CodeGen: Cast alloca to expected address space

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 expected address space when necessary.

Differential Revision: https://reviews.llvm.org/D32248

llvm-svn: 303370

1 files changed, 11 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/TargetInfo.h b/clang/lib/CodeGen/TargetInfo.h
index 223d6d047af..247d01dcb08 100644
--- a/clang/lib/CodeGen/TargetInfo.h
+++ b/clang/lib/CodeGen/TargetInfo.h
@@ -229,13 +229,20 @@ public:
   virtual llvm::Constant *getNullPointer(const CodeGen::CodeGenModule &CGM,
       llvm::PointerType *T, QualType QT) const;
 
+  /// Get the AST address space for alloca.
+  virtual unsigned getASTAllocaAddressSpace() const { return LangAS::Default; }
+
   /// Perform address space cast of an expression of pointer type.
   /// \param V is the LLVM value to be casted to another address space.
-  /// \param SrcTy is the QualType of \p V.
-  /// \param DestTy is the destination QualType.
+  /// \param SrcAddr is the language address space of \p V.
+  /// \param DestAddr is the targeted language address space.
+  /// \param DestTy is the destination LLVM pointer type.
+  /// \param IsNonNull is the flag indicating \p V is known to be non null.
   virtual llvm::Value *performAddrSpaceCast(CodeGen::CodeGenFunction &CGF,
-      llvm::Value *V, QualType SrcTy, QualType DestTy) const;
-
+                                            llvm::Value *V, unsigned SrcAddr,
+                                            unsigned DestAddr,
+                                            llvm::Type *DestTy,
+                                            bool IsNonNull = false) const;
 };
 
 } // namespace CodeGen