[clang] a27ca15 - [OpenMP] Fix non-determinism in clang task codegen

[Giorgis Georgakoudis via cfe-commits]

Author: Giorgis Georgakoudis
Date: 2021-05-03T10:34:38-07:00
New Revision: a27ca15dd08342b199e2feb5ae896475fd90a518

URL: https://github.com/llvm/llvm-project/commit/a27ca15dd08342b199e2feb5ae896475fd90a518
DIFF: https://github.com/llvm/llvm-project/commit/a27ca15dd08342b199e2feb5ae896475fd90a518.diff

LOG: [OpenMP] Fix non-determinism in clang task codegen

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D101739

Added: 
    

Modified: 
    clang/lib/CodeGen/CGOpenMPRuntime.cpp
    clang/lib/CodeGen/CGOpenMPRuntime.h
    clang/lib/CodeGen/CGStmtOpenMP.cpp

Removed: 
    


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diff  --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index fce6efe9fee0..1980c5c91af2 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -12107,8 +12107,8 @@ CGOpenMPRuntime::NontemporalDeclsRAII::~NontemporalDeclsRAII() {
 
 CGOpenMPRuntime::UntiedTaskLocalDeclsRAII::UntiedTaskLocalDeclsRAII(
     CodeGenFunction &CGF,
-    const llvm::DenseMap<CanonicalDeclPtr<const VarDecl>,
-                         std::pair<Address, Address>> &LocalVars)
+    const llvm::MapVector<CanonicalDeclPtr<const VarDecl>,
+                          std::pair<Address, Address>> &LocalVars)
     : CGM(CGF.CGM), NeedToPush(!LocalVars.empty()) {
   if (!NeedToPush)
     return;

diff  --git a/clang/lib/CodeGen/CGOpenMPRuntime.h b/clang/lib/CodeGen/CGOpenMPRuntime.h
index 7be9c3b1da22..5155370f46cf 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.h
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.h
@@ -253,8 +253,8 @@ class CGOpenMPRuntime {
   public:
     UntiedTaskLocalDeclsRAII(
         CodeGenFunction &CGF,
-        const llvm::DenseMap<CanonicalDeclPtr<const VarDecl>,
-                             std::pair<Address, Address>> &LocalVars);
+        const llvm::MapVector<CanonicalDeclPtr<const VarDecl>,
+                              std::pair<Address, Address>> &LocalVars);
     ~UntiedTaskLocalDeclsRAII();
   };
 
@@ -723,8 +723,8 @@ class CGOpenMPRuntime {
   llvm::SmallVector<NontemporalDeclsSet, 4> NontemporalDeclsStack;
 
   using UntiedLocalVarsAddressesMap =
-      llvm::DenseMap<CanonicalDeclPtr<const VarDecl>,
-                     std::pair<Address, Address>>;
+      llvm::MapVector<CanonicalDeclPtr<const VarDecl>,
+                      std::pair<Address, Address>>;
   llvm::SmallVector<UntiedLocalVarsAddressesMap, 4> UntiedLocalVarsStack;
 
   /// Stack for list of addresses of declarations in current context marked as

diff  --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 83d3dd0fc813..e7ddc0aa4c8d 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -4339,7 +4339,8 @@ void CodeGenFunction::EmitOMPTaskBasedDirective(
   auto &&CodeGen = [&Data, &S, CS, &BodyGen, &LastprivateDstsOrigs,
                     CapturedRegion](CodeGenFunction &CGF,
                                     PrePostActionTy &Action) {
-    llvm::DenseMap<CanonicalDeclPtr<const VarDecl>, std::pair<Address, Address>>
+    llvm::MapVector<CanonicalDeclPtr<const VarDecl>,
+                    std::pair<Address, Address>>
         UntiedLocalVars;
     // Set proper addresses for generated private copies.
     OMPPrivateScope Scope(CGF);
@@ -4392,7 +4393,12 @@ void CodeGenFunction::EmitOMPTaskBasedDirective(
           Ty = CGF.getContext().getPointerType(Ty);
         Address PrivatePtr = CGF.CreateMemTemp(
             CGF.getContext().getPointerType(Ty), ".local.ptr.addr");
-        UntiedLocalVars.try_emplace(VD, PrivatePtr, Address::invalid());
+        auto Result = UntiedLocalVars.insert(
+            std::make_pair(VD, std::make_pair(PrivatePtr, Address::invalid())));
+        // If key exists update in place.
+        if (Result.second == false)
+          *Result.first = std::make_pair(
+              VD, std::make_pair(PrivatePtr, Address::invalid()));
         CallArgs.push_back(PrivatePtr.getPointer());
         ParamTypes.push_back(PrivatePtr.getType());
       }
@@ -4424,14 +4430,14 @@ void CodeGenFunction::EmitOMPTaskBasedDirective(
         if (isAllocatableDecl(Pair.first)) {
           llvm::Value *Ptr = CGF.Builder.CreateLoad(Pair.second.first);
           Address Replacement(Ptr, CGF.getPointerAlign());
-          Pair.getSecond().first = Replacement;
+          Pair.second.first = Replacement;
           Ptr = CGF.Builder.CreateLoad(Replacement);
           Replacement = Address(Ptr, CGF.getContext().getDeclAlign(Pair.first));
-          Pair.getSecond().second = Replacement;
+          Pair.second.second = Replacement;
         } else {
           llvm::Value *Ptr = CGF.Builder.CreateLoad(Pair.second.first);
           Address Replacement(Ptr, CGF.getContext().getDeclAlign(Pair.first));
-          Pair.getSecond().first = Replacement;
+          Pair.second.first = Replacement;
         }
       }
     }