[flang-commits] [flang] e27654f - [Flang][OpenMP] Add more sema checks for ordered construct

[Arnamoy Bhattacharyya via flang-commits]

Author: Arnamoy Bhattacharyya
Date: 2021-03-19T14:56:40-04:00
New Revision: e27654f737da8e3a80d8c1e3509868ab7fb4265b

URL: https://github.com/llvm/llvm-project/commit/e27654f737da8e3a80d8c1e3509868ab7fb4265b
DIFF: https://github.com/llvm/llvm-project/commit/e27654f737da8e3a80d8c1e3509868ab7fb4265b.diff

LOG: [Flang][OpenMP] Add more sema checks for ordered construct

This patch fixes a bug to allow ordered construct within a non-worksharing loop, also adds more sema checks.

Reviewed By: kiranchandramohan

Differential Revision: https://reviews.llvm.org/D98733

Added: 
    flang/test/Semantics/omp-ordered-simd.f90

Modified: 
    flang/lib/Semantics/check-omp-structure.cpp
    flang/lib/Semantics/check-omp-structure.h

Removed: 
    


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diff  --git a/flang/lib/Semantics/check-omp-structure.cpp b/flang/lib/Semantics/check-omp-structure.cpp
index a3a3fd5d3524d..3ed86132cbea2 100644
--- a/flang/lib/Semantics/check-omp-structure.cpp
+++ b/flang/lib/Semantics/check-omp-structure.cpp
@@ -343,12 +343,22 @@ void OmpStructureChecker::Enter(const parser::OpenMPBlockConstruct &x) {
 void OmpStructureChecker::CheckIfDoOrderedClause(
     const parser::OmpBlockDirective &blkDirective) {
   if (blkDirective.v == llvm::omp::OMPD_ordered) {
-    if (!FindClauseParent(llvm::omp::Clause::OMPC_ordered)) {
+    // Loops
+    if (llvm::omp::doSet.test(GetContextParent().directive) &&
+        !FindClauseParent(llvm::omp::Clause::OMPC_ordered)) {
       context_.Say(blkDirective.source,
           "The ORDERED clause must be present on the loop"
           " construct if any ORDERED region ever binds"
           " to a loop region arising from the loop construct."_err_en_US);
     }
+    // Other disallowed nestings, these directives do not support
+    // ordered clause in them, so no need to check
+    else if (llvm::omp::nestedOrderedErrSet.test(
+                 GetContextParent().directive)) {
+      context_.Say(blkDirective.source,
+          "`ORDERED` region may not be closely nested inside of "
+          "`CRITICAL`, `ORDERED`, explicit `TASK` or `TASKLOOP` region."_err_en_US);
+    }
   }
 }
 

diff  --git a/flang/lib/Semantics/check-omp-structure.h b/flang/lib/Semantics/check-omp-structure.h
index f11ddc66b401e..0d11f72b5bc85 100644
--- a/flang/lib/Semantics/check-omp-structure.h
+++ b/flang/lib/Semantics/check-omp-structure.h
@@ -73,6 +73,9 @@ static OmpDirectiveSet simdSet{Directive::OMPD_distribute_parallel_do_simd,
     Directive::OMPD_teams_distribute_simd};
 static OmpDirectiveSet taskGeneratingSet{
     OmpDirectiveSet{Directive::OMPD_task} | taskloopSet};
+static OmpDirectiveSet nestedOrderedErrSet{Directive::OMPD_critical,
+    Directive::OMPD_ordered, Directive::OMPD_atomic, Directive::OMPD_task,
+    Directive::OMPD_taskloop};
 static OmpClauseSet privateSet{
     Clause::OMPC_private, Clause::OMPC_firstprivate, Clause::OMPC_lastprivate};
 static OmpClauseSet privateReductionSet{

