OpenCL: introduce support for function scope __local variables

llvm-svn: 140068

clang/include/clang/AST/Decl.h

@@ -815,7 +815,7 @@ public:
       return !isFileVarDecl();
 
     // Return true for:  Auto, Register.
-    // Return false for: Extern, Static, PrivateExtern.
+    // Return false for: Extern, Static, PrivateExtern, OpenCLWorkGroupLocal.
 
     return getStorageClass() >= SC_Auto;
   }

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -2589,6 +2589,8 @@ def err_at_least_one_initializer_needed_to_size_array : Error<
 def err_array_size_non_int : Error<"size of array has non-integer type %0">;
 def err_init_element_not_constant : Error<
   "initializer element is not a compile-time constant">;
+def err_local_cant_init : Error<
+  "'__local' variable cannot have an initializer">;
 def err_block_extern_cant_init : Error<
   "'extern' variable cannot have an initializer">;
 def warn_extern_init : Warning<"'extern' variable has an initializer">;

clang/include/clang/Basic/Specifiers.h

@@ -146,6 +146,7 @@ namespace clang {
     SC_PrivateExtern,
 
     // These are only legal on variables.
+    SC_OpenCLWorkGroupLocal,
     SC_Auto,
     SC_Register
   };

clang/lib/AST/Decl.cpp

@@ -1119,12 +1119,13 @@ QualifierInfo::setTemplateParameterListsInfo(ASTContext &Context,
 
 const char *VarDecl::getStorageClassSpecifierString(StorageClass SC) {
   switch (SC) {
-  case SC_None:          break;
-  case SC_Auto:          return "auto"; break;
-  case SC_Extern:        return "extern"; break;
-  case SC_PrivateExtern: return "__private_extern__"; break;
-  case SC_Register:      return "register"; break;
-  case SC_Static:        return "static"; break;
+  case SC_None:                 break;
+  case SC_Auto:                 return "auto"; break;
+  case SC_Extern:               return "extern"; break;
+  case SC_OpenCLWorkGroupLocal: return "<<work-group-local>>"; break;
+  case SC_PrivateExtern:        return "__private_extern__"; break;
+  case SC_Register:             return "register"; break;
+  case SC_Static:               return "static"; break;
   }
 
   assert(0 && "Invalid storage class");

clang/lib/AST/DeclPrinter.cpp

@@ -381,7 +381,8 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
     case SC_Extern: Out << "extern "; break;
     case SC_Static: Out << "static "; break;
     case SC_PrivateExtern: Out << "__private_extern__ "; break;
-    case SC_Auto: case SC_Register: llvm_unreachable("invalid for functions");
+    case SC_Auto: case SC_Register: case SC_OpenCLWorkGroupLocal:
+      llvm_unreachable("invalid for functions");
     }
 
     if (D->isInlineSpecified())  Out << "inline ";

clang/lib/CodeGen/CGDecl.cpp

@@ -14,6 +14,7 @@
 #include "CGDebugInfo.h"
 #include "CodeGenFunction.h"
 #include "CodeGenModule.h"
+#include "CGOpenCLRuntime.h"
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/CharUnits.h"
 #include "clang/AST/Decl.h"
@@ -131,6 +132,8 @@ void CodeGenFunction::EmitVarDecl(const VarDecl &D) {
   case SC_PrivateExtern:
     // Don't emit it now, allow it to be emitted lazily on its first use.
     return;
+  case SC_OpenCLWorkGroupLocal:
+    return CGM.getOpenCLRuntime().EmitWorkGroupLocalVarDecl(*this, D);
   }
 
   assert(0 && "Unknown storage class");

clang/lib/CodeGen/CGOpenCLRuntime.cpp

@@ -0,0 +1,28 @@
+//===----- CGOpenCLRuntime.cpp - Interface to OpenCL Runtimes -------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This provides an abstract class for OpenCL code generation.  Concrete
+// subclasses of this implement code generation for specific OpenCL
+// runtime libraries.
+//
+//===----------------------------------------------------------------------===//
+
+#include "CGOpenCLRuntime.h"
+#include "CodeGenFunction.h"
+#include "llvm/GlobalValue.h"
+
+using namespace clang;
+using namespace CodeGen;
+
+CGOpenCLRuntime::~CGOpenCLRuntime() {}
+
+void CGOpenCLRuntime::EmitWorkGroupLocalVarDecl(CodeGenFunction &CGF,
+                                                const VarDecl &D) {
+  return CGF.EmitStaticVarDecl(D, llvm::GlobalValue::InternalLinkage);
+}

