[flang][OpenMP][Lower] fix statement context cleanup insertion point #133891
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The statement context is used for lowering clauses for openmp operations using generalised helpers from flang lowering. The statement context stores closures which generate code for cleaning up temporary values generated by the lowering helper. These closures are run when the statement construct is destroyed. Keeping the statement context local to the clause or operation being lowered without any special handling was not correct because any cleanup code would be generated at the insertion point when that statement context went out of scope (which would in general be inside of the newly created container operation). It would be better to generate the cleanup code after the newly created operation (clause processing is synchronous even for deferred tasks). Currently supported clauses are mostly populated with simple scalar values that require no cleanup. Even the simple array sections added by #132994 needed no cleanup because indexing the right values of the array did not create any temporaries. Supporting array sections with vector indexing will generate hlfir.destroy operations for cleanup. This patch fixes where those will be created. Those hlfir.destroy operations don't generate any FIR (or LLVM) code, but the issue still exists theoretically. I wasn't able to find any clauses which have any cleanup to use to test this PR. It is probably NFC for the current lowering. This will be tested in the PR adding vector subscripting of array sections.
tblah
requested review from
ergawy,
skatrak,
kiranchandramohan,
NimishMishra and
kparzysz
|
The change is visible in #133892 Without this change: With this change the |
|
The bot doesn't seem to run on stacked PRs: @llvm/pr-subscribers-flang-openmp |
|
I had a patch where some temporaries were destroyed before the OpenMP region. Could you look at that PR and check whether it is OK or use it as a test reference? |
NimishMishra
reviewed
Apr 7, 2025
There was a problem hiding this comment.
Thanks for the PR. I am okay with the approach: the corresponding gen* functions return the operation, set the insertion point to after the region of the operation, and emit the finalisation operation(s).
Can the following tests be extended to test the PR? There seems to be cleanup in these tests.
- flang/test/Lower/OpenMP/parallel-reduction3.f90
- flang/test/Lower/OpenMP/wsloop-reduction-allocatable-array-minmax.f90
skatrak
approved these changes
Apr 7, 2025
There was a problem hiding this comment.
Thank you, this LGTM.
At the time I refactored the processing of clauses I remember noticing there was some inconsistency between passing StatementContext references in and creating local ones, and wasn't sure what the right approach actually was. Good to see this finally straightened out.
llvmbot
added
flang
|
@llvm/pr-subscribers-flang-openmp @llvm/pr-subscribers-flang-fir-hlfir Author: Tom Eccles (tblah) ChangesThe statement context is used for lowering clauses for openmp operations using generalised helpers from flang lowering. The statement context stores closures which generate code for cleaning up temporary values generated by the lowering helper. These closures are run when the statement construct is destroyed. Keeping the statement context local to the clause or operation being lowered without any special handling was not correct because any cleanup code would be generated at the insertion point when that statement context went out of scope (which would in general be inside of the newly created container operation). It would be better to generate the cleanup code after the newly created operation (clause processing is synchronous even for deferred tasks). Currently supported clauses are mostly populated with simple scalar values that require no cleanup. Even the simple array sections added by #132994 needed no cleanup because indexing the right values of the array did not create any temporaries. Supporting array sections with vector indexing will generate hlfir.destroy operations for cleanup. This patch fixes where those will be created. Those hlfir.destroy operations don't generate any FIR (or LLVM) code, but the issue still exists theoretically. I wasn't able to find any clauses which have any cleanup to use to test this PR. It is probably NFC for the current lowering. This will be tested in the PR adding vector subscripting of array sections. Patch is 31.26 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/133891.diff 2 Files Affected:
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index ab90b4609e855..0968df4f88e28 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -1763,7 +1763,6 @@ static void genTaskClauses(lower::AbstractConverter &converter,
cp.processPriority(stmtCtx, clauseOps);
cp.processUntied(clauseOps);
cp.processDetach(clauseOps);
- // TODO Support delayed privatization.
