now nvptx allows extern "C" task void, which is emits a kernel that should (?) be callable by driver API from external code

decl.cpp

@@ -539,12 +539,14 @@ Declarator::InitFromType(const Type *baseType, DeclSpecs *ds) {
             Error(pos, "Function can't have both \"task\" and \"export\" "
                   "qualifiers");
             return;
-        }
+        }j
+#if 0 /* NVPTX64::task_and_externC */
         if (isExternC && isTask) {
             Error(pos, "Function can't have both \"extern \"C\"\" and \"task\" "
                   "qualifiers");
             return;
         }
+#endif
         if (isExternC && isExported) {
             Error(pos, "Function can't have both \"extern \"C\"\" and \"export\" "
                   "qualifiers");

func.cpp

@@ -186,6 +186,7 @@ lCopyInTaskParameter(int i, llvm::Value *structArgPtr, const
                      FunctionEmitContext *ctx) {
     // We expect the argument structure to come in as a poitner to a
     // structure.  Confirm and figure out its type here.
+    
     const llvm::Type *structArgType = structArgPtr->getType();
     Assert(llvm::isa<llvm::PointerType>(structArgType));
     const llvm::PointerType *pt = llvm::dyn_cast<const llvm::PointerType>(structArgType);
@@ -240,9 +241,11 @@ Function::emitCode(FunctionEmitContext *ctx, llvm::Function *function,
         // For tasks, we there should always be three parmeters: the
         // pointer to the structure that holds all of the arguments, the
         // thread index, and the thread count variables.
+
+        if (g->target->getISA() != Target::NVPTX64)
+        {
           llvm::Function::arg_iterator argIter = function->arg_begin();
           llvm::Value *structParamPtr = argIter++;
-
           // Copy the function parameter values from the structure into local
           // storage
           for (unsigned int i = 0; i < args.size(); ++i)
@@ -258,8 +261,6 @@ Function::emitCode(FunctionEmitContext *ctx, llvm::Function *function,
             ctx->SetFunctionMask(ptrval);
           }
 
-        if (g->target->getISA() != Target::NVPTX64)
-        {
           llvm::Value *threadIndex = argIter++;
           llvm::Value *threadCount = argIter++;
           llvm::Value *taskIndex = argIter++;
@@ -320,6 +321,28 @@ Function::emitCode(FunctionEmitContext *ctx, llvm::Function *function,
         }
         else
         {
+          llvm::Function::arg_iterator argIter = function->arg_begin();
+          for (unsigned int i = 0; i < args.size(); ++i, ++argIter) {
+            Symbol *sym = args[i];
+            if (sym == NULL)
+              // anonymous function parameter
+              continue;
+
+            argIter->setName(sym->name.c_str());
+
+            // Allocate stack storage for the parameter and emit code
+            // to store the its value there.
+            sym->storagePtr = ctx->AllocaInst(argIter->getType(), sym->name.c_str());
+            ctx->StoreInst(argIter, sym->storagePtr);
+            ctx->EmitFunctionParameterDebugInfo(sym, i);
+          }
+          if (argIter == function->arg_end()) {
+            Assert(type->isUnmasked || type->isExported);
+            ctx->SetFunctionMask(LLVMMaskAllOn);
+          }
+          else
+            assert(0);
+
           llvm::NamedMDNode* annotations =
             m->module->getOrInsertNamedMetadata("nvvm.annotations");
           llvm::SmallVector<llvm::Value*, 3> av;

module.cpp

@@ -733,11 +733,13 @@ Module::AddFunctionDeclaration(const std::string &name,
     if (storageClass == SC_EXTERN_C) {
         // Make sure the user hasn't supplied both an 'extern "C"' and a
         // 'task' qualifier with the function
+#if 0 /* NVPTX64::task_and_externC */
         if (functionType->isTask) {
             Error(pos, "\"task\" qualifier is illegal with C-linkage extern "
                   "function \"%s\".  Ignoring this function.", name.c_str());
             return;
         }
+#endif
 
         std::vector<Symbol *> funcs;
         symbolTable->LookupFunction(name.c_str(), &funcs);
@@ -795,7 +797,7 @@ Module::AddFunctionDeclaration(const std::string &name,
 #else // LLVM 3.1 and 3.3+
         function->addFnAttr(llvm::Attribute::AlwaysInline);
 #endif
-    if (functionType->isTask)
+    if (functionType->isTask && g->target->getISA() != Target::NVPTX64)
         // This also applies transitively to members I think?
 #if defined(LLVM_3_1)
         function->setDoesNotAlias(1, true);

type.cpp

@@ -2924,8 +2924,11 @@ FunctionType::GetReturnTypeString() const {
 
 llvm::FunctionType *
 FunctionType::LLVMFunctionType(llvm::LLVMContext *ctx, bool removeMask) const {
+
+#if 0 /* NVPTX64::task_and_externC */
     if (isTask == true)
         Assert(removeMask == false);
+#endif
 
     // Get the LLVM Type *s for the function arguments
     std::vector<llvm::Type *> llvmArgTypes;
@@ -2955,10 +2958,10 @@ FunctionType::LLVMFunctionType(llvm::LLVMContext *ctx, bool removeMask) const {
         // threads the tasks system has running.  (Task arguments are
         // marshalled in a struct so that it's easy to allocate space to
         // hold them until the task actually runs.)
-        llvm::Type *st = llvm::StructType::get(*ctx, llvmArgTypes);
-        callTypes.push_back(llvm::PointerType::getUnqual(st));
         if (g->target->getISA() != Target::NVPTX64)
         {
+          llvm::Type *st = llvm::StructType::get(*ctx, llvmArgTypes);
+          callTypes.push_back(llvm::PointerType::getUnqual(st));
           callTypes.push_back(LLVMTypes::Int32Type); // threadIndex
           callTypes.push_back(LLVMTypes::Int32Type); // threadCount
           callTypes.push_back(LLVMTypes::Int32Type); // taskIndex
@@ -2970,6 +2973,11 @@ FunctionType::LLVMFunctionType(llvm::LLVMContext *ctx, bool removeMask) const {
           callTypes.push_back(LLVMTypes::Int32Type); // taskCount1
           callTypes.push_back(LLVMTypes::Int32Type); // taskCount2
         }
+        else
+        {
+          callTypes = llvmArgTypes;
+        }
+
     }
     else
         // Otherwise we already have the types of the arguments