[Flang][OpenMP] Add Lowering support for lastprivate in taskloops #166584
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@llvm/pr-subscribers-flang-fir-hlfir @llvm/pr-subscribers-flang-openmp Author: Jack Styles (Stylie777) Changeslastprivate support already exists within the DataSharingProcessor, Full diff: https://github.com/llvm/llvm-project/pull/166584.diff 6 Files Affected:
diff --git a/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp b/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
index 146a252b049ec..83c2eda0a2dc7 100644
--- a/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
+++ b/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
@@ -342,7 +342,8 @@ void DataSharingProcessor::insertLastPrivateCompare(mlir::Operation *op) {
if (!hasLastPrivate)
return;
- if (mlir::isa<mlir::omp::WsloopOp>(op) || mlir::isa<mlir::omp::SimdOp>(op)) {
+ if (mlir::isa<mlir::omp::WsloopOp>(op) || mlir::isa<mlir::omp::SimdOp>(op) ||
+ mlir::isa<mlir::omp::TaskloopOp>(op)) {
mlir::omp::LoopRelatedClauseOps result;
llvm::SmallVector<const semantics::Symbol *> iv;
collectLoopRelatedInfo(converter, converter.getCurrentLocation(), eval,
@@ -408,7 +409,7 @@ void DataSharingProcessor::insertLastPrivateCompare(mlir::Operation *op) {
} else {
TODO(converter.getCurrentLocation(),
"lastprivate clause in constructs other than "
- "simd/worksharing-loop");
+ "simd/worksharing-loop/taskloop");
}
}
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index ad456d89bc432..8c56480390e58 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -1763,21 +1763,22 @@ static void genTaskgroupClauses(
cp.processTaskReduction(loc, clauseOps, taskReductionSyms);
}
-static void genTaskloopClauses(lower::AbstractConverter &converter,
- semantics::SemanticsContext &semaCtx,
- lower::StatementContext &stmtCtx,
- const List<Clause> &clauses, mlir::Location loc,
- mlir::omp::TaskloopOperands &clauseOps) {
+static void genTaskloopClauses(
+ lower::AbstractConverter &converter, semantics::SemanticsContext &semaCtx,
+ lower::StatementContext &stmtCtx, const List<Clause> &clauses,
+ mlir::Location loc, mlir::omp::TaskloopOperands &clauseOps,
+ llvm::SmallVectorImpl<const semantics::Symbol *> &taskReductionSyms) {
ClauseProcessor cp(converter, semaCtx, clauses);
cp.processGrainsize(stmtCtx, clauseOps);
cp.processNumTasks(stmtCtx, clauseOps);
+ cp.processReduction(loc, clauseOps, taskReductionSyms);
cp.processTODO<clause::Allocate, clause::Collapse, clause::Default,
clause::Final, clause::If, clause::InReduction,
- clause::Lastprivate, clause::Mergeable, clause::Nogroup,
- clause::Priority, clause::Reduction, clause::Shared,
- clause::Untied>(loc, llvm::omp::Directive::OMPD_taskloop);
+ clause::Mergeable, clause::Nogroup, clause::Priority,
+ clause::Shared, clause::Untied>(
+ loc, llvm::omp::Directive::OMPD_taskloop);
}
static void genTaskwaitClauses(lower::AbstractConverter &converter,
@@ -2979,8 +2980,9 @@ static mlir::omp::TaskloopOp genStandaloneTaskloop(
lower::pft::Evaluation &eval, mlir::Location loc,
const ConstructQueue &queue, ConstructQueue::const_iterator item) {
mlir::omp::TaskloopOperands taskloopClauseOps;
+ llvm::SmallVector<const semantics::Symbol *> taskReductionSyms;
genTaskloopClauses(converter, semaCtx, stmtCtx, item->clauses, loc,
- taskloopClauseOps);
+ taskloopClauseOps, taskReductionSyms);
DataSharingProcessor dsp(converter, semaCtx, item->clauses, eval,
