/* Copyright 2015-2017 Philippe Tillet
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <fstream>
#include <memory>
#include "triton/driver/module.h"
#include "triton/driver/context.h"
#include "triton/driver/error.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Verifier.h"
#include "llvm/IR/IRPrintingPasses.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/TargetSelect.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/IR/LegacyPassManager.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/SectionMemoryManager.h"
#include "llvm/Transforms/Utils/Cloning.h"

namespace triton
{
namespace driver
{

/* ------------------------ */
//         Base             //
/* ------------------------ */

void module::init_llvm() {
  static bool init = false;
  if(!init){
    llvm::InitializeAllTargetInfos();
    llvm::InitializeAllTargets();
    llvm::InitializeAllTargetMCs();
    llvm::InitializeAllAsmParsers();
    llvm::InitializeAllAsmPrinters();
    init = true;
  }
}

module::module(CUmodule mod, bool has_ownership)
  : polymorphic_resource(mod, has_ownership) {
}

module::module(host_module_t mod, bool has_ownership)
  : polymorphic_resource(mod, has_ownership) {
}


module* module::create(driver::device* device, std::unique_ptr<llvm::Module> src) {
  switch(device->backend()){
    case CUDA: return new cu_module(device, std::move(src));
    case Host: return new host_module(std::move(src));
    default: throw std::runtime_error("unknown backend");
  }
}

void module::compile_llvm_module(std::unique_ptr<llvm::Module> module, const std::string& triple,
                                 const std::string &proc, std::string layout,
                                 llvm::SmallVectorImpl<char> &buffer,
                                 const std::string& features,
                                 file_type_t ft) {
  init_llvm();
//  // debug
//  llvm::legacy::PassManager pm;
//  pm.add(llvm::createPrintModulePass(llvm::outs()));
//  pm.add(llvm::createVerifierPass());
//  pm.run(*module);
  // create machine
  module->setTargetTriple(triple);
  std::string error;
  auto target = llvm::TargetRegistry::lookupTarget(module->getTargetTriple(), error);
  llvm::TargetOptions opt;
  opt.AllowFPOpFusion = llvm::FPOpFusion::Fast;
  opt.UnsafeFPMath = false;
  opt.NoInfsFPMath = false;
  opt.NoNaNsFPMath = true;
  llvm::TargetMachine *machine = target->createTargetMachine(module->getTargetTriple(), proc, features, opt,
                                                             llvm::Reloc::PIC_, llvm::None, llvm::CodeGenOpt::Aggressive);
  // set data layout
  if(layout.empty())
    module->setDataLayout(machine->createDataLayout());
  else
    module->setDataLayout(layout);
  // emit machine code
  for (llvm::Function &f : module->functions())
    f.addFnAttr(llvm::Attribute::AlwaysInline);
  llvm::legacy::PassManager pass;
  llvm::raw_svector_ostream stream(buffer);
  // convert triton file type to llvm file type
  auto ll_file_type = [&](module::file_type_t type){
    if(type == Object)
      return llvm::CodeGenFileType::CGFT_ObjectFile;
    return llvm::CodeGenFileType::CGFT_AssemblyFile;
  };
  // emit
  machine->addPassesToEmitFile(pass, stream, nullptr, ll_file_type(ft));
  pass.run(*module);
}


/* ------------------------ */
//        Host              //
/* ------------------------ */

host_module::host_module(std::unique_ptr<llvm::Module> src): module(host_module_t(), true) {
  init_llvm();
  // create kernel wrapper
  llvm::LLVMContext &ctx = src->getContext();
  llvm::Type *void_ty = llvm::Type::getVoidTy(ctx);
  llvm::Type *args_ty = llvm::Type::getInt8PtrTy(ctx)->getPointerTo();
  llvm::Type *int32_ty = llvm::Type::getInt32Ty(ctx);
  std::vector<llvm::Type*> tys = {args_ty, int32_ty, int32_ty, int32_ty};
  llvm::FunctionType *main_ty = llvm::FunctionType::get(void_ty, tys, false);
  llvm::Function* main = llvm::Function::Create(main_ty, llvm::Function::ExternalLinkage, "_main", &*src);
  llvm::Function* fn = &*src->getFunctionList().begin();
  llvm::FunctionType *fn_ty = fn->getFunctionType();
  std::vector<llvm::Value*> fn_args(fn_ty->getNumParams());
  std::vector<llvm::Value*> ptrs(fn_args.size() - 3);
  llvm::BasicBlock* entry = llvm::BasicBlock::Create(ctx, "entry", main);
  llvm::IRBuilder<> ir_builder(ctx);
  ir_builder.SetInsertPoint(entry);
  auto get_size = [](llvm::Type* ty) { return ty->isPointerTy() ? sizeof(char*) : ty->getPrimitiveSizeInBits() / 8; };
  llvm::Value* base = main->arg_begin();
  llvm::Value* args_base = ir_builder.CreateBitCast(base, base->getType()->getPointerElementType());

