// SPDX-License-Identifier: 0BSD

///////////////////////////////////////////////////////////////////////////////

//

/// \file       ia64.c

/// \brief      Filter for IA64 (Itanium) binaries

///

//  Authors:    Igor Pavlov

//              Lasse Collin

//

///////////////////////////////////////////////////////////////////////////////

#include "simple_private.h"

static size_t

ia64_code(void *simple lzma_attribute((__unused__)),

    uint32_t now_pos, bool is_encoder,

    uint8_t *buffer, size_t size)

{

  static const uint32_t BRANCH_TABLE[32] = {

    0, 0, 0, 0, 0, 0, 0, 0,

    0, 0, 0, 0, 0, 0, 0, 0,

    4, 4, 6, 6, 0, 0, 7, 7,

    4, 4, 0, 0, 4, 4, 0, 0

  };

  size_t i;

  for (i = 0; i + 16 <= size; i += 16) {

    const uint32_t instr_template = buffer[i] & 0x1F;

    const uint32_t mask = BRANCH_TABLE[instr_template];

    uint32_t bit_pos = 5;

    for (size_t slot = 0; slot < 3; ++slot, bit_pos += 41) {

      if (((mask >> slot) & 1) == 0)

        continue;

      const size_t byte_pos = (bit_pos >> 3);

      const uint32_t bit_res = bit_pos & 0x7;

      uint64_t instruction = 0;

      for (size_t j = 0; j < 6; ++j)

        instruction += (uint64_t)(

            buffer[i + j + byte_pos])

            << (8 * j);

      uint64_t inst_norm = instruction >> bit_res;

      if (((inst_norm >> 37) & 0xF) == 0x5

          && ((inst_norm >> 9) & 0x7) == 0

          /* &&  (inst_norm & 0x3F)== 0 */

          ) {

        uint32_t src = (uint32_t)(

            (inst_norm >> 13) & 0xFFFFF);

        src |= ((inst_norm >> 36) & 1) << 20;

        src <<= 4;

        uint32_t dest;

        if (is_encoder)

          dest = now_pos + (uint32_t)(i) + src;

        else

          dest = src - (now_pos + (uint32_t)(i));

        dest >>= 4;

        inst_norm &= ~((uint64_t)(0x8FFFFF) << 13);

        inst_norm |= (uint64_t)(dest & 0xFFFFF) << 13;

        inst_norm |= (uint64_t)(dest & 0x100000)

            << (36 - 20);

        instruction &= (1U << bit_res) - 1;

        instruction |= (inst_norm << bit_res);

        for (size_t j = 0; j < 6; j++)

          buffer[i + j + byte_pos] = (uint8_t)(

              instruction

              >> (8 * j));

      }

    }

  }

  return i;

}

static lzma_ret

ia64_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,

    const lzma_filter_info *filters, bool is_encoder)

{

  return lzma_simple_coder_init(next, allocator, filters,

      &ia64_code, 0, 16, 16, is_encoder);

}

#ifdef HAVE_ENCODER_IA64

extern lzma_ret

lzma_simple_ia64_encoder_init(lzma_next_coder *next,

    const lzma_allocator *allocator,

    const lzma_filter_info *filters)

{

  return ia64_coder_init(next, allocator, filters, true);

}

#endif

#ifdef HAVE_DECODER_IA64

extern lzma_ret

lzma_simple_ia64_decoder_init(lzma_next_coder *next,

    const lzma_allocator *allocator,

    const lzma_filter_info *filters)

{

  return ia64_coder_init(next, allocator, filters, false);

}

#endif