[flang-commits] [flang] [flang][mlir] Add flang to mlir lowering for groupprivate (PR #180934)
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Wed Feb 11 05:00:18 PST 2026
https://github.com/skc7 created https://github.com/llvm/llvm-project/pull/180934
None
>From f2441cb25f2cf3f6cae82f3202c0eeb0bbfdfab5 Mon Sep 17 00:00:00 2001
From: skc7 <Krishna.Sankisa at amd.com>
Date: Wed, 11 Feb 2026 18:24:52 +0530
Subject: [PATCH] [flang][mlir] Add flang to mlir lowering for groupprivate
---
flang/include/flang/Lower/OpenMP.h | 1 +
flang/lib/Lower/OpenMP/OpenMP.cpp | 136 +++++++++++++++++-
flang/test/Lower/OpenMP/Todo/groupprivate.f90 | 9 --
flang/test/Lower/OpenMP/groupprivate.f90 | 57 ++++++++
4 files changed, 193 insertions(+), 10 deletions(-)
delete mode 100644 flang/test/Lower/OpenMP/Todo/groupprivate.f90
create mode 100644 flang/test/Lower/OpenMP/groupprivate.f90
diff --git a/flang/include/flang/Lower/OpenMP.h b/flang/include/flang/Lower/OpenMP.h
index 0080b306d4867..9b4dac2feef2c 100644
--- a/flang/include/flang/Lower/OpenMP.h
+++ b/flang/include/flang/Lower/OpenMP.h
@@ -82,6 +82,7 @@ void genOpenMPSymbolProperties(AbstractConverter &converter,
const pft::Variable &var);
void genThreadprivateOp(AbstractConverter &, const pft::Variable &);
+void genGroupprivateOp(AbstractConverter &, const pft::Variable &);
void genDeclareTargetIntGlobal(AbstractConverter &, const pft::Variable &);
bool isOpenMPTargetConstruct(const parser::OpenMPConstruct &);
bool isOpenMPDeviceDeclareTarget(Fortran::lower::AbstractConverter &,
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index 3eeaab48d1447..a6a6a6e21cdbf 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -692,6 +692,91 @@ static void threadPrivatizeVars(lower::AbstractConverter &converter,
}
}
+static void groupprivatizeVars(lower::AbstractConverter &converter,
+ lower::pft::Evaluation &eval) {
+ fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+ mlir::Location currentLocation = converter.getCurrentLocation();
+ mlir::OpBuilder::InsertionGuard guard(firOpBuilder);
+ firOpBuilder.setInsertionPointToStart(firOpBuilder.getAllocaBlock());
+
+ auto module = converter.getModuleOp();
+
+ // Create a groupprivate operation for the symbol.
+ // TODO: Extract device_type from the groupprivate directive.
+ auto genGroupprivateOp = [&](const semantics::Symbol &sym) -> mlir::Value {
+ std::string globalName = converter.mangleName(sym);
+ fir::GlobalOp global = module.lookupSymbol<fir::GlobalOp>(globalName);
+ if (!global) {
+ return mlir::Value();
+ }
+
+ // Generate fir.address_of to get the global address
+ mlir::Value symAddr = fir::AddrOfOp::create(
+ firOpBuilder, currentLocation, global.resultType(), global.getSymbol());
+
+ mlir::omp::DeclareTargetDeviceType deviceTypeEnum =
+ mlir::omp::DeclareTargetDeviceType::any;
+ mlir::omp::DeclareTargetDeviceTypeAttr deviceTypeAttr =
+ mlir::omp::DeclareTargetDeviceTypeAttr::get(firOpBuilder.getContext(),
+ deviceTypeEnum);
+
+ return mlir::omp::GroupprivateOp::create(firOpBuilder, currentLocation,
+ symAddr.getType(), symAddr,
+ deviceTypeAttr);
+ };
+
+ llvm::SetVector<const semantics::Symbol *> groupprivateSyms;
+ converter.collectSymbolSet(eval, groupprivateSyms,
+ semantics::Symbol::Flag::OmpGroupPrivate,
+ /*collectSymbols=*/true,
+ /*collectHostAssociatedSymbols=*/true);
+ std::set<semantics::SourceName> groupprivateSymNames;
+
+ // For a COMMON block, the GroupprivateOp is generated for the block itself
+ // instead of its members.
