commit 729e242a7972f4802f982a4b4dabb964aa299675
author Alexey Bataev <a.bataev@hotmail.com> Fri Aug 23 16:11:14 2019 +0000
committer Alexey Bataev <a.bataev@hotmail.com> Fri Aug 23 16:11:14 2019 +0000
tree 2dd14a03a492c3edbbb4fd95f31cf9768fda9923
parent f692963600cc2a2748a2963bb3553bbdb4732ac8

[OPENMP5.0]Add support for device_type clause in declare target
construct.

OpenMP 5.0 introduced new clause for declare target directive, device_type clause, which may accept values host, nohost, and any. Host means
that the function must be emitted only for the host, nohost - only for
the device, and any - for both, device and the host.

llvm-svn: 369775

clang/lib/CodeGen/CGOpenMPRuntime.cpp

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 8b04d2e..84211e3 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -9604,14 +9604,28 @@
 bool CGOpenMPRuntime::emitTargetFunctions(GlobalDecl GD) {
   // If emitting code for the host, we do not process FD here. Instead we do
   // the normal code generation.
-  if (!CGM.getLangOpts().OpenMPIsDevice)
+  if (!CGM.getLangOpts().OpenMPIsDevice) {
+    if (const auto *FD = dyn_cast<FunctionDecl>(GD.getDecl())) {
+      Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
+          OMPDeclareTargetDeclAttr::getDeviceType(FD);
+      // Do not emit device_type(nohost) functions for the host.
+      if (DevTy && *DevTy == OMPDeclareTargetDeclAttr::DT_NoHost)
+        return true;
+    }
     return false;
+  }
 
   const ValueDecl *VD = cast<ValueDecl>(GD.getDecl());
   StringRef Name = CGM.getMangledName(GD);
   // Try to detect target regions in the function.
-  if (const auto *FD = dyn_cast<FunctionDecl>(VD))
+  if (const auto *FD = dyn_cast<FunctionDecl>(VD)) {
     scanForTargetRegionsFunctions(FD->getBody(), Name);
+    Optional<OMPDeclareTargetDeclAttr::DevTypeTy> DevTy =
+        OMPDeclareTargetDeclAttr::getDeviceType(FD);
+    // Do not emit device_type(nohost) functions for the host.
+    if (DevTy && *DevTy == OMPDeclareTargetDeclAttr::DT_Host)
+      return true;
+  }
 
   // Do not to emit function if it is not marked as declare target.
   return !OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD) &&

clang/lib/CodeGen/CGStmtOpenMP.cpp

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 2ca7ebc..473c6f7 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -4021,6 +4021,7 @@
   case OMPC_reverse_offload:
   case OMPC_dynamic_allocators:
   case OMPC_atomic_default_mem_order:
+  case OMPC_device_type:
     llvm_unreachable("Clause is not allowed in 'omp atomic'.");
   }
 }

clang/lib/CodeGen/CodeGenModule.cpp

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 3dc40a8..eedf70b 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -2122,6 +2122,10 @@
     if (!GV->isDeclaration())
       continue;
 
+    // If this is OpenMP, check if it is legal to emit this global normally.
+    if (LangOpts.OpenMP && OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(D))
+      continue;
+
     // Otherwise, emit the definition and move on to the next one.
     EmitGlobalDefinition(D, GV);
 
@@ -2318,11 +2322,20 @@
 }
 
 bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
-  if (const auto *FD = dyn_cast<FunctionDecl>(Global))
+  if (const auto *FD = dyn_cast<FunctionDecl>(Global)) {
     if (FD->getTemplateSpecializationKind() == TSK_ImplicitInstantiation)
       // Implicit template instantiations may change linkage if they are later
       // explicitly instantiated, so they should not be emitted eagerly.
       return false;
+    // In OpenMP 5.0 function may be marked as device_type(nohost) and we should
+    // not emit them eagerly unless we sure that the function must be emitted on
+    // the host.
+    if (LangOpts.OpenMP >= 50 && !LangOpts.OpenMPSimd &&
+        !LangOpts.OpenMPIsDevice &&
+        !OMPDeclareTargetDeclAttr::getDeviceType(FD) &&
+        !FD->isUsed(/*CheckUsedAttr=*/false) && !FD->isReferenced())
+      return false;
+  }
   if (const auto *VD = dyn_cast<VarDecl>(Global))
     if (Context.getInlineVariableDefinitionKind(VD) ==
         ASTContext::InlineVariableDefinitionKind::WeakUnknown)
@@ -2445,8 +2458,7 @@
   }
 
   if (LangOpts.OpenMP) {
-    // If this is OpenMP device, check if it is legal to emit this global
-    // normally.
+    // If this is OpenMP, check if it is legal to emit this global normally.
     if (OpenMPRuntime && OpenMPRuntime->emitTargetGlobal(GD))
       return;
     if (auto *DRD = dyn_cast<OMPDeclareReductionDecl>(Global)) {