[OpenMP 5.0] Codegen support for user-defined mappers.

This patch implements the code generation for OpenMP 5.0 declare mapper
(user-defined mapper) constructs. For each declare mapper, a mapper
function is generated. These mapper functions will be called by the
runtime and/or other mapper functions to achieve user defined mapping.

The design slides can be found at
https://github.com/lingda-li/public-sharing/blob/master/mapper_runtime_design.pptx

Re-commit after revert in r367773 because r367755 changed the LLVM-IR
output such that a CHECK line failed.

Patch by Lingda Li <lildmh@gmail.com>

Differential Revision: https://reviews.llvm.org/D59474

llvm-svn: 367905

1 files changed, 4 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index c6c2ff57e1c..a9e01619aab 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -2530,10 +2530,11 @@ void CodeGenModule::EmitOMPDeclareReduction(const OMPDeclareReductionDecl *D,
 }
 
 void CodeGenModule::EmitOMPDeclareMapper(const OMPDeclareMapperDecl *D,
-                                            CodeGenFunction *CGF) {
-  if (!LangOpts.OpenMP || (!LangOpts.EmitAllDecls && !D->isUsed()))
+                                         CodeGenFunction *CGF) {
+  if (!LangOpts.OpenMP || LangOpts.OpenMPSimd ||
+      (!LangOpts.EmitAllDecls && !D->isUsed()))
     return;
-  // FIXME: need to implement mapper code generation
+  getOpenMPRuntime().emitUserDefinedMapper(D, CGF);
 }
 
 void CodeGenModule::EmitOMPRequiresDecl(const OMPRequiresDecl *D) {