[OPENMP] Codegen for 'lastprivate' clause in 'for' directive.
#pragma omp for lastprivate(<var>)
for (i = a; i < b; ++b)
<BODY>;
This construct is translated into something like:
<last_iter> = alloca i32
<lastprivate_var> = alloca <type>
<last_iter> = 0
; No initializer for simple variables or a default constructor is called for objects.
; For arrays perform element by element initialization by the call of the default constructor.
...
OMP_FOR_START(...,<last_iter>, ..); sets <last_iter> to 1 if this is the last iteration.
<BODY>
...
OMP_FOR_END
if (<last_iter> != 0) {
<var> = <lastprivate_var> ; Update original variable with the lastprivate value.
}
call __kmpc_cancel_barrier() ; an implicit barrier to avoid possible data race.
Differential Revision: http://reviews.llvm.org/D8658
llvm-svn: 235074
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index b6c751d..cbe252c 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -573,46 +573,44 @@
// class type, unless the list item is also specified in a firstprivate
// clause.
if (auto D = dyn_cast_or_null<OMPExecutableDirective>(CurDirective)) {
- for (auto C : D->clauses()) {
- if (auto Clause = dyn_cast<OMPLastprivateClause>(C)) {
- for (auto VarRef : Clause->varlists()) {
- if (VarRef->isValueDependent() || VarRef->isTypeDependent())
+ for (auto *C : D->clauses()) {
+ if (auto *Clause = dyn_cast<OMPLastprivateClause>(C)) {
+ SmallVector<Expr *, 8> PrivateCopies;
+ for (auto *DE : Clause->varlists()) {
+ if (DE->isValueDependent() || DE->isTypeDependent()) {
+ PrivateCopies.push_back(nullptr);
continue;
- auto VD = cast<VarDecl>(cast<DeclRefExpr>(VarRef)->getDecl());
+ }
+ auto *VD = cast<VarDecl>(cast<DeclRefExpr>(DE)->getDecl());
auto DVar = DSAStack->getTopDSA(VD, false);
if (DVar.CKind == OMPC_lastprivate) {
- SourceLocation ELoc = VarRef->getExprLoc();
- auto Type = VarRef->getType();
- if (Type->isArrayType())
- Type = QualType(Type->getArrayElementTypeNoTypeQual(), 0);
- CXXRecordDecl *RD =
- getLangOpts().CPlusPlus ? Type->getAsCXXRecordDecl() : nullptr;
- // FIXME This code must be replaced by actual constructing of the
- // lastprivate variable.
- if (RD) {
- CXXConstructorDecl *CD = LookupDefaultConstructor(RD);
- PartialDiagnostic PD =
- PartialDiagnostic(PartialDiagnostic::NullDiagnostic());
- if (!CD ||
- CheckConstructorAccess(
- ELoc, CD, InitializedEntity::InitializeTemporary(Type),
- CD->getAccess(), PD) == AR_inaccessible ||
- CD->isDeleted()) {
- Diag(ELoc, diag::err_omp_required_method)
- << getOpenMPClauseName(OMPC_lastprivate) << 0;
- bool IsDecl = VD->isThisDeclarationADefinition(Context) ==
- VarDecl::DeclarationOnly;
- Diag(VD->getLocation(), IsDecl ? diag::note_previous_decl
- : diag::note_defined_here)
- << VD;
- Diag(RD->getLocation(), diag::note_previous_decl) << RD;
- continue;
- }
- MarkFunctionReferenced(ELoc, CD);
- DiagnoseUseOfDecl(CD, ELoc);
- }
+ // Generate helper private variable and initialize it with the
+ // default value. The address of the original variable is replaced
+ // by the address of the new private variable in CodeGen. This new
+ // variable is not added to IdResolver, so the code in the OpenMP
+ // region uses original variable for proper diagnostics.
+ auto *VDPrivate = VarDecl::Create(
+ Context, CurContext, DE->getLocStart(), DE->getExprLoc(),
+ VD->getIdentifier(), VD->getType(), VD->getTypeSourceInfo(),
+ SC_Auto);
+ ActOnUninitializedDecl(VDPrivate, /*TypeMayContainAuto=*/false);
+ if (VDPrivate->isInvalidDecl())
+ continue;
+ CurContext->addDecl(VDPrivate);
+ PrivateCopies.push_back(DeclRefExpr::Create(
+ Context, NestedNameSpecifierLoc(), SourceLocation(), VDPrivate,
+ /*RefersToEnclosingVariableOrCapture=*/false, SourceLocation(),
+ DE->getType(), VK_LValue));
+ } else {
+ // The variable is also a firstprivate, so initialization sequence
+ // for private copy is generated already.
+ PrivateCopies.push_back(nullptr);
}
}
+ // Set initializers to private copies if no errors were found.
+ if (PrivateCopies.size() == Clause->varlist_size()) {
+ Clause->setPrivateCopies(PrivateCopies);
+ }
}
}
}
@@ -4971,11 +4969,17 @@
SourceLocation LParenLoc,
SourceLocation EndLoc) {
SmallVector<Expr *, 8> Vars;
+ SmallVector<Expr *, 8> SrcExprs;
+ SmallVector<Expr *, 8> DstExprs;
+ SmallVector<Expr *, 8> AssignmentOps;
for (auto &RefExpr : VarList) {
assert(RefExpr && "NULL expr in OpenMP lastprivate clause.");
if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
// It will be analyzed later.
