[OPENMP, NVPTX] Fix globalization of the variables passed to orphaned

parallel region.

If the current construct requires sharing of the local variable in the
inner parallel region, this variable must be globalized to avoid
runtime crash.

llvm-svn: 335285

1 files changed, 55 insertions, 43 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp b/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
index 9452bdea4c7..e3cec13f7d5 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntimeNVPTX.cpp
@@ -184,9 +184,10 @@ class CheckVarsEscapingDeclContext final
   llvm::SetVector<const ValueDecl *> EscapedDecls;
   llvm::SetVector<const ValueDecl *> EscapedVariableLengthDecls;
   llvm::SmallPtrSet<const Decl *, 4> EscapedParameters;
-  bool AllEscaped = false;
   RecordDecl *GlobalizedRD = nullptr;
   llvm::SmallDenseMap<const ValueDecl *, const FieldDecl *> MappedDeclsFields;
+  bool AllEscaped = false;
+  bool IsForParallelRegion = false;
 
   static llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy>
   isDeclareTargetDeclaration(const ValueDecl *VD) {
@@ -207,23 +208,32 @@ class CheckVarsEscapingDeclContext final
     // Variables captured by value must be globalized.
     if (auto *CSI = CGF.CapturedStmtInfo) {
       if (const FieldDecl *FD = CSI->lookup(cast<VarDecl>(VD))) {
-        if (!FD->hasAttrs())
-          return;
-        const auto *Attr = FD->getAttr<OMPCaptureKindAttr>();
-        if (!Attr)
-          return;
-        if (!isOpenMPPrivate(
-                static_cast<OpenMPClauseKind>(Attr->getCaptureKind())) ||
-            Attr->getCaptureKind() == OMPC_map)
-          return;
-        if (FD->getType()->isReferenceType())
+        // Check if need to capture the variable that was already captured by
+        // value in the outer region.
+        if (!IsForParallelRegion) {
+          if (!FD->hasAttrs())
+            return;
+          const auto *Attr = FD->getAttr<OMPCaptureKindAttr>();
+          if (!Attr)
+            return;
+          if (!isOpenMPPrivate(
+                  static_cast<OpenMPClauseKind>(Attr->getCaptureKind())) ||
+              Attr->getCaptureKind() == OMPC_map)
+            return;
+        }
+        if (!FD->getType()->isReferenceType()) {
+          assert(!VD->getType()->isVariablyModifiedType() &&
+                 "Parameter captured by value with variably modified type");
+          EscapedParameters.insert(VD);
+        } else if (!IsForParallelRegion) {
           return;
-        assert(!VD->getType()->isVariablyModifiedType() &&
-               "Parameter captured by value with variably modified type");
-        EscapedParameters.insert(VD);
+        }
       }
-    } else if (VD->getType()->isReferenceType())
-      // Do not globalize variables with reference or pointer type.
+    }
+    if ((!CGF.CapturedStmtInfo ||
+         (IsForParallelRegion && CGF.CapturedStmtInfo)) &&
+        VD->getType()->isReferenceType())
+      // Do not globalize variables with reference type.
       return;
     if (VD->getType()->isVariablyModifiedType())
       EscapedVariableLengthDecls.insert(VD);
@@ -243,15 +253,18 @@ class CheckVarsEscapingDeclContext final
       }
     }
   }
-  void VisitOpenMPCapturedStmt(const CapturedStmt *S) {
+  void VisitOpenMPCapturedStmt(const CapturedStmt *S, bool IsParallelRegion) {
     if (!S)
       return;
     for (const CapturedStmt::Capture &C : S->captures()) {
       if (C.capturesVariable() && !C.capturesVariableByCopy()) {
         const ValueDecl *VD = C.getCapturedVar();
+        bool SavedIsParallelRegion = IsForParallelRegion;
+        IsForParallelRegion = IsParallelRegion;
         markAsEscaped(VD);
         if (isa<OMPCapturedExprDecl>(VD))
           VisitValueDecl(VD);
+        IsForParallelRegion = SavedIsParallelRegion;
       }
     }
   }
@@ -316,20 +329,19 @@ public:
   void VisitOMPExecutableDirective(const OMPExecutableDirective *D) {
     if (!D)
       return;
-    if (D->hasAssociatedStmt()) {
-      if (const auto *S =
-              dyn_cast_or_null<CapturedStmt>(D->getAssociatedStmt())) {
-        // Do not analyze directives that do not actually require capturing,
-        // like `omp for` or `omp simd` directives.
-        llvm::SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
-        getOpenMPCaptureRegions(CaptureRegions, D->getDirectiveKind());
-        if (CaptureRegions.size() == 1 &&
-            CaptureRegions.back() == OMPD_unknown) {
-          VisitStmt(S->getCapturedStmt());
-          return;
-        }
-        VisitOpenMPCapturedStmt(S);
+    if (!D->hasAssociatedStmt())
+      return;
+    if (const auto *S =
+            dyn_cast_or_null<CapturedStmt>(D->getAssociatedStmt())) {
+      // Do not analyze directives that do not actually require capturing,
+      // like `omp for` or `omp simd` directives.
+      llvm::SmallVector<OpenMPDirectiveKind, 4> CaptureRegions;
+      getOpenMPCaptureRegions(CaptureRegions, D->getDirectiveKind());
+      if (CaptureRegions.size() == 1 && CaptureRegions.back() == OMPD_unknown) {
+        VisitStmt(S->getCapturedStmt());
+        return;
       }
+      VisitOpenMPCapturedStmt(S, CaptureRegions.back() == OMPD_parallel);
     }
   }
   void VisitCapturedStmt(const CapturedStmt *S) {
@@ -551,9 +563,9 @@ static void syncParallelThreads(CodeGenFunction &CGF, llvm::Value *NumThreads) {
 /// CTA. The threads in the last warp are reserved for master execution.
 /// For the 'spmd' execution mode, all threads in a CTA are part of the team.
 static llvm::Value *getThreadLimit(CodeGenFunction &CGF,
-                                   bool IsInSpmdExecutionMode = false) {
+                                   bool IsInSPMDExecutionMode = false) {
   CGBuilderTy &Bld = CGF.Builder;
-  return IsInSpmdExecutionMode
+  return IsInSPMDExecutionMode
              ? getNVPTXNumThreads(CGF)
              : Bld.CreateNUWSub(getNVPTXNumThreads(CGF), getNVPTXWarpSize(CGF),
                                 "thread_limit");
@@ -930,7 +942,7 @@ void CGOpenMPRuntimeNVPTX::emitNonSPMDEntryFooter(CodeGenFunction &CGF,
   EST.ExitBB = nullptr;
 }
 
