[flang] Add support for workdistribute construct in flang frontend

skc7 · skc7 · commit cb89a7f7d8ed · 2025-07-16T17:43:38.000+05:30
diff --git a/flang/include/flang/Semantics/openmp-directive-sets.h b/flang/include/flang/Semantics/openmp-directive-sets.h
@@ -143,6 +143,7 @@ static const OmpDirectiveSet topTargetSet{
     Directive::OMPD_target_teams_distribute_parallel_do_simd,
     Directive::OMPD_target_teams_distribute_simd,
     Directive::OMPD_target_teams_loop,
+    Directive::OMPD_target_teams_workdistribute,
 };
 
 static const OmpDirectiveSet allTargetSet{topTargetSet};
@@ -172,6 +173,7 @@ static const OmpDirectiveSet topTeamsSet{
     Directive::OMPD_teams_distribute_parallel_do_simd,
     Directive::OMPD_teams_distribute_simd,
     Directive::OMPD_teams_loop,
+    Directive::OMPD_teams_workdistribute,
 };
 
 static const OmpDirectiveSet bottomTeamsSet{
@@ -187,9 +189,16 @@ static const OmpDirectiveSet allTeamsSet{
         Directive::OMPD_target_teams_distribute_parallel_do_simd,
         Directive::OMPD_target_teams_distribute_simd,
         Directive::OMPD_target_teams_loop,
+        Directive::OMPD_target_teams_workdistribute,
     } | topTeamsSet,
 };
 
+static const OmpDirectiveSet allWorkdistributeSet{
+    Directive::OMPD_workdistribute,
+    Directive::OMPD_teams_workdistribute,
+    Directive::OMPD_target_teams_workdistribute,
+};
+
 //===----------------------------------------------------------------------===//
 // Directive sets for groups of multiple directives
 //===----------------------------------------------------------------------===//
@@ -230,6 +239,9 @@ static const OmpDirectiveSet blockConstructSet{
     Directive::OMPD_taskgroup,
     Directive::OMPD_teams,
     Directive::OMPD_workshare,
+    Directive::OMPD_target_teams_workdistribute,
+    Directive::OMPD_teams_workdistribute,
+    Directive::OMPD_workdistribute,
 };
 
 static const OmpDirectiveSet loopConstructSet{
@@ -294,6 +306,7 @@ static const OmpDirectiveSet workShareSet{
         Directive::OMPD_scope,
         Directive::OMPD_sections,
         Directive::OMPD_single,
+        Directive::OMPD_workdistribute,
     } | allDoSet,
 };
 
@@ -376,6 +389,7 @@ static const OmpDirectiveSet nestedReduceWorkshareAllowedSet{
 };
 
 static const OmpDirectiveSet nestedTeamsAllowedSet{
+    Directive::OMPD_workdistribute,
     Directive::OMPD_distribute,
     Directive::OMPD_distribute_parallel_do,
     Directive::OMPD_distribute_parallel_do_simd,
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -618,6 +618,16 @@ static void processHostEvalClauses(lower::AbstractConverter &converter,
       cp.processCollapse(loc, eval, hostInfo->ops, hostInfo->iv);
       break;
 
+    case OMPD_teams_workdistribute:
+      cp.processThreadLimit(stmtCtx, hostInfo.ops);
+      [[fallthrough]];
+    case OMPD_target_teams_workdistribute:
+      cp.processNumTeams(stmtCtx, hostInfo.ops);
+      processSingleNestedIf([](Directive nestedDir) {
+        return topDistributeSet.test(nestedDir) || topLoopSet.test(nestedDir);
+      });
+      break;
+
     // Standalone 'target' case.
     case OMPD_target: {
       processSingleNestedIf(
@@ -2719,6 +2729,17 @@ genTeamsOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
       queue, item, clauseOps);
 }
 
