[OPENMP 4.0] Initial support for '#pragma omp declare simd' directive.

Initial parsing/sema/serialization/deserialization support for '#pragma
omp declare simd' directive.
The 'declare simd' construct can be applied to a function to enable the
creation of one or more versions that can process multiple arguments
using SIMD instructions from a single invocation from a SIMD loop.
If the function has any declarations, then the declare simd construct
for any declaration that has one must be equivalent to the one specified
 for the definition. Otherwise, the result is unspecified.
This pragma can be applied many times to the same declaration.
Internally this pragma is represented as an attribute. But we need special processing for this pragma because it must be used before function declaration, this directive is applied to.
Differential Revision: http://reviews.llvm.org/D10599

llvm-svn: 264853

1 files changed, 28 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 8ce67c8f9c2..3c50eec3a67 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -1701,6 +1701,7 @@ void Sema::ActOnOpenMPRegionStart(OpenMPDirectiveKind DKind, Scope *CurScope) {
   case OMPD_target_enter_data:
   case OMPD_target_exit_data:
   case OMPD_declare_reduction:
+  case OMPD_declare_simd:
     llvm_unreachable("OpenMP Directive is not allowed");
   case OMPD_unknown:
     llvm_unreachable("Unknown OpenMP directive");
@@ -3155,6 +3156,7 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
     break;
   case OMPD_threadprivate:
   case OMPD_declare_reduction:
+  case OMPD_declare_simd:
     llvm_unreachable("OpenMP Directive is not allowed");
   case OMPD_unknown:
     llvm_unreachable("Unknown OpenMP directive");
@@ -3175,6 +3177,32 @@ StmtResult Sema::ActOnOpenMPExecutableDirective(
   return Res;
 }
 
+Sema::DeclGroupPtrTy
+Sema::ActOnOpenMPDeclareSimdDirective(DeclGroupPtrTy DG,
+                                      SourceLocation StartLoc) {
+  if (!DG || DG.get().isNull())
+    return DeclGroupPtrTy();
+
+  if (!DG.get().isSingleDecl()) {
+    Diag(StartLoc, diag::err_omp_single_decl_in_declare_simd);
+    return DG;
+  }
+  auto *ADecl = DG.get().getSingleDecl();
+  if (auto *FTD = dyn_cast<FunctionTemplateDecl>(ADecl))
+    ADecl = FTD->getTemplatedDecl();
+
+  if (!isa<FunctionDecl>(ADecl)) {
+    Diag(ADecl->getLocation(), diag::err_omp_function_expected)
+        << ADecl->getDeclContext()->isFileContext();
+    return DeclGroupPtrTy();
+  }
+
+  auto *NewAttr = OMPDeclareSimdDeclAttr::CreateImplicit(
+      Context, SourceRange(StartLoc, StartLoc));
+  ADecl->addAttr(NewAttr);
+  return ConvertDeclToDeclGroup(ADecl);
+}
+
 StmtResult Sema::ActOnOpenMPParallelDirective(ArrayRef<OMPClause *> Clauses,
                                               Stmt *AStmt,
                                               SourceLocation StartLoc,