[flang-commits] [flang] [flang][OpenMP] incorrect handling for local variable in OpenMP parallel workshare firstprivate(P) (PR #195616)

[Leandro Lupori via flang-commits]

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@@ -0,0 +1,101 @@
+!===----------------------------------------------------------------------===!
+! This directory can be used to add Integration tests involving multiple
+! stages of the compiler (for eg. from Fortran to LLVM IR). It should not
+! contain executable tests. We should only add tests here sparingly and only
+! if there is no other way to test. Repeat this message in each test that is
+! added to this directory and sub-directories.
+!===----------------------------------------------------------------------===!
+
+!RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=51 %s -o - | FileCheck %s --check-prefix HLFIR
+!RUN: %flang_fc1 -emit-fir -fopenmp -fopenmp-version=51 %s -o - | FileCheck %s --check-prefix FIR
+!RUN: %flang_fc1 -emit-llvm -fopenmp -fopenmp-version=51 %s -o - | FileCheck %s --check-prefix LLVM
+
+! Test that parallel workshare with firstprivate(P) where P is a pointer
+! correctly places stores through the pointer target in omp.single rather
+! than parallelizing them. The pointer descriptor is thread-local (firstprivate),
+! but the target data is shared memory.
+
+subroutine test_workshare_firstprivate_pointer(P)
+  integer, pointer, intent(in) :: P(:)
+  integer :: i
+  !$omp parallel workshare firstprivate(P)
+  forall (i = 1:SIZE(P)) P(i) = i
+  !$omp end parallel workshare
+end subroutine
+
+! HLFIR:     omp.parallel {
+! HLFIR:       omp.workshare {
+! The firstprivate copy: alloca, zero-init, declare, then copy from original
+! HLFIR:         fir.alloca !fir.box<!fir.ptr<!fir.array<?xi32>>>
+! HLFIR:         fir.store
+! HLFIR:         hlfir.declare
+! HLFIR:         fir.load
+! HLFIR:         fir.store
+! HLFIR:         hlfir.forall
+! HLFIR:         omp.terminator
+! HLFIR:       }
+! HLFIR:       omp.terminator
+! HLFIR:     }
+
+! After workshare lowering, the forall body (which stores through the pointer
+! target) must be inside omp.single, not parallelized.
+! FIR:     omp.parallel {
+! FIR:       %[[DESC:.*]] = fir.alloca !fir.box<!fir.ptr<!fir.array<?xi32>>>
+! The firstprivate init + copy and the forall loop must be in omp.single
+! FIR:       omp.single copyprivate(%[[DESC]]
----------------
luporl wrote:

```suggestion
! FIR:       omp.single copyprivate(%[[DESC]] {{.*}}) {{.*}} {
```

nit: this would help to associate `omp.single` with the `}` below.

https://github.com/llvm/llvm-project/pull/195616