + 1 && t2 <= 4)
     write_shared_A(3, t1 + 4, t2 + 32);
   write_shared_A(4, ((t1 + 3) % 4) + 1, ((t2 + 31) % 32) + 1);
   if (t2 >= 1 && t2 <= 2 && t1 % 3 == 0)
     write_shared_A(4, (-t1 / 3) + 4, t2 + 32);
-  if (((-((t1 + 3) % 4) + t2 + 30) % 32) + t1 >= ((t1 + 3) % 4) + ((t2 + 1) % 2) - 4 * ((-t1 + 4) / 4) + 1)
+  if (((t1 + 3) % 4) + 1 >= t2 || t2 >= ((t1 + 3) % 4) + ((t2 + 1) % 2) + 2)
     write_shared_A(4, ((t1 + 3) % 4) + 5, -((((t1 + 3) % 4) - t2 + 33) % 32) + t1 + 4 * ((-t1 + 4) / 4) + 32);
   if (t1 >= 1 && t2 >= t1 + 1 && t2 <= 4)
     write_shared_A(4, t1 + 4, t2 + 32);