-void CGOpenMPRuntimeNVPTX::emitSpmdKernel(const OMPExecutableDirective &D,
+void CGOpenMPRuntimeNVPTX::emitSPMDKernel(const OMPExecutableDirective &D,
                                           StringRef ParentName,
                                           llvm::Function *&OutlinedFn,
                                           llvm::Constant *&OutlinedFnID,
@@ -951,10 +963,10 @@ void CGOpenMPRuntimeNVPTX::emitSpmdKernel(const OMPExecutableDirective &D,
                          const OMPExecutableDirective &D)
         : RT(RT), EST(EST), D(D) {}
     void Enter(CodeGenFunction &CGF) override {
-      RT.emitSpmdEntryHeader(CGF, EST, D);
+      RT.emitSPMDEntryHeader(CGF, EST, D);
     }
     void Exit(CodeGenFunction &CGF) override {
-      RT.emitSpmdEntryFooter(CGF, EST);
+      RT.emitSPMDEntryFooter(CGF, EST);
     }
   } Action(*this, EST, D);
   CodeGen.setAction(Action);
@@ -962,7 +974,7 @@ void CGOpenMPRuntimeNVPTX::emitSpmdKernel(const OMPExecutableDirective &D,
                                    IsOffloadEntry, CodeGen);
 }
 