  size_t offset = 0;
  for(unsigned i = 0; i < ptrs.size(); i++){
    ptrs[i] = ir_builder.CreateGEP(args_base, ir_builder.getInt32(offset));
    size_t nbytes = get_size(fn_ty->getParamType(i));
    offset += nbytes;
    if(i < ptrs.size() - 1){
      size_t np1bytes = get_size(fn_ty->getParamType(i+1));
      offset = (offset + np1bytes - 1) / np1bytes * np1bytes;
    }
  }
  for(unsigned i = 0; i < ptrs.size(); i++)
    ptrs[i] = ir_builder.CreateBitCast(ptrs[i], fn_ty->getParamType(i)->getPointerTo());
  for(unsigned i = 0; i < ptrs.size(); i++)
    fn_args[i] = ir_builder.CreateLoad(ptrs[i]);

  fn_args[fn_args.size() - 3] = main->arg_begin() + 1;
  fn_args[fn_args.size() - 2] = main->arg_begin() + 2;
  fn_args[fn_args.size() - 1] = main->arg_begin() + 3;
  ir_builder.CreateCall(fn, fn_args);
  ir_builder.CreateRetVoid();

//  llvm::legacy::PassManager pm;
//  pm.add(llvm::createPrintModulePass(llvm::outs()));
//  pm.add(llvm::createVerifierPass());
//  pm.run(*src);

//   create execution engine
  for(llvm::Function& fn: src->functions())
    hst_->functions[fn.getName()] = &fn;

//  llvm::orc::JITTargetMachineBuilder JTMB = *llvm::orc::JITTargetMachineBuilder::detectHost();
//  auto DL = JTMB.getDefaultDataLayoutForTarget();
//  auto CIRC = std::unique_ptr<llvm::orc::ConcurrentIRCompiler>(new llvm::orc::ConcurrentIRCompiler(JTMB));
//  hst_->ES = new llvm::orc::ExecutionSession();
//  hst_->ObjectLayer = new llvm::orc::RTDyldObjectLinkingLayer(*hst_->ES, []() { return std::unique_ptr<llvm::SectionMemoryManager>(new llvm::SectionMemoryManager()); });
//  hst_->CompileLayer = new llvm::orc::IRCompileLayer(*hst_->ES, *hst_->ObjectLayer, *CIRC);
//  hst_->DL = new llvm::DataLayout(std::move(*DL));
//  hst_->Mangle = new llvm::orc::MangleAndInterner(*hst_->ES, *hst_->DL);
//  hst_->Ctx = new llvm::orc::ThreadSafeContext(std::unique_ptr<llvm::LLVMContext>(new llvm::LLVMContext()));
//  hst_->MainJD =  &hst_->ES->createJITDylib("<main>");
//  hst_->MainJD->setGenerator(llvm::cantFail(llvm::orc::DynamicLibrarySearchGenerator::GetForCurrentProcess(
//                                            hst_->DL->getGlobalPrefix())));
//  llvm::cantFail(hst_->CompileLayer->add(*hst_->MainJD, llvm::orc::ThreadSafeModule(std::move(src), *hst_->Ctx)));
//  hst_->fn = (void(*)(char**, int32_t, int32_t, int32_t))(hst_->ES->lookup({hst_->MainJD}, (*hst_->Mangle)("_main"))->getAddress());



  llvm::EngineBuilder builder(std::move(src));
  builder.setErrorStr(&hst_->error);
  builder.setMCJITMemoryManager(std::make_unique<llvm::SectionMemoryManager>());
  builder.setOptLevel(llvm::CodeGenOpt::Aggressive);
  builder.setEngineKind(llvm::EngineKind::JIT);
  hst_->engine = builder.create();
  hst_->fn = (void(*)(char**, int32_t, int32_t, int32_t))(hst_->engine->getFunctionAddress("_main"));
}

std::unique_ptr<buffer> host_module::symbol(const char *name) const {
  throw std::runtime_error("not implemented");
}