+ llvm::SetVector<const semantics::Symbol *> commonSyms;
+
+ for (std::size_t i = 0; i < groupprivateSyms.size(); i++) {
+ const semantics::Symbol *sym = groupprivateSyms[i];
+ mlir::Value symGroupprivateValue;
+ // The variable may be used more than once, and each reference has one
+ // symbol with the same name. Only do once for references of one variable.
+ if (groupprivateSymNames.find(sym->name()) != groupprivateSymNames.end())
+ continue;
+ groupprivateSymNames.insert(sym->name());
+
+ if (const semantics::Symbol *common =
+ semantics::FindCommonBlockContaining(sym->GetUltimate())) {
+ // Handle common block members: create groupprivate op for the entire
+ // common block, then compute member offset.
+ mlir::Value commonGroupprivateValue;
+ if (commonSyms.contains(common)) {
+ commonGroupprivateValue = converter.getSymbolAddress(*common);
+ } else {
+ commonGroupprivateValue = genGroupprivateOp(*common);
+ if (!commonGroupprivateValue)
+ continue;
+ converter.bindSymbol(*common, commonGroupprivateValue);
+ commonSyms.insert(common);
+ }
+ symGroupprivateValue = lower::genCommonBlockMember(
+ converter, currentLocation, sym->GetUltimate(),
+ commonGroupprivateValue, common->size());
+ } else {
+ symGroupprivateValue = genGroupprivateOp(*sym);
+ }
+
+ if (!symGroupprivateValue) {
+ continue;
+ }
+
+ fir::ExtendedValue sexv = converter.getSymbolExtendedValue(*sym);
+ fir::ExtendedValue symGroupprivateExv =
+ getExtendedValue(sexv, symGroupprivateValue);
+ converter.bindSymbol(*sym, symGroupprivateExv);
+ }
+}
+
static mlir::Operation *setLoopVar(lower::AbstractConverter &converter,
mlir::Location loc, mlir::Value indexVal,
const semantics::Symbol *sym) {
@@ -1230,6 +1315,10 @@ static void createBodyOfOp(mlir::Operation &op, const OpWithBodyGenInfo &info,
}
}
+ if (info.dir == llvm::omp::Directive::OMPD_teams) {
+ groupprivatizeVars(info.converter, info.eval);
+ }
+
if (!info.genSkeletonOnly) {
if (ConstructQueue::const_iterator next = std::next(item);
next != queue.end()) {
@@ -2737,6 +2826,11 @@ genTargetOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
!symbolsWithDynamicSubstring.contains(&sym.GetUltimate()))
return;
+ // Skip groupprivate symbols - they don't need to be mapped because
+ // groupprivate creates its own LDS storage.
+ if (sym.GetUltimate().test(semantics::Symbol::Flag::OmpGroupPrivate))
+ return;
+
if (!isDuplicateMappedSymbol(sym, dsp.getAllSymbolsToPrivatize(),
hasDeviceAddrSyms, mapSyms, isDevicePtrSyms)) {
if (const auto *details =
@@ -4018,7 +4112,8 @@ static void genOMP(lower::AbstractConverter &converter, lower::SymMap &symTable,
semantics::SemanticsContext &semaCtx,
lower::pft::Evaluation &eval,
const parser::OpenMPGroupprivate &directive) {
- TODO(converter.getCurrentLocation(), "GROUPPRIVATE");
+ // The groupprivate directive is lowered when the variable is referenced
+ // inside target/teams regions.
}
static void genOMP(lower::AbstractConverter &converter, lower::SymMap &symTable,
@@ -4422,6 +4517,9 @@ void Fortran::lower::genOpenMPSymbolProperties(
if (sym.test(semantics::Symbol::Flag::OmpDeclareTarget))
lower::genDeclareTargetIntGlobal(converter, var);
+
+ if (sym.test(semantics::Symbol::Flag::OmpGroupPrivate))
+ lower::genGroupprivateOp(converter, var);
}
void Fortran::lower::genThreadprivateOp(lower::AbstractConverter &converter,
@@ -4490,6 +4588,42 @@ void Fortran::lower::genThreadprivateOp(lower::AbstractConverter &converter,
converter.bindSymbol(sym, symThreadprivateExv);
}
+void Fortran::lower::genGroupprivateOp(lower::AbstractConverter &converter,
+ const lower::pft::Variable &var) {
+ fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+ mlir::Location currentLocation = converter.getCurrentLocation();
+
+ const semantics::Symbol &sym = var.getSymbol();
+
+ // For common block members, the groupprivate op is generated for the entire
+ // common block in groupprivatizeVars, not for individual members here.
