[OpenCL] Add to_{global|local|private} builtin functions.

OpenCL builtin functions to_{global|local|private} accepts argument of pointer type to arbitrary pointee type, and return a pointer to the same pointee type in different addr space, i.e.

global gentype *to_global(gentype *p);
It is not desirable to declare it as

global void *to_global(void *);
in opencl header file since it misses diagnostics.

This patch implements these builtin functions as Clang builtin functions. In the builtin def file they are defined to have signature void*(void*). When handling call expressions, their declarations are re-written to have correct parameter type and return type corresponding to the call argument.

In codegen call to addr void *to_addr(void*) is generated with addrcasts or bitcasts to facilitate implementation in builtin library.

Differential Revision: http://reviews.llvm.org/D19932

llvm-svn: 270261

2 files changed, 75 insertions, 0 deletions

diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 81ae61857ad..daf89b4a744 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -2124,6 +2124,29 @@ RValue CodeGenFunction::EmitBuiltinExpr(const FunctionDecl *FD,
         Builder.CreateCall(CGM.CreateRuntimeFunction(FTy, Name), {Arg0}));
   }
 
+  // OpenCL v2.0 s6.13.9 - Address space qualifier functions.
+  case Builtin::BIto_global:
+  case Builtin::BIto_local:
+  case Builtin::BIto_private: {
+    auto Arg0 = EmitScalarExpr(E->getArg(0));
+    auto NewArgT = llvm::PointerType::get(Int8Ty,
+      CGM.getContext().getTargetAddressSpace(LangAS::opencl_generic));
+    auto NewRetT = llvm::PointerType::get(Int8Ty,
+      CGM.getContext().getTargetAddressSpace(
+        E->getType()->getPointeeType().getAddressSpace()));
+    auto FTy = llvm::FunctionType::get(NewRetT, {NewArgT}, false);
+    llvm::Value *NewArg;
+    if (Arg0->getType()->getPointerAddressSpace() !=
+        NewArgT->getPointerAddressSpace())
+      NewArg = Builder.CreateAddrSpaceCast(Arg0, NewArgT);
+    else
+      NewArg = Builder.CreateBitOrPointerCast(Arg0, NewArgT);
+    auto NewCall = Builder.CreateCall(CGM.CreateRuntimeFunction(FTy,
+      E->getDirectCallee()->getName()), {NewArg});
+    return RValue::get(Builder.CreateBitOrPointerCast(NewCall,
+      ConvertType(E->getType())));
+  }
+
   case Builtin::BIprintf:
     if (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
       return EmitCUDADevicePrintfCallExpr(E, ReturnValue);
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index dc91b93f202..670a67de2b5 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -455,6 +455,52 @@ static bool SemaBuiltinPipePackets(Sema &S, CallExpr *Call) {
   return false;
 }
 
+// \brief Performs semantic analysis for the to_global/local/private call.
+// \param S Reference to the semantic analyzer.
+// \param BuiltinID ID of the builtin function.
+// \param Call A pointer to the builtin call.
+// \return True if a semantic error has been found, false otherwise.
+static bool SemaOpenCLBuiltinToAddr(Sema &S, unsigned BuiltinID,
+                                    CallExpr *Call) {
+  // OpenCL v2.0 s6.13.9 - Address space qualifier functions.
+  if (S.getLangOpts().OpenCLVersion < 200) {
+    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_requires_version)
+        << Call->getDirectCallee() << "2.0" << 1 << Call->getSourceRange();
+    return true;
+  }
+
+  if (Call->getNumArgs() != 1) {
+    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_to_addr_arg_num)
+        << Call->getDirectCallee() << Call->getSourceRange();
+    return true;
+  }
+
+  auto RT = Call->getArg(0)->getType();
+  if (!RT->isPointerType() || RT->getPointeeType()
+      .getAddressSpace() == LangAS::opencl_constant) {
+    S.Diag(Call->getLocStart(), diag::err_opencl_builtin_to_addr_invalid_arg)
+        << Call->getArg(0) << Call->getDirectCallee() << Call->getSourceRange();
+    return true;
+  }
+
+  RT = RT->getPointeeType();
+  auto Qual = RT.getQualifiers();
+  switch (BuiltinID) {
+  case Builtin::BIto_global:
+    Qual.setAddressSpace(LangAS::opencl_global);
+    break;
+  case Builtin::BIto_local:
+    Qual.setAddressSpace(LangAS::opencl_local);
+    break;
+  default:
+    Qual.removeAddressSpace();
+  }
+  Call->setType(S.Context.getPointerType(S.Context.getQualifiedType(
+      RT.getUnqualifiedType(), Qual)));
+
+  return false;
+}
+
 ExprResult
 Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
                                CallExpr *TheCall) {
@@ -789,6 +835,12 @@ Sema::CheckBuiltinFunctionCall(FunctionDecl *FDecl, unsigned BuiltinID,
     if (SemaBuiltinPipePackets(*this, TheCall))
       return ExprError();
     break;
+  case Builtin::BIto_global:
+  case Builtin::BIto_local:
+  case Builtin::BIto_private:
+    if (SemaOpenCLBuiltinToAddr(*this, BuiltinID, TheCall))
+      return ExprError();
+    break;
   }
 
   // Since the target specific builtins for each arch overlap, only check those