[OpenMP] Add TLS-based implementation for threadprivate directive.

llvm-svn: 242080

6 files changed, 46 insertions, 7 deletions

diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 74c0e2dc69d..ea4b2f517cd 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -1803,15 +1803,19 @@ void VarDecl::setStorageClass(StorageClass SC) {
 VarDecl::TLSKind VarDecl::getTLSKind() const {
   switch (VarDeclBits.TSCSpec) {
   case TSCS_unspecified:
-    if (!hasAttr<ThreadAttr>())
+    if (!hasAttr<ThreadAttr>() &&
+        !(getASTContext().getLangOpts().OpenMPUseTLS &&
+          getASTContext().getTargetInfo().isTLSSupported() &&
+          hasAttr<OMPThreadPrivateDeclAttr>()))
       return TLS_None;
-    return getASTContext().getLangOpts().isCompatibleWithMSVC(
-               LangOptions::MSVC2015)
+    return ((getASTContext().getLangOpts().isCompatibleWithMSVC(
+                LangOptions::MSVC2015)) ||
+            hasAttr<OMPThreadPrivateDeclAttr>())
                ? TLS_Dynamic
                : TLS_Static;
   case TSCS___thread: // Fall through.
   case TSCS__Thread_local:
-      return TLS_Static;
+    return TLS_Static;
   case TSCS_thread_local:
     return TLS_Dynamic;
   }
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 8c534846cf9..81488398bb8 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -932,6 +932,8 @@ llvm::Constant *CGOpenMPRuntime::createDispatchNextFunction(unsigned IVSize,
 
 llvm::Constant *
 CGOpenMPRuntime::getOrCreateThreadPrivateCache(const VarDecl *VD) {
+  assert(!CGM.getLangOpts().OpenMPUseTLS ||
+         !CGM.getContext().getTargetInfo().isTLSSupported());
   // Lookup the entry, lazily creating it if necessary.
   return getOrCreateInternalVariable(CGM.Int8PtrPtrTy,
                                      Twine(CGM.getMangledName(VD)) + ".cache.");
@@ -941,6 +943,10 @@ llvm::Value *CGOpenMPRuntime::getAddrOfThreadPrivate(CodeGenFunction &CGF,
                                                      const VarDecl *VD,
                                                      llvm::Value *VDAddr,
                                                      SourceLocation Loc) {
+  if (CGM.getLangOpts().OpenMPUseTLS &&
+      CGM.getContext().getTargetInfo().isTLSSupported())
+    return VDAddr;
+
   auto VarTy = VDAddr->getType()->getPointerElementType();
   llvm::Value *Args[] = {emitUpdateLocation(CGF, Loc), getThreadID(CGF, Loc),
                          CGF.Builder.CreatePointerCast(VDAddr, CGM.Int8PtrTy),
@@ -970,6 +976,10 @@ void CGOpenMPRuntime::emitThreadPrivateVarInit(
 llvm::Function *CGOpenMPRuntime::emitThreadPrivateVarDefinition(
     const VarDecl *VD, llvm::Value *VDAddr, SourceLocation Loc,
     bool PerformInit, CodeGenFunction *CGF) {
+  if (CGM.getLangOpts().OpenMPUseTLS &&
+      CGM.getContext().getTargetInfo().isTLSSupported())
+    return nullptr;
+
   VD = VD->getDefinition(CGM.getContext());
   if (VD && ThreadPrivateWithDefinition.count(VD) == 0) {
     ThreadPrivateWithDefinition.insert(VD);
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index b905bd2b36b..a179ad42eac 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -1262,6 +1262,11 @@ bool CodeGenModule::MayBeEmittedEagerly(const ValueDecl *Global) {
       // Implicit template instantiations may change linkage if they are later
       // explicitly instantiated, so they should not be emitted eagerly.
       return false;
+  // If OpenMP is enabled and threadprivates must be generated like TLS, delay
+  // codegen for global variables, because they may be marked as threadprivate.
+  if (LangOpts.OpenMP && LangOpts.OpenMPUseTLS &&
+      getContext().getTargetInfo().isTLSSupported() && isa<VarDecl>(Global))
+    return false;
 
