[flang][OpenMP] Enhance parser support for atomic construct to OpenMP 5.0

Summary:
This patch enhances parser support for atomic construct to OpenMP 5.0.
2.17.7 atomic -> ATOMIC [clause [,]] atomic-clause [[,] clause] |
                 ATOMIC [clause]
       clause -> memory-order-clause | HINT(hint-expression)
       memory-order-clause -> SEQ_CST | ACQ_REL | RELEASE | ACQUIRE | RELAXED
       atomic-clause -> READ | WRITE | UPDATE | CAPTURE

The patch includes code changes and testcase modifications.

Reviewed By: DavidTruby, kiranchandramohan, sameeranjoshi

Differential Revision: https://reviews.llvm.org/D82931

2 files changed, 45 insertions, 28 deletions

diff --git a/flang/include/flang/Parser/dump-parse-tree.h b/flang/include/flang/Parser/dump-parse-tree.h
index 41ff963..921e617 100644
--- a/flang/include/flang/Parser/dump-parse-tree.h
+++ b/flang/include/flang/Parser/dump-parse-tree.h
@@ -445,6 +445,9 @@ public:
   NODE(parser, OmpAtomicCapture)
   NODE(OmpAtomicCapture, Stmt1)
   NODE(OmpAtomicCapture, Stmt2)
+  NODE(parser, OmpAtomicMemoryOrderClause)
+  NODE(parser, OmpAtomicMemoryOrderClauseList)
+  NODE(parser, OmpAtomicMemoryOrderClausePostList)
   NODE(parser, OmpAtomicRead)
   NODE(parser, OmpAtomicUpdate)
   NODE(parser, OmpAtomicWrite)
@@ -464,7 +467,6 @@ public:
 #include "llvm/Frontend/OpenMP/OMP.cpp.inc"
   NODE(parser, OmpClauseList)
   NODE(parser, OmpCriticalDirective)
-  NODE(OmpCriticalDirective, Hint)
   NODE(parser, OmpDeclareTargetSpecifier)
   NODE(parser, OmpDeclareTargetWithClause)
   NODE(parser, OmpDeclareTargetWithList)
@@ -487,6 +489,7 @@ public:
   NODE(parser, OmpEndCriticalDirective)
   NODE(parser, OmpEndLoopDirective)
   NODE(parser, OmpEndSectionsDirective)
+  NODE(parser, OmpHintExpr)
   NODE(parser, OmpIfClause)
   NODE_ENUM(OmpIfClause, DirectiveNameModifier)
   NODE(parser, OmpLinearClause)
@@ -499,10 +502,12 @@ public:
   NODE(parser, OmpMapType)
   NODE(OmpMapType, Always)
   NODE_ENUM(OmpMapType, Type)
-  NODE(parser, OmpMemoryClause)
-  NODE_ENUM(OmpMemoryClause, MemoryOrder)
-  NODE(parser, OmpMemoryClauseList)
-  NODE(parser, OmpMemoryClausePostList)
+  NODE(parser, OmpMemoryOrderClause)
+  static std::string GetNodeName(const llvm::omp::Clause &x) {
+    return llvm::Twine(
+        "llvm::omp::Clause = ", llvm::omp::getOpenMPClauseName(x))
+        .str();
+  }
   NODE(parser, OmpNowait)
   NODE(parser, OmpObject)
   NODE(parser, OmpObjectList)
@@ -549,7 +554,6 @@ public:
   NODE(parser, OpenMPDeclareSimdConstruct)
   NODE(parser, OpenMPDeclareTargetConstruct)
   NODE(parser, OmpFlushMemoryClause)
-  NODE_ENUM(OmpFlushMemoryClause, FlushMemoryOrder)
   NODE(parser, OpenMPFlushConstruct)
   NODE(parser, OpenMPLoopConstruct)
   NODE(parser, OpenMPSimpleStandaloneConstruct)
diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
index 166e573b..a9fb92c 100644
--- a/flang/include/flang/Parser/parse-tree.h
+++ b/flang/include/flang/Parser/parse-tree.h
@@ -3591,12 +3591,14 @@ struct OpenMPDeclarativeConstruct {
       u;
 };
 
+// HINT(hint-expression)
+WRAPPER_CLASS(OmpHintExpr, ConstantExpr);
+
 // 2.13.2 CRITICAL [Name] <block> END CRITICAL [Name]
 struct OmpCriticalDirective {
   TUPLE_CLASS_BOILERPLATE(OmpCriticalDirective);
-  WRAPPER_CLASS(Hint, ConstantExpr);
   CharBlock source;
-  std::tuple<Verbatim, std::optional<Name>, std::optional<Hint>> t;
+  std::tuple<Verbatim, std::optional<Name>, std::optional<OmpHintExpr>> t;
 };
 struct OmpEndCriticalDirective {
   TUPLE_CLASS_BOILERPLATE(OmpEndCriticalDirective);
@@ -3608,44 +3610,56 @@ struct OpenMPCriticalConstruct {
   std::tuple<OmpCriticalDirective, Block, OmpEndCriticalDirective> t;
 };
 
