[flang-commits] [flang] [Flang][OpenMP] Add semantic support for Loop Sequences and OpenMP loop fuse (PR #161213)

[Krzysztof Parzyszek via flang-commits]

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@@ -2254,85 +2258,86 @@ void OmpAttributeVisitor::CheckPerfectNestAndRectangularLoop(
   // Find the associated region by skipping nested loop-associated constructs
   // such as loop transformations
   const parser::NestedConstruct *innermostAssocRegion{nullptr};
-  const parser::OpenMPLoopConstruct *innermostConstruct{&x};
-  while (const auto &innerAssocStmt{
-      std::get<std::optional<parser::NestedConstruct>>(
-          innermostConstruct->t)}) {
-    innermostAssocRegion = &(innerAssocStmt.value());
+  const parser::OpenMPLoopConstruct *innermostConstruct = &x;
+  auto &loopConsList =
+      std::get<std::list<parser::NestedConstruct>>(innermostConstruct->t);
+  for (auto &loopCons : loopConsList) {
+    innermostAssocRegion = &loopCons;
     if (const auto *innerConstruct{
             std::get_if<common::Indirection<parser::OpenMPLoopConstruct>>(
                 innermostAssocRegion)}) {
-      innermostConstruct = &innerConstruct->value();
+      CheckPerfectNestAndRectangularLoop(innerConstruct->value());
+      return;
     } else {
-      break;
-    }
-  }
 
-  if (!innermostAssocRegion)
-    return;
-  const auto &outer{std::get_if<parser::DoConstruct>(innermostAssocRegion)};
-  if (!outer)
-    return;
+      if (!innermostAssocRegion)
+        continue;
+      const auto &outer{std::get_if<parser::DoConstruct>(innermostAssocRegion)};
+      if (!outer)
+        continue;
 
-  llvm::SmallVector<Symbol *> ivs;
-  int curLevel{0};
-  const parser::DoConstruct *loop{outer};
-  while (true) {
-    auto [iv, lb, ub, step] = GetLoopBounds(*loop);
-
-    if (lb)
-      checkExprHasSymbols(ivs, lb);
-    if (ub)
-      checkExprHasSymbols(ivs, ub);
-    if (step)
-      checkExprHasSymbols(ivs, step);
-    if (iv) {
-      if (auto *symbol{currScope().FindSymbol(iv->source)})
-        ivs.push_back(symbol);
-    }
+      llvm::SmallVector<Symbol *> ivs;
+      int curLevel{0};
+      const parser::DoConstruct *loop{outer};
+      while (true) {
+        auto [iv, lb, ub, step] = GetLoopBounds(*loop);
+
+        if (lb)
+          checkExprHasSymbols(ivs, lb);
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kparzysz wrote:

Not necessarily.  LGTM as far as I'm concerned.

https://github.com/llvm/llvm-project/pull/161213