+ // The common block already has a global, so nothing to do here.
+ if (semantics::FindCommonBlockContaining(sym.GetUltimate())) {
+ return;
+ }
+
+ fir::GlobalOp global;
+ auto module = converter.getModuleOp();
+ std::string globalName = converter.mangleName(sym);
+
+ // Handle non-global variables - create a GlobalOp for them.
+ // Local variables with SAVE attribute can be groupprivate.
+ // Promote them to fir.global so that omp.groupprivate
+ // can reference them via fir.address_of.
+ if (!var.isGlobal()) {
+ if (module.lookupSymbol<fir::GlobalOp>(globalName))
+ global = module.lookupSymbol<fir::GlobalOp>(globalName);
+ else
+ global = globalInitialization(converter, firOpBuilder, sym, var,
+ currentLocation);
+ } else {
+ global = module.lookupSymbol<fir::GlobalOp>(globalName);
+ }
+
+ // The actual omp.groupprivate operation is created by groupprivatizeVars
+ // when entering a teams region.
+}
+
// This function replicates threadprivate's behaviour of generating
// an internal fir.GlobalOp for non-global variables in the main program
// that have the implicit SAVE attribute, to simplifiy LLVM-IR and MLIR
diff --git a/flang/test/Lower/OpenMP/Todo/groupprivate.f90 b/flang/test/Lower/OpenMP/Todo/groupprivate.f90
deleted file mode 100644
index 9ad9b9382760c..0000000000000
--- a/flang/test/Lower/OpenMP/Todo/groupprivate.f90
+++ /dev/null
@@ -1,9 +0,0 @@
-!RUN: %not_todo_cmd %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=60 -o - %s 2>&1 | FileCheck %s
-
-!CHECK: not yet implemented: GROUPPRIVATE
-
-module m
-implicit none
-integer :: x
-!$omp groupprivate(x)
-end module
diff --git a/flang/test/Lower/OpenMP/groupprivate.f90 b/flang/test/Lower/OpenMP/groupprivate.f90
new file mode 100644
index 0000000000000..328c2769de465
--- /dev/null
+++ b/flang/test/Lower/OpenMP/groupprivate.f90
@@ -0,0 +1,57 @@
+!RUN: %flang_fc1 -emit-hlfir -fopenmp -fopenmp-version=60 %s -o - | FileCheck %s
+
+! Test lowering of groupprivate directive to omp.groupprivate.
+
+! CHECK-DAG: fir.global common @blk_
+! CHECK-DAG: fir.global @_QMmEx : i32
+
+! Test: basic groupprivate with single variable
+
+module m
+ implicit none
+ integer, save :: x
+ !$omp groupprivate(x)
+end module
+
+! CHECK-LABEL: func.func @_QPtest_groupprivate
+! CHECK: omp.target
+! CHECK: omp.teams
+! CHECK: fir.address_of(@_QMmEx)
+! CHECK: omp.groupprivate
+subroutine test_groupprivate()
+ use m
+
+ !$omp target
+ !$omp teams
+ x = 10
+ !$omp end teams
+ !$omp end target
+end subroutine
+
+! Test: groupprivate with common block
+module m2
+ implicit none
+ integer :: cb_x, cb_y
+ real :: cb_z
+ common /blk/ cb_x, cb_y, cb_z
+ !$omp groupprivate(/blk/)
+end module
+
+! CHECK-LABEL: func.func @_QPtest_common_block_groupprivate
+! CHECK: omp.target
+! CHECK: omp.teams
+! CHECK: fir.address_of(@blk_)
+! CHECK: omp.groupprivate
+! CHECK: fir.convert
+! CHECK: fir.coordinate_of
+subroutine test_common_block_groupprivate()
+ use m2
+
+ !$omp target
+ !$omp teams
+ cb_x = 1
+ cb_y = 2
+ cb_z = 3.0
+ !$omp end teams
+ !$omp end target
+end subroutine
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