+static mlir::omp::WorkdistributeOp genWorkdistributeOp(
+    lower::AbstractConverter &converter, lower::SymMap &symTable,
+    semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
+    mlir::Location loc, const ConstructQueue &queue,
+    ConstructQueue::const_iterator item) {
+  return genOpWithBody<mlir::omp::WorkdistributeOp>(
+      OpWithBodyGenInfo(converter, symTable, semaCtx, loc, eval,
+                        llvm::omp::Directive::OMPD_workdistribute),
+      queue, item);
+}
+
 //===----------------------------------------------------------------------===//
 // Code generation functions for the standalone version of constructs that can
 // also be a leaf of a composite construct
@@ -3339,7 +3360,10 @@ static void genOMPDispatch(lower::AbstractConverter &converter,
     TODO(loc, "Unhandled loop directive (" +
                   llvm::omp::getOpenMPDirectiveName(dir, version) + ")");
   }
-  // case llvm::omp::Directive::OMPD_workdistribute:
+  case llvm::omp::Directive::OMPD_workdistribute:
+    newOp = genWorkdistributeOp(converter, symTable, semaCtx, eval, loc, queue,
+                                item);
+    break;
   case llvm::omp::Directive::OMPD_workshare:
     newOp = genWorkshareOp(converter, symTable, stmtCtx, semaCtx, eval, loc,
                            queue, item);
diff --git a/flang/lib/Parser/openmp-parsers.cpp b/flang/lib/Parser/openmp-parsers.cpp
@@ -1567,12 +1567,17 @@ TYPE_PARSER(
         "TARGET DATA" >> pure(llvm::omp::Directive::OMPD_target_data),
         "TARGET_DATA" >> pure(llvm::omp::Directive::OMPD_target_data),
         "TARGET PARALLEL" >> pure(llvm::omp::Directive::OMPD_target_parallel),
+        "TARGET TEAMS WORKDISTRIBUTE" >>
+            pure(llvm::omp::Directive::OMPD_target_teams_workdistribute),
         "TARGET TEAMS" >> pure(llvm::omp::Directive::OMPD_target_teams),
         "TARGET" >> pure(llvm::omp::Directive::OMPD_target),
         "TASK"_id >> pure(llvm::omp::Directive::OMPD_task),
         "TASKGROUP" >> pure(llvm::omp::Directive::OMPD_taskgroup),
+        "TEAMS WORKDISTRIBUTE" >>
+            pure(llvm::omp::Directive::OMPD_teams_workdistribute),
         "TEAMS" >> pure(llvm::omp::Directive::OMPD_teams),
-        "WORKSHARE" >> pure(llvm::omp::Directive::OMPD_workshare))))
+        "WORKSHARE" >> pure(llvm::omp::Directive::OMPD_workshare),
+        "WORKDISTRIBUTE" >> pure(llvm::omp::Directive::OMPD_workdistribute))))
 
