[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, 42 insertions, 0 deletions

diff --git a/clang/test/OpenMP/declare_reduction_ast_print.c b/clang/test/OpenMP/declare_reduction_ast_print.c
new file mode 100644
index 00000000000..7b97a7c1da7
--- /dev/null
+++ b/clang/test/OpenMP/declare_reduction_ast_print.c
@@ -0,0 +1,42 @@
+// RUN: %clang_cc1 -verify -fopenmp -ast-print %s | FileCheck %s
+// RUN: %clang_cc1 -fopenmp -emit-pch -o %t %s
+// RUN: %clang_cc1 -fopenmp -include-pch %t -fsyntax-only -verify %s -ast-print | FileCheck %s
+// expected-no-diagnostics
+
+#ifndef HEADER
+#define HEADER
+
+#pragma omp declare reduction(+ : int, char : omp_out *= omp_in)
+// CHECK: #pragma omp declare reduction (+ : int : omp_out *= omp_in)
+// CHECK-NEXT: #pragma omp declare reduction (+ : char : omp_out *= omp_in)
+
+#pragma omp declare reduction(fun : float : omp_out += omp_in) initializer(omp_priv = omp_orig + 15)
+// CHECK: #pragma omp declare reduction (fun : float : omp_out += omp_in) initializer(omp_priv = omp_orig + 15)
+
+// CHECK: struct SSS {
+struct SSS {
+  int field;
+#pragma omp declare reduction(+ : int, char : omp_out *= omp_in)
+  // CHECK: #pragma omp declare reduction (+ : int : omp_out *= omp_in)
+  // CHECK-NEXT: #pragma omp declare reduction (+ : char : omp_out *= omp_in)
+};
+// CHECK: };
+
+void init(struct SSS *priv, struct SSS orig);
+
+#pragma omp declare reduction(fun : struct SSS : omp_out = omp_in) initializer(init(&omp_priv, omp_orig))
+// CHECK: #pragma omp declare reduction (fun : struct SSS : omp_out = omp_in) initializer(init(&omp_priv, omp_orig))
+
+// CHECK: int main() {
+int main() {
+#pragma omp declare reduction(fun : struct SSS : omp_out = omp_in) initializer(init(&omp_priv, omp_orig))
+  // CHECK: #pragma omp declare reduction (fun : struct SSS : omp_out = omp_in) initializer(init(&omp_priv, omp_orig))
+  {
+#pragma omp declare reduction(fun : struct SSS : omp_out = omp_in) initializer(init(&omp_priv, omp_orig))
+  // CHECK: #pragma omp declare reduction (fun : struct SSS : omp_out = omp_in) initializer(init(&omp_priv, omp_orig))
+  }
+  return 0;
+}
+// CHECK: }
+
+#endif