[clang] [OpenMP] Restore loop variable values after loop-tranformation constructs. (PR #208533)
via cfe-commits
cfe-commits at lists.llvm.org
Thu Jul 23 14:55:45 PDT 2026
llvmorg-github-actions[bot] wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-clang
Author: Zahira Ammarguellat (zahiraam)
<details>
<summary>Changes</summary>
This patch fixes loop variable finalization for OpenMP 6.0 loop-transformations constructs: `tile`, `stripe`, `reverse`, `interchange` and `fuse` to comply with spec requirement page 371, lines 19-21. The spec requires that "After the execution of the loop-transforming construct, the loop-iteration variables of any of its transformation-affected loops have the values that they would have without the loop-transforming directive".
---
Patch is 385.41 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/208533.diff
10 Files Affected:
- (modified) clang/include/clang/AST/StmtOpenMP.h (+52-16)
- (modified) clang/lib/AST/StmtOpenMP.cpp (+24-24)
- (modified) clang/lib/CodeGen/CGStmtOpenMP.cpp (+25)
- (modified) clang/lib/Sema/SemaOpenMP.cpp (+104-17)
- (modified) clang/test/OpenMP/fuse_codegen.cpp (+1328-1156)
- (modified) clang/test/OpenMP/interchange_codegen.cpp (+134-45)
- (added) clang/test/OpenMP/loop_transform_final_iv.c (+114)
- (modified) clang/test/OpenMP/reverse_codegen.cpp (+180-85)
- (modified) clang/test/OpenMP/stripe_codegen.cpp (+224-110)
- (modified) clang/test/OpenMP/tile_codegen.cpp (+224-110)
``````````diff
diff --git a/clang/include/clang/AST/StmtOpenMP.h b/clang/include/clang/AST/StmtOpenMP.h
index dbc76e7df8ecd..82c093b9219d7 100644
--- a/clang/include/clang/AST/StmtOpenMP.h
+++ b/clang/include/clang/AST/StmtOpenMP.h
@@ -5601,6 +5601,7 @@ class OMPTileDirective final
enum {
PreInitsOffset = 0,
TransformedStmtOffset,
+ FinalsOffset,
};
explicit OMPTileDirective(SourceLocation StartLoc, SourceLocation EndLoc,
@@ -5617,6 +5618,8 @@ class OMPTileDirective final
Data->getChildren()[TransformedStmtOffset] = S;
}
+ void setFinals(Stmt *Finals) { Data->getChildren()[FinalsOffset] = Finals; }
+
public:
/// Create a new AST node representation for '#pragma omp tile'.
///
@@ -5630,11 +5633,11 @@ class OMPTileDirective final
/// \param TransformedStmt The loop nest after tiling, or nullptr in
/// dependent contexts.
/// \param PreInits Helper preinits statements for the loop nest.
- static OMPTileDirective *Create(const ASTContext &C, SourceLocation StartLoc,
- SourceLocation EndLoc,
- ArrayRef<OMPClause *> Clauses,
- unsigned NumLoops, Stmt *AssociatedStmt,
- Stmt *TransformedStmt, Stmt *PreInits);
+ /// \param Finals Loop variable finalization statements.
+ static OMPTileDirective *
+ Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
+ ArrayRef<OMPClause *> Clauses, unsigned NumLoops, Stmt *AssociatedStmt,
+ Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals);
/// Build an empty '#pragma omp tile' AST node for deserialization.
///
@@ -5662,6 +5665,9 @@ class OMPTileDirective final
/// Return preinits statement.
Stmt *getPreInits() const { return Data->getChildren()[PreInitsOffset]; }
+ /// Return finals statement (loop variable finalization).