 TYPE_PARSER(sourced(construct<OmpBeginBlockDirective>(
     sourced(Parser<OmpBlockDirective>{}), Parser<OmpClauseList>{})))
diff --git a/flang/lib/Semantics/resolve-directives.cpp b/flang/lib/Semantics/resolve-directives.cpp
@@ -1680,10 +1680,13 @@ bool OmpAttributeVisitor::Pre(const parser::OpenMPBlockConstruct &x) {
   case llvm::omp::Directive::OMPD_task:
   case llvm::omp::Directive::OMPD_taskgroup:
   case llvm::omp::Directive::OMPD_teams:
+  case llvm::omp::Directive::OMPD_workdistribute:
   case llvm::omp::Directive::OMPD_workshare:
   case llvm::omp::Directive::OMPD_parallel_workshare:
   case llvm::omp::Directive::OMPD_target_teams:
+  case llvm::omp::Directive::OMPD_target_teams_workdistribute:
   case llvm::omp::Directive::OMPD_target_parallel:
+  case llvm::omp::Directive::OMPD_teams_workdistribute:
     PushContext(beginDir.source, beginDir.v);
     break;
   default:
@@ -1713,9 +1716,12 @@ void OmpAttributeVisitor::Post(const parser::OpenMPBlockConstruct &x) {
   case llvm::omp::Directive::OMPD_target:
   case llvm::omp::Directive::OMPD_task:
   case llvm::omp::Directive::OMPD_teams:
+  case llvm::omp::Directive::OMPD_workdistribute:
   case llvm::omp::Directive::OMPD_parallel_workshare:
   case llvm::omp::Directive::OMPD_target_teams:
-  case llvm::omp::Directive::OMPD_target_parallel: {
+  case llvm::omp::Directive::OMPD_target_parallel:
+  case llvm::omp::Directive::OMPD_target_teams_workdistribute:
+  case llvm::omp::Directive::OMPD_teams_workdistribute: {
     bool hasPrivate;
     for (const auto *allocName : allocateNames_) {
       hasPrivate = false;
diff --git a/flang/test/Lower/OpenMP/workdistribute.f90 b/flang/test/Lower/OpenMP/workdistribute.f90
@@ -0,0 +1,59 @@
+! RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
+
+! CHECK-LABEL: func @_QPtarget_teams_workdistribute
+subroutine target_teams_workdistribute()
+  ! CHECK: omp.target
+  ! CHECK: omp.teams
+  ! CHECK: omp.workdistribute
+  !$omp target teams workdistribute
+  ! CHECK: fir.call
+  call f1()
+  ! CHECK: omp.terminator
+  ! CHECK: omp.terminator
+  ! CHECK: omp.terminator
+  !$omp end target teams workdistribute
+end subroutine target_teams_workdistribute
+
+! CHECK-LABEL: func @_QPteams_workdistribute
+subroutine teams_workdistribute()
+  ! CHECK: omp.teams
+  ! CHECK: omp.workdistribute
+  !$omp teams workdistribute
+  ! CHECK: fir.call
+  call f1()
+  ! CHECK: omp.terminator
+  ! CHECK: omp.terminator
+  !$omp end teams workdistribute
+end subroutine teams_workdistribute
+
+! CHECK-LABEL: func @_QPtarget_teams_workdistribute_m
+subroutine target_teams_workdistribute_m()
+  ! CHECK: omp.target
+  ! CHECK: omp.teams
+  ! CHECK: omp.workdistribute
+  !$omp target
+  !$omp teams
+  !$omp workdistribute
+  ! CHECK: fir.call
+  call f1()
+  ! CHECK: omp.terminator
+  ! CHECK: omp.terminator
+  ! CHECK: omp.terminator
+  !$omp end workdistribute
+  !$omp end teams
+  !$omp end target
+end subroutine target_teams_workdistribute_m
+
+! CHECK-LABEL: func @_QPteams_workdistribute_m
+subroutine teams_workdistribute_m()
+  ! CHECK: omp.teams
+  ! CHECK: omp.workdistribute
+  !$omp teams
+  !$omp workdistribute
+  ! CHECK: fir.call
+  call f1()
+  ! CHECK: omp.terminator
+  ! CHECK: omp.terminator
+  !$omp end workdistribute
+  !$omp end teams
+end subroutine teams_workdistribute_m
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMP.td b/llvm/include/llvm/Frontend/OpenMP/OMP.td
@@ -1309,6 +1309,15 @@ def OMP_EndWorkshare : Directive<[Spelling<"end workshare">]> {
   let category = OMP_Workshare.category;
   let languages = [L_Fortran];
 }
+def OMP_Workdistribute : Directive<[Spelling<"workdistribute">]> {
+  let association = AS_Block;
+  let category = CA_Executable;
+}
+def OMP_EndWorkdistribute : Directive<[Spelling<"end workdistribute">]> {
+  let leafConstructs = OMP_Workdistribute.leafConstructs;
+  let association = OMP_Workdistribute.association;
+  let category = OMP_Workdistribute.category;
+}
 
