/* Copyright (c) 2023 PaddlePaddle Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License. */

#include "paddle/phi/kernels/funcs/jit/gen_base.h"

#include <fstream>

#include "paddle/phi/backends/cpu/cpu_info.h"
#include "paddle/phi/core/enforce.h"

#ifdef _WIN32
#define posix_memalign_free _aligned_free
#else
#define posix_memalign_free free
#endif

PHI_DEFINE_bool(dump_jitcode, false, "Whether to dump the jitcode to file");

namespace phi {
namespace jit {

// refer do not need CanBeUsed, it would be the last one.
void GenBase::dumpCode(const unsigned char* code) const {
  if (code) {
    static int counter = 0;
    std::ostringstream filename;
    filename << "paddle_jitcode_" << name() << "." << counter << ".bin";
    counter++;
    std::ofstream fout(filename.str(), std::ios::out);
    if (fout.is_open()) {
      fout.write(reinterpret_cast<const char*>(code),
                 static_cast<int>(this->getSize()));
      fout.close();
    }
  }
}

void* GenBase::operator new(size_t size) {
  void* ptr;
  constexpr size_t alignment = 32ul;
#ifdef _WIN32
  ptr = _aligned_malloc(size, alignment);
#else
  PADDLE_ENFORCE_EQ(
      posix_memalign(&ptr, alignment, size),
      0,
      phi::errors::InvalidArgument(
          "Jitcode generator (GenBase) allocate %ld memory error!", size));
#endif
  PADDLE_ENFORCE_NOT_NULL(
      ptr,
      phi::errors::InvalidArgument("Fail to allocate jitcode generator "
                                   "(GenBase) CPU memory: size = %d .",
                                   size));
  return ptr;
}

void GenBase::operator delete(void* ptr) { posix_memalign_free(ptr); }

std::vector<int> packed_groups(int n, int k, int* block_out, int* rest_out) {
  int block;
  int max_num_regs;
  if (phi::backends::cpu::MayIUse(phi::backends::cpu::avx512f)) {
    block = ZMM_FLOAT_BLOCK;
    max_num_regs = 32;
  } else {
    block = YMM_FLOAT_BLOCK;
    max_num_regs = 16;
  }
  // one for x, one for y, others for z
  const int max_used_regs_for_n = max_num_regs - 2;
  const int aligned_n = n % block == 0 ? n : (n / block + 1) * block;
  const int num_block = aligned_n / block;
  const int num_groups = num_block / max_used_regs_for_n;
  std::vector<int> groups(num_groups, max_used_regs_for_n);
  int rest_num_regs = num_block % max_used_regs_for_n;
  if (rest_num_regs != 0) {
    groups.push_back(rest_num_regs);
  }
  if (block_out) {
    *block_out = block;
  }
  if (rest_out) {
    *rest_out = n % block;
  }
  return groups;
}

}  // namespace jit
}  // namespace phi
