Revert "[OpenACC] Sema changes for +*&|^ reduction combiner recipes (… (#162920)

…#162740)"

This reverts commit 6010df0.

This apparently fails some sanitizer test as reported here:
#162740

It isn't really clear where this happens, but reverting as it is a
friday, and I have no idea if I'll be able to repro this anytime soon,
  let alone fix it.

Author: erichkeane

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -13665,11 +13665,6 @@ def warn_acc_var_referenced_lacks_op
               "reference has no effect">,
       InGroup<DiagGroup<"openacc-var-lacks-operation">>,
       DefaultError;
-def err_acc_reduction_recipe_no_op
-    : Error<"variable of type %0 referenced in OpenACC 'reduction' clause does "
-            "not have a valid operation available">;
-def note_acc_reduction_recipe_noop_field
-    : Note<"while forming combiner for compound type %0">;
 
 // AMDGCN builtins diagnostics
 def err_amdgcn_load_lds_size_invalid_value : Error<"invalid size value">;

clang/include/clang/Sema/SemaOpenACC.h

@@ -228,11 +228,6 @@ class SemaOpenACC : public SemaBase {
 
   bool DiagnoseAllowedClauses(OpenACCDirectiveKind DK, OpenACCClauseKind CK,
                               SourceLocation ClauseLoc);
-  bool CreateReductionCombinerRecipe(
-      SourceLocation loc, OpenACCReductionOperator ReductionOperator,
-      QualType VarTy,
-      llvm::SmallVectorImpl<OpenACCReductionRecipe::CombinerRecipe>
-          &CombinerRecipes);
 
 public:
   // Needed from the visitor, so should be public.

clang/lib/Sema/SemaOpenACC.cpp

@@ -2898,15 +2898,6 @@ OpenACCReductionRecipe SemaOpenACC::CreateReductionInitRecipe(
           dyn_cast<ArraySectionExpr>(VarExpr->IgnoreParenImpCasts()))
     VarTy = ASE->getElementType();
 
