[flang-commits] [flang] [flang][OpenMP] Try to unify induction var privatization (PR #91116)

[via flang-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-flang-semantics

Author: Kareem Ergawy (ergawy)

<details>
<summary>Changes</summary>

This PR tries to unify the paths taken by flang to privatize the induction variable of loops. With the changes introduced here, both cases below are now privatized in the same way:

```fortran
subroutine nested_constructs
    implicit none
    integer :: i

    !$omp parallel default(private)
      do i = 1, 10
      end do
    !$omp end parallel
end subroutine
```

```fortran
subroutine nested_constructs
    implicit none
    integer :: i

    !$omp parallel private(i)
      do i = 1, 10
      end do
    !$omp end parallel
end subroutine
```

---
Full diff: https://github.com/llvm/llvm-project/pull/91116.diff


4 Files Affected:

- (modified) flang/lib/Semantics/resolve-directives.cpp (-1) 
- (modified) flang/test/Lower/OpenMP/default-clause.f90 (+9-4) 
- (modified) flang/test/Semantics/OpenMP/do05-positivecase.f90 (+1-1) 
- (modified) flang/test/Semantics/OpenMP/symbol08.f90 (+4-4) 


``````````diff
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
index c99b1c413970ef..ba013dcd5d2831 100644
--- a/flang/lib/Semantics/resolve-directives.cpp
+++ b/flang/lib/Semantics/resolve-directives.cpp
@@ -1674,7 +1674,6 @@ void OmpAttributeVisitor::ResolveSeqLoopIndexInParallelOrTaskConstruct(
   // parallel or task
   if (auto *symbol{ResolveOmp(iv, Symbol::Flag::OmpPrivate, targetIt->scope)}) {
     targetIt++;
-    symbol->set(Symbol::Flag::OmpPreDetermined);
     iv.symbol = symbol; // adjust the symbol within region
     for (auto it{dirContext_.rbegin()}; it != targetIt; ++it) {
       AddToContextObjectWithDSA(*symbol, Symbol::Flag::OmpPrivate, *it);
diff --git a/flang/test/Lower/OpenMP/default-clause.f90 b/flang/test/Lower/OpenMP/default-clause.f90
index c9e76780de5de6..f09da04d244946 100644
--- a/flang/test/Lower/OpenMP/default-clause.f90
+++ b/flang/test/Lower/OpenMP/default-clause.f90
@@ -537,16 +537,21 @@ subroutine nested_constructs
 
     integer :: y, z
 !CHECK: omp.parallel {
-!CHECK: %[[INNER_J:.*]] = fir.alloca i32 {bindc_name = "j", pinned}
-!CHECK: %[[INNER_J_DECL:.*]]:2 = hlfir.declare %[[INNER_J]] {{.*}}
-!CHECK: %[[INNER_I:.*]] = fir.alloca i32 {bindc_name = "i", pinned}
-!CHECK: %[[INNER_I_DECL:.*]]:2 = hlfir.declare %[[INNER_I]] {{.*}}
+
 !CHECK: %[[INNER_Y:.*]] = fir.alloca i32 {bindc_name = "y", pinned, uniq_name = "_QFnested_constructsEy"}
 !CHECK: %[[INNER_Y_DECL:.*]]:2 = hlfir.declare %[[INNER_Y]] {{.*}}
 !CHECK: %[[TEMP:.*]] = fir.load %[[Y_DECL]]#0 : !fir.ref<i32>
 !CHECK: hlfir.assign %[[TEMP]] to %[[INNER_Y_DECL]]#0 temporary_lhs : i32, !fir.ref<i32>
+
+!CHECK: %[[INNER_I:.*]] = fir.alloca i32 {bindc_name = "i", pinned, uniq_name
