CodeGen: Cast temporary variable to proper address space

In C++ all variables are in default address space. Previously change has been
made to cast automatic variables to default address space. However that is
not sufficient since all temporary variables need to be casted to default
address space.

This patch casts all temporary variables to default address space except those
for passing indirect arguments since they are only used for load/store.

This patch only affects target having non-zero alloca address space.

Differential Revision: https://reviews.llvm.org/D33706


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@305711 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 33 insertions, 11 deletions

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 7359006677..2ee1c96a66 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -61,18 +61,36 @@ llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) {
 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
 /// block.
 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
-                                          const Twine &Name) {
-  auto Alloca = CreateTempAlloca(Ty, Name);
+                                          const Twine &Name,
+                                          llvm::Value *ArraySize,
+                                          bool CastToDefaultAddrSpace) {
+  auto Alloca = CreateTempAlloca(Ty, Name, ArraySize);
   Alloca->setAlignment(Align.getQuantity());
-  return Address(Alloca, Align);
+  llvm::Value *V = Alloca;
+  // Alloca always returns a pointer in alloca address space, which may
+  // be different from the type defined by the language. For example,
+  // in C++ the auto variables are in the default address space. Therefore
+  // cast alloca to the default address space when necessary.
+  if (CastToDefaultAddrSpace && getASTAllocaAddressSpace() != LangAS::Default) {
+    auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default);
+    V = getTargetHooks().performAddrSpaceCast(
+        *this, V, getASTAllocaAddressSpace(), LangAS::Default,
+        Ty->getPointerTo(DestAddrSpace), /*non-null*/ true);
+  }
+
+  return Address(V, Align);
 }
 
-/// CreateTempAlloca - This creates a alloca and inserts it into the entry
-/// block.
+/// CreateTempAlloca - This creates an alloca and inserts it into the entry
+/// block if \p ArraySize is nullptr, otherwise inserts it at the current
+/// insertion point of the builder.
 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
-                                                    const Twine &Name) {
+                                                    const Twine &Name,
+                                                    llvm::Value *ArraySize) {
+  if (ArraySize)
+    return Builder.CreateAlloca(Ty, ArraySize, Name);
   return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(),
-                              nullptr, Name, AllocaInsertPt);
+                              ArraySize, Name, AllocaInsertPt);
 }
 
 /// CreateDefaultAlignTempAlloca - This creates an alloca with the
@@ -99,14 +117,18 @@ Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) {
   return CreateTempAlloca(ConvertType(Ty), Align, Name);
 }
 
-Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name) {
+Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name,
+                                       bool CastToDefaultAddrSpace) {
   // FIXME: Should we prefer the preferred type alignment here?
-  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name);
+  return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name,
+                       CastToDefaultAddrSpace);
 }
 
 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align,
-                                       const Twine &Name) {
-  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name);
+                                       const Twine &Name,
+                                       bool CastToDefaultAddrSpace) {
+  return CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name, nullptr,
+                          CastToDefaultAddrSpace);
 }
 
 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified