halide2isl.cc: extractAccess: construct expressions on parameter space

Since 2ab86bb (makeIslAffFromExpr: only accept parametric expressions,
Mon Mar 26 14:50:33 2018 +0200), makeIslAffFromExpr only constructs
parametric expressions.  However, it would still accept a set space
as input and extractAccess continued to do so.
Call it on a parameter space instead for consistency.
This will make it easier to provide proper typing of makeIslAffFromExpr
when switching to templated isl types.

Author: Sven Verdoolaege

tc/core/CMakeLists.txt

@@ -34,6 +34,7 @@ add_library(
   polyhedral/scop.cc
   polyhedral/separation.cc
   polyhedral/unroll.cc
+  polyhedral/utils.cc
 )
 target_include_directories(tc_core PUBLIC ${LLVM_INCLUDE_DIRS})
 target_link_libraries(

tc/core/halide2isl.cc

@@ -24,6 +24,7 @@
 #include "tc/core/polyhedral/schedule_isl_conversion.h"
 #include "tc/core/polyhedral/schedule_transforms.h"
 #include "tc/core/polyhedral/schedule_tree.h"
+#include "tc/core/polyhedral/utils.h"
 #include "tc/core/tc2halide.h"
 
 namespace tc {
@@ -259,7 +260,8 @@ isl::map extractAccess(
 
   isl::space paramSpace = domain.paramSpace;
   isl::id tensorID(paramSpace.get_ctx(), tensor);
-  auto tensorSpace = paramSpace.add_named_tuple_id_ui(tensorID, args.size());
+  auto tensorTuple = constructTensorTuple(paramSpace, tensorID, args.size());
+  auto tensorSpace = tensorTuple.get_space();
 
   // Start with a totally unconstrained set - every point in
   // the allocation could be accessed.
@@ -275,8 +277,9 @@ isl::map extractAccess(
     // The coordinate written to in the range ...
     auto rangePoint = identity.get_aff(i);
     // ... equals the coordinate accessed as a function of the parameters.
-    auto domainPoint = halide2isl::makeIslAffFromExpr(tensorSpace, args[i]);
+    auto domainPoint = halide2isl::makeIslAffFromExpr(paramSpace, args[i]);
     if (!domainPoint.is_null()) {
+      domainPoint = domainPoint.unbind_params_insert_domain(tensorTuple);
       access = access.intersect(domainPoint.eq_set(rangePoint));
     }
   }

tc/core/polyhedral/utils.cc

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2018, Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "tc/core/polyhedral/utils.h"
+
+namespace tc {
+namespace polyhedral {
+
+/* Construct a tuple representing the tensor with identifier "tensorId" and
+ * dimension "dim" from the parameter space "paramSpace",
+ * without any specific names for the indices, from the perspective
+ * of the user.
+ * Since some names are required, use names of the form "__tc_tensor_arg*".
+ */
+isl::multi_id
+constructTensorTuple(isl::space paramSpace, isl::id tensorId, size_t dim) {
+  auto tensorSpace = paramSpace.add_named_tuple_id_ui(tensorId, dim);
+  isl::id_list tensorArgs(paramSpace.get_ctx(), 0);
+  for (size_t i = 0; i < dim; ++i) {
+    auto name = std::string("__tc_tensor_arg") + std::to_string(i);
+    tensorArgs = tensorArgs.add(isl::id(paramSpace.get_ctx(), name));
+  }
+  return isl::multi_id(tensorSpace, tensorArgs);
+}
+
+} // namespace polyhedral
+} // namespace tc

tc/core/polyhedral/utils.h

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) 2018, Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include "tc/external/isl.h"
+
+namespace tc {
+namespace polyhedral {
+
+/* Construct a tuple representing the tensor with identifier "tensorId" and
+ * dimension "dim" from the parameter space "paramSpace",
+ * without any specific names for the indices.
+ */
+isl::multi_id
+constructTensorTuple(isl::space paramSpace, isl::id tensorId, size_t dim);
+
+} // namespace polyhedral
+} // namespace tc