+ Stmt *getFinals() const { return Data->getChildren()[FinalsOffset]; }
+
static bool classof(const Stmt *T) {
return T->getStmtClass() == OMPTileDirectiveClass;
}
@@ -5677,6 +5683,7 @@ class OMPStripeDirective final
enum {
PreInitsOffset = 0,
TransformedStmtOffset,
+ FinalsOffset,
};
explicit OMPStripeDirective(SourceLocation StartLoc, SourceLocation EndLoc,
@@ -5693,6 +5700,8 @@ class OMPStripeDirective final
Data->getChildren()[TransformedStmtOffset] = S;
}
+ void setFinals(Stmt *Finals) { Data->getChildren()[FinalsOffset] = Finals; }
+
public:
/// Create a new AST node representation for '#pragma omp stripe'.
///
@@ -5706,10 +5715,11 @@ class OMPStripeDirective final
/// \param TransformedStmt The loop nest after striping, or nullptr in
/// dependent contexts.
/// \param PreInits Helper preinits statements for the loop nest.
+ /// \param Finals Loop variable finalization statements.
static OMPStripeDirective *
Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
ArrayRef<OMPClause *> Clauses, unsigned NumLoops, Stmt *AssociatedStmt,
- Stmt *TransformedStmt, Stmt *PreInits);
+ Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals);
/// Build an empty '#pragma omp stripe' AST node for deserialization.
///
@@ -5736,6 +5746,9 @@ class OMPStripeDirective final
/// Return preinits statement.
Stmt *getPreInits() const { return Data->getChildren()[PreInitsOffset]; }
+ /// Return finals statement (loop variable finalization).
+ Stmt *getFinals() const { return Data->getChildren()[FinalsOffset]; }
+
static bool classof(const Stmt *T) {
return T->getStmtClass() == OMPStripeDirectiveClass;
}
@@ -5756,6 +5769,7 @@ class OMPUnrollDirective final
enum {
PreInitsOffset = 0,
TransformedStmtOffset,
+ FinalsOffset,
};
explicit OMPUnrollDirective(SourceLocation StartLoc, SourceLocation EndLoc)
@@ -5832,6 +5846,7 @@ class OMPReverseDirective final
enum {
PreInitsOffset = 0,
TransformedStmtOffset,
+ FinalsOffset,
};
explicit OMPReverseDirective(SourceLocation StartLoc, SourceLocation EndLoc,
@@ -5848,6 +5863,8 @@ class OMPReverseDirective final
Data->getChildren()[TransformedStmtOffset] = S;
}
+ void setFinals(Stmt *Finals) { Data->getChildren()[FinalsOffset] = Finals; }
+
public:
/// Create a new AST node representation for '#pragma omp reverse'.
///
@@ -5859,11 +5876,11 @@ class OMPReverseDirective final
/// \param TransformedStmt The loop nest after tiling, or nullptr in
/// dependent contexts.
/// \param PreInits Helper preinits statements for the loop nest.
- static OMPReverseDirective *Create(const ASTContext &C,
- SourceLocation StartLoc,
- SourceLocation EndLoc,
- Stmt *AssociatedStmt, unsigned NumLoops,
- Stmt *TransformedStmt, Stmt *PreInits);
+ /// \param Finals Loop variable finalization statements.
+ static OMPReverseDirective *
+ Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
+ Stmt *AssociatedStmt, unsigned NumLoops, Stmt *TransformedStmt,
+ Stmt *PreInits, Stmt *Finals);
/// Build an empty '#pragma omp reverse' AST node for deserialization.
///
@@ -5881,6 +5898,9 @@ class OMPReverseDirective final
/// Return preinits statement.
Stmt *getPreInits() const { return Data->getChildren()[PreInitsOffset]; }
+ /// Return finals statement.
+ Stmt *getFinals() const { return Data->getChildren()[FinalsOffset]; }
+
static bool classof(const Stmt *T) {
return T->getStmtClass() == OMPReverseDirectiveClass;
}
@@ -5903,6 +5923,7 @@ class OMPInterchangeDirective final
enum {
PreInitsOffset = 0,
TransformedStmtOffset,
+ FinalsOffset,
};
explicit OMPInterchangeDirective(SourceLocation StartLoc,
@@ -5919,6 +5940,8 @@ class OMPInterchangeDirective final
Data->getChildren()[TransformedStmtOffset] = S;
}
+ void setFinals(Stmt *Finals) { Data->getChildren()[FinalsOffset] = Finals; }
+
public:
/// Create a new AST node representation for '#pragma omp interchange'.
