[clang] [flang] [llvm] [openmp] [Clang][OpenMP][LoopTransformations] Add support for "#pragma omp fuse" loop transformation directive and "looprange" clause (PR #139293)

[Alexey Bataev via llvm-commits]

================
@@ -1485,7 +1498,81 @@ class SemaOpenMP : public SemaBase {
   bool checkTransformableLoopNest(
       OpenMPDirectiveKind Kind, Stmt *AStmt, int NumLoops,
       SmallVectorImpl<OMPLoopBasedDirective::HelperExprs> &LoopHelpers,
-      Stmt *&Body, SmallVectorImpl<SmallVector<Stmt *, 0>> &OriginalInits);
+      Stmt *&Body, SmallVectorImpl<SmallVector<Stmt *>> &OriginalInits);
+
+  /// Holds the result of the analysis of a (possibly canonical) loop.
+  struct LoopAnalysis {
+    /// The analyzed loop or loop transformation.
+    Stmt *AStmt;
+    /// Loop analyses results.
+    OMPLoopBasedDirective::HelperExprs HelperExprs;
+    /// The for-statement of the loop. ForStmt equals AStmt only when the latter
+    /// is a canonical loop (i.e. not a loop transformation).
+    Stmt *ForStmt;
+    /// Initialization statements before transformations.
+    SmallVector<Stmt *> OriginalInits;
+    /// Initialization statements required after transformation of this loop.
+    SmallVector<Stmt *> TransformsPreInits;
+
+    explicit LoopAnalysis(Stmt *S) : AStmt(S) {}
+
+    bool isRegularLoop() const { return isRegularLoop(AStmt); }
+    bool isLoopTransformation() const { return isLoopTransformation(AStmt); }
+
+    // Convenience functions used when building LoopSequenceAnalysis.
+    static bool isRegularLoop(Stmt *S) {
+      return isa<clang::ForStmt, CXXForRangeStmt>(S);
----------------
alexey-bataev wrote:

```suggestion
      return isa<ForStmt, CXXForRangeStmt>(S);
```

https://github.com/llvm/llvm-project/pull/139293