[flang] [llvm] [mlir] [flang][OpenMP] Enable tiling (PR #143715)

[Krzysztof Parzyszek via llvm-commits]

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@@ -1890,39 +1910,124 @@ bool OmpAttributeVisitor::Pre(const parser::DoConstruct &x) {
   return true;
 }
 
+static bool isSizesClause(const parser::OmpClause *clause) {
+  return std::holds_alternative<parser::OmpClause::Sizes>(clause->u);
+}
+
+std::int64_t OmpAttributeVisitor::SetAssociatedMaxClause(
+    llvm::SmallVector<std::int64_t> &levels,
+    llvm::SmallVector<const parser::OmpClause *> &clauses) {
+
+  // Find the tile level to know how much to reduce the level for collapse
+  std::int64_t tileLevel = 0;
+  for (auto [level, clause] : llvm::zip_equal(levels, clauses)) {
+    if (isSizesClause(clause)) {
+      tileLevel = level;
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kparzysz wrote:

Shouldn't it be `tileLevel += level`?  You can stack `tile`s...

https://github.com/llvm/llvm-project/pull/143715