 //===----------------------------------------------------------------------===//
 // Definitions of OpenMP compound directives
@@ -2452,6 +2461,34 @@ def OMP_TargetTeamsDistributeSimd
   let leafConstructs = [OMP_Target, OMP_Teams, OMP_Distribute, OMP_Simd];
   let category = CA_Executable;
 }
+def OMP_TargetTeamsWorkdistribute : Directive<[Spelling<"target teams workdistribute">]> {
+  let allowedClauses = [
+    VersionedClause<OMPC_Allocate>,
+    VersionedClause<OMPC_Depend>,
+    VersionedClause<OMPC_FirstPrivate>,
+    VersionedClause<OMPC_HasDeviceAddr, 51>,
+    VersionedClause<OMPC_If>,
+    VersionedClause<OMPC_IsDevicePtr>,
+    VersionedClause<OMPC_Map>,
+    VersionedClause<OMPC_OMPX_Attribute>,
+    VersionedClause<OMPC_Private>,
+    VersionedClause<OMPC_Reduction>,
+    VersionedClause<OMPC_Shared>,
+    VersionedClause<OMPC_UsesAllocators, 50>,
+  ];
+  let allowedOnceClauses = [
+    VersionedClause<OMPC_Default>,
+    VersionedClause<OMPC_DefaultMap>,
+    VersionedClause<OMPC_Device>,
+    VersionedClause<OMPC_NoWait>,
+    VersionedClause<OMPC_NumTeams>,
+    VersionedClause<OMPC_OMPX_DynCGroupMem>,
+    VersionedClause<OMPC_OMPX_Bare>,
+    VersionedClause<OMPC_ThreadLimit>,
+  ];
+  let leafConstructs = [OMP_Target, OMP_Teams, OMP_Workdistribute];
+  let category = CA_Executable;
+}
 def OMP_target_teams_loop : Directive<[Spelling<"target teams loop">]> {
   let allowedClauses = [
     VersionedClause<OMPC_Allocate>,
@@ -2682,6 +2719,24 @@ def OMP_TeamsDistributeSimd : Directive<[Spelling<"teams distribute simd">]> {
   let leafConstructs = [OMP_Teams, OMP_Distribute, OMP_Simd];
   let category = CA_Executable;
 }
+def OMP_TeamsWorkdistribute : Directive<[Spelling<"teams workdistribute">]> {
+  let allowedClauses = [
+    VersionedClause<OMPC_Allocate>,
+    VersionedClause<OMPC_FirstPrivate>,
+    VersionedClause<OMPC_OMPX_Attribute>,
+    VersionedClause<OMPC_Private>,
+    VersionedClause<OMPC_Reduction>,
+    VersionedClause<OMPC_Shared>,
+  ];
+  let allowedOnceClauses = [
+    VersionedClause<OMPC_Default>,
+    VersionedClause<OMPC_If, 52>,
+    VersionedClause<OMPC_NumTeams>,
+    VersionedClause<OMPC_ThreadLimit>,
+  ];
+  let leafConstructs = [OMP_Teams, OMP_Workdistribute];
+  let category = CA_Executable;
+}
 def OMP_teams_loop : Directive<[Spelling<"teams loop">]> {
   let allowedClauses = [
     VersionedClause<OMPC_Allocate>,
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -2113,4 +2113,26 @@ def AllocateDirOp : OpenMP_Op<"allocate_dir", clauses = [
   let hasVerifier = 1;
 }
 
+//===----------------------------------------------------------------------===//
+// workdistribute Construct
+//===----------------------------------------------------------------------===//
+
+def WorkdistributeOp : OpenMP_Op<"workdistribute"> {
+  let summary = "workdistribute directive";
+  let description = [{
+    workdistribute divides execution of the enclosed structured block into
+    separate units of work, each executed only once by each
+    initial thread in the league.
+    ```
+    !$omp target teams
+        !$omp workdistribute
+        y = a * x + y 
+        !$omp end workdistribute
+    !$omp end target teams
+    ```
+  }];
+  let regions = (region AnyRegion:$region);
+  let assemblyFormat = "$region attr-dict";
+}
+
 #endif // OPENMP_OPS
