/**
 ******************************************************************************
 * Xenia : Xbox 360 Emulator Research Project                                 *
 ******************************************************************************
 * Copyright 2013 Ben Vanik. All rights reserved.                             *
 * Released under the BSD license - see LICENSE in the root for more details. *
 ******************************************************************************
 */

#include "xenia/cpu/frontend/ppc_translator.h"

#include "xenia/cpu/compiler/compiler_passes.h"
#include "xenia/cpu/cpu-private.h"
#include "xenia/cpu/frontend/ppc_disasm.h"
#include "xenia/cpu/frontend/ppc_frontend.h"
#include "xenia/cpu/frontend/ppc_hir_builder.h"
#include "xenia/cpu/frontend/ppc_instr.h"
#include "xenia/cpu/frontend/ppc_scanner.h"
#include "xenia/cpu/runtime.h"
#include "poly/reset_scope.h"
#include "xenia/profiling.h"

namespace xe {
namespace cpu {
namespace frontend {

// TODO(benvanik): remove when enums redefined.
using namespace xe::cpu;

using xe::cpu::backend::Backend;
using xe::cpu::compiler::Compiler;
namespace passes = xe::cpu::compiler::passes;

PPCTranslator::PPCTranslator(PPCFrontend* frontend) : frontend_(frontend) {
  Backend* backend = frontend->runtime()->backend();

  scanner_.reset(new PPCScanner(frontend));
  builder_.reset(new PPCHIRBuilder(frontend));
  compiler_.reset(new Compiler(frontend->runtime()));
  assembler_ = std::move(backend->CreateAssembler());
  assembler_->Initialize();

  bool validate = FLAGS_validate_hir;

  // Merge blocks early. This will let us use more context in other passes.
  // The CFG is required for simplification and dirtied by it.
  compiler_->AddPass(std::make_unique<passes::ControlFlowAnalysisPass>());
  compiler_->AddPass(std::make_unique<passes::ControlFlowSimplificationPass>());
  compiler_->AddPass(std::make_unique<passes::ControlFlowAnalysisPass>());

  // Passes are executed in the order they are added. Multiple of the same
  // pass type may be used.
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());
  compiler_->AddPass(std::make_unique<passes::ContextPromotionPass>());
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());
  compiler_->AddPass(std::make_unique<passes::SimplificationPass>());
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());
  compiler_->AddPass(std::make_unique<passes::ConstantPropagationPass>());
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());
  compiler_->AddPass(std::make_unique<passes::SimplificationPass>());
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());
  // compiler_->AddPass(std::make_unique<passes::DeadStoreEliminationPass>());
  // if (validate)
  // compiler_->AddPass(std::make_unique<passes::ValidationPass>());
  compiler_->AddPass(std::make_unique<passes::DeadCodeEliminationPass>());
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());

  //// Removes all unneeded variables. Try not to add new ones after this.
  // compiler_->AddPass(new passes::ValueReductionPass());
  // if (validate) compiler_->AddPass(new passes::ValidationPass());

  // Register allocation for the target backend.
  // Will modify the HIR to add loads/stores.
  // This should be the last pass before finalization, as after this all
  // registers are assigned and ready to be emitted.
  compiler_->AddPass(std::make_unique<passes::RegisterAllocationPass>(
      backend->machine_info()));
  if (validate) compiler_->AddPass(std::make_unique<passes::ValidationPass>());

  // Must come last. The HIR is not really HIR after this.
  compiler_->AddPass(std::make_unique<passes::FinalizationPass>());
}

PPCTranslator::~PPCTranslator() = default;

int PPCTranslator::Translate(FunctionInfo* symbol_info,
                             uint32_t debug_info_flags, uint32_t trace_flags,
                             Function** out_function) {
  SCOPE_profile_cpu_f("cpu");

  // Reset() all caching when we leave.
  poly::make_reset_scope(builder_);
  poly::make_reset_scope(compiler_);
  poly::make_reset_scope(assembler_);
  poly::make_reset_scope(&string_buffer_);

