[OPENMP] Codegen for 'private' clause in 'parallel' directive.
This patch generates some helper variables which used as a private copies of the corresponding original variables inside an OpenMP 'parallel' directive. These generated variables are initialized by default (with the default constructor, if any). In outlined function references to original variables are replaced by the references to these private helper variables. At the end of the initialization of the private variables and implicit barier is set by calling __kmpc_barrier(...) runtime function to be sure that all threads were initialized using original values of the variables.
Differential Revision: http://reviews.llvm.org/D4752
llvm-svn: 220262
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 133bffa..b7c773d 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3912,11 +3912,13 @@
SourceLocation LParenLoc,
SourceLocation EndLoc) {
SmallVector<Expr *, 8> Vars;
+ SmallVector<Expr *, 8> PrivateCopies;
for (auto &RefExpr : VarList) {
assert(RefExpr && "NULL expr in OpenMP private clause.");
if (isa<DependentScopeDeclRefExpr>(RefExpr)) {
// It will be analyzed later.
Vars.push_back(RefExpr);
+ PrivateCopies.push_back(nullptr);
continue;
}
@@ -3938,6 +3940,7 @@
if (Type->isDependentType() || Type->isInstantiationDependentType()) {
// It will be analyzed later.
Vars.push_back(DE);
+ PrivateCopies.push_back(nullptr);
continue;
}
@@ -3963,54 +3966,8 @@
// A variable of class type (or array thereof) that appears in a private
// clause requires an accessible, unambiguous default constructor 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 constructing/destructing of
- // the private 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_private) << 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);
-
- CXXDestructorDecl *DD = RD->getDestructor();
- if (DD) {
- if (CheckDestructorAccess(ELoc, DD, PD) == AR_inaccessible ||
- DD->isDeleted()) {
- Diag(ELoc, diag::err_omp_required_method)
- << getOpenMPClauseName(OMPC_private) << 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);
- }
+ while (Type->isArrayType()) {
+ Type = cast<ArrayType>(Type.getTypePtr())->getElementType();
}
// OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
@@ -4028,14 +3985,35 @@
continue;
}
+ // 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(), /*S*/ SC_Auto);
+ ActOnUninitializedDecl(VDPrivate, /*TypeMayContainAuto*/ false);
+ if (VDPrivate->isInvalidDecl())
+ continue;
+ CurContext->addDecl(VDPrivate);
+ auto VDPrivateRefExpr = DeclRefExpr::Create(
+ Context, /*QualifierLoc*/ NestedNameSpecifierLoc(),
+ /*TemplateKWLoc*/ SourceLocation(), VDPrivate,
+ /*isEnclosingLocal*/ false, /*NameLoc*/ SourceLocation(), DE->getType(),
+ /*VK*/ VK_LValue);
+
DSAStack->addDSA(VD, DE, OMPC_private);
Vars.push_back(DE);
+ PrivateCopies.push_back(VDPrivateRefExpr);
}
if (Vars.empty())
return nullptr;
- return OMPPrivateClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars);
+ return OMPPrivateClause::Create(Context, StartLoc, LParenLoc, EndLoc, Vars,
+ PrivateCopies);
}
namespace {