///
@@ -5932,10 +5955,11 @@ class OMPInterchangeDirective final
/// \param TransformedStmt The loop nest after tiling, or nullptr in
/// dependent contexts.
/// \param PreInits Helper preinits statements for the loop nest.
+ /// \param Finals Loop variable finalization statements.
static OMPInterchangeDirective *
Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
ArrayRef<OMPClause *> Clauses, unsigned NumLoops, Stmt *AssociatedStmt,
- Stmt *TransformedStmt, Stmt *PreInits);
+ Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals);
/// Build an empty '#pragma omp interchange' AST node for deserialization.
///
@@ -5954,6 +5978,9 @@ class OMPInterchangeDirective final
/// Return preinits statement.
Stmt *getPreInits() const { return Data->getChildren()[PreInitsOffset]; }
+ /// Return finals statement.
+ Stmt *getFinals() const { return Data->getChildren()[FinalsOffset]; }
+
static bool classof(const Stmt *T) {
return T->getStmtClass() == OMPInterchangeDirectiveClass;
}
@@ -6009,6 +6036,7 @@ class OMPFuseDirective final
enum {
PreInitsOffset = 0,
TransformedStmtOffset,
+ FinalsOffset,
};
explicit OMPFuseDirective(SourceLocation StartLoc, SourceLocation EndLoc)
@@ -6023,6 +6051,8 @@ class OMPFuseDirective final
Data->getChildren()[TransformedStmtOffset] = S;
}
+ void setFinals(Stmt *Finals) { Data->getChildren()[FinalsOffset] = Finals; }
+
public:
/// Create a new AST node representation for #pragma omp fuse'
///
@@ -6038,10 +6068,13 @@ class OMPFuseDirective final
/// \param TransformedStmt The loop nest after fusion, or nullptr in
/// dependent
/// \param PreInits Helper preinits statements for the loop nest
- static OMPFuseDirective *
- Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
- ArrayRef<OMPClause *> Clauses, unsigned NumGeneratedTopLevelLoops,
- Stmt *AssociatedStmt, Stmt *TransformedStmt, Stmt *PreInits);
+ /// \param Finals Loop variable finalization statements
+ static OMPFuseDirective *Create(const ASTContext &C, SourceLocation StartLoc,
+ SourceLocation EndLoc,
+ ArrayRef<OMPClause *> Clauses,
+ unsigned NumGeneratedTopLevelLoops,
+ Stmt *AssociatedStmt, Stmt *TransformedStmt,
+ Stmt *PreInits, Stmt *Finals);
/// Build an empty '#pragma omp fuse' AST node for deserialization
///
@@ -6060,6 +6093,9 @@ class OMPFuseDirective final
/// Return preinits statement.
Stmt *getPreInits() const { return Data->getChildren()[PreInitsOffset]; }
+ /// Return finals statement.