clang/lib/CodeGen/CGOpenCLRuntime.h

@@ -0,0 +1,46 @@
+//===----- CGOpenCLRuntime.h - Interface to OpenCL Runtimes -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This provides an abstract class for OpenCL code generation.  Concrete
+// subclasses of this implement code generation for specific OpenCL
+// runtime libraries.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CODEGEN_OPENCLRUNTIME_H
+#define CLANG_CODEGEN_OPENCLRUNTIME_H
+
+namespace clang {
+
+class VarDecl;
+
+namespace CodeGen {
+
+class CodeGenFunction;
+class CodeGenModule;
+
+class CGOpenCLRuntime {
+protected:
+  CodeGenModule &CGM;
+
+public:
+  CGOpenCLRuntime(CodeGenModule &CGM) : CGM(CGM) {}
+  virtual ~CGOpenCLRuntime();
+
+  /// Emit the IR required for a work-group-local variable declaration, and add
+  /// an entry to CGF's LocalDeclMap for D.  The base class does this using
+  /// CodeGenFunction::EmitStaticVarDecl to emit an internal global for D.
+  virtual void EmitWorkGroupLocalVarDecl(CodeGenFunction &CGF,
+                                         const VarDecl &D);
+};
+
+}
+}
+
+#endif

clang/lib/CodeGen/CMakeLists.txt

@@ -31,6 +31,7 @@ add_clang_library(clangCodeGen
   CGObjCGNU.cpp
   CGObjCMac.cpp
   CGObjCRuntime.cpp
+  CGOpenCLRuntime.cpp
   CGRecordLayoutBuilder.cpp
   CGRTTI.cpp
   CGStmt.cpp

clang/lib/CodeGen/CodeGenModule.cpp

@@ -18,6 +18,7 @@
 #include "CGCall.h"
 #include "CGCXXABI.h"
 #include "CGObjCRuntime.h"
+#include "CGOpenCLRuntime.h"
 #include "TargetInfo.h"
 #include "clang/Frontend/CodeGenOptions.h"
 #include "clang/AST/ASTContext.h"
@@ -65,15 +66,17 @@ CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
     ABI(createCXXABI(*this)), 
     Types(C, M, TD, getTargetCodeGenInfo().getABIInfo(), ABI, CGO),
     TBAA(0),
-    VTables(*this), ObjCRuntime(0), DebugInfo(0), ARCData(0), RRData(0),
-    CFConstantStringClassRef(0), ConstantStringClassRef(0),
+    VTables(*this), ObjCRuntime(0), OpenCLRuntime(0), DebugInfo(0), ARCData(0),
+    RRData(0), CFConstantStringClassRef(0), ConstantStringClassRef(0),
     NSConstantStringType(0),
     VMContext(M.getContext()),
     NSConcreteGlobalBlock(0), NSConcreteStackBlock(0),
     BlockObjectAssign(0), BlockObjectDispose(0),
     BlockDescriptorType(0), GenericBlockLiteralType(0) {
   if (Features.ObjC1)
-     createObjCRuntime();
+    createObjCRuntime();
+  if (Features.OpenCL)
+    createOpenCLRuntime();
 
   // Enable TBAA unless it's suppressed.
   if (!CodeGenOpts.RelaxedAliasing && CodeGenOpts.OptimizationLevel > 0)
@@ -109,6 +112,7 @@ CodeGenModule::CodeGenModule(ASTContext &C, const CodeGenOptions &CGO,
 
 CodeGenModule::~CodeGenModule() {
   delete ObjCRuntime;
+  delete OpenCLRuntime;
   delete &ABI;
   delete TBAA;
   delete DebugInfo;
@@ -123,6 +127,10 @@ void CodeGenModule::createObjCRuntime() {
     ObjCRuntime = CreateMacObjCRuntime(*this);
 }
 