-// 2.13.6 atomic -> ATOMIC [seq_cst[,]] atomic-clause [[,]seq_cst] |
-//                  ATOMIC [seq_cst]
+// 2.17.7 atomic -> ATOMIC [clause[,]] atomic-clause [[,]clause] |
+//                  ATOMIC [clause]
+//        clause -> memory-order-clause | HINT(hint-expression)
+//        memory-order-clause -> SEQ_CST | ACQ_REL | RELEASE | ACQUIRE | RELAXED
 //        atomic-clause -> READ | WRITE | UPDATE | CAPTURE
 
 // END ATOMIC
 EMPTY_CLASS(OmpEndAtomic);
 
-// ATOMIC Memory related clause
-struct OmpMemoryClause {
-  ENUM_CLASS(MemoryOrder, SeqCst)
-  WRAPPER_CLASS_BOILERPLATE(OmpMemoryClause, MemoryOrder);
+// Memory order clause
+struct OmpMemoryOrderClause {
+  WRAPPER_CLASS_BOILERPLATE(OmpMemoryOrderClause, llvm::omp::Clause);
   CharBlock source;
 };
 
-WRAPPER_CLASS(OmpMemoryClauseList, std::list<OmpMemoryClause>);
-WRAPPER_CLASS(OmpMemoryClausePostList, std::list<OmpMemoryClause>);
+// ATOMIC Memory order clause or hint expression
+struct OmpAtomicMemoryOrderClause {
+  UNION_CLASS_BOILERPLATE(OmpAtomicMemoryOrderClause);
+  std::variant<OmpMemoryOrderClause, OmpHintExpr> u;
+};
+
+WRAPPER_CLASS(
+    OmpAtomicMemoryOrderClauseList, std::list<OmpAtomicMemoryOrderClause>);
+WRAPPER_CLASS(
+    OmpAtomicMemoryOrderClausePostList, std::list<OmpAtomicMemoryOrderClause>);
 
 // ATOMIC READ
 struct OmpAtomicRead {
   TUPLE_CLASS_BOILERPLATE(OmpAtomicRead);
-  std::tuple<OmpMemoryClauseList, Verbatim, OmpMemoryClausePostList,
-      Statement<AssignmentStmt>, std::optional<OmpEndAtomic>>
+  std::tuple<OmpAtomicMemoryOrderClauseList, Verbatim,
+      OmpAtomicMemoryOrderClausePostList, Statement<AssignmentStmt>,
+      std::optional<OmpEndAtomic>>
       t;
 };
 
 // ATOMIC WRITE
 struct OmpAtomicWrite {
   TUPLE_CLASS_BOILERPLATE(OmpAtomicWrite);
-  std::tuple<OmpMemoryClauseList, Verbatim, OmpMemoryClausePostList,
-      Statement<AssignmentStmt>, std::optional<OmpEndAtomic>>
+  std::tuple<OmpAtomicMemoryOrderClauseList, Verbatim,
+      OmpAtomicMemoryOrderClausePostList, Statement<AssignmentStmt>,
+      std::optional<OmpEndAtomic>>
       t;
 };
 
 // ATOMIC UPDATE
 struct OmpAtomicUpdate {
   TUPLE_CLASS_BOILERPLATE(OmpAtomicUpdate);
-  std::tuple<OmpMemoryClauseList, Verbatim, OmpMemoryClausePostList,
-      Statement<AssignmentStmt>, std::optional<OmpEndAtomic>>
+  std::tuple<OmpAtomicMemoryOrderClauseList, Verbatim,
+      OmpAtomicMemoryOrderClausePostList, Statement<AssignmentStmt>,
+      std::optional<OmpEndAtomic>>
       t;
 };
 
@@ -3654,16 +3668,16 @@ struct OmpAtomicCapture {
   TUPLE_CLASS_BOILERPLATE(OmpAtomicCapture);
   WRAPPER_CLASS(Stmt1, Statement<AssignmentStmt>);
   WRAPPER_CLASS(Stmt2, Statement<AssignmentStmt>);
-  std::tuple<OmpMemoryClauseList, Verbatim, OmpMemoryClausePostList, Stmt1,
-      Stmt2, OmpEndAtomic>
+  std::tuple<OmpAtomicMemoryOrderClauseList, Verbatim,
+      OmpAtomicMemoryOrderClausePostList, Stmt1, Stmt2, OmpEndAtomic>
       t;
 };
 
 // ATOMIC
 struct OmpAtomic {
   TUPLE_CLASS_BOILERPLATE(OmpAtomic);
-  std::tuple<Verbatim, OmpMemoryClauseList, Statement<AssignmentStmt>,
-      std::optional<OmpEndAtomic>>
+  std::tuple<Verbatim, OmpAtomicMemoryOrderClauseList,
+      Statement<AssignmentStmt>, std::optional<OmpEndAtomic>>
       t;
 };
 
@@ -3707,8 +3721,7 @@ struct OpenMPCancelConstruct {
 //                        release
 //                        acquire
 struct OmpFlushMemoryClause {
-  ENUM_CLASS(FlushMemoryOrder, AcqRel, Release, Acquire)
-  WRAPPER_CLASS_BOILERPLATE(OmpFlushMemoryClause, FlushMemoryOrder);
+  WRAPPER_CLASS_BOILERPLATE(OmpFlushMemoryClause, llvm::omp::Clause);
   CharBlock source;
 };