Vars.push_back(RefExpr);
+ SrcExprs.push_back(nullptr);
+ DstExprs.push_back(nullptr);
+ AssignmentOps.push_back(nullptr);
continue;
}
@@ -4997,6 +5001,9 @@
if (Type->isDependentType() || Type->isInstantiationDependentType()) {
// It will be analyzed later.
Vars.push_back(DE);
+ SrcExprs.push_back(nullptr);
+ DstExprs.push_back(nullptr);
+ AssignmentOps.push_back(nullptr);
continue;
}
@@ -5060,65 +5067,39 @@
// A variable of class type (or array thereof) that appears in a
// lastprivate clause requires an accessible, unambiguous copy assignment
// operator for the class type.
- while (Type.getNonReferenceType()->isArrayType())
- Type = cast<ArrayType>(Type.getNonReferenceType().getTypePtr())
- ->getElementType();
- CXXRecordDecl *RD = getLangOpts().CPlusPlus
- ? Type.getNonReferenceType()->getAsCXXRecordDecl()
- : nullptr;
- // FIXME This code must be replaced by actual copying and destructing of the
- // lastprivate variable.
- if (RD) {
- CXXMethodDecl *MD = LookupCopyingAssignment(RD, 0, false, 0);
- DeclAccessPair FoundDecl = DeclAccessPair::make(MD, MD->getAccess());
- if (MD) {
- if (CheckMemberAccess(ELoc, RD, FoundDecl) == AR_inaccessible ||
- MD->isDeleted()) {
- Diag(ELoc, diag::err_omp_required_method)
- << getOpenMPClauseName(OMPC_lastprivate) << 2;
- bool IsDecl = VD->isThisDeclarationADefinition(Context) ==
- VarDecl::DeclarationOnly;
- Diag(VD->getLocation(),
- IsDecl ? diag::note_previous_decl : diag::note_defined_here)
- << VD;
- Diag(RD->getLocation(), diag::note_previous_decl) << RD;
- continue;
- }
- MarkFunctionReferenced(ELoc, MD);
- DiagnoseUseOfDecl(MD, ELoc);
- }
-
- CXXDestructorDecl *DD = RD->getDestructor();
- if (DD) {
- PartialDiagnostic PD =
- PartialDiagnostic(PartialDiagnostic::NullDiagnostic());
- if (CheckDestructorAccess(ELoc, DD, PD) == AR_inaccessible ||
- DD->isDeleted()) {
- Diag(ELoc, diag::err_omp_required_method)
- << getOpenMPClauseName(OMPC_lastprivate) << 4;
- bool IsDecl = VD->isThisDeclarationADefinition(Context) ==
- VarDecl::DeclarationOnly;
- Diag(VD->getLocation(),
- IsDecl ? diag::note_previous_decl : diag::note_defined_here)
- << VD;
- Diag(RD->getLocation(), diag::note_previous_decl) << RD;
- continue;
- }
- MarkFunctionReferenced(ELoc, DD);
- DiagnoseUseOfDecl(DD, ELoc);
- }
- }
+ Type = Context.getBaseElementType(Type).getNonReferenceType();
+ auto *SrcVD = BuildVarDecl(*this, DE->getLocStart(),
+ Type.getUnqualifiedType(), ".lastprivate.src");
+ auto *PseudoSrcExpr = BuildDeclRefExpr(SrcVD, Type.getUnqualifiedType(),
+ VK_LValue, DE->getExprLoc()).get();
+ auto *DstVD =
+ BuildVarDecl(*this, DE->getLocStart(), Type, ".lastprivate.dst");
+ auto *PseudoDstExpr =
+ BuildDeclRefExpr(DstVD, Type, VK_LValue, DE->getExprLoc()).get();
+ // For arrays generate assignment operation for single element and replace
+ // it by the original array element in CodeGen.
+ auto AssignmentOp = BuildBinOp(/*S=*/nullptr, DE->getExprLoc(), BO_Assign,
+ PseudoDstExpr, PseudoSrcExpr);
+ if (AssignmentOp.isInvalid())
+ continue;
+ AssignmentOp = ActOnFinishFullExpr(AssignmentOp.get(), DE->getExprLoc(),
+ /*DiscardedValue=*/true);
+ if (AssignmentOp.isInvalid())
+ continue;
if (DVar.CKind != OMPC_firstprivate)
DSAStack->addDSA(VD, DE, OMPC_lastprivate);
Vars.push_back(DE);
+ SrcExprs.push_back(PseudoSrcExpr);
+ DstExprs.push_back(PseudoDstExpr);
+ AssignmentOps.push_back(AssignmentOp.get());
}
if (Vars.empty())
return nullptr;
return OMPLastprivateClause::Create(Context, StartLoc, LParenLoc, EndLoc,
- Vars);
+ Vars, SrcExprs, DstExprs, AssignmentOps);
}
OMPClause *Sema::ActOnOpenMPSharedClause(ArrayRef<Expr *> VarList,