/* ------------------------ */
//         CUDA             //
/* ------------------------ */
static bool find_and_replace(std::string& str, const std::string& begin, const std::string& end, const std::string& target){
  size_t start_replace = str.find(begin);
  size_t end_replace = str.find(end, start_replace);
  if(start_replace == std::string::npos)
    return false;
  str.replace(start_replace, end_replace + 1 - start_replace, target);
  return true;
}

static std::map<int, int> vptx = {
  {10000, 63},
  {10010, 64},
  {10020, 65},
  {11000, 70},
  {11010, 71}
};

std::string cu_module::compile_llvm_module(std::unique_ptr<llvm::Module> module, driver::device* device) {
  // LLVM version in use may not officially support target hardware
  int max_nvvm_cc = 75;
  int max_nvvm_ptx = 64;
  // options
  auto options = llvm::cl::getRegisteredOptions();
  auto* short_ptr = static_cast<llvm::cl::opt<bool>*>(options["nvptx-short-ptr"]);
  assert(short_ptr);
  short_ptr->setValue(true);
  // compute capability
  auto _cc = ((driver::cu_device*)device)->compute_capability();
  int cc = _cc.first*10 + _cc.second;
  cc = std::min(cc, max_nvvm_cc);
  std::string sm = "sm_" + std::to_string(cc);
  // driver version
  int version;
  dispatch::cuDriverGetVersion(&version);
  int major = version / 1000;
  int minor = (version - major*1000) / 10;
  if(major < 10)
    throw std::runtime_error("Triton requires CUDA 10+");
  // PTX version
  int ptx = vptx.at(version);
  ptx = std::min(ptx, max_nvvm_ptx);
  int ptx_major = ptx / 10;
  int ptx_minor = ptx % 10;
  // create
  llvm::SmallVector<char, 0> buffer;
  module::compile_llvm_module(std::move(module), "nvptx64-nvidia-cuda", sm, "", buffer, "+ptx" + std::to_string(ptx), Assembly);
  std::string result(buffer.begin(), buffer.end());
  find_and_replace(result, ".version", "\n", ".version " + std::to_string(ptx_major) + "." + std::to_string(ptx_minor) + "\n");
  find_and_replace(result, ".target", "\n", ".target " + sm + "\n");
  while(find_and_replace(result, "\t// begin inline asm", "\n", ""));
  while(find_and_replace(result, "\t// end inline asm", "\n", ""));
  return result;
}


cu_module::cu_module(driver::device* device, std::unique_ptr<llvm::Module> ll_module): cu_module(compile_llvm_module(std::move(ll_module), device)) { }

cu_module::cu_module(std::string const & source) : module(CUmodule(), true), source_(source){
  // JIT compile source-code
  CUjit_option opt[] = {CU_JIT_ERROR_LOG_BUFFER_SIZE_BYTES, CU_JIT_ERROR_LOG_BUFFER};
  unsigned int errbufsize = 8096;
  std::string errbuf(errbufsize, 0);
  void* optval[] = {(void*)(uintptr_t)errbufsize, (void*)errbuf.data()};
  try{
    dispatch::cuModuleLoadDataEx(&*cu_, source_.data(), 2, opt, optval);
  }catch(exception::cuda::invalid_ptx const &){
//#ifdef TRITON_LOG_PTX_ERROR
    std::cout << source << std::endl;
    std::cerr << "It appears that Triton produced invalid PTX code:" << std::endl;
    std::cerr << errbuf << std::endl;
//    exit(1);
//#endif
    throw;
  }
}

std::unique_ptr<buffer> cu_module::symbol(const char *name) const{
  CUdeviceptr handle;
  size_t size;
  dispatch::cuModuleGetGlobal_v2(&handle, &size, *cu_, name);
  std::unique_ptr<buffer> res(new cu_buffer(size, handle, false));
  return std::move(res);
}


}
}