-  llvm::SmallVector<OpenACCReductionRecipe::CombinerRecipe, 1> CombinerRecipes;
-
-  // We use the 'set-ness' of the alloca-decl to determine whether the combiner
-  // is 'set' or not, so we can skip any attempts at it if we're going to fail
-  // at any of the combiners.
-  if (CreateReductionCombinerRecipe(VarExpr->getBeginLoc(), ReductionOperator,
-                                    VarTy, CombinerRecipes))
-    return OpenACCReductionRecipe::Empty();
-
   VarDecl *AllocaDecl = CreateAllocaDecl(
       getASTContext(), SemaRef.getCurContext(), VarExpr->getBeginLoc(),
       &getASTContext().Idents.get("openacc.reduction.init"), VarTy);
@@ -2955,163 +2946,5 @@ OpenACCReductionRecipe SemaOpenACC::CreateReductionInitRecipe(
     AllocaDecl->setInit(Init.get());
     AllocaDecl->setInitStyle(VarDecl::CallInit);
   }
-
-  return OpenACCReductionRecipe(AllocaDecl, CombinerRecipes);
-}
-
-bool SemaOpenACC::CreateReductionCombinerRecipe(
-    SourceLocation Loc, OpenACCReductionOperator ReductionOperator,
-    QualType VarTy,
-    llvm::SmallVectorImpl<OpenACCReductionRecipe::CombinerRecipe>
-        &CombinerRecipes) {
-  // Now we can try to generate the 'combiner' recipe. This is a little
-  // complicated in that if the 'VarTy' is an array type, we want to take its
-  // element type so we can generate that.  Additionally, if this is a struct,
-  // we have two options: If there is overloaded operators, we want to take
-  // THOSE, else we want to do the individual elements.
-
-  BinaryOperatorKind BinOp;
-  switch (ReductionOperator) {
-  case OpenACCReductionOperator::Invalid:
-    // This can only happen when there is an error, and since these inits
-    // are used for code generation, we can just ignore/not bother doing any
-    // initialization here.
-    CombinerRecipes.push_back({nullptr, nullptr, nullptr});
-    return false;
-  case OpenACCReductionOperator::Addition:
-    BinOp = BinaryOperatorKind::BO_AddAssign;
-    break;
-  case OpenACCReductionOperator::Multiplication:
-    BinOp = BinaryOperatorKind::BO_MulAssign;
-    break;
-  case OpenACCReductionOperator::BitwiseAnd:
-    BinOp = BinaryOperatorKind::BO_AndAssign;
-    break;
-  case OpenACCReductionOperator::BitwiseOr:
-    BinOp = BinaryOperatorKind::BO_OrAssign;
-    break;
-  case OpenACCReductionOperator::BitwiseXOr:
-    BinOp = BinaryOperatorKind::BO_XorAssign;
-    break;
-
-  case OpenACCReductionOperator::Max:
-  case OpenACCReductionOperator::Min:
-  case OpenACCReductionOperator::And:
-  case OpenACCReductionOperator::Or:
-    // We just want a 'NYI' error in the backend, so leave an empty combiner
-    // recipe, and claim success.
-    CombinerRecipes.push_back({nullptr, nullptr, nullptr});
-    return false;
-  }
-
-  // If VarTy is an array type, at the top level only, we want to do our
-  // compares/decomp/etc at the element level.
-  if (auto *AT = getASTContext().getAsArrayType(VarTy))
-    VarTy = AT->getElementType();
-
-  assert(!VarTy->isArrayType() && "Only 1 level of array allowed");
-
-  auto tryCombiner = [&, this](DeclRefExpr *LHSDRE, DeclRefExpr *RHSDRE,
-                               bool IncludeTrap) {
-    // TODO: OpenACC: we have to figure out based on the bin-op how to do the
-    // ones that we can't just use compound operators for.  So &&, ||, max, and
-    // min aren't really clear what we could do here.
-    if (IncludeTrap) {
-      // Trap all of the errors here, we'll emit our own at the end.
-      Sema::TentativeAnalysisScope Trap{SemaRef};
-
-      return SemaRef.BuildBinOp(SemaRef.getCurScope(), Loc, BinOp, LHSDRE,
-                                RHSDRE,
-                                /*ForFoldExpr=*/false);
-    } else {
-      return SemaRef.BuildBinOp(SemaRef.getCurScope(), Loc, BinOp, LHSDRE,
-                                RHSDRE,
-                                /*ForFoldExpr=*/false);
-    }
-  };
-
-  struct CombinerAttemptTy {
-    VarDecl *LHS;
-    DeclRefExpr *LHSDRE;
-    VarDecl *RHS;
-    DeclRefExpr *RHSDRE;
-    Expr *Op;
-  };
-
-  auto formCombiner = [&, this](QualType Ty) -> CombinerAttemptTy {
-    VarDecl *LHSDecl = CreateAllocaDecl(
-        getASTContext(), SemaRef.getCurContext(), Loc,
-        &getASTContext().Idents.get("openacc.reduction.combiner.lhs"), Ty);
-    auto *LHSDRE = DeclRefExpr::Create(
-        getASTContext(), NestedNameSpecifierLoc{}, SourceLocation{}, LHSDecl,
-        /*ReferstoEnclosingVariableOrCapture=*/false,
-        DeclarationNameInfo{DeclarationName{LHSDecl->getDeclName()},
-                            LHSDecl->getBeginLoc()},
-        Ty, clang::VK_LValue, LHSDecl, nullptr, NOUR_None);
-    VarDecl *RHSDecl = CreateAllocaDecl(
-        getASTContext(), SemaRef.getCurContext(), Loc,
-        &getASTContext().Idents.get("openacc.reduction.combiner.lhs"), Ty);
-    auto *RHSDRE = DeclRefExpr::Create(
-        getASTContext(), NestedNameSpecifierLoc{}, SourceLocation{}, RHSDecl,
-        /*ReferstoEnclosingVariableOrCapture=*/false,
-        DeclarationNameInfo{DeclarationName{RHSDecl->getDeclName()},
-                            RHSDecl->getBeginLoc()},
-        Ty, clang::VK_LValue, RHSDecl, nullptr, NOUR_None);
-
-    ExprResult BinOpResult = tryCombiner(LHSDRE, RHSDRE, /*IncludeTrap=*/true);
-
-    return {LHSDecl, LHSDRE, RHSDecl, RHSDRE, BinOpResult.get()};
-  };
-
-  CombinerAttemptTy TopLevelCombinerInfo = formCombiner(VarTy);
-
-  if (TopLevelCombinerInfo.Op) {
-    if (!TopLevelCombinerInfo.Op->containsErrors() &&
-        TopLevelCombinerInfo.Op->isInstantiationDependent()) {
-      // If this is instantiation dependent, we're just going to 'give up' here
-      // and count on us to get it right during instantaition.
-      CombinerRecipes.push_back({nullptr, nullptr, nullptr});
-      return false;
-    } else if (!TopLevelCombinerInfo.Op->containsErrors()) {
-      // Else, we succeeded, we can just return this combiner.
-      CombinerRecipes.push_back({TopLevelCombinerInfo.LHS,
-                                 TopLevelCombinerInfo.RHS,
-                                 TopLevelCombinerInfo.Op});
-      return false;
-    }
-  }
-
-  // Since the 'root' level didn't fail, the only thing that could be successful
-  // is a struct that we decompose on its individual fields.
-
-  RecordDecl *RD = VarTy->getAsRecordDecl();
-  if (!RD) {
-    Diag(Loc, diag::err_acc_reduction_recipe_no_op) << VarTy;
-    tryCombiner(TopLevelCombinerInfo.LHSDRE, TopLevelCombinerInfo.RHSDRE,
-                /*IncludeTrap=*/false);
-    return true;
-  }
-
-  for (const FieldDecl *FD : RD->fields()) {
-    CombinerAttemptTy FieldCombinerInfo = formCombiner(FD->getType());
-
-    if (!FieldCombinerInfo.Op || FieldCombinerInfo.Op->containsErrors()) {
-      Diag(Loc, diag::err_acc_reduction_recipe_no_op) << FD->getType();
-      Diag(FD->getBeginLoc(), diag::note_acc_reduction_recipe_noop_field) << RD;
-      tryCombiner(FieldCombinerInfo.LHSDRE, FieldCombinerInfo.RHSDRE,
-                  /*IncludeTrap=*/false);
-      return true;
-    }
-
-    if (FieldCombinerInfo.Op->isInstantiationDependent()) {
-      // If this is instantiation dependent, we're just going to 'give up' here
-      // and count on us to get it right during instantaition.
-      CombinerRecipes.push_back({nullptr, nullptr, nullptr});
-    } else {
-      CombinerRecipes.push_back(
-          {FieldCombinerInfo.LHS, FieldCombinerInfo.RHS, FieldCombinerInfo.Op});
-    }
-  }
-
-  return false;
+  return OpenACCReductionRecipe(AllocaDecl, {});
 }