https://github.com/skc7 updated https://github.com/llvm/llvm-project/pull/175792
>From d13ee30093a64a6da59e35172b9b58b30516cfcd Mon Sep 17 00:00:00 2001 From: skc7 <[email protected]> Date: Fri, 28 Nov 2025 13:37:14 +0530 Subject: [PATCH] [Flang] Add lowering from flang to mlir for num_threads --- flang/lib/Lower/OpenMP/ClauseProcessor.cpp | 8 ++- flang/lib/Lower/OpenMP/Clauses.cpp | 13 ++++- flang/test/Lower/OpenMP/num-threads-dims.f90 | 61 ++++++++++++++++++++ llvm/include/llvm/Frontend/OpenMP/ClauseT.h | 4 +- 4 files changed, 79 insertions(+), 7 deletions(-) create mode 100644 flang/test/Lower/OpenMP/num-threads-dims.f90 diff --git a/flang/lib/Lower/OpenMP/ClauseProcessor.cpp b/flang/lib/Lower/OpenMP/ClauseProcessor.cpp index 159fe371c7ef3..5d2ebe6e1572a 100644 --- a/flang/lib/Lower/OpenMP/ClauseProcessor.cpp +++ b/flang/lib/Lower/OpenMP/ClauseProcessor.cpp @@ -515,9 +515,11 @@ bool ClauseProcessor::processNumThreads( lower::StatementContext &stmtCtx, mlir::omp::NumThreadsClauseOps &result) const { if (auto *clause = findUniqueClause<omp::clause::NumThreads>()) { - // OMPIRBuilder expects `NUM_THREADS` clause as a `Value`. - result.numThreadsVars.push_back( - fir::getBase(converter.genExprValue(clause->v, stmtCtx))); + // OMPIRBuilder expects `NUM_THREADS` clause as a list of Values. + for (const auto &expr : clause->v) { + result.numThreadsVars.push_back( + fir::getBase(converter.genExprValue(expr, stmtCtx))); + } return true; } return false; diff --git a/flang/lib/Lower/OpenMP/Clauses.cpp b/flang/lib/Lower/OpenMP/Clauses.cpp index c739249bff211..cf03d4af788a5 100644 --- a/flang/lib/Lower/OpenMP/Clauses.cpp +++ b/flang/lib/Lower/OpenMP/Clauses.cpp @@ -1290,9 +1290,16 @@ NumTeams make(const parser::OmpClause::NumTeams &inp, NumThreads make(const parser::OmpClause::NumThreads &inp, semantics::SemanticsContext &semaCtx) { // inp.v -> parser::OmpNumThreadsClause - auto &t1 = std::get<std::list<parser::ScalarIntExpr>>(inp.v.t); - assert(!t1.empty()); - return NumThreads{/*Nthreads=*/makeExpr(t1.front(), semaCtx)}; + // With dims modifier (OpenMP 6.1): multiple values for multi-dimensional grid + // Without dims modifier: single value + auto &values = std::get<std::list<parser::ScalarIntExpr>>(inp.v.t); + assert(!values.empty()); + + List<NumThreads::Nthreads> v; + for (const auto &val : values) { + v.push_back(makeExpr(val, semaCtx)); + } + return NumThreads{/*Nthreads=*/v}; } // OmpxAttribute: empty diff --git a/flang/test/Lower/OpenMP/num-threads-dims.f90 b/flang/test/Lower/OpenMP/num-threads-dims.f90 new file mode 100644 index 0000000000000..f3a8d706b7283 --- /dev/null +++ b/flang/test/Lower/OpenMP/num-threads-dims.f90 @@ -0,0 +1,61 @@ +! RUN: %flang_fc1 -emit-hlfir %openmp_flags -fopenmp-version=61 %s -o - | FileCheck %s + +!=============================================================================== +! `num_threads` clause with dims modifier (OpenMP 6.1) +!=============================================================================== + +! CHECK-LABEL: func @_QPparallel_numthreads_dims4 +subroutine parallel_numthreads_dims4() + ! CHECK: omp.parallel + ! CHECK-SAME: num_threads(%{{.*}}, %{{.*}}, %{{.*}}, %{{.*}} : i32, i32, i32, i32) + !$omp parallel num_threads(dims(4): 4, 5, 6, 7) + call f1() + ! CHECK: omp.terminator + !$omp end parallel +end subroutine parallel_numthreads_dims4 + +! CHECK-LABEL: func @_QPparallel_numthreads_dims2 +subroutine parallel_numthreads_dims2() + ! CHECK: omp.parallel + ! CHECK-SAME: num_threads(%{{.*}}, %{{.*}} : i32, i32) + !$omp parallel num_threads(dims(2): 8, 4) + call f1() + ! CHECK: omp.terminator + !$omp end parallel +end subroutine parallel_numthreads_dims2 + +! CHECK-LABEL: func @_QPparallel_numthreads_dims_var +subroutine parallel_numthreads_dims_var(a, b, c) + integer, intent(in) :: a, b, c + ! CHECK: omp.parallel + ! CHECK-SAME: num_threads(%{{.*}}, %{{.*}}, %{{.*}} : i32, i32, i32) + !$omp parallel num_threads(dims(3): a, b, c) + call f1() + ! CHECK: omp.terminator + !$omp end parallel +end subroutine parallel_numthreads_dims_var + +!=============================================================================== +! `num_threads` clause without dims modifier (legacy) +!=============================================================================== + +! CHECK-LABEL: func @_QPparallel_numthreads_legacy +subroutine parallel_numthreads_legacy(n) + integer, intent(in) :: n + ! CHECK: omp.parallel + ! CHECK-SAME: num_threads(%{{.*}} : i32) + !$omp parallel num_threads(n) + call f1() + ! CHECK: omp.terminator + !$omp end parallel +end subroutine parallel_numthreads_legacy + +! CHECK-LABEL: func @_QPparallel_numthreads_const +subroutine parallel_numthreads_const() + ! CHECK: omp.parallel + ! CHECK-SAME: num_threads(%{{.*}} : i32) + !$omp parallel num_threads(16) + call f1() + ! CHECK: omp.terminator + !$omp end parallel +end subroutine parallel_numthreads_const diff --git a/llvm/include/llvm/Frontend/OpenMP/ClauseT.h b/llvm/include/llvm/Frontend/OpenMP/ClauseT.h index 05ee1ae36a23d..e9f972b5b313e 100644 --- a/llvm/include/llvm/Frontend/OpenMP/ClauseT.h +++ b/llvm/include/llvm/Frontend/OpenMP/ClauseT.h @@ -1011,11 +1011,13 @@ struct NumTeamsT { }; // V5.2: [10.1.2] `num_threads` clause +// V6.1: Extended with dims modifier support template <typename T, typename I, typename E> // struct NumThreadsT { using Nthreads = E; + // Changed to list to support dims modifier with multiple values (OpenMP 6.1) using WrapperTrait = std::true_type; - Nthreads v; + ListT<Nthreads> v; }; template <typename T, typename I, typename E> // _______________________________________________ llvm-branch-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