diff  --git a/flang/test/Semantics/omp-ordered-simd.f90 b/flang/test/Semantics/omp-ordered-simd.f90
new file mode 100644
index 0000000000000..d597191650e78
--- /dev/null
+++ b/flang/test/Semantics/omp-ordered-simd.f90
@@ -0,0 +1,95 @@
+! RUN: %S/test_errors.sh %s %t %flang -fopenmp
+! OpenMP Version 4.5
+! Various checks with the ordered construct
+
+SUBROUTINE WORK(I)
+  INTEGER I
+END SUBROUTINE WORK
+
+SUBROUTINE ORDERED_GOOD(N)
+  INTEGER N, I, A(10), B(10), C(10) 
+  !$OMP SIMD
+  DO I = 1,N
+    IF (I <= 10) THEN
+      !$OMP ORDERED SIMD
+      CALL WORK(I)
+      !$OMP END ORDERED
+    ENDIF
+  END DO
+  !$OMP END SIMD
+END SUBROUTINE ORDERED_GOOD
+
+SUBROUTINE ORDERED_BAD(N)
+  INTEGER N, I, A(10), B(10), C(10)
+
+  !$OMP DO SIMD
+  DO I = 1,N
+    IF (I <= 10) THEN
+      !ERROR: The ORDERED clause must be present on the loop construct if any ORDERED region ever binds to a loop region arising from the loop construct.
+      !$OMP ORDERED 
+      CALL WORK(I)
+      !$OMP END ORDERED
+    ENDIF
+  END DO
+  !$OMP END DO SIMD
+
+  !$OMP PARALLEL DO
+  DO I = 1,N
+    IF (I <= 10) THEN
+      !ERROR: The ORDERED clause must be present on the loop construct if any ORDERED region ever binds to a loop region arising from the loop construct.
+      !$OMP ORDERED 
+      CALL WORK(I)
+      !$OMP END ORDERED
+    ENDIF
+  END DO
+  !$OMP END PARALLEL DO
+
+  !$OMP CRITICAL  
+  DO I = 1,N
+    IF (I <= 10) THEN
+      !ERROR: `ORDERED` region may not be closely nested inside of `CRITICAL`, `ORDERED`, explicit `TASK` or `TASKLOOP` region.
+      !$OMP ORDERED 
+      CALL WORK(I)
+      !$OMP END ORDERED
+    ENDIF
+  END DO
+  !$OMP END CRITICAL
+
+  !$OMP CRITICAL
+    WRITE(*,*) I
+    !ERROR: `ORDERED` region may not be closely nested inside of `CRITICAL`, `ORDERED`, explicit `TASK` or `TASKLOOP` region.
+    !$OMP ORDERED 
+    CALL WORK(I)
+    !$OMP END ORDERED
+  !$OMP END CRITICAL
+
+  !$OMP ORDERED 
+    WRITE(*,*) I
+    IF (I <= 10) THEN
+      !ERROR: `ORDERED` region may not be closely nested inside of `CRITICAL`, `ORDERED`, explicit `TASK` or `TASKLOOP` region.
+      !$OMP ORDERED 
+      CALL WORK(I)
+      !$OMP END ORDERED
+    ENDIF
+  !$OMP END ORDERED
+
+  !$OMP TASK  
+    C =  C - A * B
+    !ERROR: `ORDERED` region may not be closely nested inside of `CRITICAL`, `ORDERED`, explicit `TASK` or `TASKLOOP` region.
+    !$OMP ORDERED 
+    CALL WORK(I)
+    !$OMP END ORDERED
+  !$OMP END TASK
+
+  !$OMP TASKLOOP 
+  DO I = 1,N
+    IF (I <= 10) THEN
+      !ERROR: `ORDERED` region may not be closely nested inside of `CRITICAL`, `ORDERED`, explicit `TASK` or `TASKLOOP` region.
+      !$OMP ORDERED 
+      CALL WORK(I)
+      !$OMP END ORDERED
+    ENDIF
+  END DO
+  !$OMP END TASKLOOP
+
+END SUBROUTINE ORDERED_BAD