[OPENMP 4.0] Initial support for 'omp declare reduction' construct.

Add parsing, sema analysis and serialization/deserialization for 'declare reduction' construct.
User-defined reductions are defined as

#pragma omp declare reduction( reduction-identifier : typename-list : combiner ) [initializer ( initializer-expr )]
These custom reductions may be used in 'reduction' clauses of OpenMP constructs. The combiner specifies how partial results can be combined into a single value. The
combiner can use the special variable identifiers omp_in and omp_out that are of the type of the variables being reduced with this reduction-identifier. Each of them will
denote one of the values to be combined before executing the combiner. It is assumed that the special omp_out identifier will refer to the storage that holds the resulting
combined value after executing the combiner.
As the initializer-expr value of a user-defined reduction is not known a priori the initializer-clause can be used to specify one. Then the contents of the initializer-clause
will be used as the initializer for private copies of reduction list items where the omp_priv identifier will refer to the storage to be initialized. The special identifier
omp_orig can also appear in the initializer-clause and it will refer to the storage of the original variable to be reduced.
Differential Revision: http://reviews.llvm.org/D11182

llvm-svn: 262582

1 files changed, 4 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 7df90346571..e171abeacee 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -3796,6 +3796,10 @@ void CodeGenModule::EmitTopLevelDecl(Decl *D) {
     break;
   }
 
+  case Decl::OMPDeclareReduction:
+    EmitOMPDeclareReduction(cast<OMPDeclareReductionDecl>(D));
+    break;
+
   default:
     // Make sure we handled everything we should, every other kind is a
     // non-top-level decl.  FIXME: Would be nice to have an isTopLevelDeclKind