Revert "[OpenMP] Avoid VLAs for some reductions on array sections"

This breaks at least two buildbots:
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/1175
http://lab.llvm.org:8011/builders/clang-atom-d525-fedora-rel/builds/10478

This reverts commit r316229 during local investigation.

llvm-svn: 316235

2 files changed, 8 insertions, 9 deletions

diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 3396c63cd62..f98ff85565f 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -925,7 +925,7 @@ void ReductionCodeGen::emitAggregateType(CodeGenFunction &CGF, unsigned N) {
       cast<VarDecl>(cast<DeclRefExpr>(ClausesData[N].Private)->getDecl());
   QualType PrivateType = PrivateVD->getType();
   bool AsArraySection = isa<OMPArraySectionExpr>(ClausesData[N].Ref);
-  if (!PrivateType->isVariablyModifiedType()) {
+  if (!AsArraySection && !PrivateType->isVariablyModifiedType()) {
     Sizes.emplace_back(
         CGF.getTypeSize(
             SharedAddresses[N].first.getType().getNonReferenceType()),
@@ -963,9 +963,10 @@ void ReductionCodeGen::emitAggregateType(CodeGenFunction &CGF, unsigned N,
   auto *PrivateVD =
       cast<VarDecl>(cast<DeclRefExpr>(ClausesData[N].Private)->getDecl());
   QualType PrivateType = PrivateVD->getType();
-  if (!PrivateType->isVariablyModifiedType()) {
+  bool AsArraySection = isa<OMPArraySectionExpr>(ClausesData[N].Ref);
+  if (!AsArraySection && !PrivateType->isVariablyModifiedType()) {
     assert(!Size && !Sizes[N].second &&
-           "Size should be nullptr for non-variably modified reduction "
+           "Size should be nullptr for non-variably modified redution "
            "items.");
     return;
   }
@@ -993,7 +994,8 @@ void ReductionCodeGen::emitInitialization(
                                        CGF.ConvertTypeForMem(SharedType)),
       SharedType, SharedAddresses[N].first.getBaseInfo(),
       CGF.CGM.getTBAAAccessInfo(SharedType));
-  if (CGF.getContext().getAsArrayType(PrivateVD->getType())) {
+  if (isa<OMPArraySectionExpr>(ClausesData[N].Ref) ||
+      CGF.getContext().getAsArrayType(PrivateVD->getType())) {
     emitAggregateInitialization(CGF, N, PrivateAddr, SharedLVal, DRD);
   } else if (DRD && (DRD->getInitializer() || !PrivateVD->hasInit())) {
     emitInitWithReductionInitializer(CGF, DRD, ClausesData[N].ReductionOp,
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 0e5ea798ebd..cdec3e35f97 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -996,9 +996,7 @@ void CodeGenFunction::EmitOMPReductionClauseInit(
 
     auto *LHSVD = cast<VarDecl>(cast<DeclRefExpr>(*ILHS)->getDecl());
     auto *RHSVD = cast<VarDecl>(cast<DeclRefExpr>(*IRHS)->getDecl());
-    QualType Type = PrivateVD->getType();
-    bool isaOMPArraySectionExpr = isa<OMPArraySectionExpr>(IRef);
-    if (isaOMPArraySectionExpr && Type->isVariablyModifiedType()) {
+    if (isa<OMPArraySectionExpr>(IRef)) {
       // Store the address of the original variable associated with the LHS
       // implicit variable.
       PrivateScope.addPrivate(LHSVD, [&RedCG, Count]() -> Address {
@@ -1007,8 +1005,7 @@ void CodeGenFunction::EmitOMPReductionClauseInit(
       PrivateScope.addPrivate(RHSVD, [this, PrivateVD]() -> Address {
         return GetAddrOfLocalVar(PrivateVD);
       });
-    } else if ((isaOMPArraySectionExpr && Type->isScalarType()) ||
-               isa<ArraySubscriptExpr>(IRef)) {
+    } else if (isa<ArraySubscriptExpr>(IRef)) {
       // Store the address of the original variable associated with the LHS
       // implicit variable.
       PrivateScope.addPrivate(LHSVD, [&RedCG, Count]() -> Address {