   return true;
 }
diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 180533396c1..bf9b4baeb3b 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -3954,6 +3954,16 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     case OMPRT_IOMP5:
       // Clang can generate useful OpenMP code for these two runtime libraries.
       CmdArgs.push_back("-fopenmp");
+
+      // If no option regarding the use of TLS in OpenMP codegeneration is
+      // given, decide a default based on the target. Otherwise rely on the
+      // options and pass the right information to the frontend.
+      if (!Args.hasFlag(options::OPT_fopenmp_use_tls,
+                        options::OPT_fnoopenmp_use_tls,
+                        getToolChain().getArch() == llvm::Triple::ppc ||
+                            getToolChain().getArch() == llvm::Triple::ppc64 ||
+                            getToolChain().getArch() == llvm::Triple::ppc64le))
+        CmdArgs.push_back("-fnoopenmp-use-tls");
       break;
     default:
       // By default, if Clang doesn't know how to generate useful OpenMP code
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index baee1190595..6f13faf573b 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1651,6 +1651,8 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
 
   // Check if -fopenmp is specified.
   Opts.OpenMP = Args.hasArg(options::OPT_fopenmp);
+  Opts.OpenMPUseTLS =
+      Opts.OpenMP && !Args.hasArg(options::OPT_fnoopenmp_use_tls);
 
   // Record whether the __DEPRECATED define was requested.
   Opts.Deprecated = Args.hasFlag(OPT_fdeprecated_macro,
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 867cb9f3c83..4030d9e66e0 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -21,6 +21,7 @@
 #include "clang/AST/StmtOpenMP.h"
 #include "clang/AST/StmtVisitor.h"
 #include "clang/Basic/OpenMPKinds.h"
+#include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/Initialization.h"
 #include "clang/Sema/Lookup.h"
@@ -472,7 +473,10 @@ DSAStackTy::DSAVarData DSAStackTy::getTopDSA(VarDecl *D, bool FromParent) {
   // OpenMP [2.9.1.1, Data-sharing Attribute Rules for Variables Referenced
   // in a Construct, C/C++, predetermined, p.1]
   //  Variables appearing in threadprivate directives are threadprivate.
-  if (D->getTLSKind() != VarDecl::TLS_None ||
+  if ((D->getTLSKind() != VarDecl::TLS_None &&
+       !(D->hasAttr<OMPThreadPrivateDeclAttr>() &&
+         SemaRef.getLangOpts().OpenMPUseTLS &&
+         SemaRef.getASTContext().getTargetInfo().isTLSSupported())) ||
       (D->getStorageClass() == SC_Register && D->hasAttr<AsmLabelAttr>() &&
        !D->isLocalVarDecl())) {
     addDSA(D, buildDeclRefExpr(SemaRef, D, D->getType().getNonReferenceType(),
@@ -959,8 +963,12 @@ Sema::CheckOMPThreadPrivateDecl(SourceLocation Loc, ArrayRef<Expr *> VarList) {
       continue;
     }
 
-    // Check if this is a TLS variable.
-    if (VD->getTLSKind() != VarDecl::TLS_None ||
+    // Check if this is a TLS variable. If TLS is not being supported, produce
+    // the corresponding diagnostic.
+    if ((VD->getTLSKind() != VarDecl::TLS_None &&
+         !(VD->hasAttr<OMPThreadPrivateDeclAttr>() &&
+           getLangOpts().OpenMPUseTLS &&
+           getASTContext().getTargetInfo().isTLSSupported())) ||
         (VD->getStorageClass() == SC_Register && VD->hasAttr<AsmLabelAttr>() &&
          !VD->isLocalVarDecl())) {
       Diag(ILoc, diag::err_omp_var_thread_local)