[flang][OpenMP] Allow UPDATE clause to not have any arguments (#137521)
The UPDATE clause can be specified on both ATOMIC and DEPOBJ directives.
Currently, the ATOMIC directive has its own handling of it, and the
definition of the UPDATE clause only supports its use in the DEPOBJ
directive, where it takes a dependence-type as an argument.
The UPDATE clause on the ATOMIC directive may not have any arguments.
Since the implementation of the ATOMIC construct will be modified to use
the standard handling of clauses, the definition of UPDATE should
reflect that.
diff --git a/flang/include/flang/Parser/parse-tree.h b/flang/include/flang/Parser/parse-tree.h
index ca8473c..e39ecc1 100644
--- a/flang/include/flang/Parser/parse-tree.h
+++ b/flang/include/flang/Parser/parse-tree.h
@@ -4501,6 +4501,11 @@
// Ref: [5.0:254-255], [5.1:287-288], [5.2:321-322]
//
+// In ATOMIC construct
+// update-clause ->
+// UPDATE // Since 4.5
+//
+// In DEPOBJ construct
// update-clause ->
// UPDATE(dependence-type) // since 5.0, until 5.1
// update-clause ->
diff --git a/flang/lib/Lower/OpenMP/Clauses.cpp b/flang/lib/Lower/OpenMP/Clauses.cpp
index f1330b8..c258bef 100644
--- a/flang/lib/Lower/OpenMP/Clauses.cpp
+++ b/flang/lib/Lower/OpenMP/Clauses.cpp
@@ -1400,9 +1400,13 @@
Update make(const parser::OmpClause::Update &inp,
semantics::SemanticsContext &semaCtx) {
// inp.v -> parser::OmpUpdateClause
- auto depType =
- common::visit([](auto &&s) { return makeDepType(s); }, inp.v.u);
- return Update{/*DependenceType=*/depType};
+ if (inp.v) {
+ return common::visit(
+ [](auto &&s) { return Update{/*DependenceType=*/makeDepType(s)}; },
+ inp.v->u);
+ } else {
+ return Update{/*DependenceType=*/std::nullopt};
+ }
}
Use make(const parser::OmpClause::Use &inp,
diff --git a/flang/lib/Parser/openmp-parsers.cpp b/flang/lib/Parser/openmp-parsers.cpp
index e631922..bfca4e3 100644
--- a/flang/lib/Parser/openmp-parsers.cpp
+++ b/flang/lib/Parser/openmp-parsers.cpp
@@ -836,9 +836,9 @@
TYPE_PARSER(construct<OmpAlignedClause>(Parser<OmpObjectList>{},
maybe(":" >> nonemptyList(Parser<OmpAlignedClause::Modifier>{}))))
-TYPE_PARSER(construct<OmpUpdateClause>(
- construct<OmpUpdateClause>(Parser<OmpDependenceType>{}) ||
- construct<OmpUpdateClause>(Parser<OmpTaskDependenceType>{})))
+TYPE_PARSER( //
+ construct<OmpUpdateClause>(parenthesized(Parser<OmpDependenceType>{})) ||
+ construct<OmpUpdateClause>(parenthesized(Parser<OmpTaskDependenceType>{})))
TYPE_PARSER(construct<OmpOrderClause>(
maybe(nonemptyList(Parser<OmpOrderClause::Modifier>{}) / ":"),
@@ -1079,7 +1079,7 @@
parenthesized(nonemptyList(name)))) ||
"UNTIED" >> construct<OmpClause>(construct<OmpClause::Untied>()) ||
"UPDATE" >> construct<OmpClause>(construct<OmpClause::Update>(
- parenthesized(Parser<OmpUpdateClause>{}))) ||
+ maybe(Parser<OmpUpdateClause>{}))) ||
"WHEN" >> construct<OmpClause>(construct<OmpClause::When>(
parenthesized(Parser<OmpWhenClause>{}))) ||
// Cancellable constructs
@@ -1313,24 +1313,30 @@
endOfLine)
// Directives enclosing structured-block
-TYPE_PARSER(construct<OmpBlockDirective>(first(
- "MASKED" >> pure(llvm::omp::Directive::OMPD_masked),
- "MASTER" >> pure(llvm::omp::Directive::OMPD_master),
- "ORDERED" >> pure(llvm::omp::Directive::OMPD_ordered),
- "PARALLEL MASKED" >> pure(llvm::omp::Directive::OMPD_parallel_masked),
- "PARALLEL MASTER" >> pure(llvm::omp::Directive::OMPD_parallel_master),
- "PARALLEL WORKSHARE" >> pure(llvm::omp::Directive::OMPD_parallel_workshare),
- "PARALLEL" >> pure(llvm::omp::Directive::OMPD_parallel),
- "SCOPE" >> pure(llvm::omp::Directive::OMPD_scope),
- "SINGLE" >> pure(llvm::omp::Directive::OMPD_single),
- "TARGET DATA" >> pure(llvm::omp::Directive::OMPD_target_data),
- "TARGET PARALLEL" >> pure(llvm::omp::Directive::OMPD_target_parallel),
- "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" >> pure(llvm::omp::Directive::OMPD_teams),
- "WORKSHARE" >> pure(llvm::omp::Directive::OMPD_workshare))))
+TYPE_PARSER(
+ // In this context "TARGET UPDATE" can be parsed as a TARGET directive
+ // followed by an UPDATE clause. This is the only combination at the
+ // moment, exclude it explicitly.
