[Frontend][OpenMP] Add functions for checking construct type (#87258)

Implement helper functions to identify leaf, composite, and combined
constructs.

Author: kparzysz

llvm/include/llvm/Frontend/OpenMP/OMP.h

@@ -20,6 +20,10 @@
 namespace llvm::omp {
 ArrayRef<Directive> getLeafConstructs(Directive D);
 Directive getCompoundConstruct(ArrayRef<Directive> Parts);
+
+bool isLeafConstruct(Directive D);
+bool isCompositeConstruct(Directive D);
+bool isCombinedConstruct(Directive D);
 } // namespace llvm::omp
 
 #endif // LLVM_FRONTEND_OPENMP_OMP_H

llvm/lib/Frontend/OpenMP/OMP.cpp

@@ -84,4 +84,29 @@ Directive getCompoundConstruct(ArrayRef<Directive> Parts) {
     return Found;
   return OMPD_unknown;
 }
+
+bool isLeafConstruct(Directive D) { return getLeafConstructs(D).empty(); }
+
+bool isCompositeConstruct(Directive D) {
+  // OpenMP Spec 5.2: [17.3, 8-9]
+  // If directive-name-A and directive-name-B both correspond to loop-
+  // associated constructs then directive-name is a composite construct
+  llvm::ArrayRef<Directive> Leafs{getLeafConstructs(D)};
+  if (Leafs.empty())
+    return false;
+  if (getDirectiveAssociation(Leafs.front()) != Association::Loop)
+    return false;
+
+  size_t numLoopConstructs =
+      llvm::count_if(Leafs.drop_front(), [](Directive L) {
+        return getDirectiveAssociation(L) == Association::Loop;
+      });
+  return numLoopConstructs != 0;
+}
+
+bool isCombinedConstruct(Directive D) {
+  // OpenMP Spec 5.2: [17.3, 9-10]
+  // Otherwise directive-name is a combined construct.
+  return !getLeafConstructs(D).empty() && !isCompositeConstruct(D);
+}
 } // namespace llvm::omp

llvm/unittests/Frontend/CMakeLists.txt

@@ -14,7 +14,7 @@ add_llvm_unittest(LLVMFrontendTests
   OpenMPContextTest.cpp
   OpenMPIRBuilderTest.cpp
   OpenMPParsingTest.cpp
-  OpenMPComposeTest.cpp
+  OpenMPCompositionTest.cpp
 
   DEPENDS
   acc_gen

llvm/unittests/Frontend/OpenMPComposeTest.cpp renamed to llvm/unittests/Frontend/OpenMPCompositionTest.cpp

@@ -1,4 +1,4 @@
-//===- llvm/unittests/Frontend/OpenMPComposeTest.cpp ----------------------===//
+//===- llvm/unittests/Frontend/OpenMPCompositionTest.cpp ------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -39,3 +39,30 @@ TEST(Composition, GetCompoundConstruct) {
   Directive C7 = getCompoundConstruct({OMPD_do, OMPD_simd});
   ASSERT_EQ(C7, OMPD_do_simd); // Make sure it's not OMPD_end_do_simd
 }
+
+TEST(Composition, IsLeafConstruct) {
+  ASSERT_TRUE(isLeafConstruct(OMPD_loop));
+  ASSERT_TRUE(isLeafConstruct(OMPD_teams));
+  ASSERT_FALSE(isLeafConstruct(OMPD_for_simd));
+  ASSERT_FALSE(isLeafConstruct(OMPD_distribute_simd));
+  ASSERT_FALSE(isLeafConstruct(OMPD_parallel_for));
+}
+
+TEST(Composition, IsCompositeConstruct) {
+  ASSERT_TRUE(isCompositeConstruct(OMPD_distribute_simd));
+  ASSERT_FALSE(isCompositeConstruct(OMPD_for));
+  ASSERT_TRUE(isCompositeConstruct(OMPD_for_simd));
+  // directive-name-A = "parallel", directive-name-B = "for simd",
+  // only directive-name-B is loop-associated, so this is not a
+  // composite construct, even though "for simd" is.
+  ASSERT_FALSE(isCompositeConstruct(OMPD_parallel_for_simd));
+}
+
+TEST(Composition, IsCombinedConstruct) {
+  // "parallel for simd" is a combined construct, see comment in
+  // IsCompositeConstruct.
+  ASSERT_TRUE(isCombinedConstruct(OMPD_parallel_for_simd));
+  ASSERT_FALSE(isCombinedConstruct(OMPD_for_simd));
+  ASSERT_TRUE(isCombinedConstruct(OMPD_parallel_for));
+  ASSERT_FALSE(isCombinedConstruct(OMPD_parallel));
+}