[OPENMP] Pass scalar firstprivate vars by value.

For better performance and to unify code with offloading part we pass
scalar firstprivate values by value, instead of by reference. It will
remove some extra copying operations.

llvm-svn: 269751

1 files changed, 37 insertions, 18 deletions

diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 5cf0cae161b..d28f2cceb08 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -172,7 +172,8 @@ static Address castValueFromUintptr(CodeGenFunction &CGF, QualType DstType,
 }
 
 llvm::Function *
-CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
+CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S,
+                                                    bool CastValToPtr) {
   assert(
       CapturedStmtInfo &&
       "CapturedStmtInfo should be set when generating the captured function");
@@ -196,9 +197,11 @@ CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
     // uintptr. This is necessary given that the runtime library is only able to
     // deal with pointers. We can pass in the same way the VLA type sizes to the
     // outlined function.
-    if ((I->capturesVariableByCopy() && !ArgType->isAnyPointerType()) ||
-        I->capturesVariableArrayType())
-      ArgType = Ctx.getUIntPtrType();
+    if (CastValToPtr) {
+      if ((I->capturesVariableByCopy() && !ArgType->isAnyPointerType()) ||
+          I->capturesVariableArrayType())
+        ArgType = Ctx.getUIntPtrType();
+    }
 
     if (I->capturesVariable() || I->capturesVariableByCopy()) {
       CapVar = I->getCapturedVar();
@@ -252,9 +255,12 @@ CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
                        AlignmentSource::Decl);
     if (FD->hasCapturedVLAType()) {
       LValue CastedArgLVal =
-          MakeAddrLValue(castValueFromUintptr(*this, FD->getType(),
-                                              Args[Cnt]->getName(), ArgLVal),
-                         FD->getType(), AlignmentSource::Decl);
+          CastValToPtr
+              ? MakeAddrLValue(castValueFromUintptr(*this, FD->getType(),
+                                                    Args[Cnt]->getName(),
+                                                    ArgLVal),
+                               FD->getType(), AlignmentSource::Decl)
+              : ArgLVal;
       auto *ExprArg =
           EmitLoadOfLValue(CastedArgLVal, SourceLocation()).getScalarVal();
       auto VAT = FD->getCapturedVLAType();
@@ -274,10 +280,16 @@ CodeGenFunction::GenerateOpenMPCapturedStmtFunction(const CapturedStmt &S) {
              "Not expecting a captured pointer.");
       auto *Var = I->getCapturedVar();
       QualType VarTy = Var->getType();
-      setAddrOfLocalVar(I->getCapturedVar(),
-                        castValueFromUintptr(*this, FD->getType(),
-                                             Args[Cnt]->getName(), ArgLVal,
-                                             VarTy->isReferenceType()));
+      if (!CastValToPtr && VarTy->isReferenceType()) {
+        Address Temp = CreateMemTemp(VarTy);
+        Builder.CreateStore(ArgLVal.getPointer(), Temp);
+        ArgLVal = MakeAddrLValue(Temp, VarTy);
+      }
+      setAddrOfLocalVar(Var, CastValToPtr ? castValueFromUintptr(
+                                                *this, FD->getType(),
+                                                Args[Cnt]->getName(), ArgLVal,
+                                                VarTy->isReferenceType())
+                                          : ArgLVal.getAddress());
     } else {
       // If 'this' is captured, load it into CXXThisValue.
       assert(I->capturesThis());
@@ -564,18 +576,25 @@ bool CodeGenFunction::EmitOMPFirstprivateClause(const OMPExecutableDirective &D,
     auto InitsRef = C->inits().begin();
     for (auto IInit : C->private_copies()) {
       auto *OrigVD = cast<VarDecl>(cast<DeclRefExpr>(*IRef)->getDecl());
+      bool ThisFirstprivateIsLastprivate =
+          Lastprivates.count(OrigVD->getCanonicalDecl()) > 0;
+      auto *FD = CapturedStmtInfo->lookup(OrigVD);
+      if (!ThisFirstprivateIsLastprivate && FD &&
+          !FD->getType()->isReferenceType()) {
+        EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl());
+        ++IRef;
+        ++InitsRef;
+        continue;
+      }
       FirstprivateIsLastprivate =
-          FirstprivateIsLastprivate ||
-          (Lastprivates.count(OrigVD->getCanonicalDecl()) > 0);
+          FirstprivateIsLastprivate || ThisFirstprivateIsLastprivate;
       if (EmittedAsFirstprivate.insert(OrigVD->getCanonicalDecl()).second) {
         auto *VD = cast<VarDecl>(cast<DeclRefExpr>(IInit)->getDecl());
         auto *VDInit = cast<VarDecl>(cast<DeclRefExpr>(*InitsRef)->getDecl());
         bool IsRegistered;
-        DeclRefExpr DRE(
-            const_cast<VarDecl *>(OrigVD),
-            /*RefersToEnclosingVariableOrCapture=*/CapturedStmtInfo->lookup(
-                OrigVD) != nullptr,
-            (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
+        DeclRefExpr DRE(const_cast<VarDecl *>(OrigVD),
+                        /*RefersToEnclosingVariableOrCapture=*/FD != nullptr,
+                        (*IRef)->getType(), VK_LValue, (*IRef)->getExprLoc());
         Address OriginalAddr = EmitLValue(&DRE).getAddress();
         QualType Type = VD->getType();
         if (Type->isArrayType()) {