+ (!"TARGET UPDATE"_sptok) >=
+ construct<OmpBlockDirective>(first(
+ "MASKED" >> pure(llvm::omp::Directive::OMPD_masked),
+ "MASTER" >> pure(llvm::omp::Directive::OMPD_master),
+ "ORDERED" >> pure(llvm::omp::Directive::OMPD_ordered),
+ "PARALLEL MASKED" >> pure(llvm::omp::Directive::OMPD_parallel_masked),
+ "PARALLEL MASTER" >> pure(llvm::omp::Directive::OMPD_parallel_master),
+ "PARALLEL WORKSHARE" >>
+ pure(llvm::omp::Directive::OMPD_parallel_workshare),
+ "PARALLEL" >> pure(llvm::omp::Directive::OMPD_parallel),
+ "SCOPE" >> pure(llvm::omp::Directive::OMPD_scope),
+ "SINGLE" >> pure(llvm::omp::Directive::OMPD_single),
+ "TARGET DATA" >> pure(llvm::omp::Directive::OMPD_target_data),
+ "TARGET PARALLEL" >> pure(llvm::omp::Directive::OMPD_target_parallel),
+ "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" >> pure(llvm::omp::Directive::OMPD_teams),
+ "WORKSHARE" >> pure(llvm::omp::Directive::OMPD_workshare))))
TYPE_PARSER(sourced(construct<OmpBeginBlockDirective>(
sourced(Parser<OmpBlockDirective>{}), Parser<OmpClauseList>{})))
diff --git a/flang/lib/Semantics/check-omp-structure.cpp b/flang/lib/Semantics/check-omp-structure.cpp
index d9fe32b..f654fe6 100644
--- a/flang/lib/Semantics/check-omp-structure.cpp
+++ b/flang/lib/Semantics/check-omp-structure.cpp
@@ -4571,10 +4571,18 @@
llvm::omp::Directive dir{GetContext().directive};
unsigned version{context_.langOptions().OpenMPVersion};
- auto *depType{std::get_if<parser::OmpDependenceType>(&x.v.u)};
- auto *taskType{std::get_if<parser::OmpTaskDependenceType>(&x.v.u)};
- assert(((depType == nullptr) != (taskType == nullptr)) &&
- "Unexpected alternative in update clause");
+ const parser::OmpDependenceType *depType{nullptr};
+ const parser::OmpTaskDependenceType *taskType{nullptr};
+ if (auto &maybeUpdate{x.v}) {
+ depType = std::get_if<parser::OmpDependenceType>(&maybeUpdate->u);
+ taskType = std::get_if<parser::OmpTaskDependenceType>(&maybeUpdate->u);
+ }
+
+ if (!depType && !taskType) {
+ assert(dir == llvm::omp::Directive::OMPD_atomic &&
+ "Unexpected alternative in update clause");
+ return;
+ }
if (depType) {
CheckDependenceType(depType->v);
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMP.td b/llvm/include/llvm/Frontend/OpenMP/OMP.td
index cdfd3e3..f4e400b 100644
--- a/llvm/include/llvm/Frontend/OpenMP/OMP.td
+++ b/llvm/include/llvm/Frontend/OpenMP/OMP.td
@@ -525,6 +525,7 @@
def OMPC_Update : Clause<"update"> {
let clangClass = "OMPUpdateClause";
let flangClass = "OmpUpdateClause";
+ let isValueOptional = true;
}
def OMPC_Use : Clause<"use"> {
let clangClass = "OMPUseClause";