/*shouldCollectPreDeterminedSymbols=*/true,
enableDelayedPrivatization, symTable);
@@ -2994,6 +2996,8 @@ static mlir::omp::TaskloopOp genStandaloneTaskloop(
EntryBlockArgs taskloopArgs;
taskloopArgs.priv.syms = dsp.getDelayedPrivSymbols();
taskloopArgs.priv.vars = taskloopClauseOps.privateVars;
+ taskloopArgs.reduction.syms = taskReductionSyms;
+ taskloopArgs.reduction.vars = taskloopClauseOps.reductionVars;
auto taskLoopOp = genWrapperOp<mlir::omp::TaskloopOp>(
converter, loc, taskloopClauseOps, taskloopArgs);
diff --git a/flang/test/Lower/OpenMP/Todo/taskloop-reduction.f90 b/flang/test/Lower/OpenMP/Todo/taskloop-reduction.f90
deleted file mode 100644
index 0c16bd227257f..0000000000000
--- a/flang/test/Lower/OpenMP/Todo/taskloop-reduction.f90
+++ /dev/null
@@ -1,13 +0,0 @@
-! RUN: %not_todo_cmd bbc -emit-fir -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
-! RUN: %not_todo_cmd %flang_fc1 -emit-fir -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
-
-! CHECK: not yet implemented: Unhandled clause REDUCTION in TASKLOOP construct
-subroutine omp_taskloop_reduction()
- integer x
- x = 0
- !$omp taskloop reduction(+:x)
- do i = 1, 100
- x = x + 1
- end do
- !$omp end taskloop
-end subroutine omp_taskloop_reduction
diff --git a/flang/test/Lower/OpenMP/taskloop-lastprivate.f90 b/flang/test/Lower/OpenMP/taskloop-lastprivate.f90
new file mode 100644
index 0000000000000..a3562a971bb59
--- /dev/null
+++ b/flang/test/Lower/OpenMP/taskloop-lastprivate.f90
@@ -0,0 +1,25 @@
+! Test the lastprivate clause when used with the taskloop construct
+! RUN: bbc -emit-hlfir -fopenmp -fopenmp-version=45 %s -o - 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=45 %s -o - 2>&1 | FileCheck %s
+
+! CHECK-LABEL: omp.private
+! CHECK-SAME: {type = private} @[[I_PRIVATE:.*]] : i32
+! CHECK-LABEL: omp.private
+! CHECK-SAME: {type = private} @[[LAST_I_PRIVATE:.*]] : i32
+
+! CHECK: %[[ALLOCA_I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFlastprivateEi"}
+! CHECK: %[[DECLARE_I:.*]]:2 = hlfir.declare %[[ALLOCA_I]] {uniq_name = "_QFlastprivateEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+! CHECK: %[[ALLOCA_LAST_I:.*]] = fir.alloca i32 {bindc_name = "last_i", uniq_name = "_QFlastprivateElast_i"}
+! CHECK: %[[DECLARE_LAST_I:.*]]:2 = hlfir.declare %[[ALLOCA_LAST_I]] {uniq_name = "_QFlastprivateElast_i"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+
+subroutine lastprivate()
+ integer :: i, last_i
+
+ ! CHECK: omp.taskloop
+ ! CHECK-SAME: private(@[[LAST_I_PRIVATE]] %[[DECLARE_LAST_I]]#0 -> %arg0, @[[I_PRIVATE]] %[[DECLARE_I]]#0 -> %arg1 : !fir.ref<i32>, !fir.ref<i32>) {
+ !$omp taskloop lastprivate(last_i)
+ do i=1,10
+ last_i = i
+ end do
+ !$omp end taskloop
+end
\ No newline at end of file
diff --git a/flang/test/Lower/OpenMP/taskloop-reduction.f90 b/flang/test/Lower/OpenMP/taskloop-reduction.f90
new file mode 100644
index 0000000000000..4185a927366e7
--- /dev/null
+++ b/flang/test/Lower/OpenMP/taskloop-reduction.f90
@@ -0,0 +1,30 @@
+! This test checks the lowering of the reduction clause in the taskloop construct
+! RUN: bbc -emit-hlfir -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
+! RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=50 -o - %s 2>&1 | FileCheck %s
+! RUN %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=45 -o - %s 2>&1 | FileCheck %s --check-prefix=CHECK-VERSION
+