+ Stmt *getFinals() const { return Data->getChildren()[FinalsOffset]; }
+
static bool classof(const Stmt *T) {
return T->getStmtClass() == OMPFuseDirectiveClass;
}
diff --git a/clang/lib/AST/StmtOpenMP.cpp b/clang/lib/AST/StmtOpenMP.cpp
index 9d6b315effb41..13f1d2d94aa85 100644
--- a/clang/lib/AST/StmtOpenMP.cpp
+++ b/clang/lib/AST/StmtOpenMP.cpp
@@ -452,12 +452,12 @@ OMPTileDirective *
OMPTileDirective::Create(const ASTContext &C, SourceLocation StartLoc,
SourceLocation EndLoc, ArrayRef<OMPClause *> Clauses,
unsigned NumLoops, Stmt *AssociatedStmt,
- Stmt *TransformedStmt, Stmt *PreInits) {
+ Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals) {
OMPTileDirective *Dir = createDirective<OMPTileDirective>(
- C, Clauses, AssociatedStmt, TransformedStmtOffset + 1, StartLoc, EndLoc,
- NumLoops);
+ C, Clauses, AssociatedStmt, FinalsOffset + 1, StartLoc, EndLoc, NumLoops);
Dir->setTransformedStmt(TransformedStmt);
Dir->setPreInits(PreInits);
+ Dir->setFinals(Finals);
return Dir;
}
@@ -465,20 +465,19 @@ OMPTileDirective *OMPTileDirective::CreateEmpty(const ASTContext &C,
unsigned NumClauses,
unsigned NumLoops) {
return createEmptyDirective<OMPTileDirective>(
- C, NumClauses, /*HasAssociatedStmt=*/true, TransformedStmtOffset + 1,
+ C, NumClauses, /*HasAssociatedStmt=*/true, FinalsOffset + 1,
SourceLocation(), SourceLocation(), NumLoops);
}
-OMPStripeDirective *
-OMPStripeDirective::Create(const ASTContext &C, SourceLocation StartLoc,
- SourceLocation EndLoc, ArrayRef<OMPClause *> Clauses,
- unsigned NumLoops, Stmt *AssociatedStmt,
- Stmt *TransformedStmt, Stmt *PreInits) {
+OMPStripeDirective *OMPStripeDirective::Create(
+ const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
+ ArrayRef<OMPClause *> Clauses, unsigned NumLoops, Stmt *AssociatedStmt,
+ Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals) {
OMPStripeDirective *Dir = createDirective<OMPStripeDirective>(
- C, Clauses, AssociatedStmt, TransformedStmtOffset + 1, StartLoc, EndLoc,
- NumLoops);
+ C, Clauses, AssociatedStmt, FinalsOffset + 1, StartLoc, EndLoc, NumLoops);
Dir->setTransformedStmt(TransformedStmt);
Dir->setPreInits(PreInits);
+ Dir->setFinals(Finals);
return Dir;
}
@@ -486,7 +485,7 @@ OMPStripeDirective *OMPStripeDirective::CreateEmpty(const ASTContext &C,
unsigned NumClauses,
unsigned NumLoops) {
return createEmptyDirective<OMPStripeDirective>(
- C, NumClauses, /*HasAssociatedStmt=*/true, TransformedStmtOffset + 1,
+ C, NumClauses, /*HasAssociatedStmt=*/true, FinalsOffset + 1,
SourceLocation(), SourceLocation(), NumLoops);
}
@@ -516,31 +515,31 @@ OMPReverseDirective *
OMPReverseDirective::Create(const ASTContext &C, SourceLocation StartLoc,
SourceLocation EndLoc, Stmt *AssociatedStmt,
unsigned NumLoops, Stmt *TransformedStmt,
- Stmt *PreInits) {
+ Stmt *PreInits, Stmt *Finals) {
OMPReverseDirective *Dir = createDirective<OMPReverseDirective>(
- C, {}, AssociatedStmt, TransformedStmtOffset + 1, StartLoc, EndLoc,
- NumLoops);
+ C, {}, AssociatedStmt, FinalsOffset + 1, StartLoc, EndLoc, NumLoops);
Dir->setTransformedStmt(TransformedStmt);
Dir->setPreInits(PreInits);
+ Dir->setFinals(Finals);
return Dir;
}
OMPReverseDirective *OMPReverseDirective::CreateEmpty(const ASTContext &C,
unsigned NumLoops) {
return createEmptyDirective<OMPReverseDirective>(
- C, /*NumClauses=*/0, /*HasAssociatedStmt=*/true,
