codegenISL: outline collectIteratorMaps

There is no point for this function to be a lambda.
It only makes the code harder to read and encourages
the use of weird argument names to avoid compiler warnings
as in 020faf0 (Compilation fix for -Werror=shadow-compatible-local,
Mon May 7 15:12:13 2018 -0700).

Author: Sven Verdoolaege

tc/core/polyhedral/codegen_llvm.cc

@@ -606,46 +606,46 @@ struct IslCodegenRes {
   isl::ast_node astNode;
 };
 
+isl::ast_node collectIteratorMaps(
+    isl::ast_node node,
+    isl::ast_build build,
+    IteratorMapsType& iteratorMapsInFun,
+    const Scop& scopInFun,
+    StmtSubscriptExprMapType& stmtSubscriptsInFun) {
+  auto user = node.as<isl::ast_node_user>();
+  CHECK(user);
+  auto expr = user.get_expr().as<isl::ast_expr_op>();
+  auto schedule = build.get_schedule();
+  auto scheduleMap = isl::map::from_union_map(schedule);
+
+  auto stmtId = expr.get_arg(0).as<isl::ast_expr_id>().get_id();
+  CHECK_EQ(0u, iteratorMapsInFun.count(stmtId)) << "entry exists: " << stmtId;
+  auto iteratorMap = isl::pw_multi_aff(scheduleMap.reverse());
+  auto iterators = scopInFun.halide.iterators.at(stmtId);
+  auto& stmtIteratorMap = iteratorMapsInFun[stmtId];
+  for (size_t i = 0; i < iterators.size(); ++i) {
+    auto expr = build.expr_from(iteratorMap.get_pw_aff(i));
+    stmtIteratorMap.emplace(iterators[i], expr);
+  }
+  auto& subscripts = stmtSubscriptsInFun[stmtId];
+  auto provide =
+      scopInFun.halide.statements.at(stmtId).as<Halide::Internal::Provide>();
+  for (auto e : provide->args) {
+    const auto& map = iteratorMap;
+    auto space = map.get_space().params();
+    auto aff = scopInFun.makeIslAffFromStmtExpr(stmtId, space, e);
+    auto pulled = isl::pw_aff(aff).pullback(map);
+    CHECK_EQ(pulled.n_piece(), 1);
+    subscripts.push_back(build.expr_from(pulled));
+  }
+  return node.set_annotation(stmtId);
+}
+
 IslCodegenRes codegenISL(const Scop& scop) {
   IteratorMapsType iteratorMaps;
   StmtSubscriptExprMapType stmtSubscripts;
   auto collect = [&iteratorMaps, &scop, &stmtSubscripts](
                      isl::ast_node n, isl::ast_build b) -> isl::ast_node {
-    auto collectIteratorMaps =
-        [](isl::ast_node node,
-           isl::ast_build build,
-           IteratorMapsType& iteratorMapsInFun,
-           const Scop& scopInFun,
-           StmtSubscriptExprMapType& stmtSubscriptsInFun) -> isl::ast_node {
-      auto user = node.as<isl::ast_node_user>();
-      CHECK(user);
-      auto expr = user.get_expr().as<isl::ast_expr_op>();
-      auto schedule = build.get_schedule();
-      auto scheduleMap = isl::map::from_union_map(schedule);
-
-      auto stmtId = expr.get_arg(0).as<isl::ast_expr_id>().get_id();
-      CHECK_EQ(0u, iteratorMapsInFun.count(stmtId))
-          << "entry exists: " << stmtId;
-      auto iteratorMap = isl::pw_multi_aff(scheduleMap.reverse());
-      auto iterators = scopInFun.halide.iterators.at(stmtId);
-      auto& stmtIteratorMap = iteratorMapsInFun[stmtId];
-      for (size_t i = 0; i < iterators.size(); ++i) {
-        auto expr = build.expr_from(iteratorMap.get_pw_aff(i));
-        stmtIteratorMap.emplace(iterators[i], expr);
-      }
-      auto& subscripts = stmtSubscriptsInFun[stmtId];
-      auto provide = scopInFun.halide.statements.at(stmtId)
-                         .as<Halide::Internal::Provide>();
-      for (auto e : provide->args) {
-        const auto& map = iteratorMap;
-        auto space = map.get_space().params();
-        auto aff = scopInFun.makeIslAffFromStmtExpr(stmtId, space, e);
-        auto pulled = isl::pw_aff(aff).pullback(map);
-        CHECK_EQ(pulled.n_piece(), 1);
-        subscripts.push_back(build.expr_from(pulled));
-      }
-      return node.set_annotation(stmtId);
-    };
 
     auto& uv = iteratorMaps;
     return collectIteratorMaps(n, b, uv, scop, stmtSubscripts);