cp.processTODO<clause::Affinity, clause::InReduction>(
loc, llvm::omp::Directive::OMPD_task);
@@ -1914,12 +1913,11 @@ static mlir::omp::LoopNestOp genLoopNestOp(
queue, item, clauseOps);
}
-static void genLoopOp(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
+static mlir::omp::LoopOp
+genLoopOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
+ mlir::Location loc, const ConstructQueue &queue,
+ ConstructQueue::const_iterator item) {
mlir::omp::LoopOperands loopClauseOps;
llvm::SmallVector<const semantics::Symbol *> loopReductionSyms;
genLoopClauses(converter, semaCtx, item->clauses, loc, loopClauseOps,
@@ -1946,14 +1944,15 @@ static void genLoopOp(lower::AbstractConverter &converter,
genLoopNestOp(converter, symTable, semaCtx, eval, loc, queue, item,
loopNestClauseOps, iv, {{loopOp, loopArgs}},
llvm::omp::Directive::OMPD_loop, dsp);
+ return loopOp;
}
static mlir::omp::MaskedOp
genMaskedOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx,
semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
mlir::Location loc, const ConstructQueue &queue,
ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
mlir::omp::MaskedOperands clauseOps;
genMaskedClauses(converter, semaCtx, stmtCtx, item->clauses, loc, clauseOps);
@@ -2157,13 +2156,13 @@ genSectionsOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
return sectionsOp;
}
-static void genScopeOp(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
+static mlir::Operation *
+genScopeOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
+ mlir::Location loc, const ConstructQueue &queue,
+ ConstructQueue::const_iterator item) {
TODO(loc, "Scope construct");
+ return nullptr;
}
static mlir::omp::SingleOp
@@ -2183,11 +2182,11 @@ genSingleOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
static mlir::omp::TargetOp
genTargetOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx,
semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
mlir::Location loc, const ConstructQueue &queue,
ConstructQueue::const_iterator item) {
fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
- lower::StatementContext stmtCtx;
bool isTargetDevice =
llvm::cast<mlir::omp::OffloadModuleInterface>(*converter.getModuleOp())
.getIsTargetDevice();
@@ -2366,13 +2365,11 @@ genTargetOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
return targetOp;
}
-static mlir::omp::TargetDataOp
-genTargetDataOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
+static mlir::omp::TargetDataOp genTargetDataOp(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
mlir::omp::TargetDataOperands clauseOps;
llvm::SmallVector<const semantics::Symbol *> useDeviceAddrSyms,
useDevicePtrSyms;
@@ -2402,10 +2399,10 @@ genTargetDataOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
template <typename OpTy>
static OpTy genTargetEnterExitUpdateDataOp(
lower::AbstractConverter &converter, lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx, mlir::Location loc,
- const ConstructQueue &queue, ConstructQueue::const_iterator item) {
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ mlir::Location loc, const ConstructQueue &queue,
+ ConstructQueue::const_iterator item) {
fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
- lower::StatementContext stmtCtx;
// GCC 9.3.0 emits a (probably) bogus warning about an unused variable.
[[maybe_unused]] llvm::omp::Directive directive;
@@ -2428,10 +2425,10 @@ static OpTy genTargetEnterExitUpdateDataOp(
static mlir::omp::TaskOp
genTaskOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx,
semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
mlir::Location loc, const ConstructQueue &queue,
ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
mlir::omp::TaskOperands clauseOps;
genTaskClauses(converter, semaCtx, symTable, stmtCtx, item->clauses, loc,
clauseOps);
@@ -2498,13 +2495,11 @@ genTaskyieldOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
return converter.getFirOpBuilder().create<mlir::omp::TaskyieldOp>(loc);
}
-static mlir::omp::WorkshareOp
-genWorkshareOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
+static mlir::omp::WorkshareOp genWorkshareOp(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
mlir::omp::WorkshareOperands clauseOps;
genWorkshareClauses(converter, semaCtx, stmtCtx, item->clauses, loc,
clauseOps);
@@ -2518,11 +2513,10 @@ genWorkshareOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
static mlir::omp::TeamsOp
genTeamsOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx,
semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
mlir::Location loc, const ConstructQueue &queue,
ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
mlir::omp::TeamsOperands clauseOps;