+!CHECK: %[[INNER_I_DECL:.*]]:2 = hlfir.declare %[[INNER_I]] {{.*}}
+
+!CHECK: %[[INNER_J:.*]] = fir.alloca i32 {bindc_name = "j", pinned, uniq_name
+!CHECK: %[[INNER_J_DECL:.*]]:2 = hlfir.declare %[[INNER_J]] {{.*}}
+
 !CHECK: %[[INNER_Z:.*]] = fir.alloca i32 {bindc_name = "z", pinned, uniq_name = "_QFnested_constructsEz"}
 !CHECK: %[[INNER_Z_DECL:.*]]:2 = hlfir.declare %[[INNER_Z]] {{.*}}
+
     !$omp parallel default(private) firstprivate(y)
 !CHECK: {{.*}} = fir.do_loop {{.*}} {
       do i = 1, 10
diff --git a/flang/test/Semantics/OpenMP/do05-positivecase.f90 b/flang/test/Semantics/OpenMP/do05-positivecase.f90
index 4e02235f58a1a4..7fa6f004470529 100644
--- a/flang/test/Semantics/OpenMP/do05-positivecase.f90
+++ b/flang/test/Semantics/OpenMP/do05-positivecase.f90
@@ -9,7 +9,7 @@ program omp_do
   !DEF: /omp_do/n ObjectEntity INTEGER(4)
   integer i,n
   !$omp parallel
-  !DEF: /omp_do/OtherConstruct1/i (OmpPrivate, OmpPreDetermined) HostAssoc INTEGER(4)
+  !DEF: /omp_do/OtherConstruct1/i (OmpPrivate) HostAssoc INTEGER(4)
   do i=1,10
     !$omp single
     print *, "hello"
diff --git a/flang/test/Semantics/OpenMP/symbol08.f90 b/flang/test/Semantics/OpenMP/symbol08.f90
index 50f34b736cdb77..64643fe76c39d4 100644
--- a/flang/test/Semantics/OpenMP/symbol08.f90
+++ b/flang/test/Semantics/OpenMP/symbol08.f90
@@ -37,7 +37,7 @@ subroutine test_do
   do j=6,10
    !REF: /test_do/a
    a(1,1,1) = 0.
-   !DEF: /test_do/OtherConstruct1/k (OmpPrivate, OmpPreDetermined) HostAssoc INTEGER(4)
+   !DEF: /test_do/OtherConstruct1/k (OmpPrivate) HostAssoc INTEGER(4)
    do k=11,15
     !REF: /test_do/a
     !REF: /test_do/OtherConstruct1/k
@@ -170,9 +170,9 @@ subroutine test_simd
 !$omp parallel do simd
  !DEF: /test_simd/OtherConstruct1/i (OmpLinear, OmpPreDetermined) HostAssoc INTEGER(4)
  do i=1,5
-  !DEF: /test_simd/OtherConstruct1/j (OmpPrivate, OmpPreDetermined) HostAssoc INTEGER(4)
+  !DEF: /test_simd/OtherConstruct1/j (OmpPrivate) HostAssoc INTEGER(4)
   do j=6,10
-   !DEF: /test_simd/OtherConstruct1/k (OmpPrivate, OmpPreDetermined) HostAssoc INTEGER(4)
+   !DEF: /test_simd/OtherConstruct1/k (OmpPrivate) HostAssoc INTEGER(4)
    do k=11,15
     !REF: /test_simd/a
     !REF: /test_simd/OtherConstruct1/k
@@ -228,7 +228,7 @@ subroutine test_seq_loop
   print *, i, j
   !$omp parallel
   !REF: /test_seq_loop/i
-  !DEF: /test_seq_loop/OtherConstruct1/OtherConstruct1/j (OmpPrivate, OmpPreDetermined) HostAssoc INTEGER(4)
+  !DEF: /test_seq_loop/OtherConstruct1/OtherConstruct1/j (OmpPrivate) HostAssoc INTEGER(4)
   print *, i, j
   !$omp do
   !DEF: /test_seq_loop/OtherConstruct1/OtherConstruct1/OtherConstruct1/i (OmpPrivate, OmpPreDetermined) HostAssoc INTEGER(4)

``````````

</details>


https://github.com/llvm/llvm-project/pull/91116