[OpenCL] AMDGCN target will generate images in constant address space

Allows AMDGCN target to generate images (such as %opencl.image2d_t) in constant address space.
Images will still be generated in global address space by default.

Added tests to existing opencl-types.cl in test\CodeGenOpenCL.

Patch by Aaron En Ye Shi.

Differential Revision: https://reviews.llvm.org/D22523

llvm-svn: 276161
diff --git a/clang/lib/CodeGen/CGOpenCLRuntime.cpp b/clang/lib/CodeGen/CGOpenCLRuntime.cpp
index 38aebea..c0af6de 100644
--- a/clang/lib/CodeGen/CGOpenCLRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenCLRuntime.cpp
@@ -15,6 +15,7 @@
 
 #include "CGOpenCLRuntime.h"
 #include "CodeGenFunction.h"
+#include "TargetInfo.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/GlobalValue.h"
 #include <assert.h>
@@ -35,7 +36,7 @@
 
   llvm::LLVMContext& Ctx = CGM.getLLVMContext();
   uint32_t ImgAddrSpc =
-    CGM.getContext().getTargetAddressSpace(LangAS::opencl_global);
+    CGM.getTargetCodeGenInfo().getOpenCLImageAddrSpace(CGM);
   switch (cast<BuiltinType>(T)->getKind()) {
   default: 
     llvm_unreachable("Unexpected opencl builtin type!");
diff --git a/clang/lib/CodeGen/TargetInfo.cpp b/clang/lib/CodeGen/TargetInfo.cpp
index 0777779..be97d64 100644
--- a/clang/lib/CodeGen/TargetInfo.cpp
+++ b/clang/lib/CodeGen/TargetInfo.cpp
@@ -375,6 +375,11 @@
 unsigned TargetCodeGenInfo::getOpenCLKernelCallingConv() const {
   return llvm::CallingConv::C;
 }
+
+unsigned TargetCodeGenInfo::getOpenCLImageAddrSpace(CodeGen::CodeGenModule &CGM) const {
+  return CGM.getContext().getTargetAddressSpace(LangAS::opencl_global);
+}
+
 static bool isEmptyRecord(ASTContext &Context, QualType T, bool AllowArrays);
 
 /// isEmptyField - Return true iff a the field is "empty", that is it
@@ -6832,6 +6837,7 @@
   void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
                            CodeGen::CodeGenModule &M) const override;
   unsigned getOpenCLKernelCallingConv() const override;
+  unsigned getOpenCLImageAddrSpace(CodeGen::CodeGenModule &CGM) const override;
 };
 
 }
@@ -6868,6 +6874,10 @@
   return llvm::CallingConv::AMDGPU_KERNEL;
 }
 
+unsigned AMDGPUTargetCodeGenInfo::getOpenCLImageAddrSpace(CodeGen::CodeGenModule &CGM) const {
+  return CGM.getContext().getTargetAddressSpace(LangAS::opencl_constant);
+}
+
 //===----------------------------------------------------------------------===//
 // SPARC v8 ABI Implementation.
 // Based on the SPARC Compliance Definition version 2.4.1.
diff --git a/clang/lib/CodeGen/TargetInfo.h b/clang/lib/CodeGen/TargetInfo.h
index e463825..64a082b 100644
--- a/clang/lib/CodeGen/TargetInfo.h
+++ b/clang/lib/CodeGen/TargetInfo.h
@@ -220,6 +220,9 @@
 
   /// Get LLVM calling convention for OpenCL kernel.
   virtual unsigned getOpenCLKernelCallingConv() const;
+
+  /// Get LLVM Image Address Space for OpenCL kernel.
+  virtual unsigned getOpenCLImageAddrSpace(CodeGen::CodeGenModule &CGM) const;
 };
 
 } // namespace CodeGen