  // Scan the function to find its extents. We only need to do this if we
  // haven't already been provided with them from some other source.
  if (!symbol_info->has_end_address()) {
    // TODO(benvanik): find a way to remove the need for the scan. A fixup
    //     scheme acting on branches could go back and modify calls to branches
    //     if they are within the extents.
    int result = scanner_->FindExtents(symbol_info);
    if (result) {
      return result;
    }
  }

  // NOTE: we only want to do this when required, as it's expensive to build.
  if (FLAGS_always_disasm) {
    debug_info_flags |= DEBUG_INFO_ALL_DISASM;
  }
  std::unique_ptr<DebugInfo> debug_info;
  if (debug_info_flags) {
    debug_info.reset(new DebugInfo());
  }

  // Stash source.
  if (debug_info_flags & DEBUG_INFO_SOURCE_DISASM) {
    DumpSource(symbol_info, &string_buffer_);
    debug_info->set_source_disasm(string_buffer_.ToString());
    string_buffer_.Reset();
  }

  if (false) {
    xe::cpu::frontend::DumpAllInstrCounts();
  }

  // Emit function.
  uint32_t emit_flags = 0;
  if (debug_info) {
    emit_flags |= PPCHIRBuilder::EMIT_DEBUG_COMMENTS;
  }
  if (trace_flags & TRACE_SOURCE_VALUES) {
    emit_flags |= PPCHIRBuilder::EMIT_TRACE_SOURCE_VALUES;
  } else if (trace_flags & TRACE_SOURCE) {
    emit_flags |= PPCHIRBuilder::EMIT_TRACE_SOURCE;
  }
  int result = builder_->Emit(symbol_info, emit_flags);
  if (result) {
    return result;
  }

  // Stash raw HIR.
  if (debug_info_flags & DEBUG_INFO_RAW_HIR_DISASM) {
    builder_->Dump(&string_buffer_);
    debug_info->set_raw_hir_disasm(string_buffer_.ToString());
    string_buffer_.Reset();
  }

  // Compile/optimize/etc.
  result = compiler_->Compile(builder_.get());
  if (result) {
    return result;
  }

  // Stash optimized HIR.
  if (debug_info_flags & DEBUG_INFO_HIR_DISASM) {
    builder_->Dump(&string_buffer_);
    debug_info->set_hir_disasm(string_buffer_.ToString());
    string_buffer_.Reset();
  }

  // Assemble to backend machine code.
  result =
      assembler_->Assemble(symbol_info, builder_.get(), debug_info_flags,
                           std::move(debug_info), trace_flags, out_function);
  if (result) {
    return result;
  }

  return 0;
};

void PPCTranslator::DumpSource(FunctionInfo* symbol_info,
                               poly::StringBuffer* string_buffer) {
  Memory* memory = frontend_->memory();

  string_buffer->Append("%s fn %.8X-%.8X %s\n",
                        symbol_info->module()->name().c_str(),
                        symbol_info->address(), symbol_info->end_address(),
                        symbol_info->name().c_str());

  auto blocks = scanner_->FindBlocks(symbol_info);

  uint32_t start_address = symbol_info->address();
  uint32_t end_address = symbol_info->end_address();
  InstrData i;
  auto block_it = blocks.begin();
  for (uint32_t address = start_address, offset = 0; address <= end_address;
       address += 4, offset++) {
    i.address = address;
    i.code = poly::load_and_swap<uint32_t>(memory->TranslateVirtual(address));
    // TODO(benvanik): find a way to avoid using the opcode tables.
    i.type = GetInstrType(i.code);

    // Check labels.
    if (block_it != blocks.end() && block_it->start_address == address) {
      string_buffer->Append("%.8X          loc_%.8X:\n", address, address);
      ++block_it;
    }

    string_buffer->Append("%.8X %.8X   ", address, i.code);
    DisasmPPC(i, string_buffer);
    string_buffer->Append("\n");
  }
}

}  // namespace frontend
}  // namespace cpu
}  // namespace xe