[flang-commits] [flang] [flang][acc] Fix crash on collapse(force:N) with non-tightly nested loops (PR #191310)

[Razvan Lupusoru via flang-commits]

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@@ -0,0 +1,28 @@
+! RUN: bbc -fopenacc -emit-hlfir %s -o - | FileCheck %s
+
+! Verify that collapse(force:N) on non-tightly nested loops (with code
+! between loops) does not crash the compiler.
+
+subroutine collapse_force_non_tight(a, n)
+  implicit none
+  integer, intent(in) :: n
+  real, intent(inout) :: a(n, n, n)
+  integer :: i, j, k
+  real :: tmp
+
+  !$acc parallel loop collapse(force:3) copy(a)
+  do i = 1, n
+    do j = 1, n
+      tmp = real(i + j)
+      do k = 1, n
----------------
razvanlupusoru wrote:

Here is the example I would like to see being tested:

```
  !$acc parallel loop collapse(force:3) copy(a)
  do i = 1, n
    do j = 1, n
      tmp = real(i + j)
      !$acc loop
      do k = 1, n
        a(i, j, k) = tmp + real(k)
      end do
    end do
  end do
  !$acc end parallel loop
```

https://github.com/llvm/llvm-project/pull/191310