[flang][OpenMP] Generalize isOpenMPPrivatizingConstruct #148654
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Additionally, add sentinel values <Enum>::First_ and <Enum>::Last_ to each one of those enums. This will allow using `enum_seq_inclusive` to generate the list of enum-typed values of any generated scoped (non-bitmask) enum.
Instead of treating all block and all loop constructs as privatizing, actually check if the construct allows a privatizing clause.
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I have verified that 1052_0201 and 1052_0205 both pass with this change. |
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@llvm/pr-subscribers-flang-fir-hlfir @llvm/pr-subscribers-flang-openmp Author: Krzysztof Parzyszek (kparzysz) ChangesInstead of treating all block and all loop constructs as privatizing, actually check if the construct allows a privatizing clause. Full diff: https://github.com/llvm/llvm-project/pull/148654.diff 4 Files Affected:
diff --git a/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp b/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
index 3fae3f3a0ddfd..675a58e4f35a1 100644
--- a/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
+++ b/flang/lib/Lower/OpenMP/DataSharingProcessor.cpp
@@ -26,6 +26,8 @@
#include "flang/Optimizer/HLFIR/HLFIROps.h"
#include "flang/Semantics/attr.h"
#include "flang/Semantics/tools.h"
+#include "llvm/ADT/Sequence.h"
+#include "llvm/ADT/SmallSet.h"
namespace Fortran {
namespace lower {
@@ -49,7 +51,7 @@ DataSharingProcessor::DataSharingProcessor(
firOpBuilder(converter.getFirOpBuilder()), clauses(clauses), eval(eval),
shouldCollectPreDeterminedSymbols(shouldCollectPreDeterminedSymbols),
useDelayedPrivatization(useDelayedPrivatization), symTable(symTable),
- visitor() {
+ visitor(semaCtx) {
eval.visit([&](const auto &functionParserNode) {
parser::Walk(functionParserNode, visitor);
});
@@ -424,24 +426,55 @@ getSource(const semantics::SemanticsContext &semaCtx,
return source;
}
+static void collectPrivatizingConstructs(
+ llvm::SmallSet<llvm::omp::Directive, 16> &constructs, unsigned version) {
+ using Clause = llvm::omp::Clause;
+ using Directive = llvm::omp::Directive;
+
+ static const Clause privatizingClauses[] = {
+ Clause::OMPC_private,
+ Clause::OMPC_lastprivate,
+ Clause::OMPC_firstprivate,
+ Clause::OMPC_in_reduction,
+ Clause::OMPC_reduction,
+ Clause::OMPC_linear,
+ // TODO: Clause::OMPC_induction,
+ Clause::OMPC_task_reduction,
+ Clause::OMPC_detach,
+ Clause::OMPC_use_device_ptr,
+ Clause::OMPC_is_device_ptr,
+ };
+
+ for (auto dir : llvm::enum_seq_inclusive<Directive>(Directive::First_,
+ Directive::Last_)) {
+ bool allowsPrivatizing = llvm::any_of(privatizingClauses, [&](Clause cls) {
+ return llvm::omp::isAllowedClauseForDirective(dir, cls, version);
+ });
+ if (allowsPrivatizing)
+ constructs.insert(dir);
+ }
+}
+
bool DataSharingProcessor::isOpenMPPrivatizingConstruct(
- const parser::OpenMPConstruct &omp) {
- return common::visit(
- [](auto &&s) {
- using BareS = llvm::remove_cvref_t<decltype(s)>;
- return std::is_same_v<BareS, parser::OpenMPBlockConstruct> ||
- std::is_same_v<BareS, parser::OpenMPLoopConstruct> ||
- std::is_same_v<BareS, parser::OpenMPSectionsConstruct>;
- },
- omp.u);
+ const parser::OpenMPConstruct &omp, unsigned version) {
+ static llvm::SmallSet<llvm::omp::Directive, 16> privatizing;
+ [[maybe_unused]] static bool init =
+ (collectPrivatizingConstructs(privatizing, version), true);
+
+ // As of OpenMP 6.0, privatizing constructs (with the test being if they
+ // allow a privatizing clause) are: dispatch, distribute, do, for, loop,
+ // parallel, scope, sections, simd, single, target, target_data, task,
+ // taskgroup, taskloop, and teams.
+ return llvm::is_contained(privatizing, extractOmpDirective(omp));
}
bool DataSharingProcessor::isOpenMPPrivatizingEvaluation(
const pft::Evaluation &eval) const {
- return eval.visit([](auto &&s) {
+ unsigned version = semaCtx.langOptions().OpenMPVersion;
+ return eval.visit([=](auto &&s) {
using BareS = llvm::remove_cvref_t<decltype(s)>;
if constexpr (std::is_same_v<BareS, parser::OpenMPConstruct>) {
- return isOpenMPPrivatizingConstruct(s);
+ return isOpenMPPrivatizingConstruct(s, version);
} else {
return false;
}
diff --git a/flang/lib/Lower/OpenMP/DataSharingProcessor.h b/flang/lib/Lower/OpenMP/DataSharingProcessor.h
index ee2fc70d2e673..bc422f410403a 100644
--- a/flang/lib/Lower/OpenMP/DataSharingProcessor.h
+++ b/flang/lib/Lower/OpenMP/DataSharingProcessor.h
@@ -36,6 +36,8 @@ class DataSharingProcessor {
/// at any point in time. This is used to track Symbol definition scopes in
/// order to tell which OMP scope defined vs. references a certain Symbol.
struct OMPConstructSymbolVisitor {
+ OMPConstructSymbolVisitor(semantics::SemanticsContext &ctx)
+ : version(ctx.langOptions().OpenMPVersion) {}
template <typename T>
bool Pre(const T &) {
return true;
@@ -45,13 +47,13 @@ class DataSharingProcessor {
bool Pre(const parser::OpenMPConstruct &omp) {
// Skip constructs that may not have privatizations.