-void CGOpenMPRuntimeNVPTX::emitSpmdEntryHeader(
+void CGOpenMPRuntimeNVPTX::emitSPMDEntryHeader(
     CodeGenFunction &CGF, EntryFunctionState &EST,
     const OMPExecutableDirective &D) {
   CGBuilderTy &Bld = CGF.Builder;
@@ -974,7 +986,7 @@ void CGOpenMPRuntimeNVPTX::emitSpmdEntryHeader(
   // Initialize the OMP state in the runtime; called by all active threads.
   // TODO: Set RequiresOMPRuntime and RequiresDataSharing parameters
   // based on code analysis of the target region.
-  llvm::Value *Args[] = {getThreadLimit(CGF, /*IsInSpmdExecutionMode=*/true),
+  llvm::Value *Args[] = {getThreadLimit(CGF, /*IsInSPMDExecutionMode=*/true),
                          /*RequiresOMPRuntime=*/Bld.getInt16(1),
                          /*RequiresDataSharing=*/Bld.getInt16(1)};
   CGF.EmitRuntimeCall(
@@ -986,7 +998,7 @@ void CGOpenMPRuntimeNVPTX::emitSpmdEntryHeader(
   IsInTargetMasterThreadRegion = true;
 }
 
-void CGOpenMPRuntimeNVPTX::emitSpmdEntryFooter(CodeGenFunction &CGF,
+void CGOpenMPRuntimeNVPTX::emitSPMDEntryFooter(CodeGenFunction &CGF,
                                                EntryFunctionState &EST) {
   IsInTargetMasterThreadRegion = false;
   if (!CGF.HaveInsertPoint())
@@ -1465,7 +1477,7 @@ void CGOpenMPRuntimeNVPTX::emitTargetOutlinedFunction(
 
   bool Mode = supportsSPMDExecutionMode(CGM.getContext(), D);
   if (Mode)
-    emitSpmdKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
+    emitSPMDKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
                    CodeGen);
   else
     emitNonSPMDKernel(D, ParentName, OutlinedFn, OutlinedFnID, IsOffloadEntry,
@@ -1483,7 +1495,7 @@ CGOpenMPRuntimeNVPTX::CGOpenMPRuntimeNVPTX(CodeGenModule &CGM)
 void CGOpenMPRuntimeNVPTX::emitProcBindClause(CodeGenFunction &CGF,
                                               OpenMPProcBindClauseKind ProcBind,
                                               SourceLocation Loc) {
-  // Do nothing in case of Spmd mode and L0 parallel.
+  // Do nothing in case of SPMD mode and L0 parallel.
   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
     return;
 
@@ -1493,7 +1505,7 @@ void CGOpenMPRuntimeNVPTX::emitProcBindClause(CodeGenFunction &CGF,
 void CGOpenMPRuntimeNVPTX::emitNumThreadsClause(CodeGenFunction &CGF,
                                                 llvm::Value *NumThreads,
                                                 SourceLocation Loc) {
-  // Do nothing in case of Spmd mode and L0 parallel.
+  // Do nothing in case of SPMD mode and L0 parallel.
   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
     return;
 
@@ -1718,7 +1730,7 @@ void CGOpenMPRuntimeNVPTX::emitParallelCall(
     return;
 
   if (getExecutionMode() == CGOpenMPRuntimeNVPTX::EM_SPMD)
-    emitSpmdParallelCall(CGF, Loc, OutlinedFn, CapturedVars, IfCond);
+    emitSPMDParallelCall(CGF, Loc, OutlinedFn, CapturedVars, IfCond);
   else
     emitNonSPMDParallelCall(CGF, Loc, OutlinedFn, CapturedVars, IfCond);
 }
@@ -1904,7 +1916,7 @@ void CGOpenMPRuntimeNVPTX::emitNonSPMDParallelCall(
   }
 }
 
-void CGOpenMPRuntimeNVPTX::emitSpmdParallelCall(
+void CGOpenMPRuntimeNVPTX::emitSPMDParallelCall(
     CodeGenFunction &CGF, SourceLocation Loc, llvm::Value *OutlinedFn,
     ArrayRef<llvm::Value *> CapturedVars, const Expr *IfCond) {
   // Just call the outlined function to execute the parallel region.