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

[Sergio Afonso]

================
@@ -595,9 +656,44 @@ bool collectLoopRelatedInfo(
   if (auto *clause =
           ClauseFinder::findUniqueClause<omp::clause::Collapse>(clauses)) {
     collapseValue = evaluate::ToInt64(clause->v).value();
-    found = true;
+    numCollapse = collapseValue;
+  }
+
+  // Collect sizes from tile directive if present
+  std::int64_t sizesLengthValue = 0l;
+  if (auto *ompCons{eval.getIf<parser::OpenMPConstruct>()}) {
+    if (auto *ompLoop{std::get_if<parser::OpenMPLoopConstruct>(&ompCons->u)}) {
+      const auto &nestedOptional =
+          std::get<std::optional<parser::NestedConstruct>>(ompLoop->t);
+      assert(nestedOptional.has_value() &&
+             "Expected a DoConstruct or OpenMPLoopConstruct");
+      const auto *innerConstruct =
+          std::get_if<common::Indirection<parser::OpenMPLoopConstruct>>(
+              &(nestedOptional.value()));
+      if (innerConstruct) {
+        const auto &innerLoopDirective = innerConstruct->value();
+        const auto &innerBegin =
+            std::get<parser::OmpBeginLoopDirective>(innerLoopDirective.t);
+        const auto &innerDirective =
+            std::get<parser::OmpLoopDirective>(innerBegin.t).v;
+
+        if (innerDirective == llvm::omp::Directive::OMPD_tile) {
+          // Get the size values from parse tree and convert to a vector
+          const auto &innerClauseList{
+              std::get<parser::OmpClauseList>(innerBegin.t)};
+          for (const auto &clause : innerClauseList.v)
+            if (const auto tclause{
+                    std::get_if<parser::OmpClause::Sizes>(&clause.u)}) {
+              sizesLengthValue = tclause->v.size();
+            }
+        }
+      }
+    }
   }
 
+  collapseValue = collapseValue - sizesLengthValue;
+  collapseValue =
+      collapseValue < sizesLengthValue ? sizesLengthValue : collapseValue;
----------------
skatrak wrote:

Nit: I find this logic confusing for what it is, and using a variable named `collapseValue` to represent the number of nested loops becomes misleading when we add tiling into the mix. How about:
```suggestion
  int64_t nestedLoops = std::max(collapseValue, numTileSizes);
```
We would return `collapseValue` from the function, remove the `numCollapse` variable, rename `sizesLengthValue` to `numTileSizes` and replace the do-while loop with `for (int64_t i = 0; i < nestedLoops; ++i)`.

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