- if (isOpenMPPrivatizingConstruct(omp))
+ if (isOpenMPPrivatizingConstruct(omp, version))
constructs.push_back(&omp);
return true;
}
void Post(const parser::OpenMPConstruct &omp) {
- if (isOpenMPPrivatizingConstruct(omp))
+ if (isOpenMPPrivatizingConstruct(omp, version))
constructs.pop_back();
}
@@ -68,6 +70,9 @@ class DataSharingProcessor {
/// construct that defines symbol.
bool isSymbolDefineBy(const semantics::Symbol *symbol,
lower::pft::Evaluation &eval) const;
+
+ private:
+ unsigned version;
};
mlir::OpBuilder::InsertPoint lastPrivIP;
@@ -115,7 +120,8 @@ class DataSharingProcessor {
mlir::OpBuilder::InsertPoint *lastPrivIP);
void insertDeallocs();
- static bool isOpenMPPrivatizingConstruct(const parser::OpenMPConstruct &omp);
+ static bool isOpenMPPrivatizingConstruct(const parser::OpenMPConstruct &omp,
+ unsigned version);
bool isOpenMPPrivatizingEvaluation(const pft::Evaluation &eval) const;
public:
diff --git a/flang/test/Lower/OpenMP/taskgroup02.f90 b/flang/test/Lower/OpenMP/taskgroup02.f90
index 1e996a030c23a..4c470b7aa82d1 100644
--- a/flang/test/Lower/OpenMP/taskgroup02.f90
+++ b/flang/test/Lower/OpenMP/taskgroup02.f90
@@ -3,8 +3,9 @@
! Check that variables are not privatized twice when TASKGROUP is used.
!CHECK-LABEL: func.func @_QPsub() {
-!CHECK: omp.parallel {
-!CHECK: %[[PAR_I:.*]]:2 = hlfir.declare %{{.*}} {uniq_name = "_QFsubEi"}
+!CHECK: omp.parallel private(@_QFsubEi_private_i32 %[[SUB_I:.*]]#0 -> %[[ARG:.*]] : !fir.ref<i32>)
+!CHECK: %[[ALLOCA:.*]] = fir.alloca i32
+!CHECK: %[[PAR_I:.*]]:2 = hlfir.declare %[[ALLOCA]] {uniq_name = "_QFsubEi"}
!CHECK: omp.master {
!CHECK: omp.taskgroup {
!CHECK-NEXT: omp.task private(@_QFsubEi_firstprivate_i32 %[[PAR_I]]#0 -> %[[TASK_I:.*]] : !fir.ref<i32>) {
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMP.h b/llvm/include/llvm/Frontend/OpenMP/OMP.h
index d44c33301bde7..9d0a55432e1ae 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMP.h
+++ b/llvm/include/llvm/Frontend/OpenMP/OMP.h
@@ -51,13 +51,17 @@ static constexpr inline bool canHaveIterator(Clause C) {
// Can clause C create a private copy of a variable.
static constexpr inline bool isPrivatizingClause(Clause C) {
switch (C) {
+ case OMPC_detach:
case OMPC_firstprivate:
+ // TODO case OMPC_induction:
case OMPC_in_reduction:
+ case OMPC_is_device_ptr:
case OMPC_lastprivate:
case OMPC_linear:
case OMPC_private:
case OMPC_reduction:
case OMPC_task_reduction:
+ case OMPC_use_device_ptr:
return true;
default:
return false;
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This was referenced Jul 14, 2025
luporl
reviewed
Jul 14, 2025
Comment on lines
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| !CHECK: omp.parallel { | ||
| !CHECK: %[[PAR_I:.*]]:2 = hlfir.declare %{{.*}} {uniq_name = "_QFsubEi"} | ||
| !CHECK: omp.parallel private(@_QFsubEi_private_i32 %[[SUB_I:.*]]#0 -> %[[ARG:.*]] : !fir.ref<i32>) | ||
| !CHECK: %[[ALLOCA:.*]] = fir.alloca i32 | ||
| !CHECK: %[[PAR_I:.*]]:2 = hlfir.declare %[[ALLOCA]] {uniq_name = "_QFsubEi"} |
There was a problem hiding this comment.
In this test, was the issue the fact that i was not being privatized because taskgroup was not being considered as a privatizing construct, which made i not be collected as a symbol in nested regions?
Was i getting a private copy just by accident, because it was a loop-iteration variable inside parallel in this case?
There was a problem hiding this comment.
We treated all block-associated constructs as privatizing, including master (which isn't one). When master is no longer considered as privatizing the result is that we privatize i in `parallel.
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/27/builds/13239 Here is the relevant piece of the build log for the reference |
This was referenced Jul 23, 2025
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Instead of treating all block and all loop constructs as privatizing, actually check if the construct allows a privatizing clause.