- TransformedStmtOffset + 1, SourceLocation(), SourceLocation(), NumLoops);
+ C, /*NumClauses=*/0, /*HasAssociatedStmt=*/true, FinalsOffset + 1,
+ SourceLocation(), SourceLocation(), NumLoops);
}
OMPInterchangeDirective *OMPInterchangeDirective::Create(
const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
ArrayRef<OMPClause *> Clauses, unsigned NumLoops, Stmt *AssociatedStmt,
- Stmt *TransformedStmt, Stmt *PreInits) {
+ Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals) {
OMPInterchangeDirective *Dir = createDirective<OMPInterchangeDirective>(
- C, Clauses, AssociatedStmt, TransformedStmtOffset + 1, StartLoc, EndLoc,
- NumLoops);
+ C, Clauses, AssociatedStmt, FinalsOffset + 1, StartLoc, EndLoc, NumLoops);
Dir->setTransformedStmt(TransformedStmt);
Dir->setPreInits(PreInits);
+ Dir->setFinals(Finals);
return Dir;
}
@@ -548,7 +547,7 @@ OMPInterchangeDirective *
OMPInterchangeDirective::CreateEmpty(const ASTContext &C, unsigned NumClauses,
unsigned NumLoops) {
return createEmptyDirective<OMPInterchangeDirective>(
- C, NumClauses, /*HasAssociatedStmt=*/true, TransformedStmtOffset + 1,
+ C, NumClauses, /*HasAssociatedStmt=*/true, FinalsOffset + 1,
SourceLocation(), SourceLocation(), NumLoops);
}
@@ -576,12 +575,13 @@ OMPSplitDirective *OMPSplitDirective::CreateEmpty(const ASTContext &C,
OMPFuseDirective *OMPFuseDirective::Create(
const ASTContext &C, SourceLocation StartLoc, SourceLocation EndLoc,
ArrayRef<OMPClause *> Clauses, unsigned NumGeneratedTopLevelLoops,
- Stmt *AssociatedStmt, Stmt *TransformedStmt, Stmt *PreInits) {
+ Stmt *AssociatedStmt, Stmt *TransformedStmt, Stmt *PreInits, Stmt *Finals) {
OMPFuseDirective *Dir = createDirective<OMPFuseDirective>(
- C, Clauses, AssociatedStmt, TransformedStmtOffset + 1, StartLoc, EndLoc);
+ C, Clauses, AssociatedStmt, FinalsOffset + 1, StartLoc, EndLoc);
Dir->setTransformedStmt(TransformedStmt);
Dir->setPreInits(PreInits);
+ Dir->setFinals(Finals);
Dir->setNumGeneratedTopLevelLoops(NumGeneratedTopLevelLoops);
return Dir;
}
@@ -589,7 +589,7 @@ OMPFuseDirective *OMPFuseDirective::Create(
OMPFuseDirective *OMPFuseDirective::CreateEmpty(const ASTContext &C,
unsigned NumClauses) {
OMPFuseDirective *Dir = createEmptyDirective<OMPFuseDirective>(
- C, NumClauses, /*HasAssociatedStmt=*/true, TransformedStmtOffset + 1,
+ C, NumClauses, /*HasAssociatedStmt=*/true, FinalsOffset + 1,
SourceLocation(), SourceLocation());
return Dir;
}
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 88f698f38cce0..247cb65512b68 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -3221,18 +3221,33 @@ void CodeGenFunction::EmitOMPTileDirective(const OMPTileDirective &S) {
// Emit the de-sugared statement.
OMPTransformDirectiveScopeRAII TileScope(*this, &S);
EmitStmt(S.getTransformedStmt());
+
+ // Emit loop variable finalization as required by OpenMP 6.0 spec to restore
+ // original loop variable values after the loop-transformation construct.
+ if (auto *Finals = S.getFinals())
+ EmitStmt(Finals);
}
void CodeGenFunction::EmitOMPStripeDirective(const OMPStripeDirective &S) {
// Emit the de-sugared statement.
OMPTransformDirectiveScopeRAII StripeScope(*this, &S);
EmitStmt(S.getTransformedStmt());
+
+ // Emit loop variable finalization as required by OpenMP 6.0 spec to restore
+ // original loop variable values after the loop-transformation construct.
