[llvm-branch-commits] [flang] [flang][OpenMP] Extend `do concurrent` mapping to multi-range loops (PR #127634)

[Sergio Afonso via llvm-branch-commits]

================
@@ -210,6 +223,96 @@ mlir::LogicalResult collectLoopNest(fir::DoLoopOp currentLoop,
 
   return mlir::success();
 }
+
+/// Prepares the `fir.do_loop` nest to be easily mapped to OpenMP. In
+/// particular, this function would take this input IR:
+/// ```
+/// fir.do_loop %i_iv = %i_lb to %i_ub step %i_step unordered {
+///   fir.store %i_iv to %i#1 : !fir.ref<i32>
+///   %j_lb = arith.constant 1 : i32
+///   %j_ub = arith.constant 10 : i32
+///   %j_step = arith.constant 1 : index
+///
+///   fir.do_loop %j_iv = %j_lb to %j_ub step %j_step unordered {
+///     fir.store %j_iv to %j#1 : !fir.ref<i32>
+///     ...
+///   }
+/// }
+/// ```
+///
+/// into the following form (using generic op form since the result is
+/// technically an invalid `fir.do_loop` op:
----------------
skatrak wrote:

```suggestion
/// technically an invalid `fir.do_loop` op):
```

https://github.com/llvm/llvm-project/pull/127634