[flang-commits] [flang] [flang][OpenMP] Semantic checks for metadirective loop nests (PR #207088)

[Abid Qadeer via flang-commits]

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@@ -0,0 +1,154 @@
+!RUN: %python %S/../test_errors.py %s %flang -fopenmp -fopenmp-version=51
+
+subroutine collapse_too_deep(n, a)
+  integer :: n, a(n, n), i, j
+  !ERROR: This construct requires a perfect nest of depth 3, but the associated nest is a perfect nest of depth 2
+  !BECAUSE: COLLAPSE clause was specified with argument 3
+  !$omp metadirective when(implementation={vendor(llvm)}: do collapse(3)) default(nothing)
+  do i = 1, n
+    do j = 1, n
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine ordered_too_deep(n, a)
+  integer :: n, a(n, n), i, j
+  !ERROR: This construct requires a perfect nest of depth 3, but the associated nest is a perfect nest of depth 2
+  !BECAUSE: ORDERED clause was specified with argument 3
+  !$omp metadirective when(implementation={vendor(llvm)}: do ordered(3)) default(nothing)
+  do i = 1, n
+    do j = 1, n
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine collapse_too_deep_exec(n, a)
+  integer :: n, a(n, n), i, j
+  a = 0
+  !ERROR: This construct requires a perfect nest of depth 3, but the associated nest is a perfect nest of depth 2
+  !BECAUSE: COLLAPSE clause was specified with argument 3
+  !$omp metadirective when(implementation={vendor(llvm)}: do collapse(3)) default(nothing)
+  do i = 1, n
+    do j = 1, n
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine collapse_too_deep_compiler_directive(n, a)
+  integer :: n, a(n, n), i, j
+  a = 0
+  !ERROR: This construct requires a perfect nest of depth 3, but the associated nest is a perfect nest of depth 2
+  !BECAUSE: COLLAPSE clause was specified with argument 3
+  !$omp metadirective when(implementation={vendor(llvm)}: do collapse(3)) default(nothing)
+  !dir$ ivdep
+  do i = 1, n
+    do j = 1, n
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine noncanonical_do_while(n)
+  integer :: n, i
+  i = 0
+  !ERROR: This construct requires a canonical loop nest
+  !$omp metadirective when(implementation={vendor(llvm)}: do) default(nothing)
+  !BECAUSE: DO WHILE loop is not a valid affected loop
+  do while (i < n)
+    i = i + 1
+  end do
+end subroutine
+
+subroutine noncanonical_do_concurrent(n, a)
+  integer :: n, a(n), i
+  !ERROR: This construct requires a canonical loop nest
+  !$omp metadirective when(implementation={vendor(llvm)}: do) default(nothing)
+  !BECAUSE: DO CONCURRENT loop is not a valid affected loop
+  do concurrent(i=1:n)
+    a(i) = i
+  end do
+end subroutine
+
+subroutine noncanonical_no_control(n)
+  integer :: n, i
+  i = 0
+  !ERROR: This construct requires a canonical loop nest
+  !$omp metadirective when(implementation={vendor(llvm)}: do) default(nothing)
+  !BECAUSE: DO loop without loop control is not a valid affected loop
+  do
+    i = i + 1
+    if (i >= n) exit
+  end do
+end subroutine
+
+subroutine collapse_too_deep_interface(n, a)
+  integer :: n, a(n, n), i, j
+  !ERROR: This construct requires a perfect nest of depth 3, but the associated nest is a perfect nest of depth 2
+  !BECAUSE: COLLAPSE clause was specified with argument 3
+  !$omp metadirective when(implementation={vendor(llvm)}: do collapse(3)) default(nothing)
+  interface
+    subroutine ext()
+    end subroutine
+  end interface
+  do i = 1, n
+    do j = 1, n
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine tile_non_rectangular(n, a)
+  integer :: n, a(n, n), i, j
+  !ERROR: This construct requires a rectangular loop nest, but the associated nest is not
+  !BECAUSE: None of the loops affected by TILE can be non-rectangular
+  !$omp metadirective when(implementation={vendor(llvm)}: tile sizes(2, 2)) default(nothing)
+  do i = 1, n
+    !BECAUSE: The upper bound of the affected loop uses iteration variables of enclosing loops: 'i'
+    do j = 1, i
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine collapse_valid(n, a)
+  integer :: n, a(n, n), i, j
+  !$omp metadirective when(implementation={vendor(llvm)}: do collapse(2)) default(nothing)
+  do i = 1, n
+    do j = 1, n
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+subroutine collapse_non_rectangular_valid(n, a)
+  integer :: n, a(n, n), i, j
+  !$omp metadirective when(implementation={vendor(llvm)}: do collapse(2)) default(nothing)
+  do i = 1, n
+    do j = 1, i
+      a(j, i) = i
+    end do
+  end do
+end subroutine
+
+! A loop-associated variant with no loop nest to associate with is in error,
+! whether the metadirective is the last construct in the execution part ...
+subroutine no_loop_at_end()
+  !ERROR: This construct should contain a DO-loop or a loop-nest-generating construct
+  !$omp metadirective when(implementation={vendor(llvm)}: do) default(nothing)
+end subroutine
----------------
abidh wrote:

I was wondering if the following code would generate a similar error
```
module m
  implicit none
  !$omp metadirective when(implementation={vendor(llvm)}: do) default(nothing)
end module
```

https://github.com/llvm/llvm-project/pull/207088