From 32cc78168a9ffbdc405396a2fa411f2f03a4b057 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Fri, 21 Nov 2014 12:19:12 +0100
Subject: [PATCH] pet_stmt_build_ast_exprs: ignore expression arguments not
 appearing in index

We would fail to build an AST expression for an access with arguments
that are not themselves accesses, even if these arguments are not needed
to build the AST expression because they are not referenced in the index
expression of the access.
Ignore those arguments instead and update pet_stmt_can_build_ast_exprs
accordingly.

Reported-by: Michael Kruse <MichaelKruse@meinersbur.de>
Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 print.c | 46 ++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 40 insertions(+), 6 deletions(-)

diff --git a/print.c b/print.c
index 227cc0c..c18f68c 100644
--- a/print.c
+++ b/print.c
@@ -40,20 +40,46 @@
 #include "print.h"
 #include "scop.h"
 
-/* Given an access expression, check if any of its arguments
- * are not themselves access expressions.
+/* Return the dimension of the domain of the embedded map
+ * in the domain of "mpa".
+ */
+static int domain_domain_dim(__isl_keep isl_multi_pw_aff *mpa)
+{
+	int dim;
+	isl_space *space;
+
+	space = isl_multi_pw_aff_get_space(mpa);
+	space = isl_space_unwrap(isl_space_domain(space));
+	dim = isl_space_dim(space, isl_dim_in);
+	isl_space_free(space);
+
+	return dim;
+}
+
+/* Given an access expression, check if any of the arguments
+ * for which an isl_ast_expr would be constructed by
+ * pet_expr_build_nested_ast_exprs are not themselves access expressions.
  * If so, set *found and abort the search.
  */
 static int depends_on_expressions(__isl_keep pet_expr *expr, void *user)
 {
-	int i;
+	int i, dim;
 	int *found = user;
 
-	for (i = 0; i < expr->n_arg; ++i)
+	if (expr->n_arg == 0)
+		return 0;
+
+	dim = domain_domain_dim(expr->acc.index);
+
+	for (i = 0; i < expr->n_arg; ++i) {
+		if (!isl_multi_pw_aff_involves_dims(expr->acc.index,
+						    isl_dim_in, dim + i, 1))
+			continue;
 		if (expr->args[i]->type != pet_expr_access) {
 			*found = 1;
 			return -1;
 		}
+	}
 
 	return 0;
 }
@@ -181,20 +207,28 @@ static __isl_give isl_ast_expr *pet_expr_build_ast_expr(
  * expressions of "expr" to the corresponding isl_ast_expr.
  * The identifiers reference the corresponding arguments of "expr".
  * The same identifiers are used in parametrize_nested_exprs.
+ * Note that we only need to construct isl_ast_expr objects for
+ * those arguments that actually appear in the index expression of "expr".
  */
 static __isl_give isl_id_to_ast_expr *pet_expr_build_nested_ast_exprs(
 	__isl_keep pet_expr *expr, struct pet_build_ast_expr_data *data)
 {
-	int i;
+	int i, dim;
 	isl_ctx *ctx = isl_ast_build_get_ctx(data->build);
 	isl_id_to_ast_expr *id2expr;
 
+	dim = domain_domain_dim(expr->acc.index);
 	id2expr = isl_id_to_ast_expr_alloc(ctx, expr->n_arg);
 
 	for (i = 0; i < expr->n_arg; ++i) {
-		isl_id *id = isl_id_alloc(ctx, NULL, expr->args[i]);
+		isl_id *id;
 		isl_ast_expr *ast_expr;
 
+		if (!isl_multi_pw_aff_involves_dims(expr->acc.index,
+						    isl_dim_in, dim + i, 1))
+			continue;
+
+		id = isl_id_alloc(ctx, NULL, expr->args[i]);
 		ast_expr = pet_expr_build_ast_expr(expr->args[i], data);
 		id2expr = isl_id_to_ast_expr_set(id2expr, id, ast_expr);
 	}
-- 
2.11.4.GIT