+void CodeGenModule::createOpenCLRuntime() {
+  OpenCLRuntime = new CGOpenCLRuntime(*this);
+}
+
 void CodeGenModule::Release() {
   EmitDeferred();
   EmitCXXGlobalInitFunc();

clang/lib/CodeGen/CodeGenModule.h

@@ -75,6 +75,7 @@ namespace CodeGen {
   class CGCXXABI;
   class CGDebugInfo;
   class CGObjCRuntime;
+  class CGOpenCLRuntime;
   class BlockFieldFlags;
   class FunctionArgList;
   
@@ -226,6 +227,7 @@ class CodeGenModule : public CodeGenTypeCache {
   friend class CodeGenVTables;
 
   CGObjCRuntime* ObjCRuntime;
+  CGOpenCLRuntime* OpenCLRuntime;
   CGDebugInfo* DebugInfo;
   ARCEntrypoints *ARCData;
   RREntrypoints *RRData;
@@ -317,6 +319,8 @@ class CodeGenModule : public CodeGenTypeCache {
   /// Lazily create the Objective-C runtime
   void createObjCRuntime();
 
+  void createOpenCLRuntime();
+
   llvm::LLVMContext &VMContext;
 
   /// @name Cache for Blocks Runtime Globals
@@ -356,6 +360,12 @@ public:
   /// been configured.
   bool hasObjCRuntime() { return !!ObjCRuntime; }
 
+  /// getObjCRuntime() - Return a reference to the configured OpenCL runtime.
+  CGOpenCLRuntime &getOpenCLRuntime() {
+    assert(OpenCLRuntime != 0);
+    return *OpenCLRuntime;
+  }
+
   /// getCXXABI() - Return a reference to the configured C++ ABI.
   CGCXXABI &getCXXABI() { return ABI; }
 

clang/lib/Sema/SemaDecl.cpp

@@ -3734,6 +3734,13 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
     }
   }
   
+  if (getLangOptions().OpenCL) {
+    // Set up the special work-group-local storage class for variables in the
+    // OpenCL __local address space.
+    if (R.getAddressSpace() == LangAS::opencl_local)
+      SC = SC_OpenCLWorkGroupLocal;
+  }
+
   bool isExplicitSpecialization = false;
   VarDecl *NewVD;
   if (!getLangOptions().CPlusPlus) {
@@ -3883,6 +3890,7 @@ Sema::ActOnVariableDeclarator(Scope *S, Declarator &D, DeclContext *DC,
       case SC_Static:
       case SC_Extern:
       case SC_PrivateExtern:
+      case SC_OpenCLWorkGroupLocal:
         break;
       }
     }
@@ -5715,6 +5723,14 @@ void Sema::AddInitializerToDecl(Decl *RealDecl, Expr *Init,
     }
   }
 
+  // OpenCL 1.1 6.5.2: "Variables allocated in the __local address space inside
+  // a kernel function cannot be initialized."
+  if (VDecl->getStorageClass() == SC_OpenCLWorkGroupLocal) {
+    Diag(VDecl->getLocation(), diag::err_local_cant_init);
+    VDecl->setInvalidDecl();
+    return;
+  }
+
   // Capture the variable that is being initialized and the style of
   // initialization.
   InitializedEntity Entity = InitializedEntity::InitializeVariable(VDecl);
@@ -6131,6 +6147,9 @@ void Sema::ActOnCXXForRangeDecl(Decl *D) {
   case SC_Register:
     Error = 4;
     break;
+  case SC_OpenCLWorkGroupLocal:
+    assert(0 && "Unexpected storage class");
+    break;
   }
   // FIXME: constexpr isn't allowed here.
   //if (DS.isConstexprSpecified())

clang/test/CodeGenOpenCL/local.cl

@@ -0,0 +1,7 @@
+// RUN: %clang_cc1 %s -ffake-address-space-map -emit-llvm -o - | FileCheck %s
+
+__kernel void foo(void) {
+  // CHECK: @foo.i = internal addrspace(2)
+  __local int i;
+  ++i;
+}

clang/test/SemaOpenCL/local.cl

@@ -0,0 +1,6 @@
+// RUN: %clang_cc1 %s -verify -pedantic -fsyntax-only
+
+__kernel void foo(void) {
+  __local int i;
+  __local int j = 2; // expected-error {{'__local' variable cannot have an initializer}}
+}