llvm::SmallVector<const semantics::Symbol *> reductionSyms;
genTeamsClauses(converter, semaCtx, stmtCtx, item->clauses, loc, clauseOps,
@@ -2546,15 +2540,11 @@ genTeamsOp(lower::AbstractConverter &converter, lower::SymMap &symTable,
// also be a leaf of a composite construct
//===----------------------------------------------------------------------===//
-static void genStandaloneDistribute(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval,
- mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+static mlir::omp::DistributeOp genStandaloneDistribute(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
mlir::omp::DistributeOperands distributeClauseOps;
genDistributeClauses(converter, semaCtx, stmtCtx, item->clauses, loc,
distributeClauseOps);
@@ -2578,16 +2568,14 @@ static void genStandaloneDistribute(lower::AbstractConverter &converter,
genLoopNestOp(converter, symTable, semaCtx, eval, loc, queue, item,
loopNestClauseOps, iv, {{distributeOp, distributeArgs}},
llvm::omp::Directive::OMPD_distribute, dsp);
+ return distributeOp;
}
-static void genStandaloneDo(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+static mlir::omp::WsloopOp genStandaloneDo(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
mlir::omp::WsloopOperands wsloopClauseOps;
llvm::SmallVector<const semantics::Symbol *> wsloopReductionSyms;
genWsloopClauses(converter, semaCtx, stmtCtx, item->clauses, loc,
@@ -2614,17 +2602,14 @@ static void genStandaloneDo(lower::AbstractConverter &converter,
genLoopNestOp(converter, symTable, semaCtx, eval, loc, queue, item,
loopNestClauseOps, iv, {{wsloopOp, wsloopArgs}},
llvm::omp::Directive::OMPD_do, dsp);
+ return wsloopOp;
}
-static void genStandaloneParallel(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval,
- mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+static mlir::omp::ParallelOp genStandaloneParallel(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
mlir::omp::ParallelOperands parallelClauseOps;
llvm::SmallVector<const semantics::Symbol *> parallelReductionSyms;
genParallelClauses(converter, semaCtx, stmtCtx, item->clauses, loc,
@@ -2644,17 +2629,17 @@ static void genStandaloneParallel(lower::AbstractConverter &converter,
parallelArgs.priv.vars = parallelClauseOps.privateVars;
parallelArgs.reduction.syms = parallelReductionSyms;
parallelArgs.reduction.vars = parallelClauseOps.reductionVars;
- genParallelOp(converter, symTable, semaCtx, eval, loc, queue, item,
- parallelClauseOps, parallelArgs,
- enableDelayedPrivatization ? &dsp.value() : nullptr);
+ return genParallelOp(converter, symTable, semaCtx, eval, loc, queue, item,
+ parallelClauseOps, parallelArgs,
+ enableDelayedPrivatization ? &dsp.value() : nullptr);
}
-static void genStandaloneSimd(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
+static mlir::omp::SimdOp
+genStandaloneSimd(lower::AbstractConverter &converter, lower::SymMap &symTable,
+ semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue,
+ ConstructQueue::const_iterator item) {
mlir::omp::SimdOperands simdClauseOps;
llvm::SmallVector<const semantics::Symbol *> simdReductionSyms;
genSimdClauses(converter, semaCtx, item->clauses, loc, simdClauseOps,
@@ -2681,29 +2666,27 @@ static void genStandaloneSimd(lower::AbstractConverter &converter,
genLoopNestOp(converter, symTable, semaCtx, eval, loc, queue, item,
loopNestClauseOps, iv, {{simdOp, simdArgs}},
llvm::omp::Directive::OMPD_simd, dsp);
+ return simdOp;
}
-static void genStandaloneTaskloop(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval,
- mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
+static mlir::omp::TaskloopOp genStandaloneTaskloop(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
+ mlir::Location loc, const ConstructQueue &queue,
+ ConstructQueue::const_iterator item) {
TODO(loc, "Taskloop construct");
+ return nullptr;
}
//===----------------------------------------------------------------------===//
// Code generation functions for composite constructs
//===----------------------------------------------------------------------===//
-static void genCompositeDistributeParallelDo(
+static mlir::omp::DistributeOp genCompositeDistributeParallelDo(
lower::AbstractConverter &converter, lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
- mlir::Location loc, const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
assert(std::distance(item, queue.end()) == 3 && "Invalid leaf constructs");
ConstructQueue::const_iterator distributeItem = item;
ConstructQueue::const_iterator parallelItem = std::next(distributeItem);
@@ -2762,15 +2745,14 @@ static void genCompositeDistributeParallelDo(
loopNestClauseOps, iv,
{{distributeOp, distributeArgs}, {wsloopOp, wsloopArgs}},