+ if (auto *Finals = S.getFinals())
+ EmitStmt(Finals);
}
void CodeGenFunction::EmitOMPReverseDirective(const OMPReverseDirective &S) {
// Emit the de-sugared statement.
OMPTransformDirectiveScopeRAII ReverseScope(*this, &S);
EmitStmt(S.getTransformedStmt());
+
+ // Emit loop variable finalization as required by OpenMP 6.0 spec to restore
+ // original loop variable values after the loop-transformation construct.
+ if (auto *Finals = S.getFinals())
+ EmitStmt(Finals);
}
void CodeGenFunction::EmitOMPSplitDirective(const OMPSplitDirective &S) {
@@ -3246,12 +3261,22 @@ void CodeGenFunction::EmitOMPInterchangeDirective(
// Emit the de-sugared statement.
OMPTransformDirectiveScopeRAII InterchangeScope(*this, &S);
EmitStmt(S.getTransformedStmt());
+
+ // Emit loop variable finalization as required by OpenMP 6.0 spec to restore
+ // original loop variable values after the loop-transformation construct.
+ if (auto *Finals = S.getFinals())
+ EmitStmt(Finals);
}
void CodeGenFunction::EmitOMPFuseDirective(const OMPFuseDirective &S) {
// Emit the de-sugared statement
OMPTransformDirectiveScopeRAII FuseScope(*this, &S);
EmitStmt(S.getTransformedStmt());
+
+ // Emit loop variable finalization as required by OpenMP 6.0 spec to restore
+ // original loop variable values after the loop-transformation construct.
+ if (auto *Finals = S.getFinals())
+ EmitStmt(Finals);
}
void CodeGenFunction::EmitOMPUnrollDirective(const OMPUnrollDirective &S) {
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 0f45a21c5e461..f9d8e233e0f03 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -14960,6 +14960,24 @@ static Expr *makeFloorIVRef(Sema &SemaRef, ArrayRef<VarDecl *> FloorIndVars,
OrigCntVar->getExprLoc());
}
+/// Build loop variable finalization statement from HelperExprs.Finals.
+/// Returns a CompoundStmt containing all finalization statements, or nullptr
+/// if there are no finalization statements.
+static Stmt *buildLoopFinalization(
+ ASTContext &Context,
+ ArrayRef<OMPLoopBasedDirective::HelperExprs> LoopHelpers) {
+ SmallVector<Stmt *, 8> FinalizationStmts;
+ for (const auto &Helper : LoopHelpers) {
+ if (!Helper.Finals.empty() && Helper.Finals[0]) {
+ FinalizationStmts.push_back(Helper.Finals[0]);
+ }
+ }
+ if (FinalizationStmts.empty())
+ return nullptr;
+ return CompoundStmt::Create(Context, FinalizationStmts, FPOptionsOverride(),
+ SourceLocation(), SourceLocation());
+}
+
StmtResult SemaOpenMP::ActOnOpenMPTileDirective(ArrayRef<OMPClause *> Clauses,
Stmt *AStmt,
SourceLocation StartLoc,
@@ -14989,7 +15007,7 @@ StmtResult SemaOpenMP::ActOnOpenMPTileDirective(ArrayRef<OMPClause *> Clauses,
// Delay tiling to when template is completely instantiated.
if (SemaRef.CurContext->isDependentContext())
return OMPTileDirective::Create(Context, StartLoc, EndLoc, Clauses,
- NumLoops, AStmt, nullptr, nullptr);
+ NumLoops, AStmt, nullptr, nullptr, nullptr);
assert(LoopHelpers.size() == NumLoops &&
"Expecting loop iteration space dimensionality to match number of "
@@ -15232,7 +15250,8 @@ StmtResult SemaOpenMP::ActOnOpenMPTileDirective(ArrayRef<OMPClause *> Clauses,
return OMPTileDirective::Create(Context, StartLoc, EndLoc, Clauses, NumLoops,
...
[truncated]
``````````
</details>
https://github.com/llvm/llvm-project/pull/208533
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