[OPENMP 4.0] Support for 'aligned' clause in 'declare simd' directive.

The aligned clause declares that the object to which each list item points is aligned to the number of bytes expressed in the optional parameter of the aligned clause.
'aligned' '(' <argument-list> [ ':' <alignment> ] ')'
The optional parameter of the aligned clause, alignment, must be a constant positive integer expression. If no optional parameter is specified, implementation-defined default alignments for SIMD instructions on the target platforms are assumed.
The special this pointer can be used as if was one of the arguments to the function in any of the linear, aligned, or uniform clauses.

llvm-svn: 266052
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 43a774e..287bb36 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -3192,7 +3192,9 @@
 
 Sema::DeclGroupPtrTy Sema::ActOnOpenMPDeclareSimdDirective(
     DeclGroupPtrTy DG, OMPDeclareSimdDeclAttr::BranchStateTy BS, Expr *Simdlen,
-    ArrayRef<Expr *> Uniforms, SourceRange SR) {
+    ArrayRef<Expr *> Uniforms, ArrayRef<Expr *> Aligneds,
+    ArrayRef<Expr *> Alignments, SourceRange SR) {
+  assert(Aligneds.size() == Alignments.size());
   if (!DG || DG.get().isNull())
     return DeclGroupPtrTy();
 
@@ -3235,9 +3237,76 @@
     Diag(E->getExprLoc(), diag::err_omp_param_or_this_in_clause)
         << FD->getDeclName() << (isa<CXXMethodDecl>(ADecl) ? 1 : 0);
   }
+  // OpenMP [2.8.2, declare simd construct, Description]
+  // The aligned clause declares that the object to which each list item points
+  // is aligned to the number of bytes expressed in the optional parameter of
+  // the aligned clause.
+  // The special this pointer can be used as if was one of the arguments to the
+  // function in any of the linear, aligned, or uniform clauses.
+  // The type of list items appearing in the aligned clause must be array,
+  // pointer, reference to array, or reference to pointer.
+  llvm::DenseMap<Decl *, Expr *> AlignedArgs;
+  Expr *AlignedThis = nullptr;
+  for (auto *E : Aligneds) {
+    E = E->IgnoreParenImpCasts();
+    if (auto *DRE = dyn_cast<DeclRefExpr>(E))
+      if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
+        auto *CanonPVD = PVD->getCanonicalDecl();
+        if (FD->getNumParams() > PVD->getFunctionScopeIndex() &&
+            FD->getParamDecl(PVD->getFunctionScopeIndex())
+                    ->getCanonicalDecl() == CanonPVD) {
+          // OpenMP  [2.8.1, simd construct, Restrictions]
+          // A list-item cannot appear in more than one aligned clause.
+          if (AlignedArgs.count(CanonPVD) > 0) {
+            Diag(E->getExprLoc(), diag::err_omp_aligned_twice)
+                << 1 << E->getSourceRange();
+            Diag(AlignedArgs[CanonPVD]->getExprLoc(),
+                 diag::note_omp_explicit_dsa)
+                << getOpenMPClauseName(OMPC_aligned);
+            continue;
+          }
+          AlignedArgs[CanonPVD] = E;
+          QualType QTy = PVD->getType()
+                             .getNonReferenceType()
+                             .getUnqualifiedType()
+                             .getCanonicalType();
+          const Type *Ty = QTy.getTypePtrOrNull();
+          if (!Ty || (!Ty->isArrayType() && !Ty->isPointerType())) {
+            Diag(E->getExprLoc(), diag::err_omp_aligned_expected_array_or_ptr)
+                << QTy << getLangOpts().CPlusPlus << E->getSourceRange();
+            Diag(PVD->getLocation(), diag::note_previous_decl) << PVD;
+          }
+          continue;
+        }
+      }
+    if (isa<CXXThisExpr>(E)) {
+      if (AlignedThis) {
+        Diag(E->getExprLoc(), diag::err_omp_aligned_twice)
+            << 2 << E->getSourceRange();
+        Diag(AlignedThis->getExprLoc(), diag::note_omp_explicit_dsa)
+            << getOpenMPClauseName(OMPC_aligned);
+      }
+      AlignedThis = E;
+      continue;
+    }
+    Diag(E->getExprLoc(), diag::err_omp_param_or_this_in_clause)
+        << FD->getDeclName() << (isa<CXXMethodDecl>(ADecl) ? 1 : 0);
+  }
+  // The optional parameter of the aligned clause, alignment, must be a constant
+  // positive integer expression. If no optional parameter is specified,
+  // implementation-defined default alignments for SIMD instructions on the
+  // target platforms are assumed.
+  SmallVector<Expr *, 4> NewAligns;
+  for (auto *E : Alignments) {
+    ExprResult Align;
+    if (E)
+      Align = VerifyPositiveIntegerConstantInClause(E, OMPC_aligned);
+    NewAligns.push_back(Align.get());
+  }
   auto *NewAttr = OMPDeclareSimdDeclAttr::CreateImplicit(
       Context, BS, SL.get(), const_cast<Expr **>(Uniforms.data()),
-      Uniforms.size(), SR);
+      Uniforms.size(), const_cast<Expr **>(Aligneds.data()), Aligneds.size(),
+      const_cast<Expr **>(NewAligns.data()), NewAligns.size(), SR);
   ADecl->addAttr(NewAttr);
   return ConvertDeclToDeclGroup(ADecl);
 }
@@ -8859,7 +8928,7 @@
     // OpenMP  [2.8.1, simd construct, Restrictions]
     // A list-item cannot appear in more than one aligned clause.
     if (Expr *PrevRef = DSAStack->addUniqueAligned(D, SimpleRefExpr)) {
-      Diag(ELoc, diag::err_omp_aligned_twice) << ERange;
+      Diag(ELoc, diag::err_omp_aligned_twice) << 0 << ERange;
       Diag(PrevRef->getExprLoc(), diag::note_omp_explicit_dsa)
           << getOpenMPClauseName(OMPC_aligned);
       continue;