llvm::omp::Directive::OMPD_distribute_parallel_do, dsp);
+ return distributeOp;
}
-static void genCompositeDistributeParallelDoSimd(
+static mlir::omp::DistributeOp genCompositeDistributeParallelDoSimd(
lower::AbstractConverter &converter, lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx, lower::pft::Evaluation &eval,
- mlir::Location loc, const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
assert(std::distance(item, queue.end()) == 4 && "Invalid leaf constructs");
ConstructQueue::const_iterator distributeItem = item;
ConstructQueue::const_iterator parallelItem = std::next(distributeItem);
@@ -2854,17 +2836,14 @@ static void genCompositeDistributeParallelDoSimd(
{simdOp, simdArgs}},
llvm::omp::Directive::OMPD_distribute_parallel_do_simd,
simdItemDSP);
+ return distributeOp;
}
-static void genCompositeDistributeSimd(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval,
- mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+static mlir::omp::DistributeOp genCompositeDistributeSimd(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
assert(std::distance(item, queue.end()) == 2 && "Invalid leaf constructs");
ConstructQueue::const_iterator distributeItem = item;
ConstructQueue::const_iterator simdItem = std::next(distributeItem);
@@ -2911,16 +2890,14 @@ static void genCompositeDistributeSimd(lower::AbstractConverter &converter,
loopNestClauseOps, iv,
{{distributeOp, distributeArgs}, {simdOp, simdArgs}},
llvm::omp::Directive::OMPD_distribute_simd, dsp);
+ return distributeOp;
}
-static void genCompositeDoSimd(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval, mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
- lower::StatementContext stmtCtx;
-
+static mlir::omp::WsloopOp genCompositeDoSimd(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
assert(std::distance(item, queue.end()) == 2 && "Invalid leaf constructs");
ConstructQueue::const_iterator doItem = item;
ConstructQueue::const_iterator simdItem = std::next(doItem);
@@ -2970,30 +2947,29 @@ static void genCompositeDoSimd(lower::AbstractConverter &converter,
loopNestClauseOps, iv,
{{wsloopOp, wsloopArgs}, {simdOp, simdArgs}},
llvm::omp::Directive::OMPD_do_simd, dsp);
+ return wsloopOp;
}
-static void genCompositeTaskloopSimd(lower::AbstractConverter &converter,
- lower::SymMap &symTable,
- semantics::SemanticsContext &semaCtx,
- lower::pft::Evaluation &eval,
- mlir::Location loc,
- const ConstructQueue &queue,
- ConstructQueue::const_iterator item) {
+static mlir::omp::TaskloopOp genCompositeTaskloopSimd(
+ lower::AbstractConverter &converter, lower::SymMap &symTable,
+ lower::StatementContext &stmtCtx, semantics::SemanticsContext &semaCtx,
+ lower::pft::Evaluation &eval, mlir::Location loc,
+ const ConstructQueue &queue, ConstructQueue::const_iterator item) {
assert(std::distance(item, queue.end()) == 2 && "Invalid leaf constructs");
TODO(loc, "Composite TASKLOOP SIMD");
+ return nullptr;
}
//===----------------------------------------------------------------------===//
// Dispatch
//===--------------------------------------------------...
[truncated]
|
|
Thanks for the suggestions everyone. I have a test in 670b95b |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
The statement context is used for lowering clauses for openmp operations using generalised helpers from flang lowering. The statement context stores closures which generate code for cleaning up temporary values generated by the lowering helper. These closures are run when the statement construct is destroyed. Keeping the statement context local to the clause or operation being lowered without any special handling was not correct because any cleanup code would be generated at the insertion point when that statement context went out of scope (which would in general be inside of the newly created container operation). It would be better to generate the cleanup code after the newly created operation (clause processing is synchronous even for deferred tasks).
Currently supported clauses are mostly populated with simple scalar values that require no cleanup. Even the simple array sections added by #132994 needed no cleanup because indexing the right values of the array did not create any temporaries. Supporting array sections with vector indexing will generate hlfir.destroy operations for cleanup. This patch fixes where those will be created. Those hlfir.destroy operations don't generate any FIR (or LLVM) code, but the issue still exists theoretically.
I wasn't able to find any clauses which have any cleanup to use to test this PR. It is probably NFC for the current lowering. This will be tested in the PR adding vector subscripting of array sections.