+! CHECK-VERSION: error: REDUCTION clause is not allowed on directive TASKLOOP in OpenMP v4.5, try -fopenmp-version=50
+
+! CHECK-LABEL: omp.private
+! CHECK-SAME: {type = private} @[[I_PRIVATE:.*]] : i32
+
+! CHECK-LABEL: func.func @_QPtest_reduction()
+! CHECK: %[[ALLOCA_A:.*]] = fir.alloca !fir.array<10xi32> {bindc_name = "a", uniq_name = "_QFtest_reductionEa"}
+! CHECK: %[[DECLARE_A:.*]]:2 = hlfir.declare %[[ALLOCA_A]](%2) {uniq_name = "_QFtest_reductionEa"} : (!fir.ref<!fir.array<10xi32>>, !fir.shape<1>) -> (!fir.ref<!fir.array<10xi32>>, !fir.ref<!fir.array<10xi32>>)
+! CHECK: %[[ALLOCA_I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFtest_reductionEi"}
+! CHECK: %[[DECLARE_I:.*]]:2 = hlfir.declare %[[ALLOCA_I]] {uniq_name = "_QFtest_reductionEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+! CHECK: %[[ALLOCA_SUM_I:.*]] = fir.alloca i32 {bindc_name = "sum_i", uniq_name = "_QFtest_reductionEsum_i"}
+! CHECK: %[[DECLARE_SUM_I:.*]]:2 = hlfir.declare %[[ALLOCA_SUM_I]] {uniq_name = "_QFtest_reductionEsum_i"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
+
+subroutine test_reduction
+ integer :: i, a(10), sum_i
+
+ ! CHECK: omp.taskloop
+ ! CHECK-SAME: private(@[[I_PRIVATE]] %[[DECLARE_I]]#0 -> %arg0 : !fir.ref<i32>) reduction(@add_reduction_i32 %[[DECLARE_SUM_I]]#0 -> %arg1 : !fir.ref<i32>) {
+ !$omp taskloop reduction (+:sum_i)
+ do i = 1,10
+ sum_i = sum_i + i
+ end do
+ !$omp end taskloop
+
+end subroutine
\ No newline at end of file
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMP.td b/llvm/include/llvm/Frontend/OpenMP/OMP.td
index 208609f64f418..0afae8a013bd6 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMP.td
+++ b/llvm/include/llvm/Frontend/OpenMP/OMP.td
@@ -1284,17 +1284,16 @@ def OMP_TaskGroup : Directive<[Spelling<"taskgroup">]> {
let category = CA_Executable;
}
def OMP_TaskLoop : Directive<[Spelling<"taskloop">]> {
- let allowedClauses = [
- VersionedClause<OMPC_Allocate>,
- VersionedClause<OMPC_FirstPrivate>,
- VersionedClause<OMPC_InReduction>,
- VersionedClause<OMPC_LastPrivate>,
- VersionedClause<OMPC_Mergeable>,
- VersionedClause<OMPC_NoGroup>,
- VersionedClause<OMPC_Private>,
- VersionedClause<OMPC_Reduction>,
- VersionedClause<OMPC_Shared>,
- VersionedClause<OMPC_Untied>,
+ let allowedClauses = [VersionedClause<OMPC_Allocate>,
+ VersionedClause<OMPC_FirstPrivate>,
+ VersionedClause<OMPC_InReduction>,
+ VersionedClause<OMPC_LastPrivate>,
+ VersionedClause<OMPC_Mergeable>,
+ VersionedClause<OMPC_NoGroup>,
+ VersionedClause<OMPC_Private>,
+ VersionedClause<OMPC_Reduction, 50>,
+ VersionedClause<OMPC_Shared>,
+ VersionedClause<OMPC_Untied>,
];
let allowedOnceClauses = [
VersionedClause<OMPC_Collapse>,
|
lastprivate support already exists within the DataSharingProcessor, so this can be extended to include the use of taskloops to enable AST->FIR lowering. The related error message has also been updated to indicate that taskloops are now supported.
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kparzysz
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Nov 7, 2025
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Abandoning in favour of #166751 |
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lastprivate support already exists within the DataSharingProcessor,
so this can be extended to include the use of taskloops to enable
AST->FIR lowering. The related error message has also been updated
to indicate that taskloops are now supported.