[flang][openacc] Add missing loop construct restriction and validity tests

Add restriction on loop construct associated with DO CONCURRENT. Add couple of tests to ensure
clause validity checks.

Reviewed By: sameeranjoshi

Differential Revision: https://reviews.llvm.org/D92533

flang/lib/Semantics/canonicalize-acc.cpp

@@ -64,6 +64,8 @@ private:
         std::size_t tileArgNb = listTileExpr.size();
 
         const auto &outer{std::get<std::optional<parser::DoConstruct>>(x.t)};
+        if (outer->IsDoConcurrent())
+          return; // Tile is not allowed on DO CONURRENT
         for (const parser::DoConstruct *loop{&*outer}; loop && tileArgNb > 0;
              --tileArgNb) {
           const auto &block{std::get<parser::Block>(loop->t)};
@@ -82,6 +84,27 @@ private:
     }
   }
 
+  // Check constraint on line 1835 in Section 2.9
+  // A tile and collapse clause may not appear on loop that is associated with
+  // do concurrent.
+  template <typename C, typename D>
+  void CheckDoConcurrentClauseRestriction(const C &x) {
+    const auto &doCons{std::get<std::optional<parser::DoConstruct>>(x.t)};
+    if (!doCons->IsDoConcurrent())
+      return;
+    const auto &beginLoopDirective = std::get<D>(x.t);
+    const auto &accClauseList =
+        std::get<parser::AccClauseList>(beginLoopDirective.t);
+    for (const auto &clause : accClauseList.v) {
+      if (std::holds_alternative<parser::AccClause::Collapse>(clause.u) ||
+          std::holds_alternative<parser::AccClause::Tile>(clause.u)) {
+        messages_.Say(beginLoopDirective.source,
+            "TILE and COLLAPSE clause may not appear on loop construct "
+            "associated with DO CONCURRENT"_err_en_US);
+      }
+    }
+  }
+
   void RewriteOpenACCLoopConstruct(parser::OpenACCLoopConstruct &x,
       parser::Block &block, parser::Block::iterator it) {
     // Check the sequence of DoConstruct in the same iteration
@@ -112,8 +135,12 @@ private:
               "DO loop after the %s directive must have loop control"_err_en_US,
               parser::ToUpperCaseLetters(dir.source.ToString()));
         }
+
+        CheckDoConcurrentClauseRestriction<parser::OpenACCLoopConstruct,
+            parser::AccBeginLoopDirective>(x);
         CheckTileClauseRestriction<parser::OpenACCLoopConstruct,
             parser::AccBeginLoopDirective>(x);
+
         return; // found do-loop
       }
     }
@@ -163,8 +190,12 @@ private:
               "DO loop after the %s directive must have loop control"_err_en_US,
               parser::ToUpperCaseLetters(dir.source.ToString()));
         }
+
+        CheckDoConcurrentClauseRestriction<parser::OpenACCCombinedConstruct,
+            parser::AccBeginCombinedDirective>(x);
         CheckTileClauseRestriction<parser::OpenACCCombinedConstruct,
             parser::AccBeginCombinedDirective>(x);
+
         return; // found do-loop
       }
     }

flang/test/Semantics/acc-canonicalization-validity.f90

@@ -13,6 +13,7 @@ program openacc_clause_validity
   integer :: i, j
   integer :: N = 256
   real(8) :: a(256)
+  real(8) :: aa(256, 256)
 
   !ERROR: A DO loop must follow the LOOP directive
   !$acc loop
@@ -106,4 +107,20 @@ program openacc_clause_validity
     a(i) = 3.14
   end do
 
+  !$acc parallel
+  !ERROR: TILE and COLLAPSE clause may not appear on loop construct associated with DO CONCURRENT
+  !$acc loop collapse(2)
+  do concurrent (i = 1:N, j = 1:N)
+    aa(i, j) = 3.14
+  end do
+  !$acc end parallel
+
+  !$acc parallel
+  !ERROR: TILE and COLLAPSE clause may not appear on loop construct associated with DO CONCURRENT
+  !$acc loop tile(2, 2)
+  do concurrent (i = 1:N, j = 1:N)
+    aa(i, j) = 3.14
+  end do
+  !$acc end parallel
+
 end program openacc_clause_validity

flang/test/Semantics/acc-clause-validity.f90

@@ -219,6 +219,14 @@ program openacc_clause_validity
   end do
   !$acc end parallel
 
+  !$acc parallel
+  !ERROR: SEQ and AUTO clauses are mutually exclusive and may not appear on the same LOOP directive
+  !$acc loop auto seq
+  do i = 1, N
+    a(i) = 3.14
+  end do
+  !$acc end parallel
+
   !$acc parallel
   !$acc loop tile(2)
   do i = 1, N
@@ -287,6 +295,14 @@ program openacc_clause_validity
   end do
   !$acc end parallel
 
+  !$acc parallel
+  !ERROR: At most one VECTOR clause can appear on the LOOP directive
+  !$acc loop vector vector(128)
+  do i = 1, N
+    a(i) = 3.14
+  end do
+  !$acc end parallel
+
   !$acc parallel
   !$acc loop vector
   do i = 1, N
@@ -315,6 +331,14 @@ program openacc_clause_validity
   end do
   !$acc end parallel
 
+  !$acc parallel
+  !ERROR: At most one WORKER clause can appear on the LOOP directive
+  !$acc loop worker worker(10)
+  do i = 1, N
+    a(i) = 3.14
+  end do
+  !$acc end parallel
+
   !$acc parallel
   !$acc loop worker
   do i = 1, N
@@ -343,6 +367,14 @@ program openacc_clause_validity
   end do
   !$acc end parallel
 
+  !$acc parallel
+  !ERROR: At most one GANG clause can appear on the LOOP directive
+  !$acc loop gang gang(gang_size)
+  do i = 1, N
+    a(i) = 3.14
+  end do
+  !$acc end parallel
+
   !$acc parallel
   !$acc loop gang(gang_size)
   do i = 1, N
@@ -528,6 +560,22 @@ program openacc_clause_validity
   end do
   !$acc end parallel
 
+  !$acc parallel
+  !ERROR: Clause WORKER is not allowed if clause SEQ appears on the LOOP directive
+  !$acc loop worker seq
+  do i = 1, N
+    a(i) = 3.14
+  end do
+  !$acc end parallel
+
+  !$acc parallel
+  !ERROR: Clause VECTOR is not allowed if clause SEQ appears on the LOOP directive
+  !$acc loop vector seq
+  do i = 1, N
+    a(i) = 3.14
+  end do
+  !$acc end parallel
+
   !ERROR: Clause IF is not allowed after clause DEVICE_TYPE on the PARALLEL directive
   !$acc parallel device_type(